To see the other types of publications on this topic, follow the link: Heavy metal contamination.
Dissertations / Theses on the topic 'Heavy metal contamination'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Heavy metal contamination.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Sabet, Mitra Deliri, and n/a. "Aquatic plants as indicators of heavy metal contamination." University of Canberra. Resource, Environmental & Heritage Sciences, 1997. http://erl.canberra.edu.au./public/adt-AUC20061107.161814.
Full textAbstract:
Concentrations of heavy metals (Cu, Cd, Cr, Zn, Mn, Fe and Pb) in the water columns,
aquatic plants and sediments of fourteen lakes of varied levels of pollution were
measured.
Correlation analysis was carried out between heavy metal concentrations in aquatic
plants and heavy metal concentrations in water and sediment. The aquatic plants
which accumulated heavy metals in their tissues in proportion to that in water and
sediments were identified.
The aquatic plants studied were: 8/yxa auberti Rich, Cabomba caroliniana Gray,
Ceratophyllum demersum L, Ceratopteris thalictroides (L.) Bron, Chara globularis,
Eichhornia crassipes Solmn, Hydrilla verticillata Royle, Ipomoea aquatica Forsk,
Limnophila aromatica (Lam.) Merr., Ludwigia adscendens (L) Hara, Nelumbo nucifera
Gaertn, Nymphaea stallata Linn, Nymphoides indica (L.) Kuntze, Typha angustata
Bony & Chaub and Utricularia aurea Lour.
Metal uptake by aquatic plants varied between different species and within the same
species depending on lake water contamination levels. The level of metal uptake to a
great extent was a function of the environment water metal concentration.
Results showed that Utricularia accumulated Mn, Zn, Cr, Cd and Pb in direct proportion
to the overlying waters (r2 = 0.69, 0.63, 0.69, 0.65 and 0.39 respectively). Hydrilla
accumulated Cu, Mn, Zn, Fe, Cr, Cd and Pb in direct proportion to the overlying waters
(r2 = 0.65, 0.66, 0.44, 0.72, 0.38, 0.63, and 0.73 respectively). Blyxa leaves
accumulated Zn, Fe, Cr, Cd and Pb in direct proportion to the overlying waters (r2 =
0.74, 0.74, 0.72, 0.60 and 0.82 respectively). Echhornia leaf accumulated only Cr in
direct proportion to the overlying waters r2 = 0.81. Nymphaea leaf and Chara did not
accumulate any metal in direct proportion to the overlying waters.
Roots of Blyxa auberti, Ceratopteris thalictroides, and Eichhornia crassipes contained
higher concentrations of heavy metals than their leaves. Roots of Blyxa accumulated
Cr, Cd and Pb in direct proportion to the overlying waters (r2 = 0.91, 0.65 and 0.69
respectively). Echhornia root accumulated Cd in direct proportion to the overlying
waters with r2 = 0.90. Nymphaea stem showed no significant correlations between the
metal concentrations in the waters and in the plant.
Utricularia accumulated Zn, Fe, Cr, Cd and Pb in direct proportion to the metals in the
underlying sediment extracted by cold hydrochloric acid (r2 = 0.84, 0.51, 0.47, 0.68 and
0.80 respectively). Hydrilla accumulated Cu, Zn, Cr, Cd and Pb in direct proportion to
the underlying sediment (r2 = 0.34, 0.37, 0.91, 0.49 and 0.96 respectively). Blyxa
accumulated Zn, Fe, Cr, Cd and Pb in direct proportion to the underlying sediments (r2
= 0.99, 0.61, 0.82, 0.75 and 0.64 respectively) . Echhornia leaf showed significant
correlation between the Cu (r2 = 0.83) and Cr (i2 = 0.88) concentration in underlying
sediment and the plant. Nymphaea leaf showed a significant correlation between the
Zn (r2 = 0.83) concentration in the plant and the underlying sediments.
Roots of Blyxa showed significant correlation between concentrations of Cu, Cr and Pb
in sediment extracted by hydrochloric acid and plant (r2 = 0.9, 0.7 and 0.9
respectively). Roots of Echhornia had no significant correlation with the sediment
metal concentrations (hydrochloric acid extractable).
Two techniques (cold hydrochloric acid extractable and nitric acid extractable) to
extract metals from sediment were compared. Based on correlations of metal
concentrations in plant tissue and metal extracted from the sediment, it was concluded
that the cold hydrochloric acid extractable metal technique is more suitable for
determining bioavailable sediment metal concentration in environmental studies.
Laboratory studies investigations on the bioaccumulation of Zn and Cu in Hydrilla
confirmed that Hydrilla is a good bioindicator of Cu as it accumulated 20360 ug/g dry
weight of Cu in 72 hours. Hydrilla showed higher bioaccumulation factor with low
concentration of Cu in the solution, in the laboratory studies.
Hydrilla was determined to be the best indicator species as it reflected the heavy metal
concentration in the environment which was supported by the laboratory studies.
2
Brodd, Patrick. "Long term heavy metal contamination from leakage water sediments." Thesis, Uppsala University, Department of Earth Sciences, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-88909.
Full text
3
Gilbert, Lucy Jane. "Heavy metal contamination in the Black River, Cape Town." Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/19961.
Full textAbstract:
Urban river sediments are often contaminated as a result of development and anthropocentric activity, and the Black River in Cape Town is a prime example of a river system suffering from unsustainable development. Methods of deter mining total and background concentrations of selected heavy metals were researched and utilized in the effort to quantify heavy metal concentrations derived from anthropogenic sources in the Black River . The findings were intended for use in the aim of producing sediment quality guidelines (SQG) for South Africa as described in the Water Research Commission Phase I Report; Developing Sediment Quality Guide lines (Gordon and Muller, 2010). The ability of the invasive Eichhornia crassipes (water hyacinth) to uptake and store heavy metals was also briefly investigated to identify its potential as a phyto - remediator in the Black River. Toxicity of the sediment was quantified using the consensus - based mechanistic approach (Gordon & Muller, 2010) whereby assuming that total concentration of a heavy metal is the critical factor in its hazardousness. Sediment samples were divided into grain size and measured by X - Ray Fluorescence and concentrations of the focus elements antimony, arsenic, cadmium, chromium, copper, nickel, lead, and zinc in the mud fraction were compared with Consensus Based Sediment Quality Guidelines (McDonald et al., 2002). Based on guide line exceedances, the most toxic sample was collected from anoxic sediment conditions at the point where the N2 Highway crosses the Black River. The succeeding high toxic ity risk locations were all within areas slightly downstream of a river convergence or within 50 m of one, specifically the Vygekraal, Jakkelsvlei, Esliekraal and Kromboom rivers. Exceedances were most common for chromium, copper, lead, nickel and zinc. The least toxic sample was collected 160 m downstream of the Athlone wastewater treatment works, with the one sample collected between these two points also holding relatively low toxicity risk. Concentrations of the selected analytes were also compared to results from a previous study conducted in 2002 on the Black River sediment (Haniff). The comparison suggested contamination has generally worsened in the past 13 years however due to potentially large analytical error from the differences in sample analyses in 2002 and in this investigation; the reliability of the comparative study is limited to general observation. The data implies that the Athlone wastewater treatment works was contributing to heavy metal concentrations in the sediment in 2002, but now in 2015 appears to improve sediment quality. The Water Research Commission Phase I report identifies four ways to assess sediment quality to produce SQG; one of which is to establish normal background concentrations. In this investigation, background concentrations of heavy metals from natural sediment input to the Black River was estimated using two methods, the first was by combining globally recognized average shale values (Turekian and Wedepohl, 1961; USGS, 2000) with results obtained from studies undertaken on virgin soils of the Black River catchment area (Soderberg, 2003; Herselman, 2007) to form what is referred to as Estimated Background Values (EBV). The second method was to measure element concentrations of weakly - acid rinsed and milled coarse grain fraction of the Black River sediments. This was to see whether concentrations of the coarse fraction reflect those of the EBV, and to establish whether this would be a feasible method of estimating background concentrations which takes into account the multiple inputs of natual sediment across the river catchment. It was concluded from the application of the t - test that the coarse grain fraction held similar concentrations to 19 major and trace elements of the EBV with 95% certainty, and were comparable for all the focus elements accept antimony and arsenic. The mud fraction heavy metal concentrations were then applied to three statistical indicators; the Pollution Load Index (PLI), the Geo - accumulation Index (I - Geo) and the Enrichment Factor (EF) in the objective to quantify anthropogenic input using both the EBV and coarse grain fraction results as reference values. All statistical indicators suggest the river is most enriched with cadmium, copper, lead and zinc, which most likely derive from roadside deposit/stormwater drainage and industries. The application of EBV to the statistical indicators revealed relatively little pollution enrichment, whereas the coarse grain results suggested much higher leve ls of pollution enrichment in the Black River. This disparity verifies the importance in selecting/obtaining suitable data sets as screening values for investigating heavy metal enrichment (Gałuszka & Migaszewski, 2012). It was concluded that the coarse grain fraction element concentrations would not be feasible for use as EBV in the case of the Black River. This is due to the large assumptions made whilst using this method, namely that the coarse grain fraction is assumed to derive from the same source as the mud fraction. Due to the known disturbances to natural sedimentation in the Black River, it is doubtful that the fractions come from the same source. Also given the relatively low heavy metal concentration in the coarse grain fraction, it is likely that the majority of the sand in the sediment of the Black River derives from the coastline. Heavy metal concentrations in the water hyacinth and sediments were applied to the Bio - accumulation Factor to identify the potential of the species as a phyto - remediating agent in the Black River. All four water hyacinth samples contained high concentrations of cadmium, and high concentrations of arsenic, nickel and antimony in three samples. Mercury was present (albeit at low concentrations) in three out of the four plant samples, yet was not detected in any of the 32 sediment samples, supporting the conclusions of Buta et al (2011) that the plant has a very strong affiliation to mercury, and that the element has a high affinity to bind with dissolved organic carbon and suspended sediment. The Bio - accumulation Factor revealed the phyto - remediation potential of the water hyacinth is high for antimony, arsenic, cadmium, mercury, lead and nickel. Water hyacinth could therefore be utilized more effectively (with the use of controlled growth) to remediate sediments indirectly by removing heavy metals from the water and preventing them settling into the sediment. Short - term fluctuations in heavy metal presence and kinetic components cannot be conservatively evaluated due to sediment disturbances, complexities within river system inputs and the ever changing environmental conditions. The findings are based on equilibrium status and the conditions at the time of sampling, and are limited to confinements of the reliability of data generated from sample collection, preparation methods and sample analysis. The distribution of metals in sediments of the Black River if not controlled by dredging is generally controlled by the association of heavy metals with very fine grained, organic - rich sediment. In addition, locations of high element enrichment reflect other river inputs which drain from various areas of the Cape Flats, with the most significant being the Esliekraal convergence. Conclusions from the investigation suggest the method of establishing background concentration from the coarse grain fraction could be applicable only to urban rivers which have seen few sedimentation disturbances and are relatively isolated from externa l sources away the local catchment. This method could reduce sampling costs and be used along with the application of other means available mentioned in the Water Research Commission Phase I report to create South African sediment quality guidelines.
4
Valencia, Avellan Magaly Genoveva. "Heavy metal contamination of river water : sources, behaviour and remediation." Thesis, University of Leeds, 2017. http://etheses.whiterose.ac.uk/18772/.
Full textAbstract:
Pollution from metal mining has led to severe environmental damage. The assessment of metals is very complex as they interact with a broad spectrum of biotic and abiotic components depending on physicochemical conditions. Worldwide, discharges from ancient mines are considered one of the major causes of point and diffuse pollution. This thesis investigated the sources and mobility of metal pollution associated with historical mining in a carboniferous upland catchment, located in the Northern Pennines in the UK. From chemical analysis and geochemical modelling I identified metal sulphates and metal carbonates as the main mineral sources of metals. I also demonstrated that metal carbonates are controlling metal mobility, while seasonality is also producing changes in flow and pH conditions, affecting metal concentrations and behaviour. By using speciation modelling, ecotoxicological assessment tools and in situ macroinvertebrate survey I highlighted the dynamics of metals occurring in neutral mine drainage; and suggested the application of environmental quality standards based on bioavailability data within a realistic context relating response of aquatic organisms to river water chemistry and metals. I also evaluated the effects of episodic rainfall on aqueous metal mobility and toxicity to address some knowledge gaps. I found that rainfall conditions did not alter the circumneutral conditions of the catchment, although metal mobility and speciation were affected by the abundance of carbonate and bicarbonate minerals derived from bedrock weathering. I showed that metal toxicity occurred at circumneutral pH, and mainly attributable to zinc. Moreover, I assessed the effects of episodic rainfall in metal toxicity and calculations revealed that short-term fluctuations of metal concentrations are not reflected in the predicted acute toxicity risk to aquatic organisms, underlining the complexity of chemical speciation especially during episodic events. Likewise, I provided a baseline for future mitigation strategies for catchments under risk of metal pollution. Finally, I stressed the importance of the public perception and community involvement in a holistic management of catchments for protecting riverine ecosystems and improving their water quality. Overall, this thesis provides the evidence that a comprehensive metal assessment requires a great understanding of processes and reactions occurring from metal sources to potential endpoint environments (e.g. water, sediments, and biota). For regulatory purposes, technical knowledge needs to be sensibly transferred to the community for achieving an effective integrated catchment management. Findings from this thesis are suitable for the assessment of streams draining spoil waste areas with similar geochemical conditions and inform future management strategies.
5
Karapanagiotis, Nicolas Konstantine. "Heavy metal retention by the organic fraction of sewage sludge." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342264.
Full text
6
Sarin, Charoon. "A lux-based bioassay of heavy metal contamination of organic wastes." Thesis, University of Aberdeen, 2000. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU123515.
Full textAbstract:
The luxCDABE genes (i.e. full cassette) were inserted into the bacterial strain used in this study, E. coli HB101, using a multi copy plasmid, (pUCD607). A number of experiments were carried out in this thesis to study the potential of using the biosensor, E. coli HB101 (pUCD607), for ecotoxicity testing. Growth and bioluminescence of E. coli HB101 (pUCD607) were characterised and optimised, as well as the stability of this biosensor to a range of environmental parameters. The biosensors were found to be sensitive to a range of pollutants and provided a highly consistent bioluminescence response under conditions likely to be encountered in environmental toxicity testing. Assessment of the potential of the lux-based bioassay for revealing the combination of toxicities of metals was carried out. This is necessary because samples in ecotoxicity testing may contain a number of types of pollutants. The biosensors showed high sensitivity of response to mixed metals and identified the combined toxicity of the mixture. Biosensor bioluminescence could also be used to diagnose the distinction between toxicity after 15 and 30 minutes exposure. Results suggested that exposure time is an important factor affecting on the toxicity of metals in mixtures. The results from challenging lux-based biosensors with heavy metals with various concentration of Cl- demonstrated the effect of Cl- ion complex formation for metals on the bioluminescence of E. coli HB101 (pUCD607). The bioluminescence response of the biosensor also related to the results from computer modelling (GEOCHEM) and was used to diagnose the effect of Cl- on metal toxicity. The results showed that E. coli HB101 (pUCD607) is sensitive to complexes of metals such as are formed by Cl- ion. Immobilised cells of E. coli HB101 (pUCD607) were used to investigate the toxicity of metals, both singly and in mixture. This work aimed to assess the potential of immobilised cells, as an alternative form of biosensor, for use in ecotoxicity testing. Bioluminescence response of immobilised cells varied with the test solution pH and showed that it has great potential for use in low pH environments. Immobilised cell biosensors demonstrated sufficient sensitivity to identify the toxicity of individual and mixed metals. High levels of bioluminescence of immobilised cells lasted up to 5 hours after bead production, suggesting that biosensor immobilisation increases the flexibility of the toxicity assay.
7
Nkqenkqa, Vuyiseka. "Metal and microbial contamination of agricultural soil and the Veldwachters River, Stellenbosch, South Africa." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2423.
Full textAbstract:
Thesis (MTech (Environmental Health))--Cape Peninsula University of Technology, 2017.Surface water is used as a source of water supply in many countries, including South Africa. One of the sources of surface water pollution is leachate and surface runoff from landfills. In agricultural soils, the landfill runoff and leachate deteriorate the quality and affect the fertility of soil. The entry of metals and microorganisms from landfill leachate to adjacent environments is through surface runoff due to rainfall. Adverse effects on human- and environmental health triggers a need to monitor and control contaminants in the environment. The aims of the study are to determine the effect of landfill runoff and leachate on agricultural soil and river water (Veldwachters River) running adjacent to the Devon Valley landfill site and to identify potential metal-tolerant organisms in environmental samples collected in Stellenbosch, Western Cape, South Africa. Samples (agricultural soil, river water and sediments) were collected once a month for a period of six months from the study area for analysis. Physicochemical parameters that are known to have major effects on environmental samples were assessed and the concentrations of various metals (Al, Pb, Cr, Mn, Mo, Co, Ni, Cu, Zn, Fe, Cd and V) were also determined by means of inductively coupled plasma mass spectrometry (ICP-MS). Soil texture analysis was tested in order to monitor the metal distribution in soils under the influence of environmental factors.
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.
Full text
9
Plathe, Kelly Lee. "Nanoparticle - Heavy Metal Associations in Riverbed Sediments." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/26229.
Full textAbstract:
Relationships between trace metals and nanoparticles were investigated using analytical transmission electron microscopy (aTEM) and asymmetric flow field flow fractionation (aFlFFF) coupled to both multi-angle laser light scattering (MALLS) and high resolution-inductively coupled plasma mass spectroscopy (HR-ICPMS). Riverbed sediment samples were taken from the Clark Fork River in Montana, USA where a large-scale dam removal project has released reservoir sediment contaminated with toxic trace metals (namely Pb, Zn, Cu and As) which accumulated from one and a half centuries of mining activities upstream. An aqueous extraction method was used to attempt to separate the nanoparticles from the bulk sediment. After analysis of initial results, it was found that low density clays were being selected for in this process and made up a major portion of the particles within the extracts. However, it was also realized that the metals of interest were associated almost exclusively with nano-sized Fe and Ti oxides.
In order to more fully examine these relationships, a density separation method, using sodium polytungstate (2.8g/cm3), was developed to separate these higher density oxides from the lower density clays. The heavy fraction was then subjected to an aqueous extraction routine to extract the nanoparticulate fraction. FFF results indicated a smaller size distribution and more ideal fractionation with this method. The aFlFFF-HR-ICPMS profiles for Fe and Ti also matched strongly with the data for the trace metals. The majority of particles analyzed with the TEM were nano-sized Fe and Ti oxides (most commonly goethite, ferrihydrite and brookite), which typically had trace metals associated with them. In many cases, it was aggregates of these nano oxides that were found hosting trace metals. Nanoparticles and aggregates are known to behave differently than their bulk mineral phases or constituent particles, respectively. Nanoparticles are also capable of extended transport in the environment. For these reasons, it is important that their associations with toxic trace metals be extensively evaluated, as they will affect the bioavailability and toxicity of these metals with implications for any type of contaminant sediment relocation, dam removal or metal contaminated site.Ph. D.
10
Mamboya, Florence Alex. "Heavy metal contamination and toxicity : Studies of Macroalgae from the Tanzanian Coast." Doctoral thesis, Stockholm : Department of Botany, Stockholm University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-6818.
Full text
11
Costenla, Mariana Mascarenhas de Menezes. "Heavy metal contamination in seafood and consumer exposure in the Gulf Cooperation Council." Master's thesis, Faculdade de Ciências e Tecnologia, 2014. http://hdl.handle.net/10362/13156.
Full textAbstract:
Dissertação para obtenção do Grau de Mestre em
Tecnologia e Segurança AlimentarThe population from countries surrounded by the Gulf and Arabian Sea depend on fisheries. Industry is growing and discharges by desalination plants and refineries lead to the presence of heavy metals which accumulate in the environment and seafood. The aim is to review seafood contamination with cadmium, arsenic, lead and mercury in Saudi Arabia, Oman, Kuwait, United Arab Emirates, Bahrain and Qatar and estimate the consumer exposure to these metals. All samples of molluscs and crustaceans tested for arsenic (As) showed concentrations above maximum permitted levels, Qatar and UAE being the most contaminated. All samples from Kuwait contained lead (Pb), cadmium (Cd) and mercury (Hg). Bahrain samples contained Pb above permitted levels. On the coast of Oman and Qatar shellfish showed concentrations of Cd above permitted levels. The EWI for As from shellfish is above the PTWI for all samples. For Cd, all except shellfish from Oman, Bahrain and KSA entail a EWI above the PTWI. None of the samples, except from Kuwait, provide Pb above the PTWI and for Hg, only the clam, mussel and crab contain higher amounts. Four locations in the UAE contained fish with Cd above permitted levels. Tuna fish from KSA had higher levels of Cd and Pb. Highest levels of Hg could be found in fish from Kuwait. Bahrain and Qatar showed the highest levels of As. Hg EWI exceeded for the UAE, Kuwait and Qatar. Estimated weekly intakes of As and Cd from shellfish are extremely high and above the Provisional Tolerable Weekly Intake. Fish from these countries does not contain high levels that pose a threat to public health, except for As. The risk is probably in chronic low exposure. Risk groups should be properly advised.
12
Redfern, Farran Mack. "Heavy Metal Contamination from Landfills in Coastal Marine Sediments: Kiribati and New Zealand." The University of Waikato, 2006. http://hdl.handle.net/10289/2323.
Full textAbstract:
Landfill leachates are a concern in the Pacific Region where they may contribute contaminants to the coastal marine environment. Poor waste management and pollution of coastal waters are amongst the major environmental problems in Kiribati, particularly in South Tarawa. An investigation of areas adjacent to coastal landfill sites; Betio, Kiribati and Auckland, New Zealand was undertaken. The Kiribati case study investigated metal contamination in marine sediments at an operational landfill while the New Zealand study was adjacent to a coastal landfill decommissioned in the 1970s. Surficial sediments (top 15 cm) were collected along transects. At both the New Zealand and Kiribati sites, 3 transects adjacent to the landfill and 1 control transect were sampled. The sediments were analyzed for particle size distribution, organic matter content, and Cd, As, Cr, Cu, Pb, Hg, Ni and Zn concentrations. The pH was also measured. The Kiribati study site had a groundwater pH of 7.14 - 8.85, and sediment materials were dominated by sand with a low organic matter content (1.60 - 2.21 %). At the Kiribati sites Cd, As, and Ni were below the detection limits. The Cr, Cu, Pb and Zn concentrations were lower at the Kiribati control transect than the landfill transects. Cr level decreased away from the landfill indicating the landfill as a possible source. However, Cu and Zn did not show any distribution pattern suggesting other potential sources (port and shipwrecks) may have contributed to the elevated levels. At the Kiribati landfill and control transects the Cr, As, Cd, Cu, Pb, Ni, and Zn concentration were below the Effects Range-Low (ERL) and the threshold Effects levels (TEL) of the Sediment Quality Guidelines (SQCs) of the National Oceanographic and Atmospheric Administration (NOAA) and the Florida Department of Environmental Protection, indicating no potential adverse ecological effects on the biota. At the Kiribati control site the Cr, As, Cd, Cu, Pb, Ni and Zn concentrations were within the background ranges published for clean reef sediment but the concentration at the landfill transects exceeded the background ranges. The concentration of mercury at both the control and landfill transects in Kiribati exceeded the Effects Range-Median (ERM) and the Probable Effects Level (PEL) of the SQGs indicating potential adverse ecological effects on the local benthic communities. The New Zealand study site sediments had a pH of 6.22 - 7.24, and comprised up to 90 % clay/silt, with an organic matter content of 5 - 22 %. At the New Zealand landfill transects Arsenic concentrations decreased away from the landfill indicating the landfill as a possible source. Other metals such as Cr did not show a pattern of distribution along the transects, or with depth, suggesting that the landfill was not the only source of these metals. There was a weak correlation between organic matter content, particle size distribution, and metal enrichment. At the New Zealand site, there were no marked differences in metal concentrations between the landfill and control transects suggesting the landfill was not the only source of metals and that the wider urban or industrial run-off may have contributed. All the metal concentrations, except Hg and Zn, exceeded the ERL and the TEL values indicating the potential for adverse ecological effects of metals on the benthic communities. At the New Zealand site the Hg and Zn concentrations exceeded both the ERM and PEL of the SQGs and are considered highly contaminated.
13
Opfer, Sarah E. "Heavy Metal Uptake by Burrowing Mayflies in Western Lake Erie." Bowling Green State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1213907121.
Full text
14
Cebrian, Pujol Emma. "Sublethal effects of heavy metal contamination on marine sponges: Responses at different biological levels." Doctoral thesis, Universitat de Barcelona, 2007. http://hdl.handle.net/10803/805.
Full textAbstract:
Many antrophic activities release pollutants to the marine environment. Among them heavy metals are of great importance, since they are conservative pollutants, which can be accumulated through trophy chains. Sometimes, the liberation to the marine waters is acute and drastic, leading to massive mortalities. However, more often, the liberation is by means of low and chronic concentrations. The main objective of the present thesis is to analyze the sponge responses in face to sublethal concentrations of heavy metals and to determine, if it is possible, whether they can be used as biomonitors of such kind of pollution. First, we have studied their availability to accumulate havey metals in both, temporal and especial scales. And then, by means of the use of different biomarkers, to analyze the sublethal effects of heavy metals on sponges at different levels of biological organization, from molecules to populations. The present thesis has been performed by means of experiments in situ and at the laboratory, in order to elucidate heavy metal accumulation patterns and their effects depending on the specie and metal considered.TÍTOL DE LA TESI: "Efectes subletals de la contaminació per metalls pesats en esponges marines: Respostes a diferents nivells d'organització".
TEXT:
Moltes activitats antròpiques alliberen contaminants en el medi. Entre els contaminants hem de destacar els metalls pesants, ja que són contaminants conservatius y que s'acumulen a través de les xarxes tròfiques. En alguns casos la alliberació dels contaminants en el medi es dona de forma aguda i dràstica, el què pot provovar mortalitats massives. De totes formes, de forma general l'alliberació al medi dels metalls pesants es dóna a baixes concentracions i de forma crónica. L'objectiu principal d'aquesta tesis és analitzar les respostes de les esponges a concentracions subletals de metalls pesants i determinar la seva utilitat com a biomonitors d'aquest tipus de contaminació. En primer lloc, s'ha d'estudiar la capacitat de les esponges per acumular metalls pesants tant a una escala temporal com espaial. En segon lloc, mitjançant l'ús de diferents biomarcadors, analitzar els efectes subletals dels metalls en les esponges, a diferents nivells d'organització biológica, desde les molècules fins a les poblacions. Aquesta tesis s'ha dut a terme mitjançant experiments que convinen aproximacions in situ i en el laboratori per tal de compendre de millor maners els models d'acumulació i els seus efectes en funció de l'espècie i el metall considerat.
15
Gorenc, Shelley Anne. "Heavy metal contamination of surficial tidal flat sediments in the Yangtze River Estuary, China." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ61896.pdf.
Full text
16
Swanton, Kerry Vivienne. "Food safety and waste water reuse : heavy metal contamination in peri-urban Varanasi, India." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428327.
Full text
17
Bunker, Adrian John. "The impact of the oil industry on subtidal meiobenthos." Thesis, Heriot-Watt University, 1999. http://hdl.handle.net/10399/1269.
Full text
18
Souza, José Ivanildo de. "Mucorales de solo contaminado com metais pesados na região do pólo cerâmico de Santa Gertrudes, SP : ocorrência e capacidade de biossorção de chumbo e zinco /." Rio Claro : [s.n.], 2006. http://hdl.handle.net/11449/103975.
Full textAbstract:
Orientador: Iracema Helena Schoenlein-CrusiusBanca: Carmen Lidia Amorim Pires-Zottarelli
Banca: Sandra Farto Botelho Trufem
Banca: Dejanira de Franceschi de Angelis
Banca: Carlos Renato Corso
Resumo: Em solo contaminado com metais pesados na região do pólo cerâmico do município de Santa Gertrudes, Estado de São Paulo, Brasil, foi realizado o levantamento taxonômico de fungos da ordem Mucorales (Zygomycota) utilizando-se o método da placa-de-solo, modificado pela aplicação de uma suspensão de solo (10%, p v-1) sobre malte agar (2%, p v-1) acrescido de Pb(NO3)2 ou Zn(NO3)2 nas concentrações de 0 (controle), 100, 200, 500 e 1000 mg L-1. As identificações e descrições taxonômicas foram realizadas utilizando-se SMA (synthetic Mucor agar), sendo obtidos os táxons: Absidia cylindrospora v. cylindrospora Hesselt. & Ellis, Cunninghamella phaeospora Boedijn, Mucor circinelloides Tiegh. f. circinelloides, M. circinelloides Tiegh. f. lusitanicus (Bruderl.) Schipper, M. circinelloides Tiegh. f. janssenii (Lendn.) Schipper, Mucor hiemalis Wehmer f. hiemalis, M. hiemalis Wehmer f. luteus (Linnem.) Schipper, Mucor racemosus Fresen. f. racemosus, Rhizopus oryzae Went & Prins. Geerl., Zygorrhynchus moelleri Vuill. e Mucor bainieri Mehrotra & Baijal, que é citado pela primeira vez para o Brasil. Análises químicas de amostras de solo coletadas em quatro locais na área estudada confirmaram a contaminação severa por metais pesados em alguns dos locais, sendo que comparações entre o número de táxons obtidos no presente estudo com os dados de literatura permitiram concluir que houve prejuízo à diversidade de fungos na região. As biomassas secas e pulverizadas (2 g L-1) de Mucor hiemalis f. hiemalis (SPC 2040) e de Mucor hiemalis f. luteus (SPC 2044) foram colocadas em contato, sob agitação a 120 rpm por 14 h, com soluções aquosas (pH 4) de Pb(NO3)2 e Zn(NO3)2 nas concentrações de 0,06, 0,13 e 0,17 mM e de 0,08, 0,16 e 0,23 mM, respectivamente, sendo comparadas ao carvão ativado (CA), utilizado como material adsorvente de referência
Abstract: In a heavy metal contaminated soil at ceramic pole of Santa Gertrudes region, São Paulo State, Brazil, a taxonomic survey of fungi of the order Mucorales (Zygomycota) have been done using the soil plate method, modified for a soil suspension (10%, p v-1) application on malt agar (2%, p v-1) added with Pb(NO3)2 or Zn(NO3)2 at 0 (control), 100, 200, 500 and 1000 mg L-1 concentrations. Taxonomic identifications and descriptions have been done with SMA (synthetic Mucor agar), obtaining the taxa: Absidia cylindrospora v. cylindrospora Hesselt. & Ellis, Cunninghamella phaeospora Boedijn, Mucor circinelloides Tiegh. f. circinelloides, M. circinelloides Tiegh. f. lusitanicus (Bruderl.) Schipper, M. circinelloides Tiegh. f. janssenii (Lendn.) Schipper, Mucor hiemalis Wehmer f. hiemalis, M. hiemalis Wehmer f. luteus (Linnem.) Schipper, Mucor racemosus Fresen. f. racemosus, Rhizopus oryzae Went & Prins. Geerl., Zygorrhynchus moelleri Vuill. and Mucor bainieri Mehrotra & Baijal, that is cited first time for Brazil. Chemical analyses of soil samples taken from four sites in the studied area confirm a severe contamination of heavy metals in some of the sites, and comparisons between taxa numbers obtained in the present study with literature data allowed conclude that there was fungal diversity disturbance in the region. The dry and grounded biomasses (2 g L-1) of Mucor hiemalis f. hiemalis (SPC 2040) and Mucor hiemalis f. luteus (SPC 2044) was kept in contact, under agitation at 120 rpm during 14 h, with aqueous solutions (pH 4) of Pb(NO3)2 and Zn(NO3)2 at 0.06, 0.13, 0.17 mM and 0.08, 0.16, 0.23 mM concentrations, respectively, being compared with activated charcoal (AC) as the reference adsorbent. The percentages amounts of metals removed from solutions, express by q% index, had presented the following adsorption sequences: AC > SPC 2044 > SPC 2040 for Pb and AC > SPC 2040 > SPC 2044 for Zn
Doutor
19
Tayab, Muhammad Rehan. "Environmental impact of heavy metal pollution in natural aquatic systems." Thesis, Brunel University, 1991. http://bura.brunel.ac.uk/handle/2438/5503.
Full textAbstract:
The distribution of heavy metals between soil and soil solutions is a key issue in evaluating the environmental impact of long term applications of heavy metals to land. Contamination of soils by heavy metals has been reported by many workers. Metal adsorption is affected by many factors, including soil pH, clay mineralogy, abundance of oxides and organic matter, soil composition and solution ionic strength. The pH is one of the many factors affecting mobility of heavy metals in soils and it is likely to be the most easily managed and the most significant. To provide the appropriate level of protection for aquatic life and other uses of the resource, it is important to be able to predict the environmental distribution of important metals on spatial and temporal scales and to do so with particular emphasis on the water column concentrations. Regulatory levels reflected in water quality criteria or standards are based on water column concentrations. Predicting water column concentrations requires a consideration of the interactions of water column contaminants with both bed sediments and suspended particulates as critical components in the assessment. The adsorption behaviour of cadmium, copper, lead and zinc onto soils is studied under the various geo-environmental conditions of pH, concentration of adsorbate and adsorbent, and solution compositions. Experiments were conducted to determine the equilibrium contact time of various adsorbates for adsorbent in different systems. Experiments were also conducted to check the efficiency of various acid-mixtures to extract heavy metal from soils into the aqueous phase. The adsorption behaviour of heavy metals onto soils was also studied from sea-water system. Soils are characterized in terms of the role of clay minerals to remove the metals from the solution phase, back-ground levels of metals, maximum adsorption capacity to adsorb various heavy metals from different adsorption systems, and type of surface sites present. The experimental data of metal adsorption is described by Langmuir adsorption model. The adsorption data are also expressed in terms of surface loading, surface acidity, adsorption density, and affinity of soils for heavy metals in different adsorption systems. Ecological implications of changes in physical and chemical conditions in aquatic systems on heavy metals uptake by soils are also discussed. This research covers the following areas: the environmental impact of heavy metal discharge into the aquatic systems, the study of the mobility patterns of different heavy metals as function of geo-environmental conditions, and determination of the pathways and the ultimate fate of heavy metals in the environment.
20
Korre, Anna. "A methodology for the statistical and spatial analysis of soil contamination in GIS." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266111.
Full text
21
MA, JUN. "Risk Assessment and Sequestered Contamination Evaluation for Legacy Heavy Metal Contaminants in Cleveland Area Brownfields." Case Western Reserve University School of Graduate Studies / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=case1106351960.
Full text
22
Simpson, Julia Marie. "Effects of heavy metal contamination on burial rates of Austrovenus stutchburyi implications for sediment transport /." The University of Waikato, 2009. http://hdl.handle.net/10289/2766.
Full textAbstract:
Urbanisation in coastal catchments has significantly increased not only the input of terrestrial sediment to the marine environment but also the input of contaminants. In Tamaki Estuary, Auckland, heavy metals have accumulated in the upper estuarine muddy sediments and metal contamination has been detected on downstream intertidal sandflats. Sub-lethal levels of heavy metal contamination may affect the growth and behaviour of benthic organisms, which in turn may influence key ecosystem processes and productivity. The aim of this study was to examine whether the burial rate of an ecologically important bivalve species (Austrovenus stutchburyi) differed between a contaminated and a lesser-contaminated site and whether burial rates were affected by density. A secondary aim was to determine whether the burial of Austrovenus affected sediment transport and consequently if this was affected by density. This study demonstrated no consistent difference in burial time between source populations (sites). This was explained by a lack of measured difference in the condition index and heavy metal tissue loading of Austrovenus used throughout this study. The present range of contamination measured in Tamaki Estuary, Auckland, did not have negative biological consequences on the key ecosystem engineer, Austrovenus stutchburyi. Contamination levels in Tamaki Estuary may not be high enough to cause major physiological or behaviour changes to infaunal organisms, such as Austrovenus. Sediment erodability was not significantly correlated with any measured environmental and biotic factors. Austrovenus density was the only predictor variable that could be used to explain any variation in sediment erodability. There was no significant density effects observed between the amounts of sediment eroded for densities gt; 150 ind. m-2. There was a significant difference between sediment void of Austrovenus (0 ind. m-2; smooth, flat undisturbed sediment surface) and sediment containing Austrovenus (gt;150ind. m-2; physical structure on/in the sediment surface, increase in bed roughness). These results indicate that there is little or no effect of Austrovenus on the critical erosion threshold, suggesting that in the absence or presence of Austrovenus the current required to erode 10 g m-2 of sediment would remain somewhere between 28.5 and 30.5 cm s-1. This study found that there was considerable variation in the burial rate of individuals and the greatest variation was recorded in the lowest density treatments (150 ind. m-2), which corresponded to the same density that had the greatest variation in sediment erodability. Further investigations are needed to gain a better understanding into the important roles (the importance of the various feedbacks and limitations and interrelationships) that Austrovenus play in the soft-sediment ecosystem, as losses of this species are likely to have large-scale impacts on the wider soft-sediment communities and ecosystem functioning.
23
Barak, Najim A.-E. "Aspects of biology and heavy metal contamination of eels and roach in East Anglia rivers." Thesis, University of Essex, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328860.
Full text
24
Thuong, Nguyen Thi. "Heavy Metal Contamination in Water and Sediment of To Lich River in Inner City Hanoi." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/180494.
Full text
25
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.
Full text
26
Wong, Sze-chung Coby. "Trace metal contamination of the riverine environment in Guiyu, China : the impacts of primitive e-waste disposal /." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B4308526X.
Full text
27
Whitfield, Lynn. "Heavy metal tolerance and mycorrhizal colonisation in Thymus polytrichus A. Kerner ex BorbaÌs ssp. britannicus (Ronn.) Kerguelen (Lamiaceae)." Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246685.
Full text
28
Irshad, Mohamed. "Environmental presence of heavy metal contamination of industrial tributary in a rural river catchment. : -A case study on Trönningeån stream in Southern Sweden." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-34797.
Full textAbstract:
Heavy metal pollutants are a worldwide concern. It causes negative effects on aquatic organisms and human health. Heavy metals concentration and transport of copper, zinc and cadmium were investigated in high and low flow conditions in Trönningeån River, southern Sweden. A total of 33 surface water samples collected from the river and Kistingebäcken tributary were analyzed. Concentration (high to low) of heavy metals in the Trönningeån river and its tributary were- copper(Cu) > zinc (Zn) > cadmium (Cd). The concentration of Copper was found to be high in low flow condition whereas in the case of zinc, high concentrations were found in both the flows (high and low). Study further showed that, the tributary has high pH and conductivity. And finally, the study concluded that there is high concentration and transport of heavy metals in the above-mentioned industrial tributary.
29
Fox, Dawn Iona. "Cactus Mucilage-Assisted Heavy Metal Separation: Design and Implementation." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3107.
Full textAbstract:
Natural contamination of groundwater by arsenic (As) has become a critical public health threat in many parts of the world. The well-known regions associated with As contamination of groundwater are Bangladesh and West Bengal, India where approximately 100 million people are exposed to high levels of arsenic by drinking arsenic-contaminated groundwater and about 35 million are already affected. Long-term drinking of arsenic-contaminated water leads to arsenicosis, which is characterized by cancers of the skin, organ disease and certain other types of cancer. Affected developing communities are at higher risk because they may not have access to conventional water treatment facilities. This problem has focused research efforts on providing accessible arsenic removal technologies. In this study, cactus mucilage, an extract from the Opuntia ficus-indica (also known as Nopal and Prickly Pear cactus), is investigated as a natural agent for As removal from water. Cactus mucilage is a natural hydrocolloid with known flocculant abilities and a demonstrated interaction with As. Two mucilage fractions were extracted - a gelling extract (GE) and a non-gelling extract (NE). Two As removal systems were studied: the cactus mucilage acting alone and a hybrid mucilage and iron treatment system. The mechanism of action of the mucilage's interaction with arsenic was also studied. Batch experiments were used to study the arsenic removal systems. Total As was determined with Hydride Generation - Atomic Fluorescence Spectroscopy (HGAFS) and Inductively Coupled Plasma - Mass Spectroscopy (ICPMS). In the hybrid system, iron (Fe) was also determined by ICP-MS. Total Organic Carbon (TOC) analysis
was used to determine mucilage concentration. Attenuated Total Reflectance - Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Ultraviolet-Visible Spectroscopy (UVVIS) were used to study the molecular composition. Additionally, the mucilage was characterized by Transmission Electron Microscopy (TEM) for physical morphology and by Laser-induced Breakdown Spectroscopy (LIBS) and High Performance Liquid Chromatography (HPLC) for inorganics and sugars composition.
Both cactus extracts showed an interaction with As by binding and transporting As to the air-water interface of the treatment container, with GE and NE causing a 14% and 9% respective increase in As concentration at the air-water interface. TOC analysis showed that the mucilage migrated to the top of the treatment container but also settled on the bottom. This interaction with As was shown to be pH dependent - optimal performance was at pH 5.5 and 9. The mucilage interaction with As was also dependent on the ionic strength of the solution. ATR-FTIR showed the role of the carboxyl functional group as the binding site for the As(V). The hybrid iron-mucilage treatment system was studied in order to capitalize on the strong affinity of iron for As, as well as to exploit the flocculant properties of the mucilage. Mucilage was successfully applied as a coagulant aid in the removal of As by Fe(III) salt, achieving between 75% to 96% As removal. The process depended on the hydrolysis of the Fe(III) salt to form iron hydroxides and oxyhydroxides, which reacted with and adsorbed the dissolved As(V). The iron arsenate colloidal precipitate which formed was then adsorbed onto the mucilage surface forming larger, heavier, denser flocs. The As removal increased with increasing mucilage concentration reaching a maximum at 100 mg/L GE. Increasing Fe(III) concentration increased the As removal reaching an optimum concentration at 40 mg/L Fe. The As removal had rapid kinetics, achieving visual separation within 10 minutes and completing the majority of the removal within 30 minutes. These results are important because they demonstrate that the mucilage is the versatile basis for an As removal treatment, being able to interact as a complexant for the arsenic as well as an effective coagulant aid for iron arsenate precipitation.
30
Mdzeke, Naomi Patience. "Contamination levels in and cellular responses of intertidal invertebrates as biomarkers of toxic stress caused by heavy metal contamination in False Bay." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/53733.
Full textAbstract:
Thesis (PhD) -- Stellenbosch University, 2004.ENGLISH ABSTRACT:Heavy metals are persistent environmental contaminants whose sources of inputs into the environment are both natural and anthropogenic. The levels of heavy metals (cadmium, copper, nickel, lead and zinc) in the False Bay intertidal zone were measured in the water, sediments and invertebrate species between August 2000 and August 2001. The results of the water and sediment analyses revealed that most pollution was associated with the northern shore of the bay between Strand and Muizenberg, where the most populated and industrial catchments occur. Significant spatial variations occurred, indicating the presence of localised contamination, while seasonal variations may be related to changes in precipitation and runoff at different times of the year. The concentrations of cadmium, nickel and lead were occasionally higher than the levels recommended by the South African Water Quality Standards. The possible sources of pollution at the different sites are also discussed. The concentrations of the five metals in the different invertebrate species (Oxystele tigrina, 0. sinensis, Choromytilus meridionalis, Patella oculus, Patiriella exigua and Tetraclita serrata) also revealed significant seasonal and spatial variations, with both the soft tissues and shells accumulating heavy metals. The barnacle T serrata from Rooiels had the highest cadmium concentration (70.67 J.lg/g dry weight), which may be related to historic pollution inputs from the military activities which took place at a weapons testing site at this site between 1987 and 1994, although no evidence was found to confirm this. The periwinkle 0. tigrina from Strand had the highest copper concentration (70.25 J.lg/g) while the limpet P. oculus from the same site had the highest nickel concentration (35.75 J.lg/g). The shells of the mussel C. meridionalis from Muizenberg had the highest concentration of lead (25.75 J.lg/g). Since cadmium occurs as a constituent of phosphate fertilisers used widely in the False Bay catchments, the effects of cadmium exposure on the different species were investigated during 14-day laboratory exposures to 200 and 400 J.lg/LCdCh. The results revealed a general pattern of tissue metal increase in the exposed organisms, followed by slight reductions after decontamination in clean seawater. The viscera and kidneys of C. meridionalis accumulated most of the dissolved cadmium. The shells of the mussels also accumulated cadmium, indicating the possible use of shells as a detoxification matrix.
AFRIKAANSE OPSOMMING:Swaarmetale is persisterende omgewingskontaminante waarvan die insetbronne beide natuurlik of van menslike oorsprong kan wees. Die kontaminasievlakke van swaarmetale (kadmium, koper, nikkel, lood en sink) in die Valsbaai tussengetysone is in die water, sedimente en invertebraatspesies bepaal vanaf Augustus 2000 tot Augustus 2001. Voorlopige resultate van die water- en sedimentontledings het getoon dat die meeste besoedeling by die noordelikke oewer van die baai voorgekom het tussen Strand and Muizenberg, waar die mees digbewoonde en ge-industrialiseerde opvangsgebiede is. Betekenisvolle ruimtelike en seisoenale variasie het in die konsentrasies van swaarmetale voorgekom, met die ruimtelike variasie wat moontlik gelokaliseerde kontaminasie aandui terwyl die seisoenale variasies weer verband mag hou met veranderings in die neerslag en afloop gedurende verskillende tye van die jaar. Die konsentrasie van kadmium, nikkel en lood was somtyds hoer as die vlakke wat deur die Suid-Afrikaanse Waterkwaliteitsstandaarde voorgestel word. Die moontlike bronne van besoedeling in die verskillende areas is ook in bespreking genoem. Die konsentrasies van die vyf swaametale in die verskillende invertebraatspesies (Oxystele tigrina, 0. sinensis, Choromytilus meridionalis, Patella oculus, Patiriella exigua and Tetraclita serrata) het ook seisoenale en ruimtelike variasies vertoon, die swaarmetale het in die sagte weefsel en skulpe van die invertebrate geakkumuleer. Die hoogste gemiddelde konsentrasie van kadmium (70.67 ).lg/g droe massa) is in die heel-liggaam monsters van die eendemossel T serrata gemeet wat by Rooiels versamel is. Die vlakke mag verband hou met die oprigting en aktiwiteite van die wapentoetsingsaanleg in die opvanggebied van die Rooiels lokaliteit tussen 1987 en 1994, maar geen bewyse daarvan is gevind nie. Die tolletjie, 0. tigrina wat in die 10kaliteit by Strand versamel is het die hoogste gemiddelde konsentrasie koper gehad 70.25 pig droe massa), terwyl die klipmossel P. oculus by dieselfde versamelpunt die hoogste konsentrasie nikkel (35.75 ).lg/gdroe massa) gehad het. Eksperimentele studies is ook uitgevoer op vier invertebraat spesies wat vir 14 dae in akwaria blootgestel is aan see-water met 200 en 400 p,g/L CdCh, en daama gedekontamineer is in skoon seewater.
The NRF and the University of Stellenbosch, for funding this study.
31
Haring, Peter G. "The nature of heavy metal contamination in organic lake sediments near the Buchans massive sulphide base metal mines, Central Newfoundland /." Internet access available to MUN users only, 2002. http://collections.mun.ca/u?/theses,25133.
Full text
32
Bernhard, Robert. "Assessment of Macroinvertebrate Communities and Heavy Metal Contamination Along the Intracoastal Waterway in Fort Lauderdale, Florida." NSUWorks, 2014. http://nsuworks.nova.edu/occ_stuetd/27.
Full textAbstract:
Sediments from four areas adjacent to marinas and a background site in the Intracoastal Waterway were assessed for macroinvertebrate composition and heavy metal contamination. Sediment core samples were collected in 2004 and 2005 for analyses of macroinvertebrate composition and sediment grain size. Additional sediment samples were collected in 2005 for chemical analyses of metals (Al, As, Cd, Cr, Cu, Fe, Pb, Hg, Ni and Zn). MANOVA and dendograms using Bray-Curtis similarity matrices grouped the sites into two clusters: the 3 sites closest to the New River formed one group, and the two end sites formed the other. The sites nearest the New River were dominated by polychaetes, half of which were pollutant-tolerant species (e.g., Capitella capitata). The macroinvertebrate communities of the two end sites were dominated by tanaids, gastropods and sipunculids with fewer annelids than the other 3 sites. The influence of the New River on the study sites appeared to outweigh the sources of metal pollution found in marinas. The 3 sites closest to the New River had higher metal concentrations than the two end sites. The background site, nearest the mouth of the New River, exceeded the Florida sediment quality guideline probable effect level for cadmium and copper while three of the four marina sites exceeded at most one probable effect level and one or more threshold effect levels for cadmium and copper. The furthest site from the New River, which was the closest site to Port Everglades, had the lowest metal concentrations. Additional studies are needed to determine the level of pollutant loading from the New River and its effects on nearby biological communities.
33
Perryman, Sarah Alicia Michelle. "The effect of heavy metal contamination on estuarine benthic fauna at varying levels of biological organisation." Thesis, University of Plymouth, 1996. http://hdl.handle.net/10026.1/1083.
Full textAbstract:
Biological monitoring techniques, selected to cover increasing levels of biological organisation (cellular, individual, population and community), were compared and contrasted to determine the relative sensitivities of these approaches to heavy metal contammation. The study was centred on the Fal Estuary in Cornwall, an ideal experimental field site-with well documented heavy metal contamination resulting firom the long-term discharge of waste from a local tin mine. Five creeks leadmg from the estuary differ dramatically in the concentrations of heavy metals in the sediments, but little in natural environmental variables (sediment granulometry, salinity etc.). The contaminant induced damage was evaluated at the cellular level in Mytilus edulis by the Neutral Red Assay to detect lysosomal membrane damage. Parameters of the energy budget of this species were determined to estmiate 'Scope for Growth' of mdividuals. along with a Larval Survival assay to estabUsh their reproductive and developmental success. At the population level. Cohort Growth studies were undertaken using the polychaete Nephtys hombergi. At the community level, data firom an extensive three year survey of benthic macrofauna structure were analysed. In addition to investigating biological parameters, contammant levels in sedunent and tissue were determuied using Atomic Absorption Spectrommetry. All techniques, except the population level, detected the extreme pollution of the most contaminated creek, Restronguet, but did not accurately reflect the known metal gradient. However, community studies established distinct macrofaunal assemblages between both sites and years. Techniques were compared and validated in a novel approach using the program BIOENV, with the multivariate analysis package PRIMER (Plymouth Routines in Multivariate Ecological Research). The cellular assay correlated reasonably well agamst the heavy metal levels, the larval survival assay correlated well to the community structure. However, the community structure approach was the most sensitive and relevant monitoring method to determme the long-term contamination of the Fal Estuary.
34
Shipp, Emily Caroline. "The impact of heavy metal contamination on invertebrates in the Fal and Hayle Estuaries, Cornwall, UK." Thesis, University of East Anglia, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426990.
Full text
35
Albanus, Celina [Verfasser]. "Microbiological and heavy metal contamination of drinking water sources in South Luangwa Valley, Zambia / Celina Albanus." Düren : Shaker, 2020. http://d-nb.info/1227824319/34.
Full text
36
Maxwell, Deborah. "REMEDIATION OF HEAVY METAL CONTAMINATION IN SEDIMENTS: APPLICATION OF IN SITU TREATMENT UTILIZING EMULSIFIED LIQUID MEMBRANE AN." Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4329.
Full textAbstract:
Heavy metal contamination of soils, sediments and groundwater presents an ongoing source of hazardous and persistent environmental pollution. How best to remediate these contaminants is the impetus of continuing research efforts. Methods include containment, ex situ and in situ techniques. A successful in situ method utilizing a combination of emulsified liquid membranes, ELM, and zero-valent metal, ZVM, and bimetals has demonstrated impressive heavy metal reduction in 100 ppm solutions of Cd, Cu, Ni, Pb, Cr and U. This promising in situ method has been employed by the Industrial Chemistry Laboratory at the University of Central Florida and it has demonstrated considerable success in treating several environmental threats. Contaminated soils, surfaces, sediments and groundwater with offending agents such as trichloroethene, polychorobiphenyls and heavy metals have been treated utilizing emulsified liquid membrane systems containing zero-valent iron or bimetal particles. In vial studies, lead spiked sediments have shown repeatable 60% removal of lead after seven days of treatment. A persistent pattern emerged at ten days whereupon remediation levels began to drop. The current study was established to determine the reason for the decline at ten days and beyond. Questions addressed: Does the formation of an impeding oxide layer diminish the remediation capacity of the iron/magnesium system? Does the emulsion reach a maximum capacity to withdraw the contaminant? Do the soil components or the soil structure interfere with the access to the contaminant? This study has yielded insight into the reasons emulsified liquid membrane systems containing zero-valent metals achieved maximum lead removal at day seven, and thereafter begin to lose their effectiveness. A three part study was implemented to address and to answer the three questions pertaining to the consistent pattern of diminishing remediation levels exhibited at day ten and beyond. Initially, from Study I results it appeared that the formation of an impeding oxide layer on the bi-metal which was inside the emulsion droplet and which plated or precipitated with the lead was not occurring at day ten. Results indicated that the iron/magnesium was still capable of removing lead. Furthermore, from Study II results the emulsion dose injected appeared adequate to remove the lead, meaning that the emulsion had not reached its maximum capacity for remediation. The emulsion dose was not a limiting factor. Lastly, Study III results seemed to indicate that the drop in remediation after day seven pertained to the soil structure. There appeared to be some merit to the idea that with aging of the sediment, the lead was diffusing and migrating to some inaccessible interior sites within the sediment particles. Additionally, indications from day ten and day fourteen delineated that a second emulsion dose injection might restore lead removal levels to approach those first observed at day seven and consequently be a useful field application. In order to explore the effectiveness of injecting a second dose of emulsion, another vial study was implemented. The typical pattern of observing sixty percent maximum lead removal at day seven was observed. In separate groups, a second injection of emulsion was added at day five, and then for another vial series, a second dose was added at day seven. The second emulsion dose treatment for either day five or day seven did not yield any increases in percent lead removal. Another theory emerged after viewing micrographs of recovered iron/magnesium compared with fresh ball-milled bimetal. In addition, scanning electron microscopy appeared to confirm the explanation that the emulsified zero-valent metal system might be compromised after day seven. This would lead to exposure of the iron/magnesium to the air and the elements. Corrosion of the bimetal might be occurring. With time, release of the plated or precipitated lead back into the sediment mixture could follow. The results of Study I had led to the conclusion that an impeding oxide layer had not formed; however, this conclusion may have been premature because the recovered iron/magnesium was exposed to lead solution in the vial study. Perhaps if the recovered iron/magnesium was inserted back into an emulsion and injected into lead spiked sediments the percent lead removed might give a more accurate picture of the iron/magnesium's capability to continue performing remediation. Remediation of sediments contaminated with lead is a complicated task because of the complex nature of sediment components. Emulsified liquid membranes utilizing zero-valent bimetals has repeatedly demonstrated impressive results at day seven; however, this treatment method is not without its limitations. Optimal results appear to be gained at day seven after emulsion injection. The bimetal and plated or precipitated lead must be removed at that point; otherwise the effective remediation of the contaminant is progressively reversed.M.S.
Department of Chemistry
Sciences
Industrial Chemistry MS
37
Jung, Myung Chae. "Heavy metal contamination of soils, plants, waters and sediments in the vicinity of metalliferous mines in Korea." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.481221.
Full text
38
Magno, Melissa A., Ingrid Luffman, Arpita Nandi, and Brian G. Evanshen. "SPATIAL INTERPOLATION OF HEAVY METAL CONCENTRATIONS IN SOILS OF BUMPUS COVE, TN." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/asrf/2018/schedule/126.
Full textAbstract:
Mining processes generate waste rock, tailings, and slag that can increase heavy metal concentrations in soils. Un-reclaimed, abandoned mine sites are particularly prone to leaching these contaminants, which may accumulate and pose significant environmental and public health concerns. The characterization and spatial delineation of heavy metals of such soils is vital for risk assessment and soil reclamation. Bumpus Cove, once one of the richest mineralized districts of eastern TN, is home to at least 47 abandoned, un-reclaimed mines that were all permanently closed by the 1950s. This study evaluated 52 soil samples collected within a 0.67 km2 study area containing 6 known abandoned Pb, Zn, and Mn mines at the headwaters of Bumpus Cove Creek for heavy metal concentrations. Soil samples were analyzed for Zn, Mn, Pb, Cu, and Cd by means of microwave-assisted acid digestion and flame atomic absorption spectrometry (FAAS). Using the measured values and digital elevation model (DEM) derived from lidar data, ordinary kriging and cokriging interpolation techniques were used to predict the trend of heavy metal concentrations throughout the study area. Concentrations for Zn, Mn, and Pb show significant variability between sample sites (ranges of 12 – 1,354 mg/kg Zn, 6 – 2,574 mg/kg Mn, 33 – 2,271 mg/kg Pb). Cu and Cd were much less variable, with ranges of 1 - 65 mg/kg and 7 – 40 mg/kg, respectively. Of the measured heavy metals, only Zn and Pb exceed permissible limits in soils. Results show that ordinary kriging interpolation methods produced improved results over ordinary cokriging with and without lognormal transformations for all metals. Mn and Pb were found to transport further downhill following the natural drainage, whereas Zn, Cu and Cd concentrations exhibit localized variability without a clear transportation path. This study can provide a reference for state and local entities responsible for heavy metal monitoring in Bumpus Cove, TN.
39
Pham, Vivian G. "Ecological Risk Assessment of Heavy Metal Content in the Hatillo River, Costa Rica." Scholarship @ Claremont, 2015. http://scholarship.claremont.edu/scripps_theses/571.
Full textAbstract:
Rivers all around the world have become increasingly polluted with heavy metals, largely due to industrialization and urbanization. Organisms exposed to high concentrations of heavy metals have shown evidence of biotoxicity and physical deformities. With biomagnification in mind, the possibility that this contamination may soon directly affect humans is a real concern, and policies in manufacturing industries worldwide may have to be reformed. In this study, we measured the concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb) in the Hatillo River and compared these values to those measured in the Tarcoles River, a highly polluted river, and Terciopelo Creek, a relatively clean river. The results showed that the Hatillo River had significantly lower levels of most detected heavy metals than both the Tarcoles and Terciopelo. Overall, sediments in all rivers showed high levels of heavy metal content--especially in chromium, copper, nickel, and lead--which could build up and affect organisms over a long period of time.
40
Culshaw, Caroline. "Heavy metal contamination of the Severn Estuary and Bristol Channel : detecting environmental impact using the shrimp Crangon crangon." Thesis, University of the West of England, Bristol, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274682.
Full textAbstract:
The Severn Estuary and Bristol Channel have a long history- of metal contamination from anthropogenic sources. Nonetheless, the Estuary- supports a large and varied faunal community including a large population of the brown shrimp Crangon crangon, which is a key species in the ecosystem. The aim of this study was to detect the impacts of chronic metal contamination in the Severn Estuary by studying the effects of metal on shrimp at the individual and population level. Shrimp were collected from the Severn Estuary and Bristol Channel and, for comparison, from the Greater Thames Estuary and analysed for metals. Metals were highest in shrimp from the Severn Estuary where cadmium was very- bioavailable. Cadmium concentrations were up to 30 times higher in Severn shrimp (15 ug g-1) than in Thames shrimp (0.5 ug g-1 although the two sites had similar environmental conditions. Chronic environmental metal exposure of Severn Estuary shrimp may have produced a cadmium tolerant population. Severn shrimp had a significantly higher LC50 and LT50 than reference shrimp from an uncontaminated site and greater levels of metallothionein were induced by cadmium exposure. Metallothionein may act as a mechanism of tolerance by sequestering harmful metal ions. Prey consumption and burying success was reduced in crangon after exposure to environmentally realistic concentrations of cadmium that were 1O fold lower than the 96 h LC50' Impairment of these behaviours may alter fitness and have consequences for population increase. However, Severn Estuary shrimp were more successful than the reference shrimp indicating a greater tolerance of the sub-lethal effects of cadmium exposure. This study has shown that Severn Estuary shrimp are able to accumulate exceptionally high levels of cadmium and show increased tolerance to acute and sub-lethal effects of cadmium exposure. These adaptations exemplify the environmental impact of heavy metal contamination in the Severn Estuary.
41
Hess, Derek E. "Impact of Heavy Metal Contamination From Coal Flue Gas on Microalgae Biofuel and Biogas Production Through Multiple Conversation Pathways." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/5012.
Full textAbstract:
Large scale biofuel production from microalgae is expected to be integrated with point source CO2 sources, such as coal fired power plants. Flue gas (CO2) integration represents a required nutrient source for accelerated growth while concurrently providing an environmental service. Heavy metals inherent in coal will ultimately be introduced into the culture system. The introduced heavy metals have the potential to bind to microalgae cells, impact growth due to toxicity, and negatively impact the quality of biofuel and other microalgal derived products. Heavy metals As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Se, Sn, V and Zn, commonly present in coal, were introduced to the microalgae growth medium at a concentration expected from a 7 day growth period using coal flue gas. Experimentation was conducted with Nannochloropsis salina cultivated in photobioreactors at a light intensity of 1000 μmol m-2 s-1. Heavy metals negatively impacted the growth with the average productivity being 0.54 ± 0.28 g L-1 d-1, corresponding to a decrease of 52% in biomass yield compared to control growths. Heavy metal analysis showed significant binding of the majority of the heavy metals to the biomass. A lipid content analysis found a decrease in lipid content from 38.8 ± 0.62% to 31.58 ± 0.50% (percent dry biomass). Control and heavy metal contaminated biomass were processed into biofuel through one of two different in-situ transesterification techniques, either acid-catalyzed or supercritical methanol conversion. The acid-catalyzed conversion resulted in an average crude biofuel production decrease from 0.31 ± 0.03 grams biofuel/gram microalgae for the control algae to 0.28 ± 0.02 grams biofuel/gram microalgae for the heavy metal algae, representing a 9.7% reduction. Supercritical methanol conversion exhibited a similar trend corresponding to a 15.8% reduction. Compared to the control, the total production of biofuel from the contaminated system was decreased by 51% for the acid-catalyzed conversion and 55% for the supercritical methanol conversion. Heavy metal analyses were performed on the biofuel, lipid extracted algae, and other biofuel conversion byproducts. Biochemical methane potential testing was performed on the lipid extracted algae to determine the effect of heavy metals on the generation of biogas. The effects of heavy metals in combination with the effects of acid catalyzed transesterification were found to have a positive effect on the amount of methane produced with an average productivity of 105.89 mL g-COD-1 from the heavy metals contaminated LEA compared to the control microalgae biomass which produced 53.25 mL g-COD-1.
42
Bomfim, Nayane Cristina Pires. "Crescimento, tolerância e potencial fitorremediador de leucaena leucocephala em solo contaminado por cobre e ferro /." Ilha Solteira, 2020. http://hdl.handle.net/11449/192747.
Full textAbstract:
Orientador: Liliane Santos de CamargosResumo: As intensas atividades antropogênicas têm aumentado as concentrações de metais pesados no solo, por meio do uso excessivo de produtos químicos e do descarte inadequado e acúmulo de resíduos sólidos e líquidos, por exemplo, surgindo assim riscos de poluição do solo e corpos d’água. O desenvolvimento de tecnologias sustentáveis, efetivas e de baixo custo para recuperação de áreas contaminadas por metais pesados é de extrema necessidade. A fitorremediação é uma técnica, de baixo custo, que utiliza plantas na recuperação de solos contaminados por metais pesados. Espécies de leguminosas apresentam características favoráveis para crescerem rapidamente em solos degradados, o que é uma característica importante quando considera-se o potencial para fitorremediação destes contaminantes. Objetivou-se caracterizar a resposta fisiológica, determinar a tolerância e o potencial fitorremediador de Leucaena leucocephala aos metais cobre e ferro. O experimento foi conduzido em casa de vegetação, em delineamento inteiramente casualizado para ambos os metais. O solo foi tratado com cinco doses, além do controle (0, 100, 200, 300, 400 e 500 mg/dm3 solo), em sacos de mudas com capacidade para 2 dm3 de solo. Sementes de L. leucocephala foram semeadas diretamente no solo contaminado e cultivadas por 120 dias. Os parâmetros fotossintéticos, foram analisados; o material vegetal foi coletado e os tecidos foram separados, medidos e pesados para avaliação de crescimento. Teores de clorofila e carotenoide... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The intense anthropogenic activities have increased the concentrations of heavy metals in the soil, through the excessive use of chemicals and the improper disposal and accumulation of solid and liquid residues, for example, thus resulting in risks of pollution of the soil and water bodies. The development of sustainable, effective and low-cost technologies for the recovery of areas contaminated by heavy metals is extremely necessary. Phytoremediation is a technique that uses plants to recover soils contaminated by heavy metals. Legume species have favorable characteristics to grow quickly in degraded soils, which is an important characteristic when considering the potential for phytoremediation of these contaminants. The objective was to characterize the physiological response, to determine the tolerance and phytoremediation potential of Leucaena leucocephala to copper and iron metals. The experiment was carried out in a greenhouse, in a completely randomized design for both metals. The soil was treated with five doses, in addition to the control (100, 200, 300, 400 and 500 mg/dm3 soil), in seedling bags with a capacity of 2 dm3 soil. Leucaena leucocephala seeds were sown and cultivated for 120 days. The photosynthetic parameters were analyzed; the plant material was collected and the tissues were separated, measured and weighed for growth evaluation. Chlorophyll and carotenoid contents were quantified in the leaves. Nutrient contents in plants and soil were determined. The ... (Complete abstract click electronic access below)
Mestre
43
Guan, Dongming Loew Sabine Susanne. "Fitness, developmental stability, and germline mutation rates in white-footed mice (Peromyscus leucopus) chronically exposed to heavy metal contamination." Normal, Ill. : Illinois State University, 2007. http://proquest.umi.com/pqdweb?index=0&did=1414115231&SrchMode=1&sid=4&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1207663717&clientId=43838.
Full textAbstract:
Thesis (Ph. D.)--Illinois State University, 2007.Title from title page screen, viewed on April 8, 2008. Dissertation Committee: Sabine S. Loew (chair), Steven A. Juliano, Charles F. Thompson, Angelo P. Capparella, William L. Perry. Includes bibliographical references (leaves 143-173) and abstract. Also available in print.
44
Al, Sawai Abdulaziz. "Determination of heavy metal contamination in the surface sediments at Sohar Industrial Port (SIP) and the nearby coastal regions." Thesis, Cardiff Metropolitan University, 2015. http://hdl.handle.net/10369/7527.
Full textAbstract:
An increase of heavy metals in the natural environment, as a result of human development activities, may lead to further impacts on environment and human health. The project aim was to investigate the potential impact of heavy metal sources on the marine sediment at Sohar Industrial Port (SIP) and nearby coastal regions. SIP was established in 1999 and this is the first comprehensive evaluation of heavy metal pollution at the port. The research focused on the levels of Al, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V, Zn , Hg, As and Sn over a period of two years. The concentration of anions F, Br, Cl and SO4 in the sediment was also evaluated. The research has, based on published literature, evaluated the public and environmental issues at SIP and nearby regions area. A theoretical fingerprinting technique was used to establish sources of pollution in the SIP region using a combination of field data, laboratory analyses of samples and statistical modeling techniques. Results from the study indicate that concentration of heavy metals was significantly higher at the SIP than in the nearby coastal regions. The data indicated that Cd, Cr, Cu, Ni, Pb, Zn, Hg and As sediment concentrations exceeded levels for International Sediment Quality Guidelines (ISQG) values from USA, Canade, Holland, Australia and New Zealand . Heavy metals that exceed ISQG provide higher potential risks of contamination and may cause human health problems at the SIP and surrounding areas. Potential sources of pollution at SIP include petrochemical industries, various metal processing industries, cooling water outfalls, dust emissions from industries and open hazardous storage sites. Consideration needs to be given to the use of addition new technologies for cleaning of pollution in the environment around SIP. The project proposes development of policies and strategies to mitigate and prevent further sediment contamination at SIP and nearby regions.
45
Dumaresq, Charles G. Carleton University Dissertation Earth Sciences. "The occurrence of arsenic and heavy metal contamination from natural and anthropogenic sources in the Cobalt Area of Ontario." Ottawa, 1993.
Find full text
46
Otomo, Patricks Voua. "Stress responses of Eisenia andrei and Enchytraeus doerjesi (Oligochaeta) to combined effects of temperature and metal contamination." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/6900.
Full textAbstract:
Thesis (PhD)--Stellenbosch University, 2011.ENGLISH ABSTRACT: The terrestrial Oligochaete species Eisenia andrei and Enchytraeus doerjesi were exposed to different concentration series of Cd and Zn, both separately and in mixtures for 28 days in artificial OECD soil at 15, 20 and 25°C. At the end of the four week exposure period, survival and reproduction were assessed in E. doerjesi and survival, reproduction, biomass change, metal uptake and biomarker responses (MTT and comet assays) in E. andrei. Survival results for both E. andrei and E. doerjesi indicated that the lethality of Cd increased at higher temperatures, whereas the opposite was observed for Zn.Cadmium LC50 values were the highest at 15°C and the lowest at 25°C. In the Zn exposures LC50 increased with increasing temperature. Mixture results in both test organisms indicated that mixtures were less lethal than the metals separately. Effects of mixtures on survival, nonetheless, increased with increasing temperature. In the Cd experiment, reproduction in E. andrei was only recorded in the control treatments at the three temperatures investigated. However, the deleterious effect of Zn on the reproduction of both E. andrei and E. doerjesi decreased with increasing temperature and Zn EC50 for reproduction increased with increasing temperature. Results for exposures to mixtures indicated in both test organisms that the interaction between Cd and Zn were antagonistic. In both E. andrei and E. doerjesi, the effect of mixture exposures on reproduction decreased with increasing temperatures. The highest mixture EC50 values for reproduction were found at higher temperature. In E. doerjesi (using reproduction results in MixToxModules) Cd and Zn interactions were dose level dependent at the three temperatures investigated. Antagonism was the predominant interaction at lower mixture concentrations whereas synergism occurred at mixture concentrations equal to or higher than the mixtures’ EC50 values. Biomass loss increased with increasing temperature in the Cd exposures (p 9 0.05) but not in the Zn exposures in E. andrei. In this species mixture results indicated antagonistic interactions between Cd and Zn at all temperatures investigated. The deleterious effect of mixtures on the biomass of E. andrei increased with increasing temperature. When Cd and Zn interactions were further investigated in E. andrei (using biomass results in MixToxModules) it was found that they were dose level dependent at the three temperatures investigated. Antagonism was the predominant interaction at lower mixture concentrations whereas synergism occurred at mixture concentrations higher than the mixtures EC50 values. The assessment of metal uptake in E. andrei revealed a temperature dependent Cd uptake with higher Cd body burdens occurring at higher exposure concentrations and temperatures (p ≤ 0.05). In the case of Zn, although uptake was lower at higher temperature, there was no statistical difference in uptake between exposure concentrations and between temperatures. Mixture results however indicated that in mixture exposures less Cd was accumulated by E. andrei than in single Cd exposures (p ≤ 0.05). Inversely, in mixture exposures more Zn was accumulated by E. andrei than in single Zn exposures (p ≤ 0.05). Biomarker studies revealed that Cd and Zn were both cytotoxic and genotoxic whether in single or mixture exposures. Factorial ANOVA analyses of the effects of temperature and metals on the reduction of MTT by E. andrei indicated that temperature rather than the metals was the most important factor controlling mitochondrial activity (p < 0.001). In both Cd and Zn exposures significant deleterious metal effects on mitochondrial processes were found to increase with temperature (p ≤ 0.01). Mixture exposures indicated decreasing cytotoxicity with increasing temperature (p ≤ 0.05) and possible antagonism between Cd and Zn at cellular level. Results of the comet assay showed that the genotoxic profile of Cd was the opposite of the genotoxic profile of Zn. Cd was less genotoxic at lower temperature and increasingly deleterious at higher temperature while Zn was more genotoxic at lower than higher temperature (p ≤ 0.05). The results of mixture exposures indicated decreasing mixture genotoxicity with increasing temperature and suggested that the interactions between Cd and Zn at molecular level were probably antagonistic.
AFRIKAANSE OPSOMMING: Eisenia andrei en Enchytraeus doerjesi is aan verskillende konsentrasiereekse van Cd en Zn, afsonderlik en in mengsels, vir 28 dae in OECD kunsmatige grond onderskeidelik by 15, 20 en 25°C blootgestel Die volgende eindpunte is aan die einde van die vier weke blootstellingsperiode gemeet: oorlewing en voortplanting (by E. doerjesi) en oorlewing, voortplanting, biomassaverandering, metaalopname, MTT en komeettoetse (by E. andrei). Oorlewingsresultate by beide E. andrei en E. doerjesi het getoon dat toenemende temperatuur die letale toksisiteit van Cd laat toeneem terwyl die teenoorgestelde waar was vir Zn. By die Cd blootstellings was die LK50 waardes die hoogste by 15°C en die laagste by 25°C. By die blootstellings aan Zn het die LK50 waardes toegeneem by hoër temperatuur. Resultate by die mengsels by beide toestspesies het aangetoon dat die mengsels minder letaal was as die afsonderlike metale. Effekte van mengsels op oorlewing het nietemin toegeneem met toenemende temperatuur. By die Cd blootstellings is voortplanting slegs by die kontroles en in die geval van E. andrei by die drie onderskeie temperature ondersoek. Die nadelige uitwerking van Zn op voortplanting by beide E. andrei en E. doerjesi het afgeneem met stygende temperatuur en die Zn LK50 vir voortplanting het toegeneem met toenemende temperatuur. Resultate van die blootstellings aan mengsels het getoon dat die wisselwerking tussen Cd en Zn by beide spesies antagonisties was. By beide spesies het die invloed van die mengsels op voortplanting afgeneem met stygende temperatuur. Die hoogste mengsel LK50 waardes vir voortplanting is by hoër temperature gevind. By E. doerjesi was Cd en Zn wisselwerkings by blootstelling aan mengsels (voortplantingsresultate ondersoek deur van MixToxModules gebruik te maak) dosisvlak verwant by die drie temperature wat ondersoek is. Antagonisme was die oorwegende wisselwerking by laer mengsel konsentrasies terwyl sinergisme voorgekom het by mengsel konsentrasies gelyk aan of hoër as die LK50 waardes van die mengsels. In die geval van die Cd blootstellings by E. andrei het biomassaverlies toegeneem met toenemende temperatuur (p ≤ 0.05) maar nie by die Zn blootstellings nie. Resultate van blootstellings aan mengsels het getoon dat die uitwerking van mengsels op die biomassa van E. fetida toegeneem het met toenemende temperatuur. By die verdere ondersoek van Cd en Zn wisselwerkings, waar gekyk is na dosis verhouding of dosisvlak antagonisme (deur van biomassa resultate in MixToxModules gebruik te maak), is gevind dat Cd en Zn wisselwerkings dosisvlak afhanklik was by die drie temperature wat ondersoek is. Antagonisme was die oorwegende wisselwerking by laer mengselkonsentrasies terwyl sinergisme voorgekom het by mengselkonsentrasies hoër as die mengsel EK50 konsentrasies. Die bepaling van metaalopname deur E. andrei het ’n temperatuurafhanklike opname van Cd getoon met hoër Cd liggaamskonsentrasies by hoër blootstellingskonsentrasies en temperature (p ≤ 0.05). Alhoewel Zn opname laer was by hoër temperatuur was daar geen statisties betekenisvolle verskille in opname tussen blootstellingskonsentrasies of temperature nie. Die bepaling van metaalopname by wurms wat aan mengsels blootgestel is, het getoon dat minder Cd deur E. andrei opgeneem is as waneer die wurms aan Cd as enkelmetaal blootgestel is (p ≤ 0.05), Daarteenoor het die teenoorgestelde gebeur in die geval van Zn, Meer van die metaal is opgeneem wanneer E. andrei aan mengsels blootgestel is as aan die enkelmetaal. Biomerkerstudie het getoon dat Cd en Zn beide sito- en genotoksies kan wees ongeag of dit as enkelmetale of in mengsels toegedien is. Faktoriale ANOVA analises van die effekte van temperatuur en metale op die verlaging van MTT by E. andrei het getoon dat temperatuur ’n belangriker faktor was as metaalbesoedeling by die kontrole van mitochondriale aktiwiteit. (p ≤ 0.001). By beide Cd en Zn blootstellings was daar in elk geval statisties betekenisvolle metaaleffekte op mitochondriale prosesse met toename in temperatuur (P ≤ 0.01). By blootstellings aan mengsels is gevind dat sitotoksisiteit afgeneem het met toenemende temperatuur (p ≤ 0.05) asook ’n moontlike antagonisme tussen Cd en Zn op sellulêre vlak. Resultate van die komeettoets het getoon dat die genotoksiese profiel van Cd die teenoorgestelde was as die van Zn. Cd was minder genotoksies by laer temperature en meer en meer skadelik by hoër temperature terwyl Zn meer genotoksies was by laer as by hoër temperature (p ≤ 0.05). Die resultate van blootstlling aan mengsels het laer genotoksisiteit getoon met toename in temperatuur. Dit dui daarop dat wisselwerkings tussen Cd en Zn op molekulêre vlak moontlik antagonisties was.
47
Blackmore, Graham Ralph. "The importance of feeding ecology in investigating accumulated heavy metal body burdens in Thais clavigera (KÜSTER) (mollusca:neogastropoda: muricidae) in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31238129.
Full text
48
Seelsaen, Nida Civil & Environmental Engineering Faculty of Engineering UNSW. "Development of an integrated approach to understanding, managing and designing strategies and recycled organics filtration treatment system to control regional heavy metal contamination of stormwater." Publisher:University of New South Wales. Civil & Environmental Engineering, 2007. http://handle.unsw.edu.au/1959.4/43900.
Full textAbstract:
Urban stormwater runoff is recognised as a substantial source of heavy metal contamination, which adversely impacts on water quality of regional receiving waterways. Conventional treatment of urban runoff mostly involves a filtration system using sand to retain particulate matters. Sand provides limited sorption of dissolved metals and the inclusion of commercial sorbents to these treatment systems is not cost effective due to the concentration of dissolved metals in the runoff. Recycled organic materials are by-products or waste from industrial or agricultural operations, and could be alternative low cost sorbents for stormwater treatment systems. The use of recycled sorbents also provides added value to the waste materials and reduces landfill disposal. The research explores the application of compost, zeolite, ash, and recyclable waste in urban runoff treatment, especially for dissolved metal removal. The research combines the two aspects of experimental studies and management analysis to develop a holistic approach to heavy metal control in urban stormwater systems. Experimental results of batch sorption test show that compost is suitable for removing dissolve copper in stormwater treatment. The comparison of the different mixing ratios between compost and glass beads in column test evaluates the optimum mixing sorbent and performance over a long period for copper removal. Substance Flow Analysis (SFA) of copper has been performed in the Upper Parramatta River Catchment, Sydney to identify the sources of copper associated with runoff, effect of using waste material such as compost in urban stormwater treatment and the copper load in urban stormwater runoff. This case study shows the relationship between copper input, copper stock, sorbent type and urban stormwater quality control in the system boundary of the catchment. Different scenarios of source control are evaluated to control copper load from the different sources. Source control focusing on roads and vehicles is the most effective copper control strategy. The combination of source control and stormwater treatment reduces copper in stormwater and receiving water. The thesis applies the analysis from SFA and experimental results to derive both a regional system-wide solution with source control, and an improved design of stormwater treatment for heavy metal removal using recycled organics.
49
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.
Full text
50
Nguyen, Thi Thu Hien. "Risk assessment of heavy metal contamination concerning residents living in the vicinity of the Cho Dien lead/zinc mine, Vietnam." 京都大学 (Kyoto University), 2012. http://hdl.handle.net/2433/161007.
Full text