Dissertations / Theses on the topic 'Trace metals'
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1
Kharnoob, H. H. "Trace metals as pollutants." Thesis, University of Bristol, 1986. http://hdl.handle.net/1983/4bf15cd4-d321-4b19-8b18-fb30c51e6786.
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Hurford, Simon Ronald. "Speciation and trace metals." Thesis, Cardiff University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.276927.
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Voigt, Astrid. "Bioavailability of trace metals to plants." Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=19561.
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Soil quality guidelines are currently based on total trace metal loads. There is a need to define indices of bioavailability to allow reasonable predictions for plant metal uptake and toxicity in soils. Trace metal toxicities to plants often correlate best with free metal ion activities. The first objective was to develop a plant bioassay that is sensitive to trace metals at concentrations realistic for soils. The root elongation of lettuce Lactuca sativa 'Buttercrunch' was used as toxicological endpoint. This endpoint was sensitive and reproducible to environmentally relevant concentrations of Cd, Cu, Ni, Pb and Zn. The second objective was to test whether free metal ion activities are constant predictors of metal toxicities in synthetic solutions and in soil extracts that differ in their concentrations of cations and ligands. The root elongation assay was used to test this hypothesis. In synthetic solutions, the rhizotoxicity of Cd, Cu, Ni, Pb and Zn decreased with increasing Ca and H concentrations. This could not be explained with the effect of higher cationic concentrations on root growth or on solution speciation. It was concluded that Ca and H inhibited the rhizotoxicity of all metals tested. The rhizotoxicity of Cu and Cd was further examined in soil extracts. Both metals became less rhizotoxic at higher H and dissolved organic matter concentrations. The rhizotoxicity endpoints from the experiments in synthetic solution were used to develop parameters for a Biotic Ligand Model (BLM) for Cd, Cu, Ni, Pb and Zn. The BLM accounts for solution speciation and interprets cationic inhibition of rhizotoxicity as competition of metals with Ca and H for potential sites of rhizotoxicity. The BLM predicted metal rhizotoxicity better than the free metal ion activity in synthetic solutions and in soil extracts. Different models were tested against literature rhizotoxicity data for metals at different Ca and H concentrations. Predictions for metal rhizotoxicity given by BLM, Gouy-Chapman-Stern model and Freundlich equation model were compared with predictions based on free metal ion activities in solution. The BLM predicted rhizotoxicity most accurately. The BLM seems promising for predictions of metal toxicity and metal bioavailability in soils to support site-specific environmental risk assessments.
4
Im, Po. "Trace metals in North Atlantic precipitation." Thesis, University of East Anglia, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.290230.
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Al-Attar, A. F. "Selenium and trace metals as pollutants." Thesis, University of Bristol, 1987. http://hdl.handle.net/1983/1858b91b-362e-422f-b91c-84aa44e23e90.
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Witt, Melanie Louise Inez. "Studies of trace metals in the atmosphere." Thesis, University of East Anglia, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399841.
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Atmospheric deposition of trace metals to the oceans is investigated in this study with analysis of aerosol samples collected during cruises from the UK to the Falklands and from South Africa to Australia. The readily soluble concentrations of Cu, Ni, Ba, Zn, Cd and Pb were measured in the aerosols, along with crustal elements and major ions to evaluate the sea spray and crustal contributions. Air mass back trajectories suggested most of the aerosol samples had spent several days over the ocean prior to collection. The highest metal concentrations were observed in aerosols close to South Africa, Australia and major cities in South America, although these concentrations were lower than had been reported previously in the literature. Apart from Ba, which had a major crustal source, the trace metals were enriched above both crustal and sea salt sources in most samples including some collected 1000s of km from emission sources. The mean trace metal concentrations in the remote Indian Ocean were lower than those measured in the Atlantic Ocean. Even lower concentrations are reported in the literature for the remote Pacific Ocean. The dry deposition rates calculated from the aerosol data were similar for the North and South Atlantic and South Indian Oceans reflecting the increase in industrialisation and atmospheric emissions in the southern hemisphere. Lead isotope ratios were measured in the aerosols with Multi Collector- Inductively Coupled Plasma - Mass Spectrometry. These results showed real differences in the isotopic ratios of aerosols collected in different marine regions and enabled the source of remote samples to be tentatively identified. Copper complexation was investigated in rain samples collected in Norwich, UK, and during the cruises. Humic material was also investigated as a potential organic ligand. The complexation was measured with Chelex resin, Sep-Pak columns and Adsorptive Cathodic Stripping Voltammetry with tropolone as a competing ligand. Strong organic complexation was observed in semi-urban and marine rain samples with conditional stability constants between 10" and 1014. Model solutions of copper and humic matter found organic complexes of a similar strength to those observed in the rain samples suggesting humic material as a potential source. A large proportion of the copper in the rains was associated with strong organic complexes over the pH range 4-8 in both filtered and unfiltered rain samples suggesting complexation is an important process both in the atmosphere and on arrival to oceans.
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Williams, Mark Richard. "Particulate trace metals in British coastal waters." Thesis, University of Plymouth, 1995. http://hdl.handle.net/10026.1/1934.
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Key processes affecting the transport of particulate trace metals in the coastal waters of the Irish and North Seas have been examined. Sample collection and experimentation was carried out on board R.R-S. Challenger in January 1992 (Irish Sea) and in December 1992 and November 1993 (North Sea). Particulate samples were digested in IM HCI and the concentrations of Ca, Cd, Co, Cu, Fe, Mn, Pb and Zn were determined, together with the 206/207Pb isotopic ratio. In the North Eastern Irish Sea the concentrations of suspended particulate trace metals were affected significantly by tidal processes, such that ebb tides transport particles of higher trace metal concentrations from the nearshore, while flood tides transport metal-depleted particles from offshore. This tidally-induced transport was confirmed by complementary 206/207Pb analyses, which showed the value of this technique in particle tracing. In the North Sea suspended particulate trace metal concentrations were higher adjacent to industrialised estuaries and high Pb concentrations were found m the Tyne/Tees region (in the range 200 - 340 ug g-1), in combination with low 206/207Pb suggesting an anthropogenic origin. Estimated fluxes of trace metals from the Humber Estuary to the North Sea were relatively small compared to the PARCOM inputs to the estuary. There was little evidence of interannual variability in these fluxes compared to those obtained in December 1988. Samples of end-members of the Humber Plume particle mixing series (estuary and cliffs) were used in radiochemical uptake studies, which indicated a response time of about 1 day for 109Cd, 137Cs and 65Zn to reach a new equihbrium. When the end-members were mixed together in various proportions they showed the uptake of 109Cd and 54Mn behaved non-additively. Settling of suspended particulate trace metals in the plume region was examined in unique experiments involving stable and radioisotopes. It was shown that trace metals were preferentially associated with different settling fractions. Lead was associated with slow settling particles whereas Cu was associated with particles settling more rapidly. The results presented in this dissertation allowed the development of a conceptual model for fine sediment transport for trace metals, which could be interfaced with established hydrodynamic models.
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Dangolle, Champa D. P. "Some aspects of trace analysis of metals." Thesis, Queen's University Belfast, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318885.
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Liu, Yang Ping. "Modelling estuarine chemical dynamics of trace metals." Thesis, University of Plymouth, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360359.
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Martin, William R. "Transport of trace metals in nearshore sediments." Thesis, Massachusetts Institute of Technology, 1985. http://hdl.handle.net/1721.1/15270.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1985.MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN.
Vita.
Bibliography: leaves 292-301.
by William R. Martin.
Ph.D.
11
Ohnemus, Daniel Chester. "The biogeochemistry of marine particulate trace metals." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/87512.
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Thesis: Ph. D., Joint Program in Chemical Oceanography (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2014.Cataloged from PDF version of thesis.
Includes bibliographical references.
Marine particles include all living and non-living solid components of seawater, representing an extremely dynamic and chemically diverse mixture of phases. The distributions of these phases are poorly constrained and undersampled in the oceans, despite interactions between living organisms and non-living minerals having central roles within many globally relevant biogeochemical processes. Through a combination of method development, basin-scale particulate collection and analyses, modeling, and field experiments, this thesis examines both the distributions of marine particulate trace metals and the underlying processes-inputs, scavenging, vertical and horizontal transport, and biotic uptake-in which marine particles participate. I first present the results of an intercalibration exercise among several US laboratories that analyzed filtered particles on shared polyethersulfone filters. We use inter-lab and intra-lab total elemental recoveries of these particles to determine our state of our intercalibration (by Daniel Chester Ohnemus.
Ph. D.
12
Morford, Jennifer Lynn. "The geochemistry of redox-sensitive trace metals /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/8508.
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Tejowulan, Raden Sri. "Remediation of trace metal contaminated soils." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0030/NQ64679.pdf.
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Manton, Graham. "The determination of trace metals in mixed matrices." Thesis, University of Central Lancashire, 1993. http://clok.uclan.ac.uk/20083/.
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Investigations into the determination of < ppb levels of Fe, Pb and Si0 2 in high purity water and Fe and Pb in buffer reagent solution, employed in chemical detector systems, have been carried out by employing the technique of electrothermal atomization - atomic absorption spectrometry (ETA-AAS). Various experimental parameters have been optimized and procedures developed for the relevant determinations. These procedures have been compared and evaluated statistically using F-test and t-test criteria. The preconcentration of Fe and Pb from high purity water using various adsorptive bubble (flotation) techniques (co-precipitation, ion-flotation and solvent sublation) has been studied and various experimental parameters for each technique investigated. The techniques have been compared with the relevant ETA-AAS procedures and the possible use of the flotation techniques for pre-concentration of trace metal ions discussed. Direct-slurry, direct current plasma (DCP) spectrometry, has been studied for possible determination of Cu, Cr and Ag chemical impregnants on activated, granular, carbons used in chemical defence protection systems. Analytical parameters have been investigated and optimized using both aqueous element and carbon slurry solutions. The DCP parameters for the determinations have been optimized using both Simplex and Univariate search procedures. Results indicated that requisite plasma optima were similar for both aqueous and carbon slurry solutions which showed it to be possible to use aqueous element solutions for calibration of the DCP for carbon slurry analyses. Procedures have been developed and compared statistically with a standard dry ashing/fusion procedure and with a wet oxidation method employing a high pressure asher. Results showed there to be no significant differences between the direct slurry method and the comparison procedures.
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Nguyen, Ngoc Trang, and not supplied. "Biomonitoring of Trace Metals in the Saigon River." RMIT University. Applied Sciences, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080102.144317.
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This study investigated trace essential metals (Cu, Zn and Cr) and non-essential metals (Pb, Cd and Hg) in water, sediment and tissues of water spinach, snake head fish and swamp eel from the Saigon River. Sampling was conducted from January to December 2004 at three sites. Three water and sediment samples, edible parts of twenty water spinach (Ipomea aquatica) samples (leaves and stems), twenty snake head fish (Channa striata) and twenty swamp eels (Monopterus albus) were collected at each site. Water, sediment and biota tissues were analysed for Cu, Zn, Cr, Pb, Cd and Hg following the method of USEPA, AOAC and NFTA. Results showed that Cu, Zn, Cr, Cd and Hg in water from the river was not higher than the maximum permitted level for protection of aquatic life by the national standards while the average Cu concentration in sediment was found to be close to the Effects range- low value and within the slightly polluted range (25- 50 ìg.g-1 dry weight). The results also showed that the river sediment was considered to be contaminated by Zn and Hg in comparison with contaminated sites in Australia and in Thailand. In water spinach, no Cu deficiency was found but Zn was accumulated. No accumulation of Cr, Cd and Hg was revealed but Pb was detectable. The results indicated that snake head and eel may have Cu deficiencies. Pb and Hg were found to be bioaccumulated in the muscle of snake head and eel at some sites on some occasions, but the levels were small. The results showed that metal in sediment liver of snake head muscle of snake head and eel water. The metals in water spinach decreased in the order Zn Cu Cr Pb Cd and Hg; in snake head the metal concentrations decreased in the order Zn Cu Cr PbHgCd and in eel as Zn Cu Cr PbCd and Hg. The ANOVA test showed no significant relationship between metals in the water and sediment and biota. Therefore it was concluded that the metals in the selected biota samples did not reflect the metals in the environment. The essential metals Cu, Zn and Cr were found to decrease at the end of the dry season and then increase at the end of the rainy season. The seasonal variations of metals in the river and biota maybe a result of the change of temperature in the area and the need for essential metals in the reproduction of fish. The results of this study clearly demonstrates that water spinach, snake head fish and swamp eel are not potential bio-indicators for metals in the Saigon River since they did not reflect concentrations of metals in their environment. It was also concluded based on consumption rates that water spinach, snake headfish and eel from the Saigon River do not present any potential health risk to consumers. However, attention should be paid to controlling the load of pollutants entering the river to avoid such risks and future problems.
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Cook, Nicola. "Bioavailability of trace metals in urban contaminated soils." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0007/NQ44391.pdf.
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Cook, Nicola. "Bioavailability of trace metals in urban contaminated soils." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34934.
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There are two main components to the research: the theoretical and the experimental. Chapter 2 contains an analysis of the state of soil quality guidelines and the scientific methods used to determine them. A number of recommendations to improve soil quality criteria for trace metals are offered including the importance of considering bioavailability and the need to use realistic conditions, trace metal sources and organisms.A critical review of the literature dealing with predicting the availability of trace metals to plants is presented in Chapter 3. We found little agreement among hundreds of similar studies which relate plant metal uptake to the amount of metal extracted by selective chemical dissolution procedures. An extensive summary of the data shows clearly that the extraction methods are not widely applicable. Differences between individual soils, their metal retention capacities, as well as plant factors and environmental conditions contribute to the variability of the results. Alternative ways of assessing bioavailability are suggested.
The experimental component of the thesis focuses on the availability of trace metals to plants. In Chapter 4 the uptake of Cu from different soil pools was examined and the free metal ion (Cu2+) was found to be the best predictor of uptake by lettuce (Latuca sativa cv. Buttercrunch), ryegrass (Lolium perenne cv. Barmultra) and radish (Raphanus sativus cv. Cherry Belle).
In Chapters 5 and 6 we examined the effect of low-cost in-situ treatments on the availability of metals to plants in greenhouse and field experiments. Synthetic zeolites, P amendments, organic matter and clean soil were used and their effect on the bioavailability of Cd, Cu, Pb, Ni and Zn evaluated. The plants for the experimental work were lettuce and perennial ryegrass. Only the clean soil treatment was consistently effective in reducing the concentration of metals in the plant. We also wanted to determine whether the trace metals in the plant tissue came from the soil or from direct deposition of pollutants on the leaf surfaces. We found little evidence that metals in plants were a result of atmospheric fallout.
A method for the accurate analysis of total metal concentrations in a range of contaminated soils including those containing oil and grease was developed (Chapter 7). For this research the trace metals of concern are Cd, Cu, Ni, Pb and Zn---all commonly found in urban/industrial soils. The proposed method using HNO3/HClO4 has several advantages over the common HNO3/H2O2 procedure. We were able to digest larger soil samples and hence the final concentration of trace metals was usually in the range for analysis by inductively coupled plasma atomic absorption spectrometry or flame atomic absorption spectrometry.
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Hardy, Simon Andrew. "The determination of trace metals by capillary electrophoresis." Thesis, University of Plymouth, 2000. http://hdl.handle.net/10026.1/2136.
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The development of a capillary electrophoresis (CE) method for the determination of inorganic and organo mercury species as their dithizone sulphonate (DzS) complexes using coated capillary columns is described. The complexes were pre-formed before injection and detection was by direct measurement of the visible absorbance of the complexes. Dithizone sulphonate was used in place of cysteine to separate methyl mercury in the final stage of a simplified Westoo extraction procedure. The method was than applied to the analysis of methyl mercury in a crab and several fish meat samples. Good quantitative performance is demonstrated by spiking experiments and analysis of DORM-1 certified reference material. The method was found to be very sensitive and a detection limit of 2 µg Kgˉ¹ could be achieved for a l0g sample of fish flesh. A CE method for the determination of uranium (VI) as the arsenazo III complex was developed and the effect of interfering metal ions was studied. The calibration was found to be linear from 10 µg 1ˉ¹ -10 mg 1ˉ¹ using gravity injections and a detection limit of less than 1 µg 1ˉ¹ was achieved with electrokinetic injection. A study was made of injection techniques and their applicability to the enhancement of sensitivity in synthetic standards and environmental samples. The effect of capillary surface chemistry on the peak shape of the migrating uranyl-arsenazo III was also studied using fused silica capillaries with two different internal coatings and three polymeric capillaries. A study was also carried out on the construction and investigation of a post-capillary reactor for the determination of trace metals by UV-Vis absorption after formation of intensely absorbing coloured complexes. The main principle of operation was based on the infusion of the colorimetric reagent into a small 50µm gap between the separation capillary and the reaction capillary. The gap was enclosed by a permeable membrane and the flow of reagent was achieved by the application of a slight pressure to the post-capillary reactor cell. Two reagents were studied, namely, xylenol orange (XO) and 4 (2-pyridylazo) resorcinol (PAR), for the separation and detection of copper (U), cadmium (II), cobalt (II), nickel (II), zinc (II), and manganese (II). Lead (II) was also included in the XO system.
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Allus, Mahmoud A. "Thallium and trace metals as pollutants : chemometric studies." Thesis, University of Bristol, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294095.
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Ahner, Beth A. (Beth Allyson). "Phytochelatin induction by trace metals in marine microalgae." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/35995.
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Mann, Elizabeth Lowell 1966. "Trace metals and the ecology of marine cyanobacteria." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/9385.
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Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and Woods Hole Oceanographic Institution), 2000.Includes bibliographical references.
The marine cyanobacteria Synechococcus and Prochlorococcus are important primary producers in oligotrophic oceans. The abundance and cell division rates of these cyanobacteria can be influenced by trace metals such as iron and copper. Iron is an essential trace metal that is present in the high nutrient, low chlorophyll waters of the equatorial Pacific in extremely low concentrations. When these waters were enriched with iron, Prochlorococcus chlorophyll fluorescence per cell and cell size increased. Cell division rates doubled inside the iron enriched patch and reached two divisions per day in bottle incubations with additional iron, indicating that Prochlorococcus were iron limited. However, cell numbers remained constant because mortality rates nearly doubled after the addition of iron and essentially matched the increases in cell division rate. Trace metals can also be present in toxic, rather than limiting concentrations. Copper is an essential trace element that is toxic to cyanobacteria in pM quantities. In stratified water columns in the Sargasso Sea, free Cu2+ concentrations are high in the mixed layer (up to 6pM) and most of the Prochlorococcus population is located below the thermocline where free Cu2+ concentrations are lower. The distribution of Synechococcus is more uniform with depth. Prochlorococcus isolates were more sensitive to copper than Synechococcus, but members of the low chi BIA (high light adapted) ecotype were less sensitive than strains with high chi BIA ratios (low light adapted). In the field, the in situ concentration of free Cu2+ had a strong effect on the copper sensitivity of Prochlorococcus. Net growth rates were substantially reduced when Prochlorococcus from environments where the in situ free Cu2+ was low (deep mixed layers and below the thermocline in stratified water) were exposed to copper. Prochlorococcus in shallow mixed layers where in situ Cu2 + was high were less sensitive to copper and may have been members of the copper resistant low chi B/ A ecotype. Synechococcus were relatively copper resistant across a range of environments. These data are consistent with the hypothesis that ambient copper levels may influence the relative abundance of Prochlorococcus and Synechococcus in the Sargasso Sea.
by Elizabeth Lowell Mann.
Ph.D.
22
Mao, Lingchen. "Lability and solubility of trace metals in soils." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/14058/.
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The continuing need for improved assessment of risk from heavy metal contamination of the environment has prompted scientific interest in quantifying and predicting metal solubility, ‘lability’ and bioavailability. This has led to the development of new techniques to fractionate and speciate trace metals in soils. The objectives of the current study were to increase understanding of the effects of (i) soil properties, (ii) contaminant source and (iii) contact time on metal lability and solubility in soils. Multi-stable isotope dilution (ID) methods were used to determine the lability (E-values) of Ni, Cu, Zn, Cd and Pb in soils, alongside more traditional approaches employed for metal fractionation including single and sequential extraction procedures. Most of the work was undertaken using (i) archived soils amended by metal salts (MA soils; n=23) and (ii) topsoils collected from Nottingham, Wolverhampton and London (Urban soils; n=100). The resulting data was used first to quantify the factors affecting trace metal lability in the MA soils using a logistic (S-shape) model which described metal E-value primarily as a function of soil pH with secondary influences from other soil properties. It was apparent that mineral oxides were important fixation phases for Ni, Zn and Cd while Pb was strongly affected by organic matter in soils. This model, parameterised on soils contaminated originally by metal nitrate solution, was then applied to the Urban soils to reveal the extent to which contaminant source still controlled metal lability. A further investigation of the long-term effect of metal source on metal lability was pursued through a third dataset of rural roadside soils (n=42) which had received Pb mainly from petrol-derived and geogenic sources, defined by their isotopic signature. It was demonstrated that petrol-derived Pb remained more labile than Pb from the parent material, despite decades of contact, although both petrol-derived and geogenic Pb contributed to both the labile and non-labile fractions. In a fourth dataset, soils that had received Pb from sewage sludge amendment (n=16), the co-existence of high phosphate concentration from sewage sludge limited the magnitude and range of Pb lability, probably through formation of Pb-phosphate minerals. No consistent agreement was found between labile fraction of Pb and any single sequential extraction (SEP) fraction in all soils contaminated by Pb from multiple sources. Both empirical equations (extended Freundlich) and mechanistic models (WHAM-VII) were used to predict metal solubility in the MA and Urban soils. The advantage of using E-values (ME) over metal extractable by dilute nitric acid (MExt) to represent the reactive metal fraction in predictions of solubility was very clear for WHAM-VII, but not for the ‘locally parameterised’ Freundlich model. This was almost certainly due to the strong links between pH and E-value becoming subsumed into the coefficient nominally describing the direct influence of pH on metal solubility in the extended Freundlich equation. However, overestimation of the solution concentration from WHAM-VII was observed for all five metals, and strongly correlated with soil pH. Fractionation information from WHAM suggested that the source of the model’s underestimation of metal binding most likely lay with errors in the description of metal binding by Fe and Mn oxides for Ni, Zn and Cd and humic acid (HA) for Cu. An additional factor is the absence of potential binding phases in the WHAM model, such as particulate CaCO3, and the greater diversity of active adsorbents in soils at high pH values. WHAM is based on the assumption that all metal bound to HA is labile. However, in the current study, ‘non-labile’ Cu, Zn and Pb fractions were observed in suspensions of HA extracted from grassland and peat soils. These were quantified by measuring metal E-values and EDTA-extraction of HA-bound metal using size-exclusion chromatography (SEC) coupled to ICP-MS to separate free and HA-complexed metal forms. Evidence of time-dependent metal fixation by HA was found for all three metals during the course of a 40 and 160 day incubation study. The proportion of non-labile Cu held by HA could be 40-50%. The presence of a non-labile metal fraction held by HA may substantially invalidate the assumption of reversible equilibrium which is central to all current geochemical models of metal binding to humic substances.
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Rusiecka, Dagmara. "Biogeochemistry of trace metals in European shelf seas." Thesis, University of Southampton, 2018. https://eprints.soton.ac.uk/425510/.
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Shelf seas are considered an important source of trace metals (TMs) to the open ocean. However, the processes controlling distributions of dissolved TMs (DTMs) in shelf seas, their seasonal variability and the mechanisms facilitating off-‐shelf transport to the open ocean are not well constrained. Reported here is the first seasonal study of the DTMs, cadmium (DCd), zinc (DZn), nickel (DNi) copper (DCu) manganese (DMn), cobalt (DCo), aluminium (DAl) and lead (DPb) and their contrasting biogeochemical behaviours in the Celtic Sea continental system. Strong correlations (r2 = 0.91 – 0.97, n = 454) between nutrient-‐like metals (DCd, DZn, DCu, DNi, DCo (surface waters only)) and macronutrients (phosphate (PO43-‐) and silicic acid (SiO44-‐) were observed over all seasons (autumn, spring and summer) indicating that biological uptake in the euphotic zone and remineralization of sinking phytoplankton debris in deeper waters form key controls on their distributions. The correlation between DAl and PO43-‐ (r2 = 0.80) and SiO44-‐ (r2 = 0.85) in the upper waters (< 1500 m depth) mimicked the DZn distributions, which was a surprising observation and requires further investigation. Variable DTM ratios relative to PO43-‐ were observed across different seasons in off-‐shelf surface waters and for DCd and DZn (full depth profiles) across the continental shelf. Observations from the Celtic Sea region suggest the influence of distinct water masses, phytoplankton community structure and potentially metal specific biogeochemical processes, on DTMs distributions on a seasonal time-‐scale. Dissolved Co and Mn were more strongly influenced by scavenging and sedimentary inputs. Vertical distributions of DMn showed a typical scavenged type behaviour with enhanced surface waters concentrations from atmospheric inputs combined with photochemical stabilisation. Enhanced DMn and DCo concentrations were observed close to slope sediments and extended away from the shelf at intermediate depths. These observations were related to suspended sediments as indicated by increased signals in turbidity and short-‐lived 223Ra and 224Ra isotopes (tracers of sediment inputs). This implies that resuspended shelf or slope sediments can act as a source of DMn and DCo that can be transported to the adjacent open ocean. The full depth relationship of DCo with PO43-‐ revealed a shift in dominant biogeochemical processes controlling DCo vertical distributions in the study region. While biological uptake and remineralization were dominant processes in surface waters, as indicated by a strong correlation with PO43-‐ (r = 0.89), a gradual decoupling of DCo from PO43-‐ at intermediate depths was suggestive of progressive scavenging and less pronounced remineralization and a significant negative correlation (r = -‐0.72) in deeper waters (> 1500 m depth) was suggestive of scavenging as the dominant process at these depths. Beside the natural sources of DTMs, anthropogenic activities have resulted in enhanced DTMs emissions to the environment over the past centuries. Lead has a strong anthropogenic signal as a result of the combustion of leaded fuel and coal. Presented here is the first combined DPb, labile Pb (LpPb) and particulate Pb (PPb) distributions from the Celtic Sea since the phasing out of leaded fuel in Europe. Concentrations of DPb in surface waters have decreased by 4-‐fold over the last four decades. Nevertheless, a distinct anthropogenic Pb signal was observed from the Mediterranean Sea at intermediate depths, showing that Pb can transported over long distances (>2500 km). Benthic DPb fluxes exceeded the atmospheric Pb fluxes in the region, indicating the importance of sediments as a contemporary Pb source. A strong positive correlation between DPb, PPb and LpPb indicates a dynamic equilibrium between the phases and the potential for particles to ‘buffer’ the DPb pool. This study highlights the requirements of continuing efforts in regulating Pb emissions but also of detailed seasonal TMs studies in coastal systems in future. Results reported here provide insights into distinct biogeochemical processes in oceanographically dynamic shelf seas and demonstrates the potential of Pb in constraining ocean circulation patterns.
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Trapp, John Michael. "Chemistry of Iron and Other Trace Elements in Trade Wind Aerosols and Precipitation." Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_dissertations/323.
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The atmospheric transport of various substances from the continents to the oceans plays an important role in biogeochemical processes. Trace metals, iron in particular is of great interest as its availability regulates the growth of phytoplankton over large areas of the ocean. This dissertation focuses on examining and characterizing the factors that affect the solubility of trace metals in Miami and Barbados aerosols and precipitation, in particular species that could play a role in surface seawater biogeochemistry (Fe and trace metals such as Al, V, Cr, Mn, Cu, Co, Ni, Zn, As, Tl, Ba, Cd, Pb, Th, Ti, Zr, and REE's). To enable this study existing methods of colorimetric spectroscopic and inductively coupled plasma mass spectrometry analysis were improved and modified. This dissertation examines several issues related to source inputs: 1.) Are single spot sources within the North African dust source distinguishable after long transport by their bulk metal composition and thus important in the characteristics of individual mineral dust samples? 2.) What is the temporal variability and controlling factors in trace metal solubility in trade wind aerosols collected over Barbados? 3.) Which factors control the observed trend of speciation and increasing iron solubility in decreasing aerosol loading? Additionally a kinetic model of species specific iron (II) to iron(III) oxidation kinetics in NaCl Brines was conducted at nano-molar levels. This study greatly expands the ability to predict rates of iron oxidation at concentrations closer to those observed in natural systems.
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Warren, Robert Stephen. "Heavy metals in urban street surface sediments." Thesis, Middlesex University, 1987. http://eprints.mdx.ac.uk/13575/.
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A literature survey has been undertaken of the sources, levels and effects of heavy metal pollution in the urban street environment. Established techniques for the determination of heavy metal levels in urban dusts have been reviewed, and appropriate methods selected for use in the research project. Spatial and temporal variations of Cd, Cu, Pb and Zn in street dust have been investigated at a number sites. Metal loadings showed stronger spatial variation than concentrations with the greatest metal loadings occurring in the gutters and kerbsides. The results have been assessed in terms of surface type and condition, traffic loadings and antecedent weather conditions. The chemical associations of heavy metals in street dust, and their relationships to particle size have been investigated. Lead and Zn were associated mainly with carbonates and Fe-Mn oxides, whereas Cu is largely found in the organic fraction. Cadmium shows the greatest affinity for the exchangeable phase, and is therefore considered the most environmentally mobile metal studied. In addition to the studies mentioned above levels and chemical associations of heavy metals In school playground dust contaminated by paint flakes have been investigated. The levels of Pb were much higher than those previously reported. Exchangeable Pb concentrations represented a significant hazard to children playing in the area. In addition to the studies mentioned above levels and chemical associations of heavy metals In school playground dust contaminated by paint flakes have been investigated. The levels of Pb were much higher than those previously reported. Exchangeable Pb concentrations represented a significant hazard to children playing in the area. The final stage of the research project involved the operation of a sampling network to establish a mass balance for Cd, Cu, Pb and Zn within a residential urban street. Metal levels in atmospheric deposition, street sediments and runoff were monitored over an eight week period. Stormwater runoff was found to remove only a minor fraction of the metal deposited in the catchment during the sampling period.
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Mellor, A. "The uptake of metals by marine macroalgae." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268333.
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Morfett, K. D. "Trace metal dynamics in a seasonally anoxic lake." Thesis, Lancaster University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235236.
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Li, Tong. "Trace metals in urban stormwater runoff and their management." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31891.
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In the Greater Vancouver Regional District (GVRD), non-point source pollution from an urban
watershed and a diesel bus loop was assessed in terms of trace metal contamination in the stormwater
runoff.
In the Brunette River watershed study, Northwest Hydraulic Consultants (NHC) collected streambed
sediment and suspended sediment from selected streams during 7 storm events over 2003. From 1993 to
2003, the major stormwater contamination happened in the most industrialized Still Creek. The
streambed Cu, Mn, Fe, and Zn concentration increased by 1.5, 1.7, 1.9, and 1.1 times, respectively. And
the suspended Cu, Mn, and Zn increased by a factor of 2.1, 4.2, and 1.5, respectively. The streambed
sediment exceeded probable effect level in Still Creek and Stoney Creek to varying degrees with Cu and
Zn. The land use is considered to be the origins of these toxicants. Statistically, the magnitude of
suspended metal concentration in μg/l is negatively correlated with the drainage areas. While the —
concentrations in mg/kg, especially for metal Cu and Zn, showed strongly and positively correlation with
the traffic density. Positive correlation existed between the suspended metal loading (kg/yr) and the
imperviousness and the catchment area. No apparent trend was observed in terms of export coefficient
(g/ha/yr) and land use. 1062 tons of sediments were trapped by Burnaby Lake in 2003. This sediment
overloading problem causes serious metal contamination in the lake.
Stormwater runoff quality was monitored in 15 storm events from October 2004 to June 2005 in the
diesel bus loop in the University of British Columbia. The dissolved Cu and Zn Event Mean
Concentration (EMC) exceeded the EPA discharge criteria in 2 and 4 events each, which occurred in the
dry season. Diesel bus traffic contributes' a large portion of Cu, Fe, Zn contamination since the average
bus loop trace metal levels were much higher than the GVRD urban levels. The runoff trace metal
concentrations are strongly related to the antecedent dry period, and are weakly related to the traffic
density and the rainfall intensity. From the catch basin filter evaluation, high removal efficiencies on
suspended metal/solids were achieved with low particulate loading in the filter chamber. The filter
performed well for the dissolved metal removal before the non-reversible saturation was reached. Each
kilogram of filter media has an absorption capacity of 52 gram oil and grease, 20 milligram Mn, and 16
milligram Zn.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Cao, Yi, and Yi Cao. "Competitive complexation of trace metals to dissolved humic acid." Thesis, The University of Arizona, 1993. http://hdl.handle.net/10150/626920.
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Effects of competing trace metals (10 µM) and Ca 2+ (5 mM) on Cd(II), Pb(II)
and Cu(II) (0 - 100 µM) complexation by a groundwater humic acid were
investigated in a series of 24 batch experiments at pH 6, 7, and 8 (I = 0.05 M).
Both trace metals and Ca 2+ have little effect on Cd(II) complexation. No effect of
Cu(II) on Pb(II) complexation is observed; Cd(II) appears to slightly enhance the
binding between Pb(II) and humic acid. For Cu(II), the addition of Pb(II)
decreases the amount of complexation, but Cd(II) also appears to slightly increase
it. Calcium, however, decreases the amount of complexation in all cases. The
effective binding constants determined show that the relative magnitudes of binding
strengths are Cu(II) ,.., Pb(II) > Cd(II). These results indicate that in groundwaters,
where more than one metal is present, the effect of other metals must be considered
when predicting metal speciation.
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Howell, Kate Ann. "In situ measurement of trace metals in coastal waters." Thesis, University of Plymouth, 2003. http://hdl.handle.net/10026.1/1120.
Full textAbstract:
This thesis describes the use of in situ and laboratory techniques for monitoring of trace metals and master variables in the environment. Chapter 1 presents a general overview of trace metals, their sources, sinks and roles in estuaries and near coastal zones, their general characteristics and the importance of their behaviour in estuaries. Filtration and commonly used analytical methods for trace metals detemriinations in natural waters are also discussed. Chapter 2 highlights the importance of colloids (in the size range 0.2 to 0.4 \im) to membrane clogging and concludes that cojloids account for a significant part of clogging of membrane filters. The aim of this study was to extend earlier studies by examining the trends of filtrate concentrations as a function of filtration volume in riverine and estuarine waters with contrasting matrix composition, over two different seasons. Based on the findings presented in this chapter some metal specific filtration protocols are suggested. Chapter 3 provides an overview of developments in instrument automation that have led to miniaturisation and resulting in manufacture of portable electrochemical instrumentation. Such instrumentation has been used for continuous trace metal measurements from the banks of estuaries and on-board ships. The most recent developments in flow-through cells with a gelcoated Iridium (Ir) micro-electrode array have resulted in submersible in s/Yu voltammetric probes which allow long-term trace metal measurements at sub-nanomolar concentrations in coastal waters. Such In situ probes hold great promise for water quality monitoring. Chapter 4 presents the optimisation and validation of a Voltammetric In situ Profiling (VIP) system for the simultaneous determinations of Cd(ll), Cu(ll) and Pb(ll) in estuarine and coastal waters. The trace metal faction measured by the VIP system is termed 'dynamic' and includes and includes these free ions and small complexes with size smaller than a few nm. Systematic studies in NaNOa and seawater were conducted and these showed that variations in ionic strength, pH and dissolved oxygen did not affect the response of the instrument, whereas an Arrhenius type temperature response was observed. During the work, physical and voltammetric settings of the VIP system were considered and tested in detail in order to achieve the analytical requirements to perform measurements in the laboratory and during in situ deployments^ The VIP instrument has a detection limit (defined as 3cj) in seawater for Cd(II) of 23 pM, Cu(ll) 1.13 nM, and Pb(ll) 23 pM. The accuracy of the VIP system was determined with certified reference material (CRM), showing good agreement. Chapter 5 discusses the results of an international laboratory inter-comparison exercise, in order to verify precision and accuracy of measurements made by 4 laboratories that operate VIP systems located in Plymouth, U.K; Geneva, Switzeriand and Ancona, Italy, using laboratory reference methods as a comparison. Inter-comparison included analysis of Tamar Estuary samples and in situ VIP system measurements in the coastal waters of the Gullmar Fjord, Sweden. Chapter 6 presents the results of field deployment of the automated Voltammetric In situ Profiling (VIP) system for the simultaneous determinations of dynamic Cd(ll), Cu(ll) and Pb(ll) in three estuaries located in the Southwest of England, UK. The VIP instrument allowed the In situ determination of 2-4 samples h'\ In addition, the VIP system measured total filterable (0.4 pm pore size filter) concentrations of Gd(ll) and Pb(ll) in discrete estuarine water samples. Through a series of tidal surveys lasting 7-12 h each and totalling 7 surveys a high resolution data set including speciation information was built up that enabled an interpretation of geochemical processes in the studied estuaries. Chapter 7 shows the results of In situ determination of VIP dynamic metal concentrations in the Po plume arid Adriatic Sea. Concentrations were similar to those previously reported for this coastal sea system. The correlation of the metals with salinity was presented and highlighted the importance of local effluent inputs close to the river mouth for Cd(ll). The data demonstrated that the Adriatic was not heavily contaminated with trace metals. Chapter 8 presents the overall conclusions from the research and makes suggestions for future work.
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Colombo, Carlo Maurizio. "Flow analysis of trace metals in seawater by voltammetry." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338581.
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Keyse, Sarah. "Factors controlling the solubility of trace metals in rainwaters." Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243029.
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Jones, Matthew. "A study of trace metals in the surface microlayer." Thesis, University of East Anglia, 2011. https://ueaeprints.uea.ac.uk/35686/.
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Marsay, Christopher Matthew. "Particulate trace metals, carbon and nitrogen in the Mesopelagic." Thesis, University of Southampton, 2012. https://eprints.soton.ac.uk/351794/.
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Sahara, Emmy. "Stripping potentiometric determination of trace metals in environmental materials." Thesis, View thesis, 1996. http://handle.uws.edu.au:8081/1959.7/29143.
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This thesis describes the development and application of stripping potentiometric methods for reliable determination of some trace metals in natural waters on a glassy carbon mercury film electrode (GCMFE). The development of these methods involved investigation of factors influencing the stripping potentiometric measurement, such as selection of adequate supporting electrolyte, choice of pH and/or concentration of supporting electrolyte, oxidant concentration, deposition potential, deposition time, stirring or sample rotation rate and equilibrium period. Moreover, the influence of complexing agents and the magnitude of constant current were carefully investigated for adsorptive cathodic stripping potentiometric methods. In addition, linear concentration range and detection limits were considered. The analytical application of the method to some natural waters was also demonstrated. It is concluded that the stripping potentiometric methods developed in this study are adequate for ultra-trace determination of copper, lead, cadmium, zinc, nickel and molybdenum. The methods provide very simple procedures, excellent precision and accuracy for the reliable determination of the six metals in natural water samples.
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Sahara, Emmy. "Stripping potentiometric determination of trace metals in environmental materials /." View thesis, 1996. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030822.171402/index.html.
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Al-farawati, Radwan. "Thiols, sulfide, and speciation with trace metals in seawater : electroanalytical studies and speciation modelling of thiols and sulfide with trace metals in seawater." Thesis, University of Liverpool, 1997. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243218.
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Miao, Aijun. "Trace metal accumulation and toxicity in marine phytoplankton /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?BIOL%202006%20MIAO.
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Upadhyay, S. "The geochemical behaviour of aluminium in estuarine waters." Thesis, University of East Anglia, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267720.
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Lohan, Maeve Carroll. "Studies on the biogeochemistry of zinc in the subArctic North Pacific." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252322.
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Guan, Rui. "Bioavailability and toxicity of trace metals to the cladoceran daphnia magna in relation to CD exposure history /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?AMCE%202006%20GUAN.
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Fones, Gary R. "Atmospheric deposition of trace metals to urban and coastal environments." Thesis, University of Central Lancashire, 1996. http://clok.uclan.ac.uk/20067/.
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The atmospheric flux (wet and dry) of trace metals (Ni, Co. Cu, Pb, Cd, Al and Na) to the Irish Sea and the North-West of England is presented. The fluxes were calculated from determined trace metal concentrations of aerosols (Al, Fe, Mn, Cd, Co, Cr, Cu, Na, Ni, Pb, V and Zn) and rainwaters (Ni, Co, Cu, Pb, Cd, Al and Na), which were collected using specially designed sampling equipment. The particulate material was analysed using inductively coupled plasma - mass spectroscopy (ICPMS) and also atomic absorption spectroscopy techniques after a complete aciddigestion (HFIHNO3). The dissolved rainwater metal concentrations were determined using the electroanalytical technique adsorptive cathodic stripping voltammetry (ACSV). This technique also enabled dissolved metal Organic complexation to be determined in the rainwater. The results indicated that the trace metal aerosol and rainwater concentrations detected for the Irish Sea and urban areas vary considerably during an annual period. This can be attributed to (i) air mass source and (ii) rainwater washout. Geometric mean aerosol concentrations (ng m 3) were calculated for the Irish Sea aerosol (Al, 210; Fe, 159; Mn, 6.2; Cd, 0.26; Co, 0.17; Cr, 2.0; Cu, 5.3; Na 1140; Ni, 4.2; Pb, 19; V, 4.1; Zn, 32) and North-West England aerosol (Al, 365; Fe, 589; Mn, 21; Cd, 0.80; Co, 0.68; Cr, 13; Cu, 17; Na 2208; Ni, 16; Pb, 45; V, 7.7; Zn, 153) along with total (dissolved + particulate) volume weighted mean concentrations (j.ig l') for the Irish Sea rainwater (Al, 32; Cd, 0.05; Co, 0.05; Cu, 1.8; Na 1998; Ni, 1.1; Pb, 0.73) and North-West England rainwater (Al, 72; Cd, 0.14; Co, 0.15; Cu, 2.9; Na 1274; Ni, 1.7; Pb, 1.82). Air mass analysis studies illustrated the affect on the aerosol trace metal concentrations. For Fe, Mn, Cd, Cu. Pb, V and Zn the Irish Sea aerosol concentrations decreased in the order E> S > N > W. Calculated total inputs to the Irish Sea for Cu (131 t yr:'), Pb (82 t yr') and Cd (3.2 t yr.') were of similar magnitude to total riverine inputs and considerably greater than those of direct discharges (sewage and drainage) for Cu and Pb. The fate of aerosol associated trace metals in the Irish Sea was investigated by laboratory simulation aerosol seawater/rainwater solubility studies. These studies indicated fast dissolution kinetics for crust-rich and urban-rich aerosol trace metals, with equilibrium times of - 5 minutes for Ni, Co, Cu, Pb and Cd. Similar solubility studies performed on collected Irish Sea aerosols in seawater and artificial rainwater indicated solubilities increased in the order Co (32 %) c Pb (37 %) < Ni (38 %) < Cd (46 %) < Cu (58 %) for seawater. These were correspondingly higher in artificial rainwater, Co (37 %)
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McConway, Alex. "The effects of trace metals on juvenile cockles (Austrovenus stutchburyi)." Thesis, University of Canterbury. Biological Sciences, 2008. http://hdl.handle.net/10092/1696.
Full textAbstract:
This thesis investigated the population structure and spatial distribution of the cockle Austrovenus stutchburyi in estuaries and bays around the Canterbury coastline. Surveys investigated population attributes (average density and density of small cockles (< 10mm)) of Austrovenus stutchburyi in relation to physical environmental characteristics such as trace metals (copper, cadmium and zinc), sediment particle size, nitrogen and phosphorus levels, pore water and percentage organic matter of the sediment. Surface cover of flora and number of fauna present was also correlated with the density of cockles and small cockles < 10mm. MDS and PCA ordination showed that the biota was similar at 14 sites but differed significantly at the Pleasant Point Yacht Club (PPY) site. There was a positive correlation between fine sand (125 μm) and the average density of cockles and small cockles < 10 mm. High population densities of Austrovenus stutchburyi were also positively correlated with phosphorus levels, and percentage cover of Sea Grass (Ulva sp). However, Austrovenus stutchburyi density was negatively correlated with cadmium and zinc concentration, and percentage of mud present. The density of small cockles < 10 mm was negatively correlated with copper and cadmium concentration in the sediment and positively correlated with Topshell (Diloma subrostrata) numbers, Sea grass (Zostera muelleri) percentage cover, Sea lettuce (Ulva sp), percentage cover, and sediment particles sizes of < 63 μm (mud), 63 μm (very fine sand), and 125 μm (fine sand). Survival and behavioural changes of juvenile Austrovenus stutchburyi were investigated in relation to increased levels of copper, cadmium, and zinc in aqueous solution and sediment in the laboratory, and artificially increased levels in the field. In laboratory experiments in contaminated seawater it was found that, over time, copper and zinc had a detrimental effect on the percentage of juvenile cockles with their siphons extended as did copper concentration. Cockles 10 - 12 mm shell length exposed to different concentrations of copper had the lowest survival rate (25%) whilst cockles that were 5 - 7 mm in length had the greatest survival rate (69%). Cadmium did not affect survival or siphon extension in aqueous experiments. In the contaminated sediment experiments in the laboratory, the concentration of zinc (0, 20, 40, 80, 160 mg Zn/kg (dry weight)) and cadmium (0, 1.8, 5.6, 18, 36 mg Cd/kg (dry weight)) both decreased survival and burial of juvenile cockles in higher concentrations. Copper concentration (0, 5, 10, 25, 50 mg Cu /kg (dry weight)) decreased burial rates of juvenile cockles but did not affect survival. Transfer of juvenile Austrovenus stutchburyi within three sites in the Avon Heathcote Estuary during May 2007, found that site and exposure to copper, cadmium and zinc decreased the survival of the juvenile cockles. However, transfer of cockles between estuaries (Takamatua, Saltwater Creek and Avon – Heathcote Estuary) in May 2007 found that exposure to copper, cadmium and zinc had the main effect on survival of juvenile cockles. In July 2007 transfers of cockles between estuaries, site and exposure to copper, cadmium and zinc had an effect of survival on juvenile cockles. Cockle populations in the present research have shown a strong correlation with environmental variables, which can be used for management and conservation. The research in this thesis is a start to understanding the effects and implications of contaminants on survival, behaviour and recruitment of juvenile cockles. This research will benefit management strategies for increasing population numbers of Austrovenus stutchburyi.
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Murray, Patricia. "Site specific evaluation of urban brownfields contaminated with trace metals." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0028/MQ50843.pdf.
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Roy, Eric G. "The Detection and Biogeochemistry of Trace Metals in Natural Waters." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/RoyE2009.pdf.
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Linde, Mats. "Trace metals in urban soils : Stockholm as a case study /." Uppsala : Dept. of Soil Sciences, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/2005111.pdf.
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Leung, Chak-cheong. "Trace metals in sharks' fins : potential health consequences for consumers /." View the Table of Contents & Abstract, 2007. http://sunzi.lib.hku.hk/hkuto/record/B39602230.
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Murray, Patricia 1964. "Site specific evaluation of urban brownfields contaminated with trace metals." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21612.
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This thesis is part of a broader project that examines three different approaches to evaluating trace metal contamination in urban brownfields: the measure of total soil metals; calculating bioavailable metals; and the use of species as bioindicators of trace metals in soils. Chapter 1 discusses the problems inherent in each approach such as; inconsistent results due to differences in techniques, extrapolation from laboratory to field, and the influence of species differences and environmental conditions. Chapter 2 is a site description measuring biodiversity, community structure and activity of three urban brownfields. The site description was used to select organisms that were subsequently evaluated for their usefulness as bioindicators of trace metals (chapter 3). Of the three plant species used (dandelion, bladder campion, and chicory), dandelion has the possibility of being a suitable bioindicator of Cd, Ni, and Zn, while bladder campion may be suitable for evaluating Cd, Ni, Pb, and Zn.
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Ge, Ying 1974. "Speciation and complexation of trace metals in eastern Canadian soils." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82879.
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An important task of research on trace metals in soils is to evaluate how much metals are potentially bioavailable and may cause toxic effects. In this thesis, the chemical speciation and complexation of cadmium (Cd), copper (Cu), mercury (Hg) and lead (Pb) were examined in eastern Canadian soils collected from different locations around smelters. Our goal is to be able to predict metal binding in the soil solution and on the solid phase under a wide range of field conditions.In Chapter 2, speciation of Cd, Cu and Pb in the lysimeter soil solutions was determined using an ion exchange technique (IET) involving a resin column. The IET-speciation data were used to estimate the metal-dissolved organic carbon (DOC) binding constants using the non-ideal competitive adsorption (MICA)-Donnan model, which assumed a continuous distribution of binding affinities on the DOC molecule. The published Cd and Pb speciation data in a variety of soils (Chapter 3) were also used to test the effectiveness of two speciation models, the MICA-Donnan model and WinHumicV. Both models satisfactorily predicted the concentrations of Cd2+ and Pb2+. The two chapters of metal speciation demonstrated that the NICA-Donnan model could estimate the binding strength of organic matter in soil solutions.
Proton and metal complexation to the surface of soil particles (Chapters 4 and 5) was investigated using back-titration and batch adsorption procedures. It was shown that the surface binding of H+, Cd2+, Hg2+ and Pb2+ was significantly related to soil organic matter (SOM). Though the soil particle surface was covered by a mixture of organic and mineral components, a two-site distribution could be identified from the titration curves. With the parameters derived from the back-titration and adsorption data, the MICA-Donnan model reasonably predicted the surface complexation of proton and metals. Furthermore, the statistically significant relationships between the model parameters and soil organic matter supported the assumptions in this thesis: (1) Organic matter was the most important sorbent on the particle surface; (2) The MICA-Donnan model may be used to interpret the surface binding data in these soils.
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Hooda, Partap Singh. "The behaviour of trace metals in sewage sludge-amended soils." Thesis, Queen Mary, University of London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343892.
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