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1
Dixon, Joanna. "Trace metal-particle water interactions in the western North Sea." Thesis, University of Plymouth, 1998. http://hdl.handle.net/10026.1/1894.
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The distribution of trace metals (Fe, Mn, Cu, Cd and Pb) has been determined in dissolved and particulate phases, along with relevant hydrographic parameters, from the nearshore coastal zone of the western North Sea (between 52ON and 56ON) during four Land Ocean Interaction Study (LOIS) surveys covering the seasonal cycle (autumn 1994 to summer 1995) The behaviour of the redox-sensitive metals, Fep and Mnp in the western North Sea were strongly correlated (r>0 44 for all seasons, P<0 05) in all surveys and exhibited maximum concentrations in winter (16 mg g -1 and 700 ug g-1 respectively) which progressively decreased throughout the year Distinct seasonal variations were also observed for particulate Cu, Cd and Pb For example, enhanced concentrations of Cup (36 ± 39 ug g-1) and Cdp (0.36 ± 0.42 ug g -1) in the Humber coastal zone during summer were attributed to preferential particulate organic/biogenic-metal interactions. In contrast enhanced, though diffuse, atmospheric inputs of Pb from continental winds were considered to have contributed to the elevated Pbp concentrations (82 ± 27 ug g -1) observed offshore during winter Results from radiotracer incubation experiments suggest that biological activity makes a significant contribution to the removal of dissolved Mn and Cd to the particulate phase. However, a phase lag of two to three months between maximum primary productivity and maximum particulate metal adsorption (KD=2 X 104 & 5 x 102 for Mn and Cd respectively) indicates a decoupling from the spring plankton bloom In general metal distributions in the Humber coastal zone were significantly influenced by freshwater discharge, tidal regime at the mouth of the estuary and prevailing wind conditions Total trace metal fluxes across the mouth of the Humber Estuary were highest during spring (311, 8 96 & 1045 kg day-1, for Cu, Cd and Pb respectively) and lowest during summer (25 7, 1 .12 & 33 4 kg day-1, for Cu, Cd and Pb respectively) They were dominated by variations in freshwater outflow and the tidal range during sampling On an annual basis comparison to estuarine inputs (rivers, industry and sewage sources) suggested retention of Cu (25%) and Cd (56%) Estimates of partitioning (KD) were derived from the dissolved and particulate data for Cu, Cd and Pb over the seasonal cycle Copper was dominated by the particulate phase (73-80%) in all seasons but summer, whilst Cd showed particulate phase dominance (54-70%) in autumn and winter only The Pb distributions were dominated by the particulate phase (94-99%) independent of season Trace metal settling velocities implied that the Humber Plume was acting as a sink for Cu, Cd and Pb in winter and spring However settling velocities calculated for Cd and Pb (flood tide) in summer were similar to background suspended particulate matter (SPM) suggesting long range transport with the residual circulation. Modelling of Pb isotopic ratios in the Humber Plume suggested that on average 32-39% of the extracted Pbp originated from anthropogenic sources The data from this study has given unique information concerning the concurrent seasonal distributions of particulate trace metals in the western North Sea and have yielded new insights into mechanisms affecting trace metal cycling and transport, essential in the development and refinement of coupled hydrodynamic-geochemical models.
2
Burton, Susan Mary. "Evaluation of stream meiofauna as a monitor of trace metal contamination." Thesis, University of Plymouth, 1998. http://hdl.handle.net/10026.1/2168.
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Members of the meiobenthos have been used extensively to determine the effects of anthropogenic perturbation in marine systems (Coull & Chandler, 1992). Despite this, the meiofauna has been virtually excluded from freshwater pollution monitoring. This thesis aimed to address this research caveat, by evaluating the potential of stream meiofauna for monitoring metal-contamination. Meiofaunal communities were sampled from streams in SW England representing a gradient in metal contamination. Environmental variables in these streams were also measured to identify the important forcing agents structuring the stream benthos. Multivariate techniques demonstrated Cu, either alone or in combination with other environmental variables was of most importance in correlations with the composition of meiofaunal communities. Comparison with the macrofaunal data demonstrated that both components of the benthos responded in a similar way to metal contamination, although the meiofauna also highlighted other differences in water chemistry. The combination of meiofauna, macrofauna and temporary meiofauna in a combined metazoan community analysis gave the best discrimination of sites. Detection of metal-contamination was retained in meiofaunal data aggregated to the family level. The abundances of the harpacticoid copepod Bryocamptus zschokkei were consistently important in contributing to between-site differences in community structure. The harpacticoid, therefore was selected as an ecologically-relevant freshwater toxicity test for Cu. Laboratory experiments demonstrated that Cu had toxic effects on the survival and reproduction of Bryocamptus zschokkei. Although acute toxicity tests gave more rapid results, these effects on survival occurred at a higher Cu concentration than those in the chronic tests. Sub-lethal concentrations of Cu led to a reduction in the numbers of offspring per brood Animals with pre-exposure to chronic concentrations of Cu exhibited greater tolerance to this metal. In conclusion, more information may be gained by including the meiofauna, alongside the macrofauna, when monitoring the impact of contaminants on freshwater systems. To reduce the effort of processing samples it appears family level data could be used to detect metal-contamination. The novel use of B. zschokkei in laboratory tests, where it showed lethal and sub-lethal responses to Cu, demonstrated that this species may have much potential as an ecologically-relevant freshwater bioassay organism for this metal. The advantages of using meiofaunal species such as B. zschokkei as toxicity test organisms are discussed.
3
Manwaring, Howard Stephen. "The application of neural networks to anodic stripping voltammetry to improve trace metal analysis." Thesis, University of Hertfordshire, 1995. http://hdl.handle.net/2299/14150.
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This thesis describes a novel application of an artificial neural network and links together the two diverse disciplines of electroanalytical chemistry and information sciences. The artificial neural network is used to process data obtained from a Differential Pulse Anodic Stripping (DPAS) electroanalytical scan and produces as an output, predictions of lead concentration in samples where the concentration is less than 100 parts per billion. A comparative study of several post analysis processing techniques is presented, both traditional and neural. Through this it is demonstrated that by using a neural network, both the accuracy and the precision of the concentration predictions are increased by a factor of approximately two, over those obtained using a traditional, peak height calibration curve method. Statistical justification for these findings is provided Furthermore it is shown that, by post processing with a neural network, good quantitative predictions of heavy metal concentration may be made from instrument responses so poor that, if using tradition methods of calibration, the analytical scan would have had to be repeated. As part of the research the author has designed and built a complete computer controlled analytical instrument which provides output both to a graphical display and to the neural network. This instrument, which is fully described in the text, is operated via a mouse driven user interface written by the author.
4
Ge, Ying 1974. "Trace metal speciation and bioavailability in urban contaminated soils." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21555.
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Urban soils are often contaminated with trace metals and the toxicity of the metals depends, in part, on their speciation in soil solutions. The objectives of this project were to estimate the metal speciation in urban soils and to evaluate the predictability of soil metal pools on plant uptake. The chemical speciation of Cd, Cu, Ni, Pb and Zn was estimated by using the Windermere Humic Aqueous Model (WHAM). In soil solutions, Cd, Ni and Zn were present mainly as free ions when the solutions were acidic and their organic complexes were dominant as the pH was over 7.5. The other two metals mostly formed complexes with organic ligands. The activities of Cd2+, Cu2+, Ni2+, Pb2+ and Zn 2+ were affected by soil pH and total soil metal burdens. All five metals were under-saturated with respect to the minerals which could potentially control the metal solubility.Metal uptake by plants in the contaminated railway yards was generally not correlated with free, dissolved and total soil metal pools. A pot experiment demonstrated better correlations between the metal pools and the metal content in wild chicory. Multiple regression analysis showed that the metals in the leaves and roots of wild chicory could be adequately predicted by the soil total metals and soil properties such as pH and exchangeable Ca.
5
Tambasco, Giuseppe. "Methods to predict and reduce trace metal levels in lettuce grown on contaminated urban soils." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0001/MQ44294.pdf.
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6
Alharbi, Mohammed Musad Mohammed. "Spatial and temporal variations in trace metal concentrations in sediments, pore water of the Forth estuary, and their potential impact on water quality." Thesis, University of Stirling, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386611.
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The concentrations of trace metals: cadmium, copper, nickel, lead and mercury, in addition to aluminium, iron and manganese were determined in the sediments and pore water (except aluminium) of the Forth estuary. Organic matter (as loss on ignition), total organic carbon (TOe), total organic nitrogen (TON), particle size and redox potential were also determined in the sediments. In addition, chloride, sulphate, conductivity, alkalinity, pH, dissolved organic carbon, phosphate and nitrate were determined in the sediments pore water. Trace metals in the pore water were determined using a modified preconcentration technique and measurements were carried out by graphite furnace. Mercury was measured using the p.s.a mercury specific fluorescence detector. organic matter (TOC & TON) in the sediments were measured using CHNS/O analyzer. Samples were collected at seasonal intervals for a period of 18 months on board the survey vessel "Forth Ranger". Six stations were selected to represent upper, middle and lower estuary. Sediment cores collected at each station were subjected to centrifugation under nitrogen gas atmosphere to separate the pore water after being sectioned at 2.5 cm intervals for a depth of 10 centimetres. Concentrations of trace metals in the Forth estuary varied from station to station and from one season to another. Mean concentrations for sediments were as follows (mg\kg): lead, 56.9; cadmium, 0.22; copper, 38.9; nickel, 33.7 and mercury, 1.86. For pore water, the mean concentraxxi tions (Jlg\l) were as follows: lead, 3.14; cadmium, 1.86; copper, 31.9; nickel, 24.7 and mercury, 0.075. Measurements of sulphates, nitrates, phosphate, conductivity and dissolved organic carbon were used to examine the processes controlling their distributions in the pore water. The results indicated that the distributions of nutrients (phosphate and nitrate) in the upper 10 cm seemed to be controlled by macro-infaunal irrigation activities and their values varied according to the overlying water conditions. The distributions of trace metals in the sediments were found to be controlled by particle size and organic matter both spatially and temporally. Vertical distribution of trace metals in the pore water were found to be controlled by redox potential variations especially for iron and manganese. Concentrations of trace metals (Pb, Hg, Ni, Cd and CU) in the pore water were found to be higher than that in the overlying water. Enrichment factors were limited to 10-50 fold increase. Lead and mercury were 10 fold higher while 50 fold higher were found for nickel, copper and cadmium. Benthic flux calculations showed a significant flux of trace metals both in the summer and winter. However, flux of copper, nickel and lead tended to increase in the summer. Spatially, the lower estuary showed a higher flux of trace metals than the upper and middle reaches of the estuary.
7
Chariton, Anthony A., and n/a. "Responses in estuarine macrobenthic invertebrate assemblages to trace metal contaminated sediments." University of Canberra. Resource, Environmental & Heritage Sciences, 2005. http://erl.canberra.edu.au./public/adt-AUC20060509.115744.
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Three approaches were employed to examine the effects of elevated sediment trace
metal concentrations on estuarine/marine macrobenthic invertebrate assemblages. The
initial study examined macroinvertebrate communities along a known polymetallic
gradient, Lake Macquarie, NSW (gradient study). The second study experimentally
tested if sediments sourced from different locations within Lake Macquarie
differentially influenced the recolonisation of benthic invertebrates. The third study
investigated the different recolonisation patterns of benthic invertebrates into
sediments spiked with increasing concentrations of sediment-bound cadmium.
In the Lake Macquarie gradient study, four locations (Cockle Bay, Warner's Bay,
Kooroora Bay and Nord's Wharf) were sampled in winter 2000 and summer 2003
using a hierarchical design (location > site > plot). On both sampling occasions, the
sediments showed strong gradients in lead, cadmium and zinc concentrations
emanating from the Cockle Bay industrialised region in the lake's north, with
concentrations being significantly lower in the most southern and less urbanised
location (Nord's Wharf). In general, concentrations of lead, cadmium and zinc in the
sediments increased among locations in the following order: Nord's Wharf >
Kooroora Bay > Warner's Bay > Cockle Bay. AVSJSEM analyses indicated that in
some sites in Cockle Bay, and to a lesser extent Warner's Bay, SEM concentrations
exceeded their molar equivalence of AVS, indicating the potential for trace metals to
be labile within the porewaters. Granulometry also changed along the gradient, with a
higher proportion of silt/clay occurring in the locations with high metal
concentrations. Conversely, the percentage of total organic carbon was higher in the
less contaminated locations.
In winter 2000, changes in benthic communities along the gradient supported the a
priori hypotheses, with diversity and richness being greater in locations with lower
concentrations of metals. Polychaetes were most numerous in Cockle Bay and
Warner's Bay, whilst bivalves and gastropods were more abundant in Nord's Wharf
and Kooroora Bay. Crustaceans were more numerous in Nord's Wharf; with all other
locations having similar, lower, abundances. Ordination maps of the assemblages
provided relatively clear separation of the assemblages among locations, with nonparametric
multivariate analysis of variance (NPMANOVA) and subsequent pair-wise
comparisons finding significant differences among the assemblages from all locations.
SIMPER analyses found the highest level of dissimilarity was between the Nord's
Wharf and Cockle Bay assemblages - primarily attributable to differences in the
relative contributions of isopods; tellenid bivalves; and the polychaete families
Spionidae, Opheliidae and Nephytidae. Weighted Spearman rank correlations (BIOENV)
identified cadmium (Pw =0.74) as the strongest environmental (single or
combination) variable to correlate with biotic assemblages.
Benthic patterns along the gradient were less defined in summer 2003 due to a
dramatic reduction in the abundance and diversity of fauna in Nord's Wharf. This
decline was possibly attributable to a sustained reduction in salinity caused by a
prolonged rainfall event. With the exception of Nord's Wharf, trends in the
community indices and abundances of key taxa among the other locations were
similar to those reported in winter 2000. Multivariate analyses discriminated the
benthic assemblages from the four locations, with the findings from the NPMANOVA
pair-wise comparisons indicating that the assemblages from all four locations were
significantly different. SIMPER analyses showed the highest level of dissimilarity
was between Nord's Wharf and Warner's Bay, with these differences being primarily
attributable to their relative abundances of amphipods and polychaetes from the
families Spionidae, Cirratulidae, Opheliidae and Capitellidae. BIOENV found that the
combination of the sedimentary concentrations of cadmium and iron provided the best
correlation (Pw =0.73) with biotic patterns, with similar correlations occumng with
the addition of lead and its covariate, zinc (Pw =0.72).
The combined findings from the gradient study established a strong correlation
between trace metal concentrations within the sediments and suite of univariate and
multivariate measurements. The low abundance and diversity of fauna in Nord's
Wharf in the summer of 2003 highlighted the dynamic changes which can occur in the
distributions of macrobenthic invertebrates. Although the study indicated that there
was a strong relationship between trace metal concentrations and benthic community
structure, the study was correlative, and requires subsequent experimental testing to
confirm the causality of the observed relationships.
The second component of the research was a translocation experiment using benthic
recolonisation as an end-point. The experiment was performed to identify if the
sediments, and not location, were influencing the composition of benthic assemblages
in Lake Macquarie. Sediments were collected from three locations (Cockle Bay,
Warner's Bay and Nord's Wharf), defaunated, and transplanted in three new locations
along the south-east edge of the lake. At each location, 10 containers of each
treatment were randomly placed in the sediment and allowed to recolonise for 22
weeks. Upon retrieval, the benthic communities were sampled and enumerated in
conjunction with a variety of chemical and sedimentary measurements. Ten replicate
invertebrate samples were also collected in the sediments adjacent to the experiment
(ambient samples) at the completion of the experiment. Due to human interference,
the containers from only two locations were analysed.
Upon retrieval, pH and redox profiles of the sediments were similar to those expected
in natural sediments. In general, concentrations of metals were low in the porewaters;
however, iron precipitation on the porewater collection devices may have artificially
increased the diffusion of metals, increasing concentrations near the sediment-water
interface. Concentrations of SEM exceeded their AVS equivalence in some samples
taken from the Cockle Bay and Warner's Bay treatments.
Two-way ANOVAs found significant interactions between location and sediment
treatments in diversity, evenness and the number of polychaetes, as well as significant
differences in the number of capitellids and crustaceans among locations. Post-hoc
comparisons of means found the Nord's Wharf sediment contained a higher mean
number of individuals than the other treatments, including the ambient samples.
nMDS ordination plots for both locations provided poor graphical discrimination of
the assemblages among treatments; however, NPMANOVA detected significant
location and treatment interactions. In both locations, pair-wise comparisons indicated
that the assemblages within the Nord's Wharf treatments were significantly different
to the Cockle Bay, Warner's Bay and ambient assemblages. No significant differences
were detected between the Cockle Bay and Warner's Bay assemblages at either
location. SIMPER analyses found the highest level of dissimilarity occurred between
the ambient assemblages in Location 2 and the Nord's Wharf treatment, primarily due
to the relative difference in the abundances of Capitellidae, Spionidae, Oweniidae,
Nereididae and isopods among the assemblages.
The findings from the translocation experiment suggest that the sediments are
influencing the recolonisation of benthos. However, because differences were not
detected between the Cockle Bay and Warner's Bay treatments, the approach used in
the study shows potential as an in situ technique which could be used to assess the
potential ecological risks of sediments fiom specific locations. Excluding cost and
time considerations, the technique's primary disadvantage is the lack of a true control.
As a result, the technique can only identify if the sediments are modifying benthic
recolonisation, and not causality.
The final component of the research experimentally tested if elevated concentrations
of sediment-bound cadmium affected benthic invertebrate recolonisation. Sediments
from the south coast of New South Wales (Durras Lake) were defaunated, and spiked
with cadmium under anaerobic conditions to obtain three targeted cadmium
concentrations: control (
8
Ginnever, Rhoda C. "Soil and plant contents of lead and other trace elements with special reference to the influences of parent rock and pollution." Thesis, Aberystwyth University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324309.
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9
Nussle, Sean Brian. "TRICHOPTERAN LARVAE AS BIOMONITORS OF TRACE AND HEAVY METAL CONTAMINATION IN NORTHEAST OHIO URBAN STREAMS." Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1534960377604447.
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10
Wong, Sze-chung Coby, and 黃詩頌. "Trace metal contamination of the riverine environment in Guiyu, China: the impacts of primitive e-wastedisposal." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B4308526X.
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11
Reeves, Alastair Ian. "Contaminant tracking through dendro-chemical analysis of tree-radii." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69688.
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The research used dendro-chemical analysis of ash tree rings and current year leaf litter to track Cd, Pb, Zn, Cu, Mn, Cr, and Sn spread and cycling from a closed garbage dump-toxic waste site. This technique allowed for determination of areal extent, contaminant levels and time period of initial contaminant contact. Only Zn, Sn, and Cu were found in elevated quantities in the xylem wood and Pb in the leaf litter. Elemental concentrations of Pb, Sn and Cd in xylem wood and leaves of ash were positively correlated. Tin was the only element to demonstrate a clear initial contact period and elemental accumulation with age. Significant levels of Cu accumulated in the heartwood while Zn revealed significant but inconsistent accumulated patterns. Expected attenuation zones associated with municipal solid waste landfill leachate dispersion were not found; thus the pathway for contaminant dispersion was likely through groundwater flow.An elemental index was developed to facilitate the use of dendro-chemical analysis in periods of suppressed tree growth resulting from environmental pollution.
12
Taylor, Anne Marie, and n/a. "Biomarkers of Cadmium, Lead and Selenium Toxicity in the Marine Bivalve Molluscs Tellina deltoidalis and Anadara trapezia: Linking Exposure, Dose and Response." University of Canberra. Environmental Science, 2009. http://erl.canberra.edu.au./public/adt-AUC20091214.104734.
Full textAbstract:
The relationships between metal exposure, dose and response were investigated in two
sediment dwelling marine bivalves: a deposit feeder Tellina deltoidalis and a filter feeder
Anadara trapezia. The bivalves were exposed in the laboratory to individual metal spiked
sediments: Cadmium 10 and 50 Ag/g; lead 100 and 300 Ag/g; selenium 5 and 20 Ag/g dry
mass, T. deltoidalis for 28 days A. trapezia for 56 days. A. trapezia was also exposed in the
laboratory for 56 days to sediments from three sites along a metal contamination gradient of
cadmium, lead, selenium, zinc and copper from Lake Macquarie, NSW. Metal total tissue
dose was measured in whole tissue of T. deltoidalis over 28 days and in gill, hepatopancreas
and haemolymph tissues in A. trapezia over 56 days. Subcellular metal distribution,
biologically active metal (BAM) versus biologically detoxified metal (BDM) was measured
in whole tissues of T. deltoidalis at day 28 and in gill and hepatopancreas tissues of
A. trapezia at day 56. Biomarkers of response measured in spiked sediment exposed, at day
28 T. deltoidalis and day 56 A. trapezia were: total antioxidant capacity (TAOC); glutathione
peroxidase enzyme activity (GPx); total glutathione concentration (GSH+2GSSG); reduced to
oxidised glutathione ratio (GSH:GSSG); lipid peroxidation (TBARS); lysosomal membrane
stability and micronuclei frequency. Response indices measured in A. trapezia exposed to
Lake Macquarie sediments were: TAOC, TBARS, lysosomal membrane stability,
micronucleus frequency and condition index. Native A. trapezia and sediments were also
collected from Lake Macquarie and measured for sediment and tissue metal concentrations,
TAOC, TBARS, lysosomal membrane stability and condition index to allow comparison
between chronically exposed and previously unexposed organisms.
T. deltoidalis and A. trapezia accumulated metal over time in all sediment metal exposures
with most reaching equilibrium tissue metal concentrations by the end of the exposure period.
T. deltoidalis generally reached equilibrium with the exposure concentration for cadmium and
lead but had significantly higher selenium tissue concentrations than the sediment metal at the
5 Ag/g exposure. A. trapezia tissue lead was below the sediment concentration for all
exposures including in the native organisms. A high proportion of accumulated lead and
copper in A. trapezia was in the haemolymph, probably associated with haemoglobin which
has a high affinity for these metals`. A. trapezia cadmium tissue concentrations were higher
than the sediment metal in the 10 Ag/g spiked sediment exposure and between half and one
eighth the sediment concentrations in other treatments, including in native organisms.
A. trapezia including the native organisms exposed to selenium sediment concentrations at or
below 5 Ag/g in the Lake Macquarie mixed metal sediments accumulated significantly higher
than ambient selenium tissue concentrations while those exposed to 5 and 20 Ag/g selenium
spiked sediments had lower than ambient selenium tissue concentrations. The majority of
accumulated cadmium, selenium and zinc was associated with the gill/mantle tissues.
A. trapezia hepatopancreas contributed significant selenium concentrations in the later part of
the exposure period indicating and increased contribution from dietary derived selenium.
Native A. trapezia had significantly lower tissue concentrations of selenium, copper and zinc,
higher cadmium and approximately equal lead compared to organisms exposed to similar
sediment metal concentrations in the laboratory.
T. deltoidalis detoxified around 50 % of accumulated cadmium and 70 % of lead while
A. trapezia detoxified around 70 % of accumulated cadmium and 60 % of lead. Much of
T. deltoidalis BDM cadmium was converted to metal rich granules (MRG), while A. trapezia
had most in the metallothionein like proteins (MTLP) fraction. The conversion of lead to
MRG was 75 % of the total BDM in T. deltoidalis while A. trapezia had an even distribution
between MRG and MTLP. The majority of recovered selenium in both species was
associated with the nuclei+cellular debris fraction, probably as protein bound selenium
associated with plasma and selenium bound directly to cell walls. Selenium exposed
organisms had increased BDM selenium burdens which were associated with both MRG and
MTLP fractions, indicating selenium detoxification. The majority of BAM cadmium, lead
and selenium was associated with the mitochondrial fraction in both species with increases in
cadmium burden in this organelle of T. deltoidalis up to 7200 fold; lead 154 fold; and
selenium 7 fold and in A. trapezia up to 84 fold cadmium, 50 fold lead and selenium 7 fold in
exposed organisms compared to controls. The subcellular distribution of all three metals in
T. deltoidalis and A. trapezia indicates active metal detoxification processes which at these
exposure concentrations were unable to prevent significant metal burdens from accumulating
in sensitive organelles.
A contamination gradient of zinc, lead, copper, cadmium and selenium was established in
Lake Macquarie sediments which emanated from the same source. A. trapezia accumulated
all metals in each sediment exposure. Accumulation and tissue distribution patterns of
cadmium, lead and selenium were similar to those of the single metal spiked sediment
exposures. Cadmium and lead BAM burdens increased at all exposures while selenium, zinc
and copper did not.
T. deltoidalis and A. trapezia in the spiked sediment metal exposures generally had reduced
GPx activity. This resulted in an increase in total glutathione concentrations which the
reduced GSH:GSSG ratios indicated was due to a build up of oxidised glutathione.
T. deltoidalis and A. trapezia had reduced TAOC in all laboratory sediment metal exposures
which corresponded with increased TBARS concentrations, lysosomal destabilisation and
micronucleus frequency. A. trapezia exposed to Lake Macquarie metal contaminated
sediments also had a reduction in physiological condition, indicated by the reduced condition
index, after 56 days at the higher metal exposures.
Clear exposure - dose - response relationships have been demonstrated for T. deltoidalis and
A. trapezia exposed to single cadmium, lead and selenium spiked sediments and for
A. trapezia exposed to Lake Macquarie mixed metal contaminated sediments. Detoxification
of all metals was evident in both T. deltoidalis and A. trapezia but detoxification capacity was
exceeded for cadmium, lead and selenium leading to significant accumulation of these metals
in sensitive organelles. The significant relationships, in the laboratory exposed T. deltoidalis
and A. trapezia, between TAOC reduction with increased TBARS, lysosomal destabilisation
and micronuclei frequency and between increased TBARS with lysosomal destabilisation and
micronuclei frequency indicates that increased tissue metal dose and BAM burdens caused
significant impairment of the antioxidant reduction capacity which resulted in a cascade of
effects from lipid peroxidation to cellular perturbation and genotoxic damage. The reduction
in physiological condition in the organisms with the highest tissue metal doses suggests the
response goes beyond subcellular perturbations to whole organism and potentially population
effects.
Chronically metal exposed native Lake Macquarie A. trapezia did not show a clear metal
exposure - dose - response relationship. Accumulation of the essential elements zinc, copper
and selenium appeared to be regulated while cadmium and lead were not. TAOC was
significantly reduced and TBARS significantly increased compared to reference organisms
but lysosomal stability and condition were not significantly affected.
The suite of interrelated biomarkers used offers a weight of evidence approach for
demonstrating adverse effects of metal tissue accumulation in T. deltoidalis and A. trapezia
13
Barbier, Lucie. "Dynamique des flux de fondants routiers et influence sur la pollution routière au sein d’un bassin de rétention-décantation." Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0031/document.
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En conditions hivernales rigoureuses, l'application des fondants routiers (principalement du chlorure de sodium - NaCl) permet d'assurer la sécurité des usagers de réseaux. Toutefois, son utilisation généralisée entraîne des risques de contamination des écosystèmes aquatiques et terrestres. En milieu routier, le Na+ et Cl- sont transportés par les eaux de ruissellement vers des ouvrages de traitement tels que les bassins de rétention-décantation. Or, ces bassins n'ont pas la capacité de traiter efficacement cet apport de fondants sous forme dissoute. L'objectif de cette thèse est d'étudier le transfert de ces fondants au sein du système routier et de déterminer leur rôle dans la libération des polluants en période hivernale. Les caractéristiques du bassin situé à Azerailles (Lorraine, France) sur une route nationale moyennement fréquentée ont été étudiées, ainsi que les conditions météorologiques, les salages, la composition des matières en suspension (MES) et la concentration en éléments traces métalliques (ETM). Les résultats ont permis de montrer que entre 50 et 90 % du Cl- ont été collectés par le bassin. Il joue un rôle de tampon qui permet une libération du Cl- dilué durant la période de ruissellement suivant la période de salage. La présence de NaCl dans les eaux a joué un rôle sur la diminution de la qualité des matières en suspension, en mettant en évidence la présence de polluants organiques en période de salage. Elle entraîne également une modification de la chimie des eaux et une augmentation des polluants métalliques (zinc)In severe winter conditions, the application of deicer salts (mainly sodium chloride -NaCl) ensures the safety of network users. However, its spreading carries contamination risks of aquatic and terrestrial ecosystems. On the road, Na+ and Cl- are transported by runoff water to retention-decantation ponds. These ponds do not have the capacity to efficiently treat this flux of deicer salts in dissolved form. In addition, they allow the modification of water and soil chemistry, generating the mobility of metallic pollutants. The objective of this thesis is to study the deicer salt transfer and to determine its role in the release of pollutants during winter. The characteristics of the pond located in Azerailles (Lorraine, France) on a medium-frequented national road were studied, as well as the weather and salting conditions, the composition of the suspended matters and the concentration of traces metals. The results highlighted that between 50 and 90 % of Cl- was collected by the pond. The pond acts as a buffer which allows a release of the collected Cl- diluted during the runoff period following the salting period. The presence of NaCl in runoff water reduced the quality of suspended solids with the presence of organic markers of road pollution and the increase of zinc. It also influenced the increase of zinc in water, the chemical composition and the speciation of elements
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Taylor, Anne, and n/a. "Zinc, copper and cadmium accumulation, detoxification and storage in the gastropod molluscs Austrocochlea constricta and Bembicium auratum and an assessment of their potential as biomonitors of trace metal pollution in estuarine environments." University of Canberra. Applied Science, 1998. http://erl.canberra.edu.au./public/adt-AUC20061109.124205.
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Zinc, copper and cadmium accumulation was measured in two herbivorous gastropod
molluscs Austrocochlea constricta and Bembicium auratum from Lake Macquarie NSW an
area with a history of trace metal pollution.
The investigation consisted of three main parts. The first part examined the influence of
organism mass and location within the Lake on whole body tissue metal concentrations.
This part of the study also compared the distributions of tissue metal concentrations of
populations from Lake Macquarie, a known polluted environment, with those of
populations from Jervis Bay NSW, an unpolluted environment, to establish whether either
species is a net accumulator of zinc copper or cadmium. The second part of the
investigation examined a range of factors which may influence whole body metal
concentrations. One location in Lake Macquarie was sampled monthly from August 1995
to July 1996. The factors examined were temporal variation, gender, breeding cycle, and
tissue distribution. The final part of the investigation examined the detoxification and
storage of excess metals in the gastropods from Lake Macquarie. The mechanisms studied
were metallothioneins and granules.
The tissue metal concentrations of both species were found to be independent of mass.
Location within Lake Macquarie did not significantly influence tissue metal concentrations.
Variation between individuals was the most significant contribution to overall variation,
resulting in a positive skewing of sample trace metal distributions. B. auratum populations
from Lake Macquarie had significantly higher copper and cadmium tissue concentrations
and A. constricta populations had significantly higher zinc, copper and cadmium tissue
concentrations than the populations from Jervis Bay. This suggests that regulation of these
metals is not occurring. A. constricta may therefore be considered a net accumulator of
zinc, copper and cadmium and B. auratum of copper and cadmium.
Tissue metal concentrations did not vary significantly over time. It is suggested that the
organisms are in equilibrium with their environment. B. auratum has higher natural
equilibrium concentrations than A. constricta particularly for copper and cadmium,
suggesting different routes of exposure, uptake or accumulation for the two species.
Gender and breeding cycle did not significantly influence tissue metal concentrations.
Most of the variability in total copper and cadmium concentrations of both species was
explained by variability in gonad tissue metal concentration, while variability in the gonad
and somatic tissues zinc concentration explained about an equal amount of the variability
in total zinc concentration.
A. constricta and B. auratum were both found to induce a cadmium binding protein which
has some features in common with metallothionein. A protein of around 10 000 Da which
binds approximately 60% of the soluble cadmium was isolated using gel filtration. This
protein was further separated into two isoforms using anion exchange. The first isoform
eluted at the same time as MT I and the second at the same time as MT II rabbit liver
standard. Large cells containing granular material which stained positive for calcium were
observed interspersed among the connective tissue immediately behind the columnar
epithelial cells lining the gut wall in both species under a light microscope. Calcium
positive granular particles were also observed within the columnar epithelial cells of B.
auratum.
These species have been shown to be net accumulators of the trace metals investigated,
with the exception of zinc in B. auratum. It has also been established that organism mass,
gender and reproductive state, the partitioning of metals between tissues, and temporal
effects are not confounding factors for the purposes of comparing trace metal
concentrations between populations. They should therefore be effective biomonitors of the
trace metals investigated, with the exception of zinc in B. auratum.
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COSTA, Welka Preston Leite da. "Metais pesados em solos do Rio Grande do Norte: valores de referência de qualidade e relações geopedológicas." Universidade Federal Rural de Pernambuco, 2013. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5401.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Industrial development and population growth have influenced the heavy metal concentrations in soils as well as impacted the soil quality. In this scenario, environmental protection agencies have been concerned on establishing heavy metal quality reference values (QRV) in order to identify contaminated sites. A first step for QRV establishment is the determination of natural concentrations of metals in soil which represent the metal concentrations with no anthropogenic interference. The work was carried out to determine natural soil concentrations and provide soil reference values for the metals Ag, Ba, Cd, Co, Cr, Cu, Ni, Pb, Sb, V, and Zn in soils of the Rio Grande do Norte state according to the Brazilian legislation. The study analyzed 416 soil samples taken from areas with minimal anthropic interference. These samples were digested by USEPA 3051A method and the metals were measured by ICP-OES or flame atomic absorption (FAA). Positive correlations were obtained for metals with pH, CEC, OC, silt and clay contents. Fe and Mg were found in concentrations higher than other Brazil regions and are due to the parent material high in these elements. The results showed that regional geochemical surveys are essential to establish QRV for heavy metals. For example, QRV for the soils of Rio Grande Norte were more restrictive than QRV adopted for other Brazilian states. The confirmation factorial analysis was useful for obtaining QRV more reliable. Such analysis indicated that these values could be obtained from two replicates only.
O crescimento industrial e populacional tem influenciado os teores de metais pesados nos solos e impactado a qualidade deste recurso. A determinação dos teores naturais é o primeiro passo para definição dos valores orientadores de qualidade do solo, os quais são primordiais para a elaboração de uma legislação direcionada ao monitoramento de metais pesados baseados em uma realidade regional. Neste contexto, as agências de proteção ambiental vêm despendendo esforços para o estabelecimento de índices que possam identificar áreas suspeitas de contaminação. Valores de Referência de Qualidade para Solos (VRQs) refletem a concentração natural de uma determinada substância no solo, sem interferência antrópica. O objetivo desse trabalho foi determinar os teores naturais dos metais Ag, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, V e Zn nos solos do Estado do Rio Grande do Norte (RN) e, a partir destes, estabelecer os VRQs para o Estado. Foram coletadas 416 amostras de solo em áreas de mata nativa, com mínima influência antrópica. Caracterização química e física foi executada, bem como, extração de metais pelo método EPA-3051A. Os metais Ag, Ba, Sb e V foram determinados por espectrometria de emissão ótica e Cd, Co, Cr, Cu, Fe Mn, Ni, Pb e Zn por espectrofotômetro de absorção atômica. Correlações significativas e positivas foram obtidas entre os metais e pH, CTC, CO, silte e argila e negativas com os teores de areia. Os teores naturais dos metais Fe e Mn foram superiores aos determinados em solos de outras regiões do país, o que se deve a composição do material de origem do Estado. Os VRQs do Estado do RN (Ag 0,88; Ba 58,91; Cd 0,10; Co 15,41; Cr 30,94; Cu 13,69; Ni 19,84; Pb 16,18; Sb 0,18; V 28,71 e Zn 23,85 mg kg-1) são menos permissivos apresentando maior rigor para o monitoramento ambiental do que os de outros Estados do Brasil. A análise fatorial de confirmação dos dados mostrou-se eficiente para obtenção de VRQs mais confiáveis.
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Deycard, Victoria. "Etude de la réactivité et l’efficacité de rétention des éléments traces métalliques dans les stations d'épuration de Bordeaux et leurs apports métalliques dans les eaux de la section Garonnaise de l'estuaire de la Gironde." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0026/document.
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Cette thèse s’intègre dans l’axe 3 du programme « ETIAGE » qui a associé pendant quatre ans (2010-2014) la Lyonnaise des Eaux, la Communauté Urbaine de Bordeaux (CUB), l’AEAG, et le FEDER, région Aquitaine avec l’université de Bordeaux, le CNRS et IRSTEA. L’objectif de l’axe 3 était de documenter les apports métalliques du bassin versant de la CUB aux eaux de la section garonnaise de l’estuaire de la Gironde. Ce vaste estuaire européen est l’un des plus turbides au monde, avec en période d’étiage la présence devant Bordeaux d’une zone de turbidité maximum (ZTM, >1 g.L-1 de MES en surface) qui transporte des particules estuariennes et des éléments traces potentiellement toxiques. Les travaux de cette thèse se sont focalisés sur les apports métalliques via le fonctionnement des deux principales stations d’épuration (STEP) de la CUB. De ce fait, l’objectif de cette recherche est d’analyser en détail les concentrations, les flux et la réactivité de huit contaminants métalliques définis comme prioritaires par l’Union Européenne Cr, Cu, Cr, Hg, Ni, Pb, Zn, As, et le contaminant émergent Ag, des STEP de la CUB. Les taux d’abattement calculés sont importants, de l’ordre de 80 % pour la majorité des métaux, essentiellement lors de l’étape de décantation. Malgré cette efficacité, les apports en éléments traces métalliques (ETM) urbains via les STEP pendant les épisodes orageux et dans des situations de faible débit peuvent augmenter les concentrations et les flux dans l’estuaire fluvial de la Gironde et ainsi avoir des conséquences sur la qualité des eaux estuariennes. Les concentrations en Ag sont supérieures aux concentrations normales de bruit de fond dans l’estuaire fluvial de la Gironde, faisant de Ag un excellent traceur urbain. Le traitement dans les STEP concentre les ETM dans les boues extraites dont les concentrations métalliques restent en-deçà des normes d’épandage. Toutefois, les concentrations en éléments traces peuvent être de 15 (Ag) à 30 (Cu) fois supérieures aux concentrations naturelles du bruit de fond en raison du fort enrichissement des boues en Hg, Ag, Cr, Cu et Zn. De plus, environ 70 % des éléments traces Cd, Ag, Pb, Cu, et Zn contenus dans ces boues sont potentiellement biodisponibles et peuvent avoir un impact néfaste à court et long terme sur les environnements récepteurs. En raison de l’augmentation prévisible de la démographie des villes côtières, les résultats de cette étude participent à l’élaboration de nouveaux concepts et outils (récupération, recyclage, valorisation) pour améliorer quantitativement et qualitativement les rejets urbains solides et liquidesThis study is a part of the third axis of the « ETIAGE » project, a four year collaboration (2010-2014) between the Lyonnaise des Eaux, the Communauté Urbaine de Bordeaux (CUB), AEAG, and FEDER, Aquitaine region with the University of Bordeaux, CNRS and IRSTEA. The axis 3 objectives were to document the trace metal inputs from the CUB watershed into the waters of the Garonne section of the Gironde estuary. The Gironde Estuary is one of the largest macrotidal and highly turbid estuaries in Western Europe characterized by the presence of a strong maximum turbidity zone (MTZ) with high suspended particulate matter (SPM) concentrations (>1 g.L-1 in surface water) transporting estuarine particles and potentially hazardous trace elements. This study has focused on the trace metal inputs from the two main wastewater treatment plants (WWTP) of the CUB. The objective of this research was therefore to study in detail the daily concentrations, fluxes, and dynamics of 8 EU priority contaminants Cr, Cu, Cr, Hg, Ni, Pb Zn, As, and the emerging contaminant Ag from the WWTPs in the CUB. The calculated removal rates are significant, around 80 % for the majority of metals, mainly as a result of the decantation phase. Despite this high removal efficiency, during periods of heavy rainstorms and low river discharges, the urban metal inputs via the WWTPs may still significantly increase metal concentrations and fluxes in the fluvial Gironde Estuary impacting water quality. In addition, the WWTP fluxes and concentrations of Ag exceeded common background concentrations in the Gironde fluvial estuary, making it an interesting urban tracer. The treatment within the WWTPs concentrates the trace metals in the sludge, yet, metal concentrations remained below legal norms for agricultural use. However, the analysis of WWTP sludge revealed that trace element concentrations are 15 (Ag) and 30 (Cu) times higher than natural background concentrations with high enrichment of Hg, Ag, Cr, Cu and Zn with over 70 % of Cd, Ag, Pb, Cu, and Zn being potentially bioavailable. Therefore, with increasing urban pressure on environmental quality, these results support the need for the development of efficient water quality monitoring tools
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Poulier, Gaelle. "Etude de l’échantillonnage intégratif passif pour l’évaluation réglementaire de la qualité des milieux aquatiques : application à la contamination en pesticides et en éléments trace métalliques des bassins versants du Trec et de l’Auvézère." Thesis, Limoges, 2014. http://www.theses.fr/2014LIMO0032/document.
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Parce qu’ils sont peu coûteux, faciles d’utilisation, et surtout très efficaces, les pesticides sont devenus une composante majeure de l’agriculture moderne et se sont imposés dans de nombreuses activités urbaines et domestiques. Ces molécules se retrouvent aujourd’hui dans tous les compartiments de l’environnement notamment dans les milieux aquatiques. Le suivi resserré des substances actives et de leurs résidus, présents dans l’environnement à des concentrations potentiellement dommageables pour les écosystèmes, apparaît aujourd’hui comme une nécessité. L’application de la Directive cadre sur l’eau, l’une des principales réglementations européenne ciblant les eaux, requiert des techniques d’échantillonnage et d’analyse performantes, alliant haute sensibilité, facilité de mise œuvre, coûts abordables, et surtout précision et fiabilité. Actuellement, la méthodologie employée consiste en des prélèvements ponctuels d’eau à pas de temps lâche (une fois par mois en général) suivi de l’analyse en laboratoire. Cette approche souffre d’un manque de représentativité temporelle, couplée à une sensibilité analytique souvent peu satisfaisante. Les techniques d’échantillonnage passif développées au cours des 20 dernières années pourraient être intégrées dans les réseaux de surveillance réglementaires afin de pallier ces manques, mais des questions subsistent encore quant à leur opérationnalité. Ces travaux de thèse visent à développer puis tester les échantillonneurs passifs sur le terrain afin de déterminer leur adéquation avec les exigences de la Directive cadre sur l’Eau, et le cas échéant, mettre en évidence les principaux verrous scientifiques résiduels. L’originalité de ce travail réside dans:- la variété des outils évalués : trois échantillonneurs différents ont été étudiés (Le Polar Organic Chemical Integrative Sampler (POCIS), le Chemcatcher et le Diffusive Gradient in Thin film (DGT). Les méthodes classiques de prélèvement ponctuels ont également été mise en œuvre.- la variété des environnements étudiés : deux bassins versant très différents ont été considérés, l’un présentant une contamination en pesticides forte, l’autre une contamination modérée.- La mise en en œuvre des échantillonneurs passifs dans un réel contexte réglementaire, les cours d’eau choisis faisant l’objet d’un contrôle opérationnel. Les données acquises avec les échantillonneurs passifs ont ainsi pu être comparées avec les suivis de l’Agence de l’EauThe intensive use of pesticides in agriculture and urban activities since the 1950s has led to diffuse contamination of environmental compartments (air, soil, water). The presence of these molecules can lead to toxic effects for biota. The implementation of the Water Framework Directive (WFD) requires the use of an efficient monitoring network, based on reliable sampling and analytical techniques. Nowadays, grab sampling followed by extraction of analytes and chromatographic analysis is the most widespread strategy because of its simplicity of implementation but it also has numerous drawbacks. The crux of the issue lies in the lack of temporal representativeness and the low analytical sensibility. An alternative strategy to overcome some of these problems could be the use of passive samplers. This contribution aims at discuss about the possible application of passive samplers in regulatory monitoring programs. The originality of this work lies in :The variety of tested devices: three different samplers was studied (The Polar Organic Chemical Integrative Sampler (POCIS), the Chemcatcher and the Diffusive Gradient in Thin Film (DGT). Conventional grab sampling strategies were also evaluated.The variety of studied environments: two very different watersheds were selected. The first one presented a high level of contamination; the second had a low contamination in pesticides.The implementation of passive samplers in a real regulatory context, as the selected streams were monitored by the Water Agency for operational control. Data from the Water Agency could therefore be compared with passive sampler data
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Petit, Jérôme. "Nouveaux outils en sciences de l'environnement: géochimie isotopique du Cu-Zn et spéciation des éléments en trace métalliques par titrage acidimétrique :développement et applications aux phases particulaires de l'estuaire de l'Escaut, aux émissions atmosphériques et aux sols contaminés d'Angleur/Prayon." Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210231.
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Les potentiels de nouveaux moyens d’investigation en sciences de l’environnement, tel que la géochimie des isotopes stables du Cu et du Zn et l’étude de la spéciation des éléments en trace métalliques (ETM) par titrage acidimétrique sont évalués dans le cadre de trois cas d’études, faisant intervenir des matériaux de matrices et de concentrations en ETM variables. Afin de mettre en évidence de très subtiles variations des compositions isotopiques du Cu et du Zn dans les matériaux particulaires variablement pollués, une attention particulière à été voué à la mise au point des méthodes de séparation chimique et d’analyse par MC-ICP-MS. La méthodologie analytique a été développée afin d’exploiter tout les avantages techniques offerts par le spectromètre de masse à l’ULB. Différents modes d’introduction (plasma humide vs plasma sec (Aridus/DSN), d’acquisition des mesures (mode statique ou dynamique) de correction du biais de masse (dopage au Cu, au Zn et au Ga; correction SSBM, SSBC et EEN)ont été évaluées, pour leurs effets sur la précision et la reproductibilité des mesures. D’autres travaux ont permis de quantifier les effets des interférences spectrales et non spectrales par les éléments de la matrice (Ti, Cr, Co,Fe, Ba, Si, Na, Mg et Ca)et par le rapport dopant/analyte en vue de comprendre les sources d’inexactitudes des mesures isotopiques et d’y remédier. Les données isotopiques acquises sur des minerais, sur des (plaques de) dépôts atmosphériques (usine Pb-Zn Metaleurop de Noyelles-Godault), sur des sédiments et des matières en suspension (estuaire de l’Escaut et mer du Nord), révèlent des variations significatives des compositions isotopiques du cuivre et du zinc. Dans l’estuaire de l’Escaut, les variations temporelles (carotte non perturbée, enregistrant la sédimentation sur 30 ans) et spatiales (matières en suspension échantillonnées sur 100 km, selon le profil de salinité) sont caractérisées par des signatures isotopiques en Zn anticorrélées à celle du Cu. Les données peuvent permettre de distinguer le fond géochimique naturel (le « réservoir naturel »), les pollutions diffuses (le « réservoir anthropique commun »- intégrant de multiples sources de contamination en provenance du bassin versant) et certaines pollutions ponctuelles associées à la métallurgie du Zn. Alors que les procédés utilisés en métallurgie sont eux,capable de produire des signatures isotopiques très fractionnées en Zn, ni la diagenèse précoce dans les sédiments, ni les gradients physicochimiques développés lors du mélange des eaux continentales et marines ne sont capables d’affecter significativement la signature isotopique du Cu et du Zn en phase particulaire. Dans de tels milieux, les signatures isotopiques en Cu et Zn (ainsi que celles en Pb) semblent n’être contrôlées que par le mélange conservatif entre le « réservoir naturel » et le « réservoir anthropique commun ». Les données en elles-mêmes constituent la seule base de données isotopiques en Cu, Zn, Pb dans des matériaux particulaires anthropisés estuariens et marins jamais produite à ce jour. Elles permettent de prédire que la signature isotopique en Cu du « réservoir naturel » devrait être légèrement plus enrichie en isotopes lourds que celle du réservoir « anthropique commun » (par analogie au Zn).Si la géochimie isotopique du Cu et du Zn a le potentiel de distinguer différentes sources de pollution, l’évaluation des risques liés à ces pollutions doit tenir compte des formes chimiques des ETM, typiquement mises en évidences par les méthodes d’extraction sélectives (séquentielles, dont le protocole BCR). La méthode alternative proposée pour l’étude de la spéciation, plus versatile (capable de mettre en évidence des phases non prédéfinies et applicable à une variété de matrices plus large) est capable de surmonter plusieurs limitations (dont les problèmes de sélectivité liées au mauvais contrôle de l’acidité du milieu réactionnel) caractéristiques des méthodes traditionnelles. Appliquée à des sédiments marins/estuariens et des sols, la méthode de titrage acidimétrique s’est révélée capable de quantifier les proportions relatives des phases acido-solubles (principal problème des méthodes d’extraction sélectives), ce qui permet d’établir univoquement la spéciation des éléments qui leurs sont associés, d’évaluer la réactivité des ETM vis-à-vis du pH, mais aussi d’évaluer la sélectivité des protocoles d’extraction séquentielle « BCR » et « Tessier ». La méthode de titrage acidimétrique apporte également des informations importantes sur la géochimie des éléments majeurs dans l’estuaire de l’Escaut et met en évidence les particularités minéralogiques des sols pollués en comparaison aux sédiments.
Les études de cas démontrent que ces nouvelles techniques ont des applications dans le domaine de la géochimie de l’environnement, mais peuvent également être vouées, sur le moyen/long terme à une utilisation sortant du cadre des sciences exactes. En effet, l’identification/discrimination des sources de pollutions et l’évaluation des risques de remobilisation des polluants métalliques font partie des nombreuses questions posées par la société aux scientifiques de l’environnement.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Tran, khac Viet. "Le rôle des facteurs environnementaux sur la concentration des métaux-tracesdans les lacs urbains -Lac de Pampulha, Lac de Créteil et 49 lacs péri-urbains d’Ile de France." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1160/document.
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Les lacs jouent un rôle particulier dans le cycle de l’eau dans les bassins versants urbains. La stratification thermique et le temps de séjour de l’eau élevé favorisent le développement phytoplanctonique. La plupart des métaux sont naturellement présents dans l’environnement à l’état de traces. Ils sont essentiels pour les organismes vivants. Néanmoins, certains métaux sont connus pour leurs effets toxiques sur les animaux et les humains. La concentration totale des métaux ne reflète pas leur toxicité. Elle dépend de leurs propriétés et de leur spéciation (fractions particulaires, dissoutes: labiles ou biodisponibles et inertes). Dans les systèmes aquatiques, les métaux peuvent être absorbés par des ligands organiques ou minéraux. Leur capacité à se complexer avec la matière organique dissoute (MOD), particulièrement les substances humiques, a été largement étudiée. Dans les lacs, le développement phytoplanctonique peut produire de la MOD non-humique, connue pour sa capacité complexante des métaux. Pourtant, peu de recherche sur la spéciation des métaux dans la colonne d’eau des lacs urbains a été réalisée jusqu’à présent.Les objectifs principaux de cette thèse sont (1) d’obtenir une base de données fiables des concentrations en métaux traces dans la colonne d’eau de lacs urbains représentatifs; (2) d’évaluer leur biodisponibilité via une technique de spéciation adéquate ; (3) d’analyser leur évolution saisonnière et spatiale et leur spéciation; (4) d’étudier l’impact des variables environnementales, en particulier de la MOD autochtone sur leur biodisponibilité; (5) de lier la concentration des métaux au mode d’occupation du sol du bassin versant.Notre méthodologie est basée sur un suivi in-situ des lacs en complément d’analyses spécifiques en laboratoire. L’étude a été conduite sur trois sites: le lac de Créteil (France), le lac de Pampulha (Brésil) et 49 lacs péri-urbains (Ile de France). Sur le lac de Créteil, plusieurs dispositifs de mesure en continu nous ont fourni une partie de la base de données limnologiques. Dans le bassin versant du lac de Pampulha, la pression anthropique est très importante. Le climat et le régime hydrologique des 2 lacs sont très différents. Les 49 lacs de la région d’Ile de France ont été échantillonnés une fois pendant trois étés successifs (2011-2013). Ces lacs nous ont fourni une base de données synoptique, représentative de la contamination métallique à l’échelle d’une région fortement anthropisée.Afin d’expliquer le rôle des variables environnementales sur la concentration métallique, le modèle Random Forest a été appliqué sur les bases de données du lac de Pampulha et des 49 lacs urbains avec 2 objectifs spécifiques: (1) dans le lac de Pampulha, comprendre le rôle des variables environnementales sur la fraction labile des métaux traces, potentiellement biodisponible et (2) dans les 49 lacs, comprendre la relation des variables environnementales, particulièrement au niveau du bassin versant, sur la concentration dissoute des métaux. L’analyse des relations entre métaux et variables environnementales constitue l’un des principaux résultats de cette thèse. Dans le lac de Pampulha, environ 80% de la variance du cobalt labile est expliqué par des variables limnologiques: Chla, O2, pH et P total. Pour les autres métaux, le modèle n’a pas réussi à expliquer plus de 50 % de la relation entre fraction labile et variables limnologiques. Dans les 49 lacs, le modèle Random Forest a donné un bon résultat pour le cobalt (60% de la variance expliquée) et un très bon résultat pour le nickel (86% de la variance expliquée). Pour Ni les variables explicatives sont liées au mode d’occupation du sol : « Activités » (Equipements pour l’eau et l’assainissement, entrepôts logistiques, bureaux…) et « Décharge ». Ce résultat est en accord avec le cas du lac de Créteil où la concentration en Ni dissous est très élevée et où les catégories d’occupation du sol « Activités » et « Décharges » sont dominantesLakes have a particular influence on the water cycle in urban catchments. Thermal stratification and a longer water residence time in the lake boost the phytoplankton production. Most metals are naturally found in the environment in trace amounts. Trace metals are essential to growth and reproduction of organisms. However, some are also well known for their toxic effects on animals and humans. Total metal concentrations do not reflect their ecotoxicity that depends on their properties and speciation (particulate, dissolved: labile or bioavailable and inert fractions). Trace metals can be adsorbed to various components in aquatic systems including inorganic and organic ligands. The ability of metal binding to dissolved organic matter (DOM), in particular humic substances, has been largely studied. In urban lakes, the phytoplankton development can produce autochthonous DOM, non humic substances that can have the ability of metal binding.. But there are few studies about trace metal speciation in lake water column.The main objectives of this thesis are (1) to obtain a consistent database of trace metal concentrations in the water column of representative urban lakes; (2) to access their bioavailability through an adapted speciation technique; (3) to analyze the seasonal and spatial evolution of the metals and their speciation; (4) to study the potential impact of environmental variables, particularly of dissolved organic matter related to phytoplankton production on metal bioavailability and (5) to link the metal concentrations to the land use in the lake watershed.Our methodology is based on a dense field survey of the water bodies in addition to specific laboratory analysis. The research has been conducted on three study sites: Lake Créteil (France), Lake Pampulha (Brazil) and a panel of 49 peri-urban lakes (Ile de France). Lake Créteil is an urban lake impacted by anthropogenic pollution. It benefits of a large number of monitoring equipment, which allowed us to collect a part of the data set. In Lake Pampulha catchment, the anthropogenic pressure is high. Lake Pampulha has to face with many pollution point and non-point sources. The climate and limnological characteristics of the lakes are also very different. The panel of 49 lakes of Ile de France was sampled once during three successive summers (2011-2013); they provided us with a synoptic, representative data set of the regional metal contamination in a densely anthropized region.In order to explain the role of the environmental variables on the metal concentrations, we applied the Random Forest model on the Lake Pampulha dataset and on the 49 urban lake dataset with 2 specific objectives: (1) in Lake Pampulha, understanding the role of environmental variables on the trace metal labile concentration, considered as potentially bioavailable and (2) in the 49 lakes, understanding the relationship of the environmental variables, more particularly the watershed variables, on the dissolved metal concentrations. The analysis of the relationships between the trace metal speciation and the environmental variables provided the following key results of this thesis.In Lake Pampulha, around 80% of the variance of the labile cobalt is explained by some limnological variables: Chl a, O2, pH, and total phosphorus. For the other metals, the RF model did not succeed in explaining more than 50% of the relationships between the metals and the limnological variables.In the 49 urban lakes in Ile de France, the RF model gave a good result for Co (66% of explained variance) and very satisfying for Ni (86% of explained variance). For Ni, the best explanatory variables are landuse variables such as “activities” (facilities for water, sanitation and energy, logistical warehouses, shops, office…) and “landfill”. This result fits with Lake Creteil where dissolved Ni concentration is particularly high and where the “activities” and “landfill” landuse categories are the highest
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Liu, Yang Ping. "Modelling estuarine chemical dynamics of trace metals." Thesis, University of Plymouth, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360359.
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Herzi, Faouzi. "Caractérisation chimique des exsudats du dinoflagellé marin toxique Alexandrium catenella et de la diatomée marine Skeletonema costatum et étude de la réponse protéomique d’Alexandrium catenella en conditions de stress métalliques." Thesis, Toulon, 2013. http://www.theses.fr/2013TOUL0014/document.
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’impact de plusieurs éléments traces métalliques (ETMs) (plomb, zinc, cuivre ou cadmium) sur la croissance de deux espèces phytoplanctoniques marines, la diatomée Skeletonema costatum et le dinoflagellé toxique Alexandrium catenella, a été étudié à partir de cultures réalisées en conditions physiologiques et en conditions contaminantes. Les résultats obtenus ont révélé des perturbations de croissance chez S. costatum et chez A. catenella, lorsque ces espèces étaient exposées à de fortes concentrations métalliques. Les effets létaux se manifestaient par une forte mortalité cellulaire, accompagnée, chez A. catenella, par la conversion d’un certain nombre de cellules végétatives en kystes de résistance. Puis, l’exsudation de la matière organique dissoute (MOD) par S. costatum et par A. catenella en réponse aux stress métalliques, a été caractérisée. L’exsudation du carbone organique dissous (COD) variait en fonction de la phase de croissance, et était associée au niveau de contamination métallique, et à la nature du métal testé. Les valeurs maximales de COD exsudé par cellule étaient mesurées en réponse à la contamination par le cuivre 16 µM pendant la phase d’adaptation, et en réponse à la contamination par le cadmium 200 µM pendant la phase exponentielle de la croissance. Plus spécifiquement, la matière organique dissoute fluorescente (FDOM) exsudée par S. costatum et par A. catenella a été analysée par spectroscopie de fluorescence 3D associée à l’algorithme PARAFAC. Les traitements PARAFAC révélaient quatre composantes, lesquelles étaient attribuées à deux contributions principales, l’une liée à l’activité biologique de l’espèce, l’autre liée à la décomposition de la matière organique. Les composantes C1 et C2 étaient combinées à des pics tryptophaniques et à des substances humiques, tandis que les composantes C3 et C4 étaient associées à la production de matière organique marine. Par ailleurs, le glucose et le galactose étaient prédominants parmi les aldoses constituant les polysaccharides exsudés dans la MOD. De plus, des modifications protéomiques étaient observées dans les protéomes d’A. catenella, en réponse aux divers stress métalliques. Les protéines de stress exprimées par A. catenella étaient mises en évidence par comparaison des profils d’expression protéiques (PEPs) obtenus par électrophorèse bidimensionnelle (électrophorèse 2D), en conditions physiologiques et en conditions contaminantes. Les protéines de stress étaient impliquées dans de nombreuses catégories fonctionnelles : réponse au stress oxydatif (superoxyde dismutase, sous – unités du protéasome), photosynthèse (ribulose 1,5-bisphosphate carboxylase, complexe péridinine chlorophylle – protéine, ferrédoxine-NADP réductase), métabolisme des carbohydrates (triosephosphate isomérase, ribose 5-phosphate isomérase, malate déshydrogénase, photorespiration et métabolisme du phosphore (phosphoglycolate phosphatase), métabolisme énergétique (ATP – synthase), signal cellulaire (calmoduline), activité chaperonne (HSP 70, HSP 90) et bioluminescence d’A. catenella (luciférine – binding protéine). La sur – expression de la phosphoglycolate phosphatase (PGP) et celle de l’ATP – synthase, observées en réponse à la contamination par le plomb, pourraient participer à une stratégie de défense mise en place par A. catenella afin (i) de se protéger du stress oxydatif lié à la contamination métallique, la PGP étant impliquée dans la dissipation de l’excès d’énergie (ii) de produire davantage de réserves énergétiques (ATP) et ainsi de répondre à des besoins accrus en raison du stress métallique, dans le but de s’y adapterMpact of several trace metals (lead, zinc, copper or cadmium) on the growth of two marine phytoplankton species: the diatom Skeletonema costatum and the toxic dinoflagellate Alexandrium catenella, has been studied from cultures grown under physiological and contaminated conditions. The results obtained revealed growth perturbations in S. costatum and in A. catenella, when these species were exposed to high metal concentrations. The lethal effects appeared through a strong cell death, coming, in A. catenella, with the conversion of vegetative cells into resistance cysts. Then, exudation of dissolved organic matter (DOM) by S. costatum and by A. catenella in response to metal stress has been characterized. Exudation of dissolved organic carbon (DOC) varied according to the growth phase, and was associated with the level of metal contamination and the nature of the tested metal. The maximal values of DOC exudated per cell were measured in response to contamination by copper 16 µM during the adaptation phase, and in response to contamination by cadmium 200 µM during the exponential phase of growth. More specifically, the fluorescent dissolved organic matter (FDOM) exudated by S. costatum and by A. catenella has been analyzed by 3D fluorescence spectroscopy combined with PARAFAC algorithm. The PARAFAC treatments revealed four components, which were attributed to two main contributions, one related to the biological activity of the species, and the other related to the decomposition of organic matter. The C1 and C2 components were combined with tryptophan peaks and with humic substances, while the C3 and C4 components were generally associated with the production of marine organic matter. Moreover, glucose and galactose were the main aldoses among the polysaccharides exudated in the DOM. Proteomic changes occurred in the proteomes of A. catenella in response to the various metal stresses. Stress proteins expressed by A. catenella were obtained by comparison of the protein expression profiles (PEPs) achieved by two-dimensional electrophoresis (2D - electrophoresis) under physiological and contaminated conditions. Stress proteins are involved in many functional categories: response to oxidative stress (superoxide dismutase, proteasome sub - units), photosynthesis (ribulose 1,5- bisphosphate carboxylase, peridinin chlorophyll protein complex, ferredoxin -NADP reductase), carbohydrate metabolism (triosephosphate isomerase, ribose 5-phosphate isomerase, malate dehydrogenase), photorespiration and phosphorus metabolism (phosphoglycolate phosphatase), energy metabolism (ATP - synthase), cell signalling (calmodulin), chaperone activity (HSP 70, HSP 90) and bioluminescence of A. catenella (luciferin - binding protein). Over - expression of phosphoglycolate phosphatase (PGP) and of ATP – synthase, occurring in response to metal contamination by lead, could represent a strategy of defence set up by A. catenella (i) to protect itself from the oxidative stress due to metal contamination, PGP being involved in the dissipation of excess energy (ii) to produce more reserves of energy (ATP) so as to satisfy the increased requirements resulting from the metal stress, in order to adapt to it
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Howell, Kate Ann. "In situ measurement of trace metals in coastal waters." Thesis, University of Plymouth, 2003. http://hdl.handle.net/10026.1/1120.
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This thesis describes the use of in situ and laboratory techniques for monitoring of trace metals and master variables in the environment. Chapter 1 presents a general overview of trace metals, their sources, sinks and roles in estuaries and near coastal zones, their general characteristics and the importance of their behaviour in estuaries. Filtration and commonly used analytical methods for trace metals detemriinations in natural waters are also discussed. Chapter 2 highlights the importance of colloids (in the size range 0.2 to 0.4 \im) to membrane clogging and concludes that cojloids account for a significant part of clogging of membrane filters. The aim of this study was to extend earlier studies by examining the trends of filtrate concentrations as a function of filtration volume in riverine and estuarine waters with contrasting matrix composition, over two different seasons. Based on the findings presented in this chapter some metal specific filtration protocols are suggested. Chapter 3 provides an overview of developments in instrument automation that have led to miniaturisation and resulting in manufacture of portable electrochemical instrumentation. Such instrumentation has been used for continuous trace metal measurements from the banks of estuaries and on-board ships. The most recent developments in flow-through cells with a gelcoated Iridium (Ir) micro-electrode array have resulted in submersible in s/Yu voltammetric probes which allow long-term trace metal measurements at sub-nanomolar concentrations in coastal waters. Such In situ probes hold great promise for water quality monitoring. Chapter 4 presents the optimisation and validation of a Voltammetric In situ Profiling (VIP) system for the simultaneous determinations of Cd(ll), Cu(ll) and Pb(ll) in estuarine and coastal waters. The trace metal faction measured by the VIP system is termed 'dynamic' and includes and includes these free ions and small complexes with size smaller than a few nm. Systematic studies in NaNOa and seawater were conducted and these showed that variations in ionic strength, pH and dissolved oxygen did not affect the response of the instrument, whereas an Arrhenius type temperature response was observed. During the work, physical and voltammetric settings of the VIP system were considered and tested in detail in order to achieve the analytical requirements to perform measurements in the laboratory and during in situ deployments^ The VIP instrument has a detection limit (defined as 3cj) in seawater for Cd(II) of 23 pM, Cu(ll) 1.13 nM, and Pb(ll) 23 pM. The accuracy of the VIP system was determined with certified reference material (CRM), showing good agreement. Chapter 5 discusses the results of an international laboratory inter-comparison exercise, in order to verify precision and accuracy of measurements made by 4 laboratories that operate VIP systems located in Plymouth, U.K; Geneva, Switzeriand and Ancona, Italy, using laboratory reference methods as a comparison. Inter-comparison included analysis of Tamar Estuary samples and in situ VIP system measurements in the coastal waters of the Gullmar Fjord, Sweden. Chapter 6 presents the results of field deployment of the automated Voltammetric In situ Profiling (VIP) system for the simultaneous determinations of dynamic Cd(ll), Cu(ll) and Pb(ll) in three estuaries located in the Southwest of England, UK. The VIP instrument allowed the In situ determination of 2-4 samples h'\ In addition, the VIP system measured total filterable (0.4 pm pore size filter) concentrations of Gd(ll) and Pb(ll) in discrete estuarine water samples. Through a series of tidal surveys lasting 7-12 h each and totalling 7 surveys a high resolution data set including speciation information was built up that enabled an interpretation of geochemical processes in the studied estuaries. Chapter 7 shows the results of In situ determination of VIP dynamic metal concentrations in the Po plume arid Adriatic Sea. Concentrations were similar to those previously reported for this coastal sea system. The correlation of the metals with salinity was presented and highlighted the importance of local effluent inputs close to the river mouth for Cd(ll). The data demonstrated that the Adriatic was not heavily contaminated with trace metals. Chapter 8 presents the overall conclusions from the research and makes suggestions for future work.
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Keyse, Sarah. "Factors controlling the solubility of trace metals in rainwaters." Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243029.
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Postill, Anthony S. "The interaction of trace metals with humic substances in estuaries." Thesis, Lancaster University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274193.
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Bloxham, Martin John. "The determination of trace metals in sea water using ICP-MS." Thesis, University of Plymouth, 1994. http://hdl.handle.net/10026.1/1073.
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Inductively coupled plasma-mass spectrometry (ICP-MS) offers exceptional sensitivity and multi-element capability for trace metal analysis but the formation of polyatomic ions (particularly below m/z = 80) can cause, serious interferences. Such species can be introduced via precursor atoms in atmospheric gases, the sample matrix or impurities in the argon support gas. This thesis describes the development of a portfolio of analytical methods coupled with ICP-MS detection for the determination of trace metals such as manganese, cobalt, copper, nickel, zinc, mercury and lead in complex matrices such as sea water. A literature review of coupled techniques is given in Chapter one. Chapter two discusses the effect of sea water on the analytical performance of ICP-MS. Initial studies were carried out using a single channel flow injection (FI) manifold and included an investigation of the addition of nitrogen to the nebulizer gas flow of the ICPMS for the reduction of the ArNa* polyatomic ion interference at m/z = 63 on the Cu signal. This was followed by a multivariate simplex optimisation for the suppression of the ArNa* polyatomic ion interference at m/z = 63 and non-spectroscopic interferences affecting other masses in sea water, for the determination of Cu, Cr, Mn, Ni, Co, Zn and Pb. In Chapter three an on-line FI-ICP-MS matrix elimination method for the determination of trace metals such as Mn, Co, Cu, Zn and Pb in sea water is discussed. The method involved chelation of the analytes onto Chelex-100 or MetPac CC-1 iminodiacetate (IDA) .resin, with the simultaneous removal of indirectly interfering matrix species, particularly Na and CI ions. Results showing how the effects of the interferences were overcome, together with validation of the method by the analysis of open ocean, coastal and estuarine certified reference materials are reported. s Chapter four compares FI approaches coupled with AFS, ICP-AES and ICP-MS detectors for the determination of total mercury. Initial studies compared figures of merit for FI (conventional pneumatic nebulization) and Fl-cold vapour generation (CVG) coupled with ICP-AES and ICP-MS. Detection limits for total Hg were improved by developing simple on- and off-line preconcentration procedures using a MetPac CC-1 micro-column incorporated in a FI manifold vAth conventional pneumatic nebulization. An AFS detector was then used in the development of a method for the determination of total mercury with an on-line bromide/bromate oxidation step. In chapter five an LC-ICP-MS method for the speciation of Hg in sea water samples is described. The method involved the separation of mercury(II) chloride, methylmercury chloride and ethylmercury chloride on a Cig ODS stationary phase with an ammonium acetate/acetonitriIe/2-mercaptoethanol mobile phase. In order to achieve the necessary detection limits required for the determination of mercury in real sea water samples (< 50 ng r^), an off-line preconcentration method using a dithiocarbamate resin was used.
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Althaus, Martin. "Dissolved trace metals in the estuarine plumes of the Humber, Thames and Rhine rivers." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316029.
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Maatouk, Elias. "Caractérisation des eaux usées au Liban : impact sur le fonctionnement des stations d’épuration." Thesis, Paris Est, 2014. http://www.theses.fr/2014PEST1110/document.
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Au Liban, 65% de la population résident à Beyrouth et au Mont Liban particulièrement dans la zone côtière et dans une bande étroite du flanc ouest du Mont Liban. Cette occupation engendre une forte pression anthropique sur les ressources hydriques. En effet environ 330 Mm3 d'eaux usées par an sont rejetés dans la Méditerranée par 53 émissaires distribués sur les villes côtières. Ces eaux, rejetées en grande majorité sans traitement, représentent le vecteur principal de pollution du milieu récepteur que représente la Mer Méditerranée (MOE/UNDP/ECODIT, 2011).Cette étude avait pour objectif principal de déterminer la qualité des eaux usées au Liban et d'établir une comparaison entre les contextes Libanais (en s'appuyant sur Beyrouth) et Français (cas de l'agglomération parisienne). Un suivi ponctuel des eaux usées provenant de 4 sites de prélèvement représentatifs de la région de Beyrouth et ses banlieues (sites d'Al Ghadir, Fleuve Beyrouth, Antelias et Jounieh) a été conduit. Deux sites ont été sélectionnés pour un suivi en continu de l'évolution des eaux usées aux échelles journalière et hebdomadaire : Jounieh et Al Ghadir. En France, une série de campagnes ont été réalisées sur les principaux émissaires des stations d'épuration de Marne Aval, Seine Amont, Seine Centre et Seine Aval, au sein de la STEP Seine Centre (au niveau des traitements primaire et secondaire), et en Seine. Ensuite les résultats à Beyrouth et Paris ont été confrontés pour déterminer l'impact sur l'environnement qu'aurait la mise en place de traitements adaptés aux effluents libanais. Les niveaux de contamination pour les paramètres globaux sont comparables pour le prélèvement ponctuel entre les bassins versants d'Al Ghadir et de Jounieh. Cependant les niveaux relevés à Al Ghadir et Jounieh sont plus élevés que ceux d'Antelias et Fleuve Beyrouth. Par ailleurs, le suivi en continu a permis de mettre en évidence que les niveaux en MES, MVS, DCOT et DBO5 sont généralement comparables sur les deux sites Al Ghadir et Jounieh. La comparaison avec les émissaires parisiens montre des différences significatives pour les MES, MVS et DBO5, ces paramètres sont significativement plus élevés sur les sites libanais. Pour la DCOT, les concentrations sont comparables entre les deux pays. En comparant les ETM totaux (Cr, Zn, Cu, Cd et Pb), on trouve que la concentration en cuivre des émissaires parisiens est plus élevée que celle du Liban pour les bassins versants d'Al Ghadir et Jounieh. Pour le plomb et le zinc, les concentrations sont comparables entre les deux pays. Enfin les concentrations en cadmium et chrome sont beaucoup plus élevées à Beyrouth qu'à Paris. Les flux en ETM au Liban exportés vers la Mer Méditerranée pour le site d'Al Ghadir sont 20,7; 20,8; 2,42; 0,6; et 1,5 kg/jour respectivement pour le CrT, ZnT, CuT, CdT et PbT et pour l'émissaire de Jounieh 0,66; 3,7; 0,38; 0,045 et 0,33 kg/jour. En s'appuyant sur l'efficacité des STEP parisiennes, les niveaux rejetés diminueraient de 90 à 98% pour les MES, de 84 à 95% pour la DCOT et de 63 à 97 % suivant l'ETM concernéIn Lebanon, 65 % of the population lives in Beirut and Mount Lebanon particularly along the coastal area and a narrow band of the western side of the Lebanon Mount. This occupation generates a strong anthropic pressure on the water resources. Indeed approximately 330 mm3 of waste waters a year are rejected into the Mediterranean by 53 trunks distributed along the coastal towns. In fact, these wastewaters are released to natural media without any significant treatment and These effluents, released in great majority without treatment, are considered as the primary vector of the Mediterranean Sea pollution (MOE/UNDP/ECODIT, 2011).This study aimed at determining the quality of wastewaters in Lebanon and at establishing a comparison between the Lebanese (with respect to Beirut) and French (case of the urban area of Paris) contexts. A specific monitoring of wastewaters was led on 4 representative sampling sites of the area of Beirut and its suburbs (Al Ghadir sites, Beirut River, Antelias and Jounieh). Two sites were selected to follow the evolution of the wastewater quality both at the daily and weekly scale: Jounieh and Al Ghadir. In France, a series of campaigns were carried out on the main trunks of several wastewater treatment plants, e.g., Marne Aval, Seine Amont, Seine Aval and Seine Centre, in the Seine Centre WWTP (within the primary and secondary treatments), and in the Seine River. Then the results in Beirut and Paris were confronted to determine the environmental impact of the installation of treatments adapted to the Lebanese effluents.Contamination levels for the water quality parameters were comparable for the punctual sampling between the Al Ghadir and Jounieh watersheds. However, the levels found in Al Ghadir and Jounieh were higher than those of Antelias and Beirut River. In addition, continuous monitoring helped to highlight the levels of TSS, VSS, BOD5 and CODT were generally comparable at both sites: Al Ghadir and Jounieh. The comparison with the Parisian trunks showed significant differences for TSS, BOD5 and VSS, these parameters were significantly higher on Lebanese sites. For CODT, concentrations were comparable between the two countries. By comparing the total ETM (Cr, Zn, Cu, Cd and Pb), we found that Cu concentrations in Parisian trunks were higher than those of Lebanese Al Ghadir and Jounieh watersheds. For lead and zinc concentrations were comparable between the two countries. Finally, the concentrations of cadmium and chromium were much higher in Beirut than in Paris. Trace metal flows to the Mediterranean Sea from the Al Ghadir site were of 20,7; 20,8; 2,42; 0,6; and 1,5 kg/day for CrT, ZnT, CuT, CdT and PbT respectively, and for Jounieh they were of 0,66; 3,7; 0,38; 0,045 and 0,33 kg/day, respectively. Based on the effectiveness of the Parisian WWTPs, released levels would decrease by 90-98 % for TSS, 84-95 % for CODt and 63-97 % depending on the ETM concerned
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Kennette, Debra. "The bioavailability of trace metals to soil invertebrates in urban contaminated soils." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0001/MQ44194.pdf.
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Cook, Nicola. "Bioavailability of trace metals in urban contaminated soils." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34934.
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There are two main components to the research: the theoretical and the experimental. Chapter 2 contains an analysis of the state of soil quality guidelines and the scientific methods used to determine them. A number of recommendations to improve soil quality criteria for trace metals are offered including the importance of considering bioavailability and the need to use realistic conditions, trace metal sources and organisms.A critical review of the literature dealing with predicting the availability of trace metals to plants is presented in Chapter 3. We found little agreement among hundreds of similar studies which relate plant metal uptake to the amount of metal extracted by selective chemical dissolution procedures. An extensive summary of the data shows clearly that the extraction methods are not widely applicable. Differences between individual soils, their metal retention capacities, as well as plant factors and environmental conditions contribute to the variability of the results. Alternative ways of assessing bioavailability are suggested.
The experimental component of the thesis focuses on the availability of trace metals to plants. In Chapter 4 the uptake of Cu from different soil pools was examined and the free metal ion (Cu2+) was found to be the best predictor of uptake by lettuce (Latuca sativa cv. Buttercrunch), ryegrass (Lolium perenne cv. Barmultra) and radish (Raphanus sativus cv. Cherry Belle).
In Chapters 5 and 6 we examined the effect of low-cost in-situ treatments on the availability of metals to plants in greenhouse and field experiments. Synthetic zeolites, P amendments, organic matter and clean soil were used and their effect on the bioavailability of Cd, Cu, Pb, Ni and Zn evaluated. The plants for the experimental work were lettuce and perennial ryegrass. Only the clean soil treatment was consistently effective in reducing the concentration of metals in the plant. We also wanted to determine whether the trace metals in the plant tissue came from the soil or from direct deposition of pollutants on the leaf surfaces. We found little evidence that metals in plants were a result of atmospheric fallout.
A method for the accurate analysis of total metal concentrations in a range of contaminated soils including those containing oil and grease was developed (Chapter 7). For this research the trace metals of concern are Cd, Cu, Ni, Pb and Zn---all commonly found in urban/industrial soils. The proposed method using HNO3/HClO4 has several advantages over the common HNO3/H2O2 procedure. We were able to digest larger soil samples and hence the final concentration of trace metals was usually in the range for analysis by inductively coupled plasma atomic absorption spectrometry or flame atomic absorption spectrometry.
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Hunt, Amelia Phryne. "The ecology of epilithic biofilms in small acidic streams and their role in the biogeochemical cycling of trace metals." Thesis, Lancaster University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266889.
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Kane, Margaret Mary. "Processes contributing to the atmospheric deposition of trace metals to the North Sea." Thesis, University of East Anglia, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317587.
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Ge, Ying 1974. "Speciation and complexation of trace metals in eastern Canadian soils." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82879.
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An important task of research on trace metals in soils is to evaluate how much metals are potentially bioavailable and may cause toxic effects. In this thesis, the chemical speciation and complexation of cadmium (Cd), copper (Cu), mercury (Hg) and lead (Pb) were examined in eastern Canadian soils collected from different locations around smelters. Our goal is to be able to predict metal binding in the soil solution and on the solid phase under a wide range of field conditions.In Chapter 2, speciation of Cd, Cu and Pb in the lysimeter soil solutions was determined using an ion exchange technique (IET) involving a resin column. The IET-speciation data were used to estimate the metal-dissolved organic carbon (DOC) binding constants using the non-ideal competitive adsorption (MICA)-Donnan model, which assumed a continuous distribution of binding affinities on the DOC molecule. The published Cd and Pb speciation data in a variety of soils (Chapter 3) were also used to test the effectiveness of two speciation models, the MICA-Donnan model and WinHumicV. Both models satisfactorily predicted the concentrations of Cd2+ and Pb2+. The two chapters of metal speciation demonstrated that the NICA-Donnan model could estimate the binding strength of organic matter in soil solutions.
Proton and metal complexation to the surface of soil particles (Chapters 4 and 5) was investigated using back-titration and batch adsorption procedures. It was shown that the surface binding of H+, Cd2+, Hg2+ and Pb2+ was significantly related to soil organic matter (SOM). Though the soil particle surface was covered by a mixture of organic and mineral components, a two-site distribution could be identified from the titration curves. With the parameters derived from the back-titration and adsorption data, the MICA-Donnan model reasonably predicted the surface complexation of proton and metals. Furthermore, the statistically significant relationships between the model parameters and soil organic matter supported the assumptions in this thesis: (1) Organic matter was the most important sorbent on the particle surface; (2) The MICA-Donnan model may be used to interpret the surface binding data in these soils.
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Hayes, Warwick Jay. "Chemical relationships in waters and sediments of some urban streams, with particular reference to heavy metals and phosphorus." University of Technology, Sydney. Department of Environmental Biology and Horticulture, 1996. http://hdl.handle.net/2100/361.
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This thesis describes two studies of the chemistry of freshwater streams in the Sydney basin. The first was a survey of 86 waterways, sampled under low conditions. Samples were generally low in salinity, soft, of poor buffering capacity and dominated by sodium and chloride. C0-dominance by calcium, magnesium and (bi)carbonate occured in a number of particular cases. Multivariate analyses indicated three groups, separated primarily by levels of dissolved nutrients, trace metals, turbidity and colour. Groupings were associated strongly with the type of catchment. Streams in areas relatively unaffected by human influence had notable uniformity in chemistry, while those from developed catchments were varied. Heavy metal contamination was relatavely low, although a few of the samples displayed inordinately large levels of one or more metals. In such cases the more extreme measurements of phosphorus and nitrogen were also seen. The findings were consistant with occasional or localised elevation of contaminant levels. The second study invloved monitoring of three Hawkesbury Sandstone streams. Sampling of surface waters, interstial waters and sediments was performing at irregular intervals over a two year period at three stations within each site. The streams predominantly existed under low conditions and showed similar major ion chemistries to the majority of the survey samples. Levels of calcium and total carbonate, plus heavy metals and nutrients were generally higher in the urbanised creeks, comapred to the reference strema. During a heavy storm, high levels of nutrients, suspended solids and colour were detected in all surface waters at peak-flow, as well as alkaline pH, oxidising redox, and reduced conductivity, alkalinity and hardness. The sandy sediments were characterised by very low levels of organic matter and cation exchange capacity. Sequential extractions identified that the sums of secondary phase lead, zinc and copper were over nine, four and two times that of the corresponding residual, respectively. Greatest proportions of zinc and lead were associated with coatings of iron and maganese oxides, or coarse waste particles. Copper was preferentially associated with organic matter. Concentration gradients between interstitial and surface waters were rare and release of sedimentary constituents should occur from the upper-most particulates. Poor water and sediment qualities were often observed in the urban sites. Poor water quality was also seen on occassion in the reference stream. However, since poor sediment quality was not detected at those times and interstitial waters for all sites displayed high within-site variability, surface waters were considered the most reliable short-term indicator of condition for Hawkesbury Sandstone streams. Multidimensional scaling showed that all streams had distinct water and sediment chemistries. High levels of temporal and spatial variability were apparant within the urbanised sites - particularly in interstitial waters - mostly due to concentrations of heavy metals, phosphorus and suspended solids. Seasonal differences were detected, but only in terms of the level of variability between summer and winter samples.
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Grochocki, Julian Lucian. "Late Holocene Environmental Variability as Recorded in the Sediment of a Northeastern Ohio Kettle Lake." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1491558782637496.
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Murray, Patricia 1964. "Site specific evaluation of urban brownfields contaminated with trace metals." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21612.
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This thesis is part of a broader project that examines three different approaches to evaluating trace metal contamination in urban brownfields: the measure of total soil metals; calculating bioavailable metals; and the use of species as bioindicators of trace metals in soils. Chapter 1 discusses the problems inherent in each approach such as; inconsistent results due to differences in techniques, extrapolation from laboratory to field, and the influence of species differences and environmental conditions. Chapter 2 is a site description measuring biodiversity, community structure and activity of three urban brownfields. The site description was used to select organisms that were subsequently evaluated for their usefulness as bioindicators of trace metals (chapter 3). Of the three plant species used (dandelion, bladder campion, and chicory), dandelion has the possibility of being a suitable bioindicator of Cd, Ni, and Zn, while bladder campion may be suitable for evaluating Cd, Ni, Pb, and Zn.
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Li, Juan 1963. "Fractionation and speciation of trace metals in contaminated urban soils from Montreal, Canada." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20266.
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A variety of extractants were used to fractionate the trace metals Cd, Cu, Mn, Ni, Pb, and Zn in contaminated urban soils. The metals were mostly held in soil solid phases but not in soluble and exchangeable forms. Except for Mn, extractability of metals by selective chemicals was mainly a function of the contamination level. The speciation of these elements in water, 0.01 M CaCl2, and pH-adjusted water extra was calculated using the chemical equilibrium model MINEQL+. The free ions of Cd, Ni, and Zn were the predominant species in most of the water and 0.01 M CaCl2 extracts while PbCO30 was the main form of Pb. Organically complexed Cu accounted for over of the total dissolved Cu. The solubility of trace metals increased as solution pH was decreased. Metals Cd, Ni, Pb and Zn combined with Cl- at low pH (<5). Organically complexed Cu was shifted to Cu2+ when pH was decreased.Except for Mn, the activities of the other metals in water, 0.01 M CaCl 2 extracts, and pH-adjusted water extracts were undersaturated with respect to established minerals in soils. MnHPO4 seems to be controlling the solubility of Mn in these extracts.
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Vaughan, Ronald L. "Resistance-in-series modeling in high-shear rotary ultrafiltration." Morgantown, W. Va : [West Virginia University Libraries], 1998. http://etd.wvu.edu/templates/showETD.cfm?recnum=189.
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Thesis (M.S.)--West Virginia University, 1998.Title from document title page. Document formatted into pages; contains xv, 233 p. : ill. Includes abstract. Includes bibliographical references (p. 227-232).
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Clark, Gillian K. "The fate of trace metals at the Garroch head sewage sludge dump site in the Firth of Clyde, Scotland." Thesis, Edinburgh Napier University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328096.
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Ghosn, Micheline. "Chemical contamination in different marine organisms along the Lebanese coast : Environmental implications and health risks." Thesis, Littoral, 2019. http://www.theses.fr/2019DUNK0552.
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La consommation mondiale des produits de la mer est en perpétuelle croissance et les produits de la pêche sont devenus parmi les produits les plus marchandés à travers le monde. Cependant, la qualité de ces derniers soulève une problématique au niveau de la santé humaine avec l’augmentation des pressions anthropiques menaçant les écosystèmes côtiers et les organismes marins. Par la suite, malgré les qualités nutritionnelles des produits de la pêche, leur consommation peut être une voie d’exposition de l’homme à différents types de contaminants chimiques dont les éléments traces métalliques (ETMs). Dans ce contexte, l’évaluation du niveau de contamination dans ces produits et les risques qu’ils peuvent engendrer s’avère être une nécessité surtout en l’absence de normes locales et de programmes de surveillance. Les objectifs de cette étude sont de deux ordres : i) l’évaluation la qualité environnementale du littoral Libanais à travers les organismes marins et, ii) l’estimation du niveau des risques sanitaires liés à la consommation d’une sélection des produits de la pêche. Le premier objectif, était d’évaluer les niveaux de contaminants métalliques (20 éléments traces) chez six espèces marines de différents niveaux du réseau trophique (algues, moules, crevettes et poissons) représentatif des eaux côtières libanaises. Les résultats ont révélé que les espèces accumulent les métaux différemment soulignant ainsi l’importance d’une approche multi-espèce pour mieux refléter le niveau de contamination du milieu. Des variations inter-sites ont été également trouvées surtout durant la période pluvieuse de l’année indiquant l’effet des apports des rivières vers la zone côtière. Les niveaux des ETMs obtenus dans les muscles et les tissus comestibles dans le cadre de notre étude étaient du même ordre de grandeur que ceux mesurés dans d’autres régions du bassin Levantin. Cependant, les foies ont montré des concentrations supérieures comparées à d’autres études, suggérant ainsi que la côte libanaise est soumise à des pressions environnementales importantes. Le deuxième objectif, concerne l’évaluation des risques sanitaires liés à la consommation de différents produits de la pêche échantillonnés le long du littoral Libanais. Pour cela, cinq espèces consommées localement (1 bivalve, 1 crustacé et 3 espèces de poisson) et échantillonnés le long du littoral Libanais au niveau de trois sites soumis à différents niveaux de pressions anthropiques ont été sélectionnés. Tous les échantillons ont été analysés pour leur contenu en éléments traces. Des métaux comme le mercure (Hg) se retrouvent sous plusieurs formes chimiques, sa forme la plus toxique étant le méthylmercure (MeHg). La voie principale de l’exposition humaine au MeHg est la consommation de produits de la pêche. Pour cela, une méthode de spéciation du Hg dans les produits de la pêche a été optimisée et validée par profil d’exactitude. Les résultats ont montré que les niveaux des ETMs et du MeHg dans les espèces concernées, étaient largement inférieurs aux limites maximales admissibles fixées par la Commission Européenne et que leur consommation ne présente pas de risques pour la santé humaineGlobal food fish consumption has been in continuous increase and fishery products have become some of the most traded items in the world. However, the quality of these products is becoming an issue of concern to human health with the increase of anthropogenic activities threatening marine coastal ecosystems. Therefore, despite the well-known health benefits of fishery products, their consumption may be a route of human exposure to different kinds of chemical contaminants including trace elements. In this context, evaluating the contamination levels in these products and the risks they may engender to human health proves to be a necessity in the absence of local guidelines and monitoring programs. Thus, the thesis has 2 main objectives: i) the evaluation of environmental quality through marine organisms and, ii) the assessment of health risks related to the consumption of a selection of fishery products.The first objective was to study the levels of metallic contaminants (20 trace elements) in six marine species from different trophic levels of a food web (algae, mussel, shrimp and fish), representative of Lebanese coastal waters. The results showed that species accumulated metals differently underlining the importance of a multi-specific approach to reflect the contamination level of a certain site. Inter-site variations have been found mainly during the rainy period of the year while they were less prominent during the dry season, highlighting the effect of land-based sources and riverine effluents on the marine coastal area. Levels of trace elements in the muscles and edible tissues in species from our study, were similar to the ones reported in the Eastern Mediterranean (Levantine Basin) whereas livers showed higher levels compared to other studies suggesting that the Lebanese coast is exposed to strong environmental pressure. The second objective was to evaluate the health risks related to the consumption of different fishery products sampled along the Lebanese coast. In this prospect, five commonly consumed local species belonging to different compartments of the food chain, (1 bivalve, 1 crustacean and 3 fish species) sampled from three sites with different levels of anthropogenic pressures were selected. The samples were all analyzed for their content of trace elements. Metals such as mercury (Hg) are found in several chemical forms, the most toxic form being methylmercury (MeHg). The main route of human exposure to MeHg is the consumption of fishery products. That’s why, a method for the speciation of mercury in fishery products by HPLC-ICP-MS was optimized and validated based on an accuracy profile. The results showed that the levels of trace elements and MeHg in the selected species were all below the allowed maximum levels set by the European commission and so their consumption is not likely to cause any adverse effects to human health
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Ferreira, Araujo Daniel. "Investigations into isotope biogeochemistry of Zn in coastal areas and mangroves." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30368/document.
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Les zones côtières du monde entier sont sous fort pression de contamination anthropique comme conséquence de la concentration de la plupart de la population mondiale et des activités économiques le long des côtes et des estuaires. La menace de contaminant sur les écosystèmes rend primordial le développement d'outils capable de détecter les modifications biogéochimiques en vue d'aider dans la prévention, la gestion, et la prédiction de risques dans les études environnementales. Dans ce but, cette thèse étudie la biogéochimie des isotopes du Zinc (Zn) en vue de développer un outil capable de tracer les sources naturelles et anthropiques, d'identifier les processus biogéochimiques et de permettre à la biosurveillance de la contamination par les métaux dans les zones côtières et les mangroves. A cette fin, les compositions isotopiques du Zn ont été déterminées à plusieurs échantillons naturels prélevés dans la baie de Sepetiba (au sud-est du Brésil), un estuaire lagunaire affecté par une côte industrialisée située près de Rio de Janeiro. Cette baie constitue un laboratoire naturel idéal pour valider le système isotopique du Zn. En effet, cette zone héberge des écosystèmes d'intérêt commercial et écologique -estuaire, mangrove, estran- menacés par la contamination d'une ancienne activité de galvanoplastie, et d'autres sources diffuses. Les échantillons collectés comprennent des carottes de sédiments, des sédiments de la superficie des mangroves, des matériaux particulaires en suspension (SPM), des feuilles provenant d'arbres de mangrove, des tissus de mollusques bivalves (huîtres et moules) et des roches. Minéraux de dépôt de Vazante (Brésil) ont été collecté pour representé matière première utilisée par l'industrie de la galvanoplastie. Tout d'abord, un travail initial de laboratoire a établi une méthode exacte et précise pour les déterminations isotopiques Zn en échantillons naturelles par spectrométrie de masse avec plasma couplé par induction et multicollecteur (MC-ICP-MS). Des analyses spatiales et temporelles des compositions isotopiques du Zn des échantillons de sédiments et de roches s'ajustent bien à un modèle de mélange entre trois principales extrémités : i) les matériaux continentaux charriés par les rivières ; ii) les sources marines ; et iii) une source anthropique majeure associée aux anciens déchets de galvanoplastie jetés dans la baie. Les carottes de sédiment collectées dans la vasière ont montré une haute corrélation entre la composition isotopique du Zn et le facteur d'enrichissement du Zn. Ceci suggère : i) une bonne préservation du registre isotopique des sources naturelle et anthropique, ii) l'absence de fractionnement isotopique significatif durant le transport de sédiments ou durant les réactions diagénétiques pos-dépositions dans le système estuarienCoastal areas worldwide are under strong pressure from anthropogenic contamination, as most of the global population and of economic activities are concentrated along the coasts and estuaries. The threaten of contaminant releasing into these ecosystems makes imperative the development of tools capable of detecting biogeochemical changes in order to help prevention, monitoring and prediction of risks in environmental studies. In this way, this thesis investigates the isotope biogeochemistry of Zinc (Zn) in order to develop a tool capable of tracing natural and anthropogenic sources, identifying biogeochemical processes and enabling the biomonitoring of metal contamination in coastal areas and mangroves. To this end, Zn isotopes compositions were determined in several natural samples collected from Sepetiba bay (southeastern Brazil), an estuarine-lagoon impacted by an industrialized coastal area near Rio de Janeiro. This bay constitutes an ideal natural laboratory for evaluating the Zn isotopic system to environmental issues, since it hosts important ecosystems of commercial and ecological interest - estuaries, mangroves and tidal flats - threaten by the metal contamination resultant of old electroplating activity and other anthropogenic diffuse sources. The collected samples include sediment cores, surface mangrove sediments, suspended particulate matter (SPM), leaves of mangrove's trees, tissues of bivalve mollusks (oysters and mussels) and rocks. Ores from Vazante deposit, Brazil were collected to represent the raw material used in the old electroplating industry. Firstly, an initial laboratory work established a method for accurate and precise determinations of Zn isotope compositions in natural samples by multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS). Spatial and temporal analysis of Zn isotope compositions of sediment and rock samples fits well in a model of mixing between three main end-members: i) continental materials brought via rivers; ii) marine sources; and iii) a major anthropogenic source associated to the old electroplating wastes released into the bay. Sediment cores collected in the mud flat showed high correlation between Zn isotope compositions and Zn enrichment factors, suggesting (i) good preservation of isotopic records of natural and anthropogenic sources and (ii) no significant isotopic fractionation during sediment transport or as a result of diagenetic reactions post-deposition in the estuarine system. The sediment core sampled from a mangrove located in the zone impacted by the old electroplating activity presented levels of Zn up to 4% (dry weight) and preserved the isotopic signatures of electroplating wastes. However, there is evidence that biogeochemical processes triggered by hydrodynamics, bioturbation or rhizosphere processes slightly changed the isotopic signatures in some layers. Calculations based in this mixing model quantified contributions of the major anthropogenic source of Zn, ranging from negligible values in the pre-industrial period to nearly 80% during periods of electroplating activities between the 60's and 90's
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Ringot, Gabrielle. "Conséquences de la pollution environnementale sur l'évolution des traits d'histoire de vie : l'exemple de la Daphnie." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS317.
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Les métaux traces sont biodisponibles, persistants et concentrés dans les milieux urbanisés. Via leur affinité pour les protéines, les métaux traces peuvent perturber les processus métaboliques et réduire la survie et le succès reproducteur. En réponse à ces nouvelles pressions de sélection imposées par ce milieu perturbé, les populations urbaines peuvent développer des adaptations telles que des stratégies de dormance, de dispersion, de détoxication ou encore de détection et d’évitement des métaux dans le milieu. Au cours de leur vie, les Daphnies peuvent switcher de reproduction parthénogénétique, lorsque les femelles produisent de nombreuses filles clonales, à reproduction sexuée. En réponse à différents stimuli environnementaux, les femelles commencent à produire des mâles et à fabriquer une enveloppe chitineuse et résistante: l’éphippie qui recevra les œufs de durée après fécondation. De manière intéressante, ces éphippies produites sexuellement peuvent disperser à la fois dans le temps (dormance) et dans l’espace et peuvent accumuler les métaux traces suggérant des propriétés de détoxication. Cette thèse montre tout d’abord, qu’il existe une relation positive entre la concentration en métaux dans le milieu et la présence d’éphippie, suggérant une sélection pour les Daphnies sexuées dans les milieux pollués aux métaux traces. De plus, suite à une exposition expérimentale à un métal chez les Daphnies urbaines, le succès de fécondation des éphippies est plus élevé chez les Daphnies exposées à la pollution comparée aux Daphnies non exposées. De plus, les individus provenant de cette même population urbaine semblent capables de détecter et d’éviter les polluants métalliques dans leur milieu. Ces résultats suggèrent que la pollution anthropique a des conséquences évolutives sur les populations urbaines et souligne la nécessité de tenir compte des aspects évolutifs dans les études écotoxicologiquesTrace metals are bioavailable, persistent and concentrate in urban areas. Because of their affinity for proteins, trace metals can disturb metabolic processes and impair survival and reproductive output. In response to these new selective pressures created by such disturbed habitats, urban populations could evolve adaptations as dormancy, dispersal, detoxification or pollutant detection and avoidance abilities. Daphnia, can switch to parthenogenetic reproduction, when females produce numerous clonal daughters, to sexual reproduction. In response to several environmental cues, females start to produce males and a chitinous and resistant envelop: the ephippium that receives diapausing eggs after fertilisation. Interestingly, these sexually produced ephippia can disperse both in time (dormancy) and space and exhibit metal accumulation ability suggesting detoxification property. First, this study shows that a positive relationship exists between the environmental concentration of metals and probability of ephippia presence suggesting selection for sexual Daphnia in metal polluted habitats. Moreover, after an experimental exposure to a trace metal in urban Daphnia, ephippial fertilisation success was higher in Daphnia exposed to metal pollution compared to non-exposed Daphnia. Additionally, Daphnia individuals originating from the same population are able to detect and avoid metal pollution. These results suggest that anthropogenic pollution has evolutionary consequences in urban population and stress the need to take into account evolutionary aspects in ecotoxicological studies
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Perlatti, Fabio. "Trace metals biogeochemistry in soils and plants affected by mining waste rocks: consequences to ecosystem and options for restoration." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14753.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorA extraÃÃo e beneficiamento de minerais metÃlicos geram grandes quantidades de rejeitos que se nÃo dispostos adequadamente, podem ser fontes de contaminaÃÃo e drenagem Ãcida; pelo contato de sulfetos com Ãgua e oxigÃnio; ocasionando diminuiÃÃo no pH e aumento na mobilidade dos metais no solo. O diagnÃstico do comportamento biogeoquÃmico de rejeitos pode fornecer informaÃÃes valiosas para que se possa dispor e controlar adequadamente os efeitos adversos causados por esse tipo de material, bem como subsidiar a adoÃÃo de medidas de controle e mitigaÃÃo mais eficientes. Esse estudo teve como objetivo geral, diagnosticar os impactos causados pela disposiÃÃo de rejeitos em uma mina de cobre (Cu) abandonada, bem como propor alternativas para mitigar os impactos e restaurar a qualidade ambiental do local, baseado na hipÃtese de que esses rejeitos podem contaminar o solo da regiÃo com os elementos traÃo presentes nos minerais, alÃm de gerar drenagem Ãcida, dada a presenÃa de sulfetos expostos Ãs condiÃÃes atmosfÃricas, impedindo a regeneraÃÃo natural do ecossistema. O capÃtulo 1 traz uma introduÃÃo ao tema, bem como uma revisÃo bibliogrÃfica sobre o assunto. O capÃtulo 2 faz um diagnÃstico geral da Ãrea, avaliando-se os teores de diversos elementos traÃo nos rejeitos, solos e plantas. No capÃtulo 3 foram aprofundados os estudos sobre o comportamento geoquÃmico dos rejeitos com foco na geraÃÃo de drenagem Ãcida, alÃm de um estudo detalhado do comportamento do Cu no solo, atravÃs da extraÃÃo sequencial. O capÃtulo 4 detalha os teores de metais nos tecidos vegetais das plantas, avalia a aptidÃo do uso dessas espÃcies para a fitoremediaÃÃo, bem como apresenta dados das alteraÃÃes que ocorrem na rizosfera. O capÃtulo 5 aprofunda-se nas alteraÃÃes que ocorrem na rizosfera das plantas e as consequÃncias na mobilidade e ecotoxicidade do Cu, via extraÃÃo sequencial, e por fim, o capÃtulo 6 apresenta um estudo experimental com a utilizaÃÃo de tecnosolos, para imobilizar o excesso de Cu lÃbil no solo. Os resultados indicam que o principal impacto à causado pelo excesso de Cu que ainda persiste nos rejeitos e que, por processos de oxidaÃÃo e dissoluÃÃo, translocam grandes quantidade do metal para o solo. A geraÃÃo de drenagem Ãcida foi descartada; dada a aÃÃo tamponante gerada pela dissoluÃÃo dos carbonatos, minimizando os efeitos negativos da oxidaÃÃo dos sulfetos. A extraÃÃo sequencial mostrou que o Cu no solo està associado principalmente aos carbonatos e Ãxidos de Fe amorfos. O ciclo geoquÃmico entre a dissoluÃÃo dos carbonatos e oxidaÃÃo dos sulfetos parece ser o principal mecanismo de liberaÃÃo e adsorÃÃo do Cu no solo. Jà as plantas estudadas, nÃo foram consideradas hiperacumuladoras, entretanto, foram observados elevados teores de metal em suas raÃzes, indicando que a estratÃgia de sobrevivÃncia dessas plantas consiste na imobilizaÃÃo do metal nas raÃzes/rizosfera. A extraÃÃo sequencial na rizosfera mostrou que a presenÃa das plantas altera as caracterÃsticas do solo sob sua influÃncia, e consequentemente o comportamento biogeoquÃmico do Cu. Jà os tecnosolos demostraram grande capacidade em imobilizar Cu. Os quatro tecnosolos elaborados imobilizaram mais de 85% do Cu, sendo a maior parte retida na fraÃÃo residual, que representa a fraÃÃo onde o cobre fica adsorvido mais fortemente, demostrando que os tecnosolos despontam como uma excelente alternativa na remediaÃÃo de solos contaminados por metais.
The extraction and processing of metallic minerals generate large amounts of waste which, if not disposed of properly, may be sources of contamination and acid mine drainage; by contact of sulphides with water and oxygen; causing a decrease in pH and an increase in the mobility of metals in the soil. The diagnosis of biogeochemical behaviour of wastes can provide valuable information to discard and control the adverse effects of this kind of material, as well to support the adoption of more efficient measures of control and mitigation. This study had as general objective diagnose the impacts of waste disposal in an abandoned copper mine (Cu), as well to propose alternatives to mitigate the impacts and restore the environmental quality of the site, based on the hypothesis that such wastes can contaminate the soil with trace elements contained in minerals, and generate acid mine drainage, given the presence of sulphides exposed to weather conditions, hindering the natural regeneration of the ecosystem. The Chapter 1 provides an introduction to the theme, as well as a literature review. Chapter 2 presents a general diagnosis from the area, assessing the levels of several trace elements in rock wastes, soils and native plant species. In chapter 3, a thorough study on the geochemical behaviour of wastes, with focus on the generation of acid drainage were done, plus a detailed study about Cu behaviour in soils, through a chemical sequential extraction. Chapter 4 details the content of metals in above-ground tissues from plants that naturally grow on the wastes, assess the ability of these plants to be used in phytoremediation and show data about the changes that occur in the rhizosphere. Chapter 5 provides through a comparative study by sequential extraction in the rhizosphere and bulk soils; details about the changes that occur in the rhizosphere of plants and their consequences for Cu mobility and ecotoxicity, and finally, the chapter 6 presents an experimental study with the use of technosols, as way to immobilize the excess of labile copper in soil solution. Based on the results, can be concluded that the major impact is caused by the excess of Cu which still persists in the waste rocks and, through oxidation and dissolution processes, translocate large amount of metal into soil. The acid mine drainage was discarded given the buffering action generated by dissolution of carbonates, minimizing the negative effects of the oxidation of sulphides. The sequential extraction showed that the Cu concentration in soil is associated mainly with carbonates and amorphous iron oxides. The geochemical cycle between the dissolution of carbonates and oxidation of sulphides appears to be the main control mechanism of release and adsorption of Cu in soil. Regarding the plants, was concluded that they cannot be considered as Cu hyperaccumulators, however, high levels of metal were observed in roots, indicating that the survival strategy of these plants consists in immobilize metal in roots/rhizosphere. The sequential extraction in the rhizosphere showed that the presence of plants alter various soil characteristics under its influence, and also the geochemical behaviour of Cu. The technosols showed great ability to immobilize Cu. The four technosols elaborated in this study can immobilize more than 85% of Cu in solution, with the largest portion retained in the residual fraction, where Cu is adsorbed strongly, demonstrating that technosols emerge as an excellent alternative to remediate soils contaminated by metals.
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Kunati, Sandeep Reddy. "Trace Measurements of Tellurium, Tin and Other Metals by Atomic and Laser Spectroscopy Techniques." Connect to resource online, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1219695278.
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Suaire, Rémi. "Dynamique de transfert des fondants routiers dans un bassin de rétention des eaux de ruissellement routières : vers une solution d’assainissement par phytoremédiation." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0116/document.
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En période hivernale, des fondants routiers sont épandus sur les chaussées afin de préserver la sécurité des usagers. Sous l'influence de divers paramètres, ces produits se retrouvent en partie dans l'environnement, le reste étant collecté par des systèmes de rétention des eaux de ruissellement routières. Or, les bassins de rétention ne sont pas conçus pour traiter ces fondants, et jouent uniquement un rôle de régulation des flux rejetés dans l’environnement. L’effet du NaCl sur l’environnement est néfaste, en raison de sa toxicité directe envers certains organismes et, indirectement parce qu’il contribue à augmenter la mobilité des ETM (Éléments Traces Métalliques), eux-mêmes toxiques. Ceci démontre un besoin d'assainissement particulier pour ces produits. L'objectif de cette thèse est d'étudier les transferts de NaCl par un bassin de rétention, mais également d'investiguer la possibilité d'utiliser la phytoremédiation comme base d'une solution d'assainissement des eaux de ruissellement routières. Le bassin de rétention choisi comme modèle est un bassin récent situé à Chenevières (Lorraine, France), en bordure d’une route nationale. La première partie du travail a porté sur la mesure et la caractérisation des transferts de NaCl dans ce bassin. L’eau a été collectée en entrée/sortie chaque semaine pendant 3 ans, et les concentrations en NaCl et ETM mesurées. Les conditions météorologiques et les données d’épandage de sel ont été suivies pour évaluer la proportion de sel effectivement transférée vers le réseau de collecte des eaux de ruissellement routières. Les résultats montrent que 25 à 50 % du sel épandu est effectivement collecté. De plus, les résultats sur la dynamique du NaCl prouvent que le bassin joue uniquement un rôle de rétention temporaire et de dilution avant rejet vers l’environnement. Ensuite, des mesures et analyses des sédiments du bassin et des sols de bord de route ont été conduites pour caractériser la spéciation et la mobilité des ETM dans ce contexte routier particulier. Dans ce cas précis, le NaCl n’a pas eu d’effet significatif sur la mobilisation des ETM, hormis le zinc (Zn). En revanche, il a provoqué la mobilisation d’autres ions majeurs. Concernant le traitement, les procédés conventionnels de dessalement d’eau sont trop coûteux et inadaptés. C’est pourquoi les potentialités d’une solution d’assainissement par phytoremédiation ont été explorées. Trois plantes halophytes ont été sélectionnées selon des critères permettant leur utilisation en contexte routier, Armeria maritima, Atriplex halimus et Atriplex hortensis L. Des expériences de germination/croissance ont été effectuées dans différentes conditions de salinité et de concentration en Zn pour évaluer leur tolérance à la salinité, à la présence de Zn et leurs capacités d’accumulation. Ces plantes ont montré une tolérance au NaCl dans des conditions de salinité représentatives de celles mesurées dans les réseaux d’assainissement routiers à Chenevières. De plus, les trois espèces accumulent dans leurs parties aériennes des quantités significatives de NaCl, ainsi que du zinc. L'utilisation des halophytes pour la phytodésalinisation en domaine routier s'avère être une technologie prometteuse pour répondre à la problématique de l'impact environnemental des fondants routiersDuring winter, deicing salts are spread on roads in order to preserve road safety for users. Under the influence of different parameters, these compounds are partly transferred to the environment, the rest of it being collected by the road runoff retention systems. However, road runoff retention ponds have not been designed for deicing salt treatment; they only play a role in the regulation of fluxes before their rejection into the environment. Furthermore, NaCl has a harmful impact on the environment, because of its toxicity to certain aquatic organisms and because it contributes to the increase of trace metal (TM) mobility, which are toxic as well. This shows the need for a specific treatment for these compounds. The objective of this research is to bring better understanding of deicing salt dynamics in a retention pond, but also to investigate the potential use of phytoremediation as a treatment solution for road runoff. A model retention pond was selected; it is located along a highway in Chenevières (Lorraine region, France). The first part of the work focused on the monitoring and the characterization of NaCl transfers in this pond. Water was weekly sampled for 3 years at the pond input and output and NaCl and TM concentrations were measured. Meteorological conditions and salt spreading data were monitored to appraise the salt fraction actually collected by the pond. Results showed that only 25 to 50 % of the spread salt is effectively collected. Moreover, results on NaCl dynamics proved that the pond only plays a role on transient storage and salt dilution before rejection into the environment. Moreover, measurements and analyses of sampled basin sediments and roadside soils were performed to assess speciation and TM mobility in this particular context. In this case, no significant effect of NaCl was recorded except for zinc (Zn); but major ions were mobilized. When it comes to treatments, conventional desalination technologies are too expensive and inappropriate in this context. Then, potentialities of phytodesalination were explored. Three halophyte plants were selected on the basis of specific criteria, allowing their use in road runoff context: Armeria maritima, Atriplex halimus and Atriplex hortensis L. Germination and growth experiments were run in various salinity conditions and in the presence/absence of Zn, in order to assess their tolerance to salt and Zn, as well as their accumulation abilities. These plants showed a high tolerance for NaCl in salinities in the range of those encountered in road runoff existing treatment systems at Chenevières. The three species accumulated significant amounts of NaCl and zinc in their aerial parts. The use of halophytes for phytodesalination of road runoff is a promising technique to address the issue of environmental impact of deicing salts
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Caner-Chabran, Anne. "(TRAPEZE) Transfert de Polluants organiques et minéraux En Zone viticole : évaluation de l’Efficacité des bassins de rétention à réduire la contamination des eaux de surface." Thesis, Reims, 2019. http://www.theses.fr/2019REIMS043.
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Les pesticides organiques et minéraux d’origine viticole sont rejetés dans l’environnement par volatilisation et/ou ruissellement. Afin de limiter leur transfert vers les eaux de surface et souterraines, des bassins de rétention (ou bassins d’orages) sont installés en bas des coteaux viticoles. Les objectifs de cette thèse étaient (1) d’évaluer l’efficacité du bassin d’orages hybride (i.e. constitué de quatre modules) de Nogent-l’Abbesse (Champagne, Marne, France) à réceptionner les eaux de ruissellement et à réduire les teneurs en pesticides organiques et minéraux issus du vignoble et (2) de comprendre le comportement des contaminants dans le bassin d’orages en identifiant les processus régissant leur dégradation, leur mobilité ou leur rétention au sein des quatre modules. Pour ce faire, le comportement hydrologique du bassin d’alimentation en eaux pluviales et le comportement hydraulique du bassin d’orages ont été étudiés pendant une année. Ceci a permis de quantifier le ruissellement et d’en déterminer les principaux facteurs, ainsi que de décrire la réponse du bassin d’orages à différents évènements pluvieux ruisselants. Les teneurs en éléments traces métalliques (ETM ; Cu, Pb, Zn) et en de nombreux pesticides ont été déterminées dans les eaux de ruissellement chargées en particules et dans les différents compartiments du bassin d’orages. Les ETM sont principalement transportés par la fraction particulaire et les pesticides par la fraction dissoute. Le module de décantation et le module de phytoremédiation assurent à eux deux plus de 70 % de la réduction des teneurs en polluants via des processus physico-chimiques tels que la décantation et l’adsorption. Cette étude servira d’outil d’aide à la décision pour la gestion, la construction ou la rénovation d’autres bassins d’oragesOrganic and mineral pesticides from the vineyard are transported in the environment through volatilization and/or runoff. To limit their transfer towards surface and groundwaters, constructed wetlands have been installed downstream in vineyard hillsides. The objectives of this work were (1) to evaluate the efficiency of the hybrid constructed wetland (i.e. built of four units) of Nogent-l’Abbesse (Champagne vineyard, Marne, France) to receive runoff waters and to reduce contaminant concentrations from vineyard and (2) to determine the behaviour of the contaminants within the constructed wetland by identifying the processes leading to their degradation, their mobility or their retention inside the units. Thus, the hydrological behavior of the catchment and the hydraulic behavior of the constructed wetland were studied during one year. The runoff was quantified, the main factors were determined and the reaction of the wetland to various runoff events were described. The concentrations of trace metals (Cu, Pb, Zn) and numerous pesticides were determined in runoff waters, suspended solids, and the others compartments of the wetland. Heavy metals were mainly transported in the particulate fraction while pesticides were mostly transported in the dissolved fraction. The decantation and the phytoremediation units are the most efficient to remove pollutants from the waters via different physico-chemical processes such as decantation and adsorption. This study will be a decisionmaking tool for the management, building or renovation of other constructed weetlands
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Sheir, Sherin Khalifa Hadda. "Effects of trace metals on cellular immune responses, tissue injury and gene expression in the mussel, Mytilus edulis : implications for biological monitoring of marine pollution." Thesis, University of Plymouth, 2010. http://hdl.handle.net/10026.1/915.
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Gaulier, Camille. "Trace metals in estuarine and coastal waters : dynamics, speciation and bioavailability under various environmental conditions." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1R013.
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Les écosystèmes estuariens et côtiers assurent de multiples services écologiques, sociaux et économiques. Ils constituent une source de nourriture, de revenus et sont au cœur du commerce et du transport maritime. Ils jouent donc un rôle clé dans notre monde moderne et leur préservation d'un point de vue environnemental est aujourd'hui crucial. Malgré tous les efforts réalisés en matière de gestion de l'environnement, la pollution associée au développement économique rapide du littoral et à une industrialisation intensive était finalement inévitable et demeure encore aujourd'hui l'une des principales menaces pesant sur les écosystèmes marins. Plus précisément, la contamination par éléments-traces métalliques est particulièrement préoccupante, car les zones côtières sont généralement enclines à les accumuler. La plupart de ces éléments-traces métalliques jouent un double rôle dans les eaux de mer : ils agissent comme nutriments à de faibles concentrations, mais peuvent rapidement avoir des effets toxiques dans des gammes de concentrations plus élevées. Une surveillance continue de leurs concentrations dans les écosystèmes estuariens et côtiers est donc nécessaire, afin de mieux comprendre leur comportement biogéochimique dans de tels environnements. Cependant, peu d’informations existent sur leur biodisponibilité vis-à-vis des organismes marins, d'autant plus que la toxicité de ces éléments traces n’est pas seulement dépendante de leur concentration, mais est également fortement liée à leur spéciation qui montre de fortes variations saisonnières et spatiales. Ainsi, l'objectif principal de ce travail de thèse était d'étudier les cycles biogéochimiques de divers éléments-traces métalliques et de percer le mystère de leur spéciation et de leur biodisponibilité dans des systèmes aquatiques variés : des zones turbulentes et dynamiques de l'estuaire de l'Escaut aux ports côtiers et aux eaux superficielles de la mer du Nord, et même jusqu’à des régions plus profondes et anoxiques de la mer Baltique. Les variations de concentration et de spéciation des éléments-traces métalliques ont été explorées dans le temps et dans l’espace, le long de gradients horizontaux et verticaux. En parallèle, une comparaison des techniques classiques d'échantillonnage des éléments-traces métalliques dissous a été réalisée avec une méthode d'échantillonnage passif (Diffusive Gradients in Thin-films ; DGT). La technique des DGT a été utilisée avec succès pour la mesure in situ de la fraction labile des éléments-traces métalliques et représente, en définitive, un substitut de qualité à la biosurveillance des éléments-traces (par exemple, en remplacement de l’utilisation de moules, d'algues, etc.). Cette méthode permet de compenser le manque de connaissances en termes de surveillance de la qualité de l'eau et les résultats remettent en cause les critères classiques utilisés par les exigences réglementaires internationales (par exemple WFD, MSFD) et les engagements locaux (par exemple OSPAR, HELCOM). En effet, de nouveaux critères basés sur les espèces métalliques labiles plutôt que sur les espèces totales dissoutes devraient être envisagés à l'avenir. Une telle approche de la spéciation et de l'évaluation des éléments-traces métalliques dans les systèmes aquatiques pourrait certainement, à termes, conduire à une gestion environnementale plus intégrée et parfaire nos connaissances sur les impacts anthropiques et les flux de polluants le long de nos côtes. En outre, c'est finalement la clé principale pour expliquer et prédire la biodisponibilité et la toxicité potentielle des éléments-traces métalliques à l’égard de la faune et de la flore marines. Ce travail vous invite donc à plonger dans un voyage le long de nos côtes, de zones peuplées et urbanisées au grand large sauvage, de la surface aux eaux les plus profondesEstuarine and coastal ecosystems provide multiple ecological, social and economic services. They are a source of food, income and are at the heart of marine trade, merchant shipping and sea transport. They therefore play a key role in our modern world and their conservation from an environmental point of view is today critical. Despite all the efforts done in environmental management, pollution associated with the rapid coastal development and intensive industrialization was inevitable and still remains one of the main threats towards marine ecosystems today. Specifically, trace metal contamination is of specific concern as coastal areas are generally prone to accumulate them. Most trace metals exhibit a dual role in marine waters: they act as nutrients in low concentrations, yet rapidly have toxic effects in higher concentration ranges. Continuous monitoring of their concentrations in estuarine and coastal ecosystems is therefore needed to better understand their biogeochemical behavior in such marine environments. However, limited knowledge exists on their bioavailability towards marine organisms: especially as the toxicity of these metals is not only related to their concentration but also strongly linked with their speciation which shows both seasonal and spatial variations. Thus, the main objective of this PhD research was to investigate the biogeochemical cycles of various trace metals and unravel their speciation and bioavailability in various aquatic systems: from very dynamic mixing zones of the Scheldt estuary to coastal harbors and shallow seawaters of the North Sea, and even to deeper and anoxic regions of the Baltic Sea. Trace metal concentrations and speciation were explored seasonally and spatially along horizontal and vertical gradients, and a comparison of classic active samplings of dissolved trace metals with a passive sampling technique (Diffusive Gradients in Thin-films; DGT) was carried out. The DGT technique was successfully used for the in-situ measurement of labile metals and eventually constitutes a good surrogate to the biomonitoring of trace elements (e.g. use of mussels, algae, etc.). This method offsets the lack of knowledge in terms of water quality monitoring and the results challenge the classic criteria which are used by international regulatory requirements (e.g. WFD, MSFD) and local commitments (e.g. OSPAR, HELCOM). Indeed, new criteria based on labile metal species instead of total dissolved species should be considered in the future. Such approach of trace metal speciation and assessment in aquatic systems could surely lead to a more integrated environmental management and improve our knowledge on anthropogenic impacts and pollutant fluxes. Moreover, it is eventually the main key to explain and predict bioavailability and potential toxicity of trace metals to the marine fauna and flora. This work therefore invites you to dive into a journey along our coasts, from urbanized areas to wild open seas, from their surface to their deepest waters
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Gounou, Catherine. "Mobilité des éléments traces métalliques dans les sédiments : couplage et comparaison des approches chimique et microbiologique." Thesis, Paris Est, 2008. http://www.theses.fr/2008PEST0074/document.
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Les activités anthropiques entraînent une contamination des sédiments de rivière en de nombreux polluants et en particulier en éléments traces métalliques (ETM). Si la majorité des ETM se retrouvent piégés dans les sédiments, ceux-ci peuvent être remobilisés et passer en solution dans certaines conditions physico-chimiques et sous l’action des microorganismes autochtones. Les métaux relargués peuvent alors constituer un danger potentiel pour les organismes vivants dans les sédiments et dans la colonne d'eau. Dans le cas des sols, l’impact de l’activité microbienne autochtone sur la mobilité des ETM a souvent été rapporté. Cependant une telle activité de solubilisation n’a été que rarement étudiée dans le cas des sédiments. Une telle connaissance est pourtant importante pour la prédiction du comportement des métaux contenus dans les sédiments et la gestion de ces derniers, notamment lors de leur stockage suite aux opérations de dragage. Dans ce contexte, l’objectif de cette thèse a été de comprendre et d’évaluer l’importance de certains des processus microbiens et chimiques de mobilité des ETM dans les sédiments en conditions anaérobies. La première phase de notre étude qui a consisté à incuber des sédiments de Seine et de Marne en milieu anaérobie dopé en glucose avait pour objectif d’étudier la corrélation entre le métabolisme microbien et le comportement des métaux en solution et dans les sédiments. Dans ces conditions opératoires, une forte solubilisation du fer et du manganèse (sous forme réduite) associée à une solubilisation de métaux traces (Co, Cu, Ni) a été mise en évidence, ce qui a laissé supposer l’intervention de bactéries ferri-réductrices dans les phénomènes observés. Une activité fermentaire importante a été observée et caractérisée par la production d’acides organiques majoritaires tels que les acides acétique et butyrique. Un tel résultat souligne l’importance des bactéries fermentatrices dans les phénomènes de dissolution observés. La deuxième étape de ce travail a consisté à confirmer l’importance de l’activité ferri-réductrice et à en identifier les acteurs principaux. Les analyses moléculaires menées ont montré que les bactéries ferri-réductrices majoritairement identifiées, appartiennent aux espèces Clostridium butyricum et Paenibacillus polymyxa. L’utilisation d’un modèle géochimique nous a permis de montrer que les voies métaboliques supportant la réduction du fer et la mobilité des métaux étaient les fermentations butyrique et acétique. La troisième étape a consisté à comparer les impacts directs (réduction enzymatique) et indirects (propriétés des acides organiques produits) de Paenibacillus polymyxa et Clostridium butyricum sur la mobilité du fer, du manganèse et des autres métaux. Une telle étude a montré que les acides organiques produits (acétique, lactique, succinique, propionique et butyrique) ont un très faible impact sur la solubilisation aux pH rencontrés dans les sédiments et que la réduction enzymatique microbienne est le principal mécanisme de dissolution des éléments métalliques en milieu anaérobieAntropic activities lead to the metallic contamination of river sediments. Most of trace metals are sorbed on sediments but a part of them can be released into aquatic environment when environmental conditions are modified. This is often due by the autochthonous microbial activity. Microbial activites and their consequences on the mobility of metals have been widely studied in soils. Metals are released through direct or indirect microbial mechanisms. Such studies in the case of sediments are very seldom. However, it can be usefull to understand the microbial mechanisms of metal release in sediments, and particularly for a good management of dredged sediments. In this environmental framework, the aim of this research work was to understand and to evaluate the role of the microbial and chemical mechanisms in the release of metals from river sediments in anaerobic conditions. Firstly, sediments from the Marne and Seine rivers were incubated in anaerobic conditions. A high solubilisation of iron and manganese occurred associated to the solubilisation of trace metals (Co, Cu, Ni, Pb). Meanwhile, organic acids were produced and the medium was acidified. Thus fermentation was supposed to be the main process of microbial metabolism. Furthermore these observations led us to suppose the presence of iron-reducing bacteria. In a second step, the extent of the iron-reducing activity was studied. The main iron-reducing bacteria identified in the Marne sediments belonged to the species Clostridium butyricum and Paenibacillus polymyxa. The use of a geochemical model revealed that fermentation and reduction of iron(III) were the main metabolic pathways. Finally direct (enzymatic reduction) and indirect (complexation with organic acids, acidification) impacts of iron-reducing bacteria on the release of metals were compared. Acidification and organic acids had a weak impact on metal solubility in the range of studied pH (between 6,5 and 5). Enzymatic reduction is the main mechanisms of metal release in anaerobic conditions. Indeed the metallic concentrations can be 40 times higher in the presence of iron-reducing bacteria
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Toefy, Rashieda. "Extant benthic Foraminifera from two bays along the SW coast of South Africa, with a comment about their use as indicators of pollution." Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8713_1307079132.
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The results of the multivariate analyses suggest that most of the variation in the composition of the samples was of an intra-sample nature, illustrating large scale patchiness in foraminiferal distribution. There were, however, definite differences between communities around Robben Island and in St Helena Bay, and least variation was found between the control and pipeline sites, and between the stations of each site. When the trace metal concentrations and the percentage nitrogen increased, the richness, diversity and abundance of foraminifera tended to decrease. Sediment grain size positively affected abundance but negatively affected diversity and richness. In both areas mean grain size did not, however, appear to play a very large role in influencing diversity. Cadmium, copper, chromium, the percentage nitrogen and the mean grain size were identified as the most important variables influencing the community structure by the BIOENV BEST routine in PRIMER. The trace metals and percentage nitrogen only had negative effects on the diversity and abundance as well as on the abundance of the dominant genera, whereas the mean grain size had variable effects.
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Dutordoir, Solène. "Bilan des flux de métaux, carbone organique et nutriments contenus dans une rivière alpine : part des rejets urbains de l'agglomération de Grenoble et apports amont (Isère et Drac)." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENU036/document.
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La prise de conscience grandissante de la contamination des cours d'eau a entraîné l'établissement de réglementations de plus en plus strictes concernant les rejets urbains et la fixation d'objectifs de qualité à atteindre pour les milieux aquatiques. Cependant, l'échantillonnage ponctuel reste une limite importante dans l'estimation des flux de contaminants, et le besoin de suivis en continu est présent dans le milieu naturel et dans les réseaux d'assainissement urbains. Cette étude porte sur la quantification de la part des rejets urbains de l'agglomération grenobloise dans les flux totaux de matières en suspension (MES), nutriments (azote, phosphore), carbone organique et éléments traces métalliques (ETM) du milieu récepteur Isère (une rivière alpine). Ce travail s'est appuyé sur un réseau de mesures en continu de débits (Q) et de MES (par turbidimétrie) à l'amont et à l'aval de l'agglomération et sur une sonde spectrométrique à l'amont, associé à des campagnes de prélèvements réguliers et renforcés pendant les épisodes de crues. Des campagnes de mesures détaillées sur les principaux sous bassins du réseau d'assainissement ont été réalisées durant la période d'étude dans le cadre du schéma directeur d'assainissement de l'agglomération grenobloise. Le croisement de ces deux approches a permis de confronter les variations spatio-temporelles des MES, nutriments, carbone organique et ETM du réseau et du milieu récepteur en 2011 et 2012. Les flux sur ces deux années ont été établis afin de déterminer la contribution des rejets urbains dans les flux du milieu récepteur. La contamination en mercure a fait l'objet d'un suivi particulier du fait de la présence d'une source significative de mercure dans la région. Enfin, une réflexion sur l'amélioration des calculs de flux par l'utilisation de relations entre les ETM/carbone organique particulaire (COP) et un paramètre mesurable en continu (MES, Q) a été menée en parallèle de l'exploitation de ces résultats. Mots-clés : Matières en suspension ; Dynamique des flux ; Nutriments ; Eléments traces métalliques ; Mercure ; Rejets urbains (par temps de pluie et temps sec), sondes de turbidité et spectrométriqueThe growing awareness of the contamination of rivers has led to the establishment of more rigorous regulations related to urban waste, and to the setting of water quality objectives to be achieved for aquatic environment. However, grab sampling remains an important limitation for the estimation of contaminant flux, and the need for constant monitoring is present in both natural environment and urban sanitation. This study focuses on the quantification of the proportion of urban waste in the Grenoble area to the total flux of 1) suspended solids (TSS), 2) nutrients (nitrogen and phosphorus), 3) organic carbon and 4) metals trace element (MTE) of the receiving environment; the Isère (an alpine river). This work was supported by a network of continuous discharge measurements (Q) and TSS (turbidimetry), both upstream and downstream of Grenoble associated with regular sampling campaigns, with a higher measurement frequency during flood events. A spectrometric probe upstream was also placed upstream. Detailed measurement campaigns on major sub-basins of the sewerage network were performed during the study period as part of the sanitation master plan of Grenoble. The combination of these two approaches allowes to relate the spatio-temporal variations of TSS, nutrients, organic carbon and MTE in the urban water network of Grenoble and in the receiving environment (the Isère) for the years 2011 and 2012. Flows of the traced parameters have been established to determine the contribution of urban waste flows in the receiving environment, over these two years. Finally, a study on how to improve the flow calculations by the use of relations between MTE / particulate organic carbon (POC ) and a continuous measurable parameter (MES, Q ) was conducted in parallel with these results. Key words: suspended solids, Nutrients, metals trace element; Mercury; urban waste; turbidimetry and spectrometric probe