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Johnson, Adam Nicholas. "Toxicological Comparison of Heavy Metal Salt and Semiconductor Nanoparticle Exposure in Zebrafish (Danio rerio)." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/JohnsonAN2007.pdf.
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Kwan, Sai-ping, and 關世平. "Heavy metals in Hong Kong rabbitfish (Siganus canaliculatus)." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31221038.
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Martinez, Maria L. 1960. "Organochlorine Pesticides and Heavy Metals in Fish From the Trinity River, Texas." Thesis, University of North Texas, 1990. https://digital.library.unt.edu/ark:/67531/metadc500474/.
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The Trinity River passes through the Dallas-Fort Worth metroplex receiving point and non-point source contaminant loadings. Lepomis spp. were collected at twelve sampling locations in the Trinity River in August 1987 and September 1988 and analyzed for organochlorine pesticides and heavy metals. Results from the study were compared to existing U.S. FDA action and tolerance levels, LC50s, and historical data. Various longitudinal trends and some concentration patterns were observed. Continual study of pesticide and metal body burdens in fish allow testing for trends, and thereby, lead to a better understanding of the distribution of contaminants in the Trinity River.
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Claus, Sonia Carmel, University of Western Sydney, of Science Technology and Environment College, and of Science Food and Horticulture School. "Heavy metals in biota from temperate Australian estuaries." THESIS_CSTE_SFH_Claus_S.xml, 2003. http://handle.uws.edu.au:8081/1959.7/503.
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The detection of anthropogenic impacts in our estuaries has become a critical social, political and scientific concern in recent years. Work has focussed on the effects of these impacts on the spatial and temporal patterns of biotic assemblages and searched for bioindicators and biomarkers of pollutants that may act as early warning signs. The estuaries in temperate Southeastern Australia have a diversity of biotic assemblages living in the soft sediment. One of the most abundant macroinvertebrates is the little studies mussel, Xenostrobus securi that is found living with an assemblage of benthic biota including amphipods, crabs, isopods and tanaids, bivalves and gastropods. Two commercial fish species bream and mullet also inhabit these estuaries. Numerous stormwater drains can be found entering the estuaries through the mangrove forests lining the shores. Along with inputs of freshwater, stormwater drains are thought to be responsible for the entry of heavy metals into estuaries. These heavy metals have the potential to alter the patterns of biotic assemblages and bioaccumulate in the tissues of miacroinvertebrates, mussels and fish living within temperate estuaries. Over the time of this study the concentrations of heavy metals in the sediment tissues and shell of X.Securis varies spatially and temporally. Although this study adds substantially to current knowledge there is still more that is needed to establish X. Securis as a bioindicator. Questions remain about uptake, depuration and response to environmental gradients of heavy metals in X. Securis. Before X Securis can be used routinely in monitoring heavy metal contamination these questions need to be further investigatedDoctor of Philosophy (PhD)
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Mohammed, Nagib F. J. B. "Effect of heavy metals on the biological activities of marine fishes, with special reference to their reproduction and development." Thesis, Swansea University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638215.
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Oogenesis is examined in two rockling species. Seven developmental stages are described in Ciliata mustela L. and six stages in Gairdropsarus mediterraneus L., since both species were collected at the same time, suggesting the possibility of an earlier spawning in the first species. Ultrastructural differences in the zona radiata occur, monopartite in G. mediterraneus and bipartite and double thickness in C. mustela. Cortical alveoli are first formed in the cortex originating from Golgi vesicles. Ultrastructural evidence suggests that protein yolk formation has a contribution from both exogenous and endogenous sources while lipid yolk is solely endogenous. The endogenous protein is synthesised by Golgi complexes. Lipid yolk is formed in close association with rough endoplasmic reticulum in G. mediterraneus and annulate lamellae in C. mustela suggesting that both organelles play a role in lipid formation. Fertilised eggs of Clupea harengus L. were exposed to different acid pHs. Egg, perivitelline space, and yolk volumes were measured in relation to osmoregulation. The effect of acid on the morphology of the hatched larvae was also demonstrated. Jaw, branchial and skeletal abnormalities were observed. Exophthalmus condition was recorded in these larvae. Acid water causes epidermal necrosis, degeneration of the chloride cells, and swelling of the membrane-bound structures of the trunk muscle tissue at the ultrastructural level. The study demonstrates that aluminium is extremely toxic at pH 5.0 causing 99.52% cumulative mortality to C. harengus eggs. Ultrastructural and morphometric evidence show that aluminium causes disruption and swelling in the cell membranes of the brain and muscle tissues of C. harengus larvae accompanied by degeneration of mitochondrial cristae. Such effects would reduce the metabolic activity and survival potential of these larvae with subsequent consequences on recruitment success of the stock.
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Leung, Siu Ying. "Accumulation of DDTs, heavy metals and PBDEs in fish collected from fish ponds and mariculture zones of the Pearl River Delta, China." HKBU Institutional Repository, 2008. http://repository.hkbu.edu.hk/etd_ra/880.
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Zhou, Hai Yun. "Evaluation of organochlorines and heavy metals in the Pearl River Delta and Hong Kong, with emphasis on bioaccumulation in freshwater fish." HKBU Institutional Repository, 1999. http://repository.hkbu.edu.hk/etd_ra/207.
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Kwok, Chun Kit. "Toxicological assessments of PAHs, OCPs and heavy metals in sediments at Mai Po and Deep Bay, Hong Kong." HKBU Institutional Repository, 2008. http://repository.hkbu.edu.hk/etd_ra/875.
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Merciai, Roberto. "Effects of global change on fish assemblages in Mediterranean streams." Doctoral thesis, Universitat de Girona, 2016. http://hdl.handle.net/10803/405192.
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L'objectiu d'aquesta tesi és de'explorar alguns aspectes de l'impacte humà sobre les poblacions de peixos i altres components dels ecosistemes fluvials Mediterranis de Catalunya. Es va mostrar com els peixos del Riu Llobregat acumulen quantitats significatives de metalls pesants, amb concentracions en el múscul que varien al llarg del riu i segons l'espècie i la talla dels peixos. En el Riu Tordera, afectat per l'extracció d'aigua, el règim de temperatures es veu alterat en correspondència dels trams intermitents, en els quals la probabilitat de supervivència i l'abundancia dels peixos , i en menor mesura el creixement i la condició corpòria, també pateixen les conseqüencies de l'alteració hidrològicaThe goal of this thesis is to explore some aspects of anthropogenic impact on the fish populations and other components of two Mediterranean stream ecosystems in Catalonia NE Spain). It was shown how Llobregat River's fish accumulate significant trace metal quantities, with muscle concentrations varying across sampling sites along the river, fish species and size. In the Tordera Stream, affected by water abstraction, the temperature regime was disrupted in correspondence of the intermittent reaches, where fish abundance and survival probability and, at a lower extent, growth and body condition, also suffered the consequences of hydrologic alteration
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Barst, Benjamin Daniel. "Hepatotoxicity of Mercury to Fish." Thesis, University of North Texas, 2010. https://digital.library.unt.edu/ark:/67531/metadc31525/.
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Tissue samples from spotted gar (Lepisosteus oculatus) and largemouth bass (Micropterus salmoides) were collected from Caddo Lake. Gar and bass livers were subjected to histological investigation and color analysis. Liver color (as abs at 400 nm) was significantly correlated with total mercury in the liver (r2 = 0.57, p = 0.02) and muscle (r2 = 0.58, p = 0.01) of gar. Evidence of liver damage as lipofuscin and discoloration was found in both species but only correlated with liver mercury concentration in spotted gar. Inorganic mercury was the predominant form in gar livers. In order to determine the role of mercury speciation in fish liver damage, a laboratory feeding study was employed. Zebrafish (Danio rerio) were fed either a control (0.12 ± 0.002 µg Hg.g-1 dry wt), inorganic mercury (5.03 ± 0.309 µg Hg.g-1 dry wt), or methylmercury (4.11 ± 0.146 µg Hg.g-1 dry wt) diet. After 78 days of feeding, total mercury was highest in the carcass of zebrafish fed methylmercury (12.49 ± 0.369 µg Hg.g-1 dry wt), intermediate in those fed inorganic mercury (1.09 ± 0.117 µg Hg.g-1 dry wt), and lowest in fish fed the control diet (0.48 ± 0.038 µg Hg.g-1 dry wt). Total mercury was highest in the viscera of methylmercury fed zebrafish (11.6 ± 1.86 µg Hg.g-1 dry wt), intermediate in those fed inorganic diets (4.3 ± 1.08 µg Hg.g-1 dry wt), and lowest in the control fish (below limit of detection). Total mercury was negatively associated with fish length and weight in methylmercury fed fish. Condition factor was not associated with total mercury and might not be the best measure of fitness for these fish. No liver pathologies were observed in zebrafish from any treatment.
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Kwan, Sai-ping. "Heavy metals in Hong Kong rabbitfish (Siganus canaliculatus) /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B20667759.
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Wainaina, Steven. "Effect of heavy metals on syngas fermentation." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-10203.
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The goal of this work was to establish the suitable and limiting concentrations of Zn, Cu and Mn compounds during syngas fermentation. The results showed that cells encased in polyvinylidene difluoride (PVDF) membranes had a faster accumulation of methane in reactors containing fermentation medium dosed with 5 mg/L of each heavy metal compared to free cells. It was also revealed that total inhibition of biohydrogen production occurred in medium containing 5 mg/L Cu, 30 mg/L Zn and 140 mg/L Mn while the most suitable metal concentration level was 0.1 mg/L Cu, 0.6 mg/L and 2.8 mg/L Mn. In addition, a comparison test showed that for the most suitable metal concentration in the medium, rate of performance at pH 6 and 7 was higher than at pH 5.
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Correa, Jean Michel. "Heavy metals in water, sediments and fishes in the Maranguapinho river, Fortaleza Metropolitan Region, Ceara." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13848.
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FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgicoAquatic ecosystems are considered receivers of contaminants released into the environment, being susceptible the actions of domestic and industrial effluents which are released directly into this ecosystem. Among the environmental contaminants are heavy metals which are highly resistant to degradation. They can occur in different chemical forms in nature and therefore may increase or reduce its toxic characteristics toward several organisms and their biological characteristics, according to their concentration in the ecosystem. The Maranguapinho river presents environmental problems, such as pollution, deforestation of its margins, among others. The river bed is silted up due to the replacement of riparian vegetation and receives several channels in the region, clandestine pipes of domestic sewages. A two-year study was carried out in three reaches located in this river: RMA-A (high basin), RMA-B (middle basin) and RMA-C (low basin). A total of 93 fishes were collected, distributed in four orders, seven families, nine genera and 11 species. The species richness was highest in RMA-B, with five species. Although above the maximum allowed value, the concentrations of Al, Fe and Mn found in the water were not considered contaminants, indicating that these elements are the result of lithological composition of the region. The geoaccumulation index indicated that all the sediment samples of Maranguapinho are classified into Class 1 due to the small variation in the intensity of pollution, revealing that the elements are natural constituents of the basin. The sample size used was 21 individuals for further toxicological representation of fishes captured. Hypostomus jaguribensis and Loricariichthys nudirostris species showed the highest amounts of the metals studied (Al = 44,34 ppm, Fe = 460,15 ppm and Sr = 1,38 ppm), trending to accumulate high amounts of metals in the body and can be considered good bioindicators. The ANOVA revealed a statistically significant difference between the concentrations of Cd and Zn in the viscera of fish and the maximum values allowed by the law, showing that these elements can cause contamination risks to fish and humans and allowed the distinction of marginal influences between the average of Fe and Mn in the viscera of fish and water stations, being the water the factor of entry of the elements in the animal organism. The Maranguapinho river is a natural environment potentially fragile. Several kinds of anthropogenic interferences, such as discharge of effluents, contributes for the its environmental degradation.
Os ecossistemas aquÃticos sÃo considerados receptores de contaminantes liberados no ambiente, estando susceptÃveis as aÃÃes de efluentes domÃsticos e industriais que sÃo lanÃados sem tratamento diretamente neste ecossistema. Dentre os contaminantes ambientais, encontram-se os metais pesados, que sÃo altamente resistentes a degradaÃÃo. Metais pesados podem ocorrer sob diferentes formas quÃmicas na natureza e conseqÃentemente podem aumentar ou reduzir suas caracterÃsticas tÃxicas para com os diversos organismos e suas caracterÃsticas biolÃgicas, de acordo com suas concentraÃÃes no ecossistema. O rio Maranguapinho apresenta problemas ambientais, a exemplo da poluiÃÃo, desmatamentos de suas margens, dentre outros. O leito do rio encontra-se praticamente todo assoreado em decorrÃncia da substituiÃÃo da mata ciliar e recebe Ãgua de diversos canais da regiÃo, de tubulaÃÃes clandestinas de efluentes domÃsticos. Nesse contexto, um estudo foi realizado nos anos de 2012 e 2013 em trÃs estaÃÃes de amostragem situadas nesse rio: RMA-A, situada no alto curso, RMA-B, situada no mÃdio curso e RMA-C, situada no baixo curso. Foram coletados 93 peixes, distribuÃdos em quatro ordens, sete famÃlias, nove gÃneros e 11 espÃcies. A riqueza de espÃcies foi maior no RMA-B, com cinco espÃcies. As concentraÃÃes de Al, Fe e Mn encontradas na Ãgua, embora acima do valor mÃximo permitido, nÃo foram consideradas contaminantes, indicando que esses elementos sÃo resultantes da composiÃÃo litolÃgica da regiÃo. O Ãndice de geoacumulaÃÃo indicou que todas as amostras de sedimentos do rio Maranguapinho estÃo enquadrados na classe 1 em virtude da pouca variaÃÃo apresentada na intensidade de poluiÃÃo, revelando que os elementos encontrados sÃo constituintes naturais da bacia. O tamanho da amostra utilizada foi de 21 exemplares para uma maior representatividade toxicolÃgica da ictiofauna capturada. As espÃcies detritÃvoras Hypostomus jaguribensis e Loricariichthys nudirostris apresentaram as maiores quantidades dos metais estudados (Al = 44,34 ppm, Fe = 460,15 ppm e Sr = 1,38 ppm), possuindo uma maior tendÃncia a acumular em seu organismo elevadas quantidades de metais e podendo ser considerados bons indicadores da qualidade ambiental. A ANOVA revelou diferenÃa estatisticamente significante entre as concentraÃÃes de Cd e Zn nas vÃsceras dos peixes e os valores mÃximos permitidos na legislaÃÃo, mostrando que esses elementos podem causar sÃrios riscos de contaminaÃÃo aos peixes e humanos e tambÃm permitiu distinguir influÃncias marginais entre as mÃdias de Fe e Mn nas vÃsceras dos peixes e na Ãgua das estaÃÃes, sendo a Ãgua o fator de ingresso dos elementos no organismo animal. A bacia do rio Maranguapinho à um ambiente natural potencialmente frÃgil. Os vÃrios tipos de interferÃncias antropogÃnicas, em especial a descarga de efluentes, contribuÃram de forma marcante para a sua degradaÃÃo ambiental.
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Omar, F. A. "The effect of heavy metals on growth of marine phytoplankton." Thesis, Swansea University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638366.
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A study has been made on the effect of zinc, calcium and copper on the growth and 14C fixation of Phaeodactylum tricornutum and Dunaliella primolecta. Experiments were carried out to examine the uptake of 65Zn by Phaeodactylum and Dunaliella in laboratory culture, to investigate the processes involved, its relationship to metabolism, and the factors affecting it. Also, experiments were carried out to investigate the effect of these metals on chlorophyll concentration and protein content of Phaeodactylum and Dunaliella. It has been found that the organisms displayed varying degrees of tolerance to the presence of the metals zinc, cadmium and copper in the growth medium. Of the three metals copper was found to be more effective upon the growth, 14C fixation, zin-65, chlorophylla concentration and protein content of Phaeodactylum and Dunaliella.
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Salah, Sharif Ali. "Heavy metals uptake by wheat under two transpiration rates." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33838.
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The present project aimed at measuring plant heavy metal uptake as a function of transpiration rates and dissolved heavy metal level in the soil solution. Two experiment was conducted separately in two season (Spring and Fall 2000). In these two experiments, young wheat plants ( Triticum aestivum) were irrigated with nine different solutions containing Cd and Zn. The study was conducted in two chambers where relative humidity was controlled to obtain two different levels of transpiration rates. Each control chambers contained 27 pots filled with sand and seeded with wheat plants, each nine triplicated pots receiving a different treatment: three Cd treatments with levels of 0.01, 0.10, and 0.50 mg/L; one Zn treatment with level of 25mg/L and four treatment combinations of Cd/Zn with levels of 0.01 Cd/25Zn, 0.10Cd/25ZN, 0.50Cd/25Zn and 0.50Cd/50Zn mg/L. The transpiration rate of the plants was monitored over a period of 30 days, measured from the emergence of the plants by weighing the pots daily. On day 15 and 30, three plants were removed from each pot, to weigh their dry matter production and to analyze their heavy metal uptake. (Abstract shortened by UMI.)
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Lawton, Michelle. "The effect of heavy metals on differentiated neuronal and glial cells." Thesis, Nottingham Trent University, 2007. http://irep.ntu.ac.uk/id/eprint/219/.
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Heavy metal poisoning poses a serious health risk among populations worldwide. The symptoms presented by exposure are varied and depend upon the species of the metal, the age of the individual and the exposure dose. All heavy metals have debilitating effects on the CNS. Children are especially sensitive to the neurological effects due to the intense growth and activity of a developing nervous system and inadequately developed defences. The aims of this study were to determine the effects of sub-lethal concentrations of numerous heavy metals on neuronal and glial cell differentiation. Using established cellular models, the toxicity of zinc, lead, mercury, methylmercury and thimerosal were investigated using assays of cell viability and morphology on differentiating N2a and C6 cells. Initial research revealed thimerosal, methylmercury and cadmium to be the most toxic compounds tested, in terms of their ability to inhibit the outgrowth of neurites in both cell lines at sub-lethal concentrations. Although cadmium chloride showed similar patterns of toxicity to the mercury compounds, thimerosal and MeHgCl were chosen for further investigation at a molecular level. Methylmercury chloride a common environmental pollutant and thimerosal; a preservative found in many medicines, were chosen for further investigation, as previous work has demonstrated the health risks posed by the two organic mercury compounds but little is known about non-lethal changes that occur in the nervous system, especially with thimerosal. Both thimerosal and MeHgCl inhibited MTT reduction and neurite outgrowth after 4 and 24 hours exposure at sub-lethal concentrations (0.1 and 1 µM). The inhibition of neurite outgrowth by sub-lethal concentrations of MeHgCl and thimerosal was accompanied by cytoskeletal changes in the cells. At 4 hours in C6 cells there was no change in the levels of tyrosinated a-tubulin, whereas in N2a cells the level of tubulin tyrosination was shown to be reduced compared to the control. Both cell lines exhibited a fall in total a-tubulin, tyrosinated a-tubulin and total ß-tubulin after 24 hours of exposure to organic mercury compounds, indicating proteolysis and/or reduced synthesis of the tubulin subunit. N2a cells also showed a decrease in the levels of phosphorylation in the neurofilament heavy chain after 4 hours of exposure to thimerosal and MeHgCl, whereas after 24 hours there appeared to be proteolytic degradation, as the total neurofilament heavy chain levels were reduced compared to the untreated controls. Reduced levels of tubulin and NFH were confirmed by immunofluorescence staining of fixed cell monolayers. Western blotting analysis also indicated increased ERK activation in glial cells incubated with 0.1 and 1 µM thimerosal for 4 hours, followed by reduced activation after 24 hours exposure, whereas exposure to MeHgCl decreased the levels of ERK activation at both time points. In the neuronal cell line ERK activation was suppressed at both 4 and 24 hours and with both concentrations of the organic mercury compounds. As ERK activation plays a key role in the regulation of neurite outgrowth and NFH phosphorylation, both of which were inhibited by the addition of thimerosal and MeHgCl, the findings are consistent with a role for disrupted ERK signalling in the sub-lethal toxicity of these compounds. Both thimerosal and MeHgCl caused redistribution of SERCA and ryanodine receptors, both of which are mechanisms by which intracellular Ca2+ concentrations are maintained. As the endoplasmic reticulum (ER) houses both SERCA and ryanodine receptors, the reorganisation may indicate that organic mercury compounds cause redistribution of the ER. Such disruption may lead to sustained increases in intracellular Ca2+, causing elevated activity in Ca2+ dependant enzymes. Indeed, western blotting analysis and enzyme assays showed that calpain activity (particularly calpain 1) increased in response to sub-lethal concentrations of the organic mercury compounds. As calpains target cytoskeletal proteins, the increased activity may be at least partly responsible for reduced levels of tubulin and NFH.
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McCluskey, Seánín Marie. "The effect of heavy metals on antibiotic resistance in the environment." Thesis, University of Strathclyde, 2014. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=24354.
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Antibiotic resistance is a significant clinical problem, with bacterial infections becoming increasingly difficult to treat. Efforts, such as reducing the use of antibiotics, have proved unsuccessful, and we now face the prospect of a future without antibiotics. The natural environment acts as a reservoir for resistance genes. The selection and maintenance of resistance could counteract clinical efforts to reduce antibiotic resistance. Heavy metals have been linked to antibiotic resistance by genetic mechanisms whereby metals potentially select for and maintain antibiotic resistance, even in the absence of the antibiotic itself. Here, the role of heavy metals in enhancing, or maintaining, antibiotic resistance in the environment is investigated. Background levels of metals in soil were found to correlate to antibiotic resistance gene abundances, implying the effect heavy metals in the environment have on antibiotic resistance is more intrinsic than anticipated. Using controlled microcosm studies, the influence of pollution levels on antibiotic resistance was further investigated.
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Al-Rasheid, Khaled A. S. "The effect of heavy metals on the marine ciliate Euplotes mutabilis (Tuffrau, 1960)." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358875.
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Ching, C. Y. Terrance, and 程振英. "Deriving critical tissue concentrations of trace metals in fishes for ecology risk assessment." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B45013718.
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Lan, Xiao Yu. "Rapid immunological detection of heavy metal cadmium in traditional Chinese medicine." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3952139.
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Chen, Xuehui. "Accumulation of heavy metals and organochlorine pesticides in human milk and adipose tissues, and its health concerns." HKBU Institutional Repository, 2007. http://repository.hkbu.edu.hk/etd_ra/779.
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Stanley, Jean Frances. "Studies on the metal-containing granules in the mussels, Mytilus galloprovincialis and Velesunio angasi." Access via Murdoch Univeristy Digital Theses Project, 2003. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040528.12421.
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Ghaderian, Seyed Majid. "The effect of toxic heavy metals upon fungi of the genus Pythium isolated from soil." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301558.
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Ball, Jihane Sokhn. "The effect of heavy metals on the degradation of polycyclic aromatic hydrocarbons by soil microorganisms." Thesis, University of Surrey, 2005. http://epubs.surrey.ac.uk/842888/.
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This study aimed to assess the effect of heavy metals, especially Cu, Zn and Cd, on the ability of the white rot fungus (WRF) Bjerkandera sp. BOS55 and several soil bacterial isolates to degrade a selection of polycyclic aromatic hydrocarbons (PAHs). To investigate the effect of heavy metals on PAH degradation by Bjerkandera sp. BOS55, the fungus was grown in both a rich undefined medium and a defined medium containing the PAH pyrene and different concentrations of Cu or Cd. It was found that both metals reduced fungal growth and production of ligninolytic enzymes but that toxicity was modified by the growth medium. The fungus exhibited adaptation and tolerance to both metals in the defined medium containing up to 600 ppm metal but was inhibited in the rich medium containing as little as 50 ppm metal. Whilst WRF are capable of PAH oxidation, complete mineralisation to CO2 is often unachieved resulting in the production of polar and often toxic metabolites. In soil, these metabolites can be further oxidised by bacterial populations to non-toxic products. However, bacteria often exhibit a greater sensitivity to heavy metals than WRF. This sensitivity to heavy metals could block the detoxification process of the soil environment. The three PAH-oxidising bacterial isolates that were tested for metal tolerance were found to be highly susceptible to Cu, Zn and Cd at concentrations of 200 ppm each, resulting in a reduced degradation of phenanthrene and pyrene. It was therefore concluded that the presence of heavy metals in the environment, even at fairly low levels, could potentially lead to the incomplete degradation of PAHs, and possible accumulation of toxic metabolites. Finally, co-cultures of the metal-sensitive bacterial isolates and the fungus were used to establish if a combination of WRF and a bacterial isolate could be used to accelerate the degradation of PAHs. Anthracene and anthraquinone were used as model PAHs because anthraquinone is a dead-end metabolite produced during the oxidation of anthracene by Bjerkandera sp. BOS55. It was found that some of the fungal-bacterial co-cultures tested synergistically removed anthracene, resulting in significantly faster degradation than observed for each organism individually. Moreover, one co-culture removed anthraquinone, suggesting that a combination of WRF and bacteria are essential for the rapid mineralisation of PAHs in the environment.
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Maleri, Rudolf A. "The ability of terrestrial Oligochaeta to survive in ultramafic soils and the assessment of toxicity at different levels of organisation." Thesis, Stellenbosch : University of Stellenbosch, 2006. http://hdl.handle.net/10019.1/1200.
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Thesis (PhD (Botany and Zoology)) -- University of Stellenbosch, 2006.Metals are natural elements of the earth crust usually present at low concentrations in all soils. Although many metals such as cobalt, copper, iron and zinc are essential to living organisms, at elevated concentrations most metals are toxic to organisms living in and on soils. Elevated concentrations of metals are caused either by anthropogenic deposition following remobilisation from the earth crust or are of natural origin. Ultramafic soils do not only pose unfavourable living conditions such as drought and poor organic content, these soils are also characterized by extremely high concentrations of a range of metals known to be toxic under normal circumstances. Ultramafic soils are of high ecological importance as a high proportion of endemic organisms, especially plants, live on these soils. As it is known that earthworms do occur in ultramafic soils, the aims of the present study were to investigate the abilities of earthworms to survive in these soils and the influences of elevated chromium, cobalt, copper, manganese and nickel levels. For the evaluation of the metal background conditions, soils originating from ultramafic rocks of the Barberton Greenstone Belt, Mpumalanga, South Africa were collected and different fractions representing different levels of bioavailability were analyzed for arsenic, chromium, cobalt, copper, manganese and nickel. To assess the mobile, readily available metal fraction, i.e. Ca2+- exchangeable metal cations, a 0.01 mol/L CaCl2 extraction was performed. To investigate the mobilisable metal fraction, representing the amount of easily remobilisable complexed and carbonated metal ions, a DTPA (di-ethylene-triamine-pentaacetic acid) extraction was conducted. In relation to non-ultramafic or anthropogenic contaminated soils, a far lower proportion of metals were extractable by the above mentioned extraction methods. To investigate the availability and effects of these metals on earthworms, two ecophysiologically different species were employed. Aporrectodea caliginosa and Eisenia fetida were long-term exposed to the ultramafic soils collected at the Barberton region and a control soil from a location at Stellenbosch with a known history of no anthropogenic metal contamination. The responses to the ecological stress originating in the ultramafic soils were measured on different levels of earthworm organisation. As endpoints affecting population development, cocoon production, fecundity and viability were evaluated. On individual level, growth, metal body burden and tissue distribution were investigated. As endpoints on subcellular level, the membrane integrity was assessed by the neutral red retention assay, the mitochondrial activity was measured by the MTT colorimetric assay and as a biomarker for the DNA integrity, the comet assay was performed. Focussing on manganese and nickel, the uptake by E. fetida of these metals was investigated with the exclusion of soil related properties using an artificial aqueous medium to draw comparisons to the uptake of these metals in natural soils. The possible development of resistance towards nickel was tested by exposing pre-exposed (for more than 10 generations) E. fetida specimens to ultramafic soils with concentrations of more than 4000 mg/kg nickel. The results showed that, except on the endpoint survival, which was less sensitive than all other bioassays, significant responses to the ultramafic challenge were observed in all earthworm bioassays and on all levels of organisation. The sensitivity of the responses of the earthworms towards the ultramafic conditions was not predictable by the level of organisation. The two species showed different strategies of metal elimination. In A. caliginosa, metals such as nickel, manganese and chromium were transported to the posterior section and the posterior section was subsequently pushed off by autotomization. In E. fetida, metals such as chromium and nickel were sequestered in storage compartments in the coelomic cells or fluid. Other metals, such as cobalt, were not taken up at elevated concentrations. Although an increased accumulation of nickel was observed in E. fetida specimens pre-exposed to nickel, development of resistance or cross resistance was not observed in this species. In contrast, pre-exposed specimen exposed to elevated concentrations of nickel showed a higher sensitivity in terms of survival, indicating the absence of acclimatisation or even genetic adaptation. A comparison of the two species employed indicated that A. caliginosa was less suited for the assessment of the ultramafic soils due to the high individual variation in metal body burden, the mass loss observed and the slow reproduction rate even in the control soils. This happened despite the fact that A. caliginosa was a soil dwelling species supposed to be better adapted to the soil substrate than the litter dwelling E. fetida. The toxicity of the ultramafic soils was not necessarily related to total or environmentally available amounts of the selected metals. Thus, it can be speculated that either these soils contained unidentified toxicants with resulting interactions between toxicants playing an important role or earthworms were able to remobilize metals occurring in these soils. As the singular application of an ecotoxicological endpoint did not give reliable results, especially seen over the duration of the exposures, it can be concluded that, when studying soils with such a complex composition, the utilisation of endpoints addressing different levels of organisation is necessary for the assessment of toxic stress emerging from these ultramafic soils.
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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.
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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.
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Yuncu, Bilgen. "Effect Of Extracellular Polymer Composition Of Activated Sludge On The Removal Of Heavy Metals By Biosorption." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1087733/index.pdf.
Full textAbstract:
Activated sludge microorganisms can remove many hazardous substances from
wastewater by adsorbing and concentrating them on their surfaces. Biosorption of
these substances onto activated sludge surfaces are influenced by the chemical
properties of the substance in question as well as the surface properties of the
microorganisms. The purpose of this study is to identify the biosorption
mechanisms of heavy metals and the effect of extracellular polymer (ECP)
composition of activated sludge on the biosorption of Pb(II), Cd(II), Cu(II), Zn(II)
and Ni(II). Microorganisms cultured under different growth conditions are expected
to have different compositions of ECPs and hence, different biosorption capacities.
For this purpose, three sets of reactors with C/N ratios of 9, representing a carbonlimited
case21, representing conventional municipal wastewater treatment plant activated sludge and 43, representing nitrogen-limited condition, were set up. The semi continuous reactors were fed synthetically and operated at a sludge age of 8 days. Isotherm and kinetic experiments that were held with three different C/N ratios was indicated that the biosorptive capacity of activated sludge was highly dependent on metal species and the C/N ratio. Although, the dependence of biosorptive capacity on C/N ratio was different for each metal, biosorption properties of activated sludge were found to be directly related with ECP composition. Among the heavy metals tested, Pb(II) was the one that was adsorbed at the highest capacity at all C/N ratios. Also, with the purpose of understanding the mechanism of the process, Ca(II) and Mg(II) ions and carbohydrates released into the solution were also monitored and it was indicated that an ion exchange process is involved in the biosorption of heavy metals especially at high metal concentrations but the whole metal removal can not be explained by ion exchange.
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Peppler, Jessica Elise. "The Effect of Heavy Metals on the Uptake of L-Histidine by the Polychaete Nereis Succinea." Thesis, University of Hawaii at Manoa, 2002. http://hdl.handle.net/10125/6957.
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Integumentary uptake of 3H-L-Histidine by Nereis succinea was measured in the presence and absence of selected heavy metals and inhibitors in 60% artificial seawater (ASW). At low concentrations of L-Histidine (10 uM), metals stimulated L-Histidine uptake from ASW. Higher concentrations of metal inhibited L-Histidine uptake. In amino acid kinetic experiments, 0.5 uM Zn2+ significantly (P < 0.003) increased both L-Histidine influx Jmax (control: 4.7 ± 0.4; treatment: 15.3 ± 1.7 nmol/g dry weight x 15 min), and Km (control: 23.8 ± 5.1; treatment: 44.0 ± 8.8 uM). Fe3+ (0.5 uM) stimulated influx of 10 uM L-Histidine (Jmax = 6.9 ± 0.4 nmol/g dry wt x 15 min; Km = 86.7 ± 12.3 uM), but neither Ag+ nor Al3+ significantly (P > 0.05) altered amino acid influx. L-Leucine (25 uM) reduced Zn2+ -stimulated L-Histidine influx, suggesting a possible role of the Na-independent L-transport system in metal-stimulated L-Histidine transport by worm integument.vii, 35 leaves
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Tsang, Chi-kin. "Analysis and control of organic vapours in air and determination of metals and toxic elements in fish samples by differential pulse voltammetry and atomic absorption spectrophotometry /." [Hong Kong : University of Hong Kong], 1991. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13408914.
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Chiu, Ki Kin. "Using organic amendments and chelates for remediation of metal-contaminated soils by vetiveria zizanioides." HKBU Institutional Repository, 2003. http://repository.hkbu.edu.hk/etd_ra/417.
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Ho, Ching-yee Christina. "The biomonitoring of heavy metal pollution in the wood and leaf chemistry of urban trees in Hong Kong." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21089978.
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Ntuli, Themba Dominic. "Preparation of chemically modified Macadamia nutshells for adsorptive removal of selected heavy metals." Thesis, Vaal University of Technology, 2017. http://hdl.handle.net/10352/379.
Full textAbstract:
M. Tech. (Chemistry, Faculty of Applied and Computer Science), Vaal University of TechnologyThe abundance of agricultural waste materials has led to its use as adsorbents for trace metal adsorption. The raw Macadamia nutshell (RMN) powder was treated with a hydrochloric acid solution to obtain acid modified Macadamia nutshells (AMM), and with sodium hydroxide solution to obtain base modified Macadamia nutshells (BMM). Then, the AMM and BMM materials were grafted with 0.5 M, 1 M, and 2 M acrylic acid. The different AMM grafted materials were labelled 0.5 GAM, 1 GAM and 2 GAM representing the different grafting ratios. The same naming order was followed for the BMM grafted materials, that is, 0.5 GBM, 1 GBM and 2 GBM corresponding to different concentrations used. The prepared Macadamia based adsorbents were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), carbon, hydrogen, nitrogen and sulphur (CHNS) analysis, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analysis. The determination of surface properties such as the point of zero charge (pHPZC), bulk density and the surface negative charge was accomplished with appropriate wet chemistry methods. The adsorption of selected trace metals (Cu(II), Cd(II), Co(II), and Cr(VI)) was done in batch experiments. Atomic absorption spectroscopy (AAS) was used for the determination of metal ions concentrations and total Cr. The ultraviolet-visible (UV–Vis) spectroscopy was used for the determination of Cr(VI) concentration remaining in solution after adsorption. The RMN, AMM, and BMM adsorbents showed potential in removing more than 45% Cu(II) ions, but less than 30% for both Cd(II) and Co(II) ions. However, more than 90% removal of Cr(VI) ions was achieved with the same adsorbents. Consequently, only the adsorption of Cr(VI) was further investigated in the study due to the higher removal efficiency displayed by the Macadamia based biosorbents. The optimum adsorption conditions for the RMN, AMM, and BMM materials were found to be pH 2, 100 mg/L initial concentration of Cr(VI), 600 min contact time and 0.2 g adsorbent mass. The ideal conditions for the 0.5 GAM and 0.5 GBM were found to be pH 2, 25 mg/L initial concentration of Cr(VI), 180 min contact time, and 0.15 g adsorbent mass. The optimum temperature was found to be 40℃ for all materials. A volume of 20 mL was used for all batch experiments. The RMN, AMM, BMM, 0.5 GBM, and 0.5 GAM adsorption mechanisms were better described by the Langmuir isotherm which predicted a monolayer sorption process. The kinetic data fitted better to the pseudo second-order rate model which signified a chemisorption type of interaction. The thermodynamic parameters showed that the adsorption reaction was feasible, spontaneous and endothermic. The Macadamia based materials showed greater potential as adsorbents for the adsorption of Cr(VI) ions from aqueous solution compared to the other selected trace metal ions [Cd(II), Cu(II) and Co(II)].
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Hong, Wei. "Investigation on heavy metals and species of arsenic in natural Cordyceps sinensis." Thesis, University of Macau, 2008. http://umaclib3.umac.mo/record=b2162715.
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Clements, William H. "Community responses of aquatic macroinvertebrates to heavy metals in laboratory and outdoor experimental streams." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/53937.
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This research describes aquatic macroinvertebrate community responses to heavy metals (copper, zinc) in experimental streams and at metal-impacted sites in the field. Experiments employed substrate-filled trays which were colonized in the field and then transferred to laboratory or outdoor streams.
Laboratory experiments conducted over three seasons showed that acute (96 h) exposure to copper (Cu) at 15-32 μg Cu/L significantly reduced macroinvertebrate abundance and number of taxa during each season. Owing to differences in sensitivity among taxa, the percent composition of dominant groups varied between control and dosed streams. Mayflies were quite sensitive to Cu, particularly during the summer when water temperatures were higher.
Community responses to Cu and Zn in outdoor experimental streams were similar to those observed at metal-impacted sites in the field. Control streams and field reference Stations were dominated by mayflies and Tanytarsini chironomids. In contrast, treated Streams and impacted field sites were dominated by net-Spinning caddisflies (Hydropsychidae) and Orthocladiini chironomids. The similarity of these experimental results to those observed in the field suggest that macroinvertebrate community responses to heavy metals are highly predictable.
Responses of these communities to Cu were greatly influenced by water quality. Effects were more severe in New River Streams, where water hardness and alkalinity were low, compared to Clinch River Streams, where hardness and alkalinity were higher. In soft water Streams, abundance was reduced by 84% after 10 d exposure to Cu (measured concentration = 13 μg/L). In contrast, abundance was reduced by only 45% in hard water Streams after 10 d at Similar Cu levels. These results demonstrate the importance of accounting for water quality characteristics of receiving systems when establishing site-specific criteria for metals.
Chronic exposure (14 d) to sublethal levels of Cu (< 6 μg/L) increased Vulnerability of caddisflies (Hydropsyche morosa and Chimarra sp.) to predation by the Stonefly, Paragnetina fumosa. Caddisflies were also the major component of stonefly diets and were consumed Significantly more frequently in dosed Streams than controls. These results demonstrate that single Species bioassays were inadequate for predicting effects of toxicants on community level processes.Ph. D.
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Bateman, Mark J. "The uptake of heavy metals by aquatic macrophytes and the development of microsampling analytical techniques." Thesis, Coventry University, 1999. http://curve.coventry.ac.uk/open/items/82ba9974-f8fc-6290-40a7-3a64e63ff8a6/1.
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This thesis reviews literature relating both to the treatment of metal rich wastewaters by the use of constructed wetlands and the use of slurry analytical procedures for the determination of heavy metals in environmental micro-samples. A survey of metal contaminated wetland sites showed that aquatic plants maintain low levels of metals in aerial parts despite some very elevated sediment metal concentrations and extreme acidity. A series of greenhouse trials investigated the uptake of metals into aerial sections of Typha, Phragmites and Equisetum in long term hydroponic experiments. Phragmites was shown to accumulate zinc to a higher level than Typha. The toxicity of zinc supplied in the nutrient solution at 5 mg.dm-3 over long periods was found to limit the viability of such non-sediment based systems. A reliable routine analytical procedure was developed along with a program of quality control for the study of metal uptake into aquatic plants. A micro sampling technique, eminently suited for the analysis of small plant sections was developed. This technique uses ozone to ash the plant samples at a low temperature and following suspension in a liquid medium provides a sample ready for slurry determinations by a variety of analytical instrumentation. It is proposed that this method may also be suitable for the determination of metals in individual invertebrates and other zoological micro-samples as well as potential applications in the medical field.
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Peterson, Robert. "Interaction Effect of Filler Material on Fungal Biomass Activity for Heavy Metal Biosorption in Stormwater." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-14984.
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In the wake of ever more occurring and evident consequences brought by climate change such as droughts and an increasing world population, a responsible use and handling of freshwater has never been as important as before. Stormwater is more than often not treated and simply released back in nature with any kind of pollution it has collected on its way, one of which being heavy metals. By treating stormwater not only would this underutilised resource be made use of, creating a new source of freshwater, but environmental pollution caused by untreated stormwater could be potentially decreased, as it can be converted into a potential resource rather than a waste caused by nature. There are a number of already established methods to lower the concentration of heavy metals in water, however there are inherent economical and practical disadvantages with each of them. A method that has shown promising results with potential to challenge these contemporary solutions is biosorption. This study has explored the use of fungal biomass of Rhizopus oryzae for heavy metal biosorption in conjuncture with an organic filler material. The metals investigated were Zn, Cu and Fe. Moreover, the effects of pre-treating the fungal biomass with primarily NaOH were also investigated together with the optimal ratio between biomass and filler material and retention time, in order to maximise biosorption.Pre-treating the fungal biomass with NaOH resulted in a considerable increase in biosorption. Moreover, the presence of the filler material had a positive impact on biosorption by further enhancing it. The best effect was obtained at a 4:1 ratio between biomass and filler material. Finally, the best retention time was determined to be around 2 hours, slowly levelling off at higher retention times. However, the use of pre-treated R. oryzae with filler material did not prove to be efficient regarding the removal of heavy metal ions in stormwater at very low concentration of metals, between approximately 4 to 10 ppb. In the future, it would be worthwhile to investigate the viability of this method on stormwater with higher metal concentrations as well as looking into the effects of pH and temperature.Som en påföljd av de konsekvenser som klimatförändringen har orsakat, som till exempel svåra torkor tillsammans med en ökande världsbefolkning, har det blivit av allt större vikt att hanteringen av sötvatten sker på ett mer ansvarsfullt och hållbart sätt. Stormvatten brukar inte behandlas överhuvudtaget utan släpps tillbaka i miljön tillsammans med föroreningarna som det samlat på sig under sin väg, bland annat tungmetaller.Det finns redan ett antal metoder för att minska koncentrationen av tungmetaller i vatten, dock inte utan ekonomiska och praktiska svårigheter. Hur som helst så har det forskats en del kring en relativt ny metod som har tidigare visat goda resultat och skulle kunna konkurrera med befintliga lösningar, nämligen biosorption. I denna studie har man utforskat möjligheten att använda svampen Rhizopus oryzae tillsammans med ett organiskt fyllmedelsmaterial för biosorptionen av tungmetaller i stormvatten. De tungmetaller som undersöktes var Zn, Cu och Fe. Dessutom har man undersökt effekterna av ett förbehandlingssteg hos biomassan med NaOH tillsammans med det optimala förhållandet mellan biomassan och fyllemedelsmaterialet och retentionstiden för att maximera biosorptionen. Förbehandlingssteget visade en markant förbättring av biosorptionen. Fyllemedelsmaterialet hade för övrigt också en positiv inverkan genom att ytterligare öka biosorptionen. Ett 4:1 förhållande mellan biomassan och fyllemedelsmaterialet resulterade i det optimala förhållandet för komponenterna med tanke på biosorptionen. För retentionstiden visade det sig de bästa resultaten erhålles vid 2 timmar i lösningen. Emellertid visade det sig att användningen av den förbehandlade svampen tillsammans med fyllemedelsmaterialet inte var effektivt på stormvatten med en väldig låg tungmetallkoncentration, ungefär mellan 4 till 10 ppb. I framtiden skulle det vara intressant att undersöka inte bara metodens genomförbarhet på stormvatten med högre metallkoncentrationer, utan även hur pH-värde samt temperatur kan påverka resultaten.
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Diouf, Aissatou. "Effect of Organic Amendments on Heavy Metal Distribution and Uptake in Vegetable Gardens in Senegal." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/73036.
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The major constraints to food production in West Africa are related to the lack of suitable lands. Consequently, farmers incorporate organic amendments and wastewater to improve their yields. Within some limits, such wastes enhance soil fertility and can improve its physical properties. However, the advantages of using organic waste as fertilizer and soil amendment should be assessed with possible environmental and toxicological impacts due to the potential presence of heavy metals. The objective of this study was to assess the effect of organic amendments on heavy metal distribution in soils and vegetables in market gardens in Senegal. Organic amendments and soils samples were collected from four sites in eastern and southern Senegal. Samples were analyzed for physicochemical properties including particle size, total heavy metals, carbon content, nutrients, and pH. A sequential extraction procedure was conducted to determine heavy metal sinks. Results showed that sites were sandy in nature, low to medium in organic carbon content (8300 to 36600 mg kg-1), and had pH ranging from 5 to 7.9. The sequential extraction procedure showed that metals were distributed in the more stable soil fractions: Fe-Mn oxide, organic and residual. The highest soil metal concentrations in soils were found in Pikine and Rufisque sites. Plant samples were collected from these two sites and analyzed for total metal content. Results showed that all metal concentrations in soils, organic amendments, and vegetables were within the safe limits proposed by the World Health Organization, with the exception of Cd, Pb and Zn levels in vegetables.Master of Science
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Obbard, Jeffrey Philip. "The effect of heavy metals on microbial processes related to nutrient cycling in sewage sludged-amended soils." Thesis, Lancaster University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306430.
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Hagos, Mebrahtu T. "Effect of heavy metals on spawning and hatching of Penaeus indicus in KwaZulu-Natal (Amatikulu Prawn Farm)." Master's thesis, University of Cape Town, 2004. http://hdl.handle.net/11427/6262.
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Includes bibliographical references.Generally aquaculture continues to suffer from pollution and this has resulted in the decline of production. The effect of pollution can be directly on the organisations cultured causing immediate death or retarding their growth and making them vulnerable to a variety of diseases, or indirectly by reducing their reproductive capacity. This study was carried out to investigate the effect of zinc and lead on the hatched eggs, and zinc and copper on spawing and hatching of eggs from mature female Penaeus indicus. The experiment for each heavy metal was conducted separately. In the post-spawning experiment, hatched eggs were counted and exposed to 0.0, 0.1, 10., 10.0 and 100 ppm of zinc and lead to see the effect of the heavy metals on hatching of the eggs and survival of the hatched eggs. Concentrations of 0.0, 0.1 and 1.0 ppm of zinc and lead did not show signicant difference of hatch rate among each other but 10.0 and 100.0 ppm of zinc and lead gave significantly lower hatch rate as compared with the lower concentrations. Hatch rate completely failed at 100.0 ppm of both heavy metals.
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Serot, Julie Lynn. "Heavy metal analysis in Heaviside's dolphins (Cephalorhyncus heavisidii)." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/193469.
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Skin and blubber tissue samples were collected from two hundred and six freeranging Heaviside’s dolphins (Cephalorhyncus heavisidii) during January through June of 2008, 2009, and 2010, along the coast of South Western Africa, to be analyzed for heavy metal concentration levels. Inductively coupled mass spectrometry (ICP-MS) was used to determine sample solution concentrations of all metals (aluminum, arsenic, cadmium, chromium, copper, iron, lead, manganese, mercury, nickel, selenium and zinc). Data provided by this thesis is the first reference of its kind for this species (Cephalorhyncus heavisidii), which is one of the least-known cetacean species in the world. In addition to baseline heavy metal concentration information for the Heaviside’s dolphin, meaningful population structural and ecological information was obtained. A level of site fidelity or specific movement pattern across certain sites was indicated by the presence of different concentration levels across individuals sampled in different areas, especially adjacent areas. With an investigation into the potential sources of the marine heavy metal contamination, it was deduced that these sources contributed to each site’s unique and characteristic toxicological and hydrological profile as reflected by the bioaccumulation patterns seen in this study. It was confirmed by this study that bioaccumulation levels are a meaningful and novel measure of population structure. Potential evidence of differences in bioaccumulation patterns between sexes was observed in this study, as well. Although not definitive, a difference in metabolism, heavy metal elimination, or ranging pattern between males and females was suggested by the results. Variation in the results suggests a deepened level of complexity in the physiological and ecological aspects of trace elements accumulation and detoxification in the tissue of an apex predator like the Heaviside’s dolphin. Finally, a general assessment of health implications for the species was established, and it was found that Heaviside’s dolphins have higher than average mammalian trace element concentrations, and higher than average concentrations as specifically compared with other odontocetes. Further research using a larger sample size and using internal organs will provide more insight and a deeper understanding of the novel information presented here.published_or_final_version
Biological Sciences
Master
Master of Philosophy
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Butler, Reece. "Effect of Heavy Metals Found in Flue Gas on Growth and Lipid Accumulation for Green Algae Scenedesmus obliquus." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/1159.
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This study evaluated the effect of several heavy metals that are present in flue gases on the algae, focusing on the growth and accumulation of lipids in the algae that can be converted to biodiesel. Concentrations for the heavy metals were calculated based on literature and assumptions. Metals were tested individually first at the highest concentrations that might be present (reference concentrations). The metals and their reference concentrations were: arsenic at 1.56 mg/L, cadmium at 0.3 mg/L, chromium at 2.6 mg/L, cobalt at 0.32 mg/L, copper at 2.62 mg/L, lead at 1.09 mg/L, nickel at 5.08 mg/L, mercury at 0.2 mg/L, selenium at 0.2 mg/L, and zinc at 8.8 mg/L. At these concentrations, most of the metals had a negative effect on the growth and lipid content of the algae. All of the metals were then tested at lower concentrations. At 1/20 the reference concentrations, the metals enhanced growth as well as lipid accumulation in the algae. At higher concentrations there was a negative effect.
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Cornelissen, Stephanie. "The impact of copper on filamentous fungi and yeasts present in soil." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/16290.
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Thesis (MSc)--University of Stellenbosch, 2004.ENGLISH ABSTRACT: Numerous workers studied the impact of pollutants and agricultural chemicals, containing heavy metals such as copper (Cu), on soil microbes. It was found that elevated soil Cu levels do have a detrimental effect on soil bacterial populations however the filamentous fungi seemed to be less affected. Most of these studies were conducted in soils containing already relatively high Cu levels and the effect of this heavy metal on the nonfilamentous fungi (i.e. yeasts) was never investigated. The aim of this study was therefore to determine the impact of elevated Cu levels on filamentous fungi and yeasts occurring in soils containing relatively low natural Cu levels. A synthetic selective medium containing glucose as carbon source, thymine as nitrogen source, vitamins, minerals and chloramphenicol as anti-bacterial agent (TMV-agar), was used to enumerate ascomycetous and basidiomycetous Cu resistant yeasts in a sample of virgin soil containing ~ 2ppm Cu. Media that were used to enumerate Cu resistant filamentous fungi were malt extract agar, malt extract agar with streptomycin sulfate, maltyeast- extract-peptone agar with chloramphenicol and streptomycin sulfate, benomyl–dichloran-streptomycin medium for the enumeration of hymenomycetous fungi and two selective media for the isolation of mucoralean fungi. Cu resistant fungi able to grow on all of the above mentioned solid media supplemented with 32 ppm Cu occurred in the soil sample. To obtain an indication of the level of Cu tolerance of fungi present in this soil sample, a number of fungal isolates were screened for the ability to grow on a series of agar plates, prepared from glucose-glutamate-yeast extract agar, containing increasing concentrations of Cu. It was found that filamentous fungi and yeasts that were able to grow on this agar medium containing up to 100 ppm Cu were present in the soil. A series of soil microcosms was subsequently prepared from the soil sample by experimentally contaminating the soil with increasing amounts of copper oxychloride, were after fungal populations in the microcosms, including Cu resistant fungi, were monitored using plate counts. At the end of the incubation period, after 245 days, fungal biomass in the microcosms was compared by determining the concentrations of the fungal sterol, ergosterol, inthe soil. Generally, Cu had little impact on the numbers of filamentous fungal colony forming units on the plates, as well as on the ergosterol content of the soil. The numbers of filamentous fungi in the soil, including the Mucorales and hymenomycetes, seemed to be less affected by the addition of copper oxychloride than the numbers of soil yeasts able to grow on TMV-agar. The focus of the next chapter was on the response of yeasts in different soils to elevated levels of Cu in the soil. TMV-agar was used to enumerate yeasts in soil microcosms prepared from four different soil samples, which were experimentally treated with copper oxychloride resulting in Cu concentrations of up to 1000 ppm. The selective medium supplemented with 32 ppm Cu was used to enumerate Cu resistant yeasts in the microcosms. The results showed that the addition of Cu at concentrations ≥ ~1000 ppm did not have a significant effect on total yeast numbers in the soil. Furthermore, it was found that Cu resistant yeasts were present in all the soil samples regardless of the amount of Cu that the soil was challenged with. At the end of the incubation period, yeasts in the microcosms with zero and ~1000 ppm additional Cu were enumerated, isolated and identified using sequence analyses of the D1/D2 600-650bp region of the large subunit of ribosomal DNA. Hymenomycetous species dominated in the control soil, while higher numbers of the urediniomycetous species were found in the soil that received Cu. These observations suggest that urediniomycetous yeasts may play an important role in re-establishing overall microbial activity in soils following perturbations such as the addition of Cu-based fungicides.
AFRIKAANSE OPSOMMING: Vele navorsers het al die impak van besoedelingstowwe en landbouchemikalieë wat swaarmetale soos koper (Cu) bevat, op grond-mikrobes bestudeer. Dit is gevind dat verhoogde Cu vlakke ‘n nadelige effek het op grond-bakteriese populasies, maar dat die filamentagtige fungi geneig is om minder geaffekteer te word. Meeste van hierdie studies is gedoen met gronde wat alreeds relatief hoë Cu vlakke bevat het en die effek van hierdie swaarmetaal op die nie-filamentagtige fungi (d.i. giste) is nooit ondersoek nie. Die doel van hierdie studie was dus om die impak van verhoogde Cu vlakke op filamentagtige fungi en giste in gronde, wat natuurlike lae vlakke van Cu bevat, te bepaal. ‘n Sintetiese selektiewe medium wat glukose as koolstofbron, timien as stikstofbron, vitamiene, minerale asook chloramfenikol as anti-bakteriese agent bevat (TMV-agar), is gebruik om askomisete en basidiomisete Cu weerstandbiedende giste in ‘n monster ongeskonde grond, bevattende ~ 2dpm Cu, te tel. Media wat gebruik is om Cu weerstandbiedende filamentagtige fungi te tel, was mout-ekstrak agar, moutekstrak agar met streptomisiensulfaat, benomiel-dichloran-streptomisien medium vir die tel van hiemenomiseetagtige fungi en twee media vir die isolasie van mukoraliese fungi. Cu-weerstandbiedende fungi wat op al die bogenoemde media, aangevul met 32 dpm Cu, kon groei, het in die grondmonster voorgekom. Om die mate van Cu-weerstandbiedendheid van fungi wat in die grondmonster voorkom, te bepaal, is ‘n getal fungus-isolate op agarplate, voorberei met glukose-glutamaat-gis ekstrak agar, bevattende verhoogde konsentrasies Cu, nagegaan. Daar is gevind dat daar filamentagtige fungi en giste in die grond voorkom wat die vermoë het om op media bevattende 100 dpm Cu te groei. ‘n Reeks grond mikrokosmosse is dus voorberei vanaf die grondmonster deur om dit eksperimenteel te kontamineer met verhoogde hoeveelhede koper oksichloried, waarna die fungus-populasies asook die Cu-weerstandbiedende fungi in die mikrokosmos gemoniteer is deur middel van plaattellings. Aan die einde van die inkubasie periode, 245 dae, is die fungus biomassa in al die mikrokosmosse bereken deur die konsentrasie van die fungus sterool ergosterool te bepaal en dit met mekaar te vergelyk. Oor die algemeen het Cu min impak ten opsigte van diegetal filamentagtige fungi kolonie vormende eenhede die plate, asook op die ergosterool inhoud van die grond gehad. Dit wil voorkom of die getal filamentagtige fungi in die grond, insluitende die Mucorales en die hymenomisete, minder geaffekteer is deur die toediening van koperoksichloried as die aantal grondgiste wat op die TMV-agar kan groei. Die fokus van die volgende hoofstuk was dus op die reaksie wat giste in verskillende grondtipes gehad het op verhoogde Cu in die grond. TMV-agar is gebruik om die getal giste te bepaal in die grond mikrokosmosse van die vier verskillende grondmonsters, wat voorberei is deur om dit eksperimenteel met koper oksikloried te kontamineer tot en met Cu konsentrasies van 1000 dpm. Die selektiewe medium wat gesupplementeer is met 32 dpm Cu, is gebruik om Cu weerstandbiedende giste in die mikrokosmosse te bepaal. Die resultate toon dat die toevoeging van Cu by konsentrasies ≥ ~1000 dpm nie enige beduidende effek op die totale gis getalle gehad het nie. Daar is ook gevind dat daar Cu weerstandbiedende giste in die grond monsters voorkom gekom het ten spyte van die hoeveelheid Cu wat tot die grond toegevoeg is. Aan die einde van die inkubasie periode is die giste wat die die mikrokosmosse bevattende nul en ~1000 dpm Cu getel, geïsoleer en geïdentifiseer deur gebruik te maak van DNA volgorde bepaling van die D1/D2 600-650 bp areas geleë in die groter subeenheid van die ribosonale DNA. Hymenomisete spesies het in die grond kontrole gedomineer, terwyl hoër getalle uredinomisete spesies in die grond met addisionele Cu gevind is. Die resultate dui daarop dat uredinomisete giste dalk ‘n belangrike rol kan speel in die hervestiging van die oorwegende mikrobiese aktiwiteit in grond na skoktoestande soos die aanwending van Cu-gebaseerde fungisiede.
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Deng, Hong. "Metal (Pb, Zn, Cu, Cd, Fe) uptake, tolerance and radial oxygen loss in typical wetland plants." HKBU Institutional Repository, 2005. http://repository.hkbu.edu.hk/etd_ra/629.
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Farris, Jerry L. "Cellulolytic responses to heavy metal accumulation in Corbicula fluminea and Mudalia dilatata." Diss., This resource online, 1986. http://scholar.lib.vt.edu/theses/available/etd-01242009-063436/.
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Piola, Richard Fabio Biological Earth & Environmental Sciences Faculty of Science UNSW. "Differential tolerance of introduced & native marine invertebrates to heavy metal pollution." Publisher:University of New South Wales. Biological, Earth & Environmental Sciences, 2007. http://handle.unsw.edu.au/1959.4/40673.
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In near-shore marine environments, two of the most prevalent anthropogenic disturbances affecting ecosystem diversity and function are the invasion of exotic species, and the release of toxic chemicals. Estuarine and harbour environments worldwide are dually subjected to high levels of toxic disturbance and ever increasing rates of invasion, via activities such as boating and shipping. It is not clear, however, whether the success of invasive species is influenced by the presence of toxic contaminants in these impacted environments. In particular, nonindigenous marine species (NIS) may be advantaged in chemically disturbed environments if they are more tolerant of toxicants. This thesis examines whether nonindigenous and native sessile invertebrate species have differential tolerance to a common aquatic contaminant, copper (Cu), which has links to both the invasion process (via its use in antifouling paints and the vector of hull fouling) and the modification of recipient environments (via human-mediated pollution). A series of laboratory- and field-based experiments showed that the cosmopolitan invasive bryozoans Watersipora subtorquata, Bugula neritina and Schizoporella errata are highly tolerant of copper pollution. The larvae and adults of W. subtorquata and B. neritina in particular were able to survive and grow in copper-polluted environments far exceeding most observed real-world levels (< 100 /??g 1-1). These nonindigenous species also showed very strong postexposure recovery. In contrast, the co-occurring native bryozoans Celleporaria nodulosa and Fenestrulina mutabilis demonstrated comparatively low tolerance to copper, with markedly reduced survival and fitness under Cu contaminated conditions, and inferior recovery abilities post-exposure. These findings were further supported by a long-term manipulative field experiment, examining the effect that varying levels of Cu exposure have on the structure and diversity of developing sessile invertebrate assemblages. Cu exposure decreased native species diversity by up to 50%, yet had no effect on NIS numbers. Consequently, in the presence of copper contamination, NIS dominated sessile communities, often resulting in substantial changes to community structure. Important insights were also gained into the nature of metal tolerance in NIS. Toxicity studies on larvae of the introduced bryozoan Bugula neritina revealed intraspecific differences in tolerance to Cu, associated with the level of pollution experienced by the adult source populations. There was also evidence of fitness costs related with increased Cu tolerance. In summary, we have found evidence that the success of invasive species is influenced by chemical contamination. NIS may be advantaged in contaminated estuaries relative to native species and this may assist in their establishment and persistence in new habitats.
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Wu, Yonghong 1969. "Bioavailability and rhizotoxicity of trace metals to pea : development of a terrestrial biotic ligand model." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103309.
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Risk assessment of trace-metal contamination in soils requires predictive models that can accurately describe the complex uptake processes at the soil-plant interface, which are usually characterized by the coexistence of and interaction between multiple components. Competing cations such as Ca and H can affect metal availability to plants and subsequent rhizotoxicity. The biotic ligand model (BLM) has been proposed as a promising approach to model these interactive processes. Under the BLM assumption, we designed experiments to investigate how the solution chemistry is correlated with metal uptake and rhizotoxicity. Our first goal is to acquire a set of BLM parameters that can accurately represent the experimental data over varied solution conditions and parameters that are easy to integrate with general speciation models. The second objective is to get insight into the physical nature of the interactions. Our titration experiments revealed three types of biotic ligands in the pea roots with defined site densities and stability constants with H. Our ion sorption experiments estimated the surface-adsorption stability constants of Ca, Mg, Cd, Cu, Ni, and Zn with excised fresh pea roots. Our 48-h root growth tests have established the formation constants (KMe's) of living pea roots with Ca, Cd, Cu, Ni, and Zn. In these studies, we hypothesized and confirmed that the concentration of the metal-root complexes correlated with observed rhizotoxicity and that Ca, H, and trace metals competed for root absorption where lower solution pH decreased both Ca and metal uptake. Root elongation was found to be highly sensitive to root Ca content rather than merely to the direct toxic effects of the trace metals. It is shown that the physiological complexity arising from a living root affected our modeling so that adjustable KMe values, as a function of solution and root chemistry, are required for good model fits. The established model parameters were tested in hydroponic mixture solutions for their ability to predict the uptake of multiple metals simultaneously. The joint effects of Cd, Cu, and Ni in mixtures on root growth were studied and the potential interactions between these ions were also investigated.
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LESSA, MARCUS PAULO FOURNIER. "STUDY OF EFFECT FOR APLICATION TO A HUMIC COMPOUND OF MINERAL SOURCE ON HEAVY METALS PRESENTS IN SEWAGE SLUDGE." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2004. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=5924@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCom base no procedimento EPA-3050B, estudou-se o teor de metais (Cd, Cr, Cu, Ni, Pb, e Zn) em lodos de esgoto da CETESB. Foram analisadas duas amostras e os resultados obtidos foram (Cd =3,4 ; Cr =367,5 ; Cu =263,0 ; Ni=290,6 ; Pb =91,5 ; Zn =1324,9 mg/ kg) para primeira amostra e (Cd =3,0 ; Cr =332,2 ; Cu =190,5 ; Ni=274,6 ; Pb =82,5 ; Zn =1284,2 mg/ kg) para segunda amostra, resultados estes inferiores aos descritos pela CETESB para amostras de lodo da mesma estação de tratamento. Dada uma potencial utilização deste material como adubo agrícola, foi determinada a fração disponível destes metais. Com exceção do níquel (25%), uma fração pequena dos metais estudados encontra-se na forma assimilável pelas plantas (< 20%), com base no procedimento descrito pela EMBRAPASolos (extração com DTPA). Os efeitos de uma eventual utilização de composto húmico mineral (CHM) como aditivo ao lodo, visando uma redução na fração assimilável de metais, foi estudada em função da quantidade de CHM aplicado e do pH da solução final. Os resultados obtidos demonstraram que o CHM possui um poder de complexação para os metais semelhante ao do DTPA e que, sua aplicação ao lodo de esgoto, teria, na realidade um efeito de potencializar a fração disponível de certos metais como o zinco.
Based on the EPA-3050B procedure, the concentration of metals (Cd, Cr, Cu, Ni, Pb and Zn) in sludge source at CETESB studied. Two samples were analyzed and the results obtained were (Cd =3,4 ; Cr =367,5 ; Cu =263,0 ; Ni=290,6 ; Pb =91,5 ; Zn =1324,9 mg/ kg) and (Cd =3,0 ; Cr =332,2 ; Cu =190,5 ; Ni=274,6 ; Pb =82,5 ; Zn =1284,2 mg/ kg). These concentrations were below those descried by SABESP for sludge samples measured in the same treatment station. Due to the potential utilization of these materials as manure in agriculture, the disposal fraction of these metals was determined. Except nickel (25%), a little fraction of metals studied is assimilated by plants (< 20%), base on the procedure already descried by EMBRAPA- Solos (extraction with DTPA). The effect of an eventual utilization to humic mineral compound (HMC), as additive in sludge, aiming the reduction of the assimilated fraction of metals, were studied in function of both, the amount of HMC applied and the final pH of the solution. The results obtained showed that HMC has a complexation potential for metals similar to DTPA and that, its application in sludge, has in fact, a potential effect on the disposal fraction of metals such as zinc.
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O'Malley, Kristen Marie. "Comparative sensitivity of the early life history stages of the Blue Crab, callinectes sapidus, to mercury exposure." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/25200.
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"Concentration of heavy metals in tissues of cultured marine fish in Hong Kong." 1998. http://library.cuhk.edu.hk/record=b5889699.
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by Wong Pik-kwan.Thesis submitted in: September 1997.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.
Includes bibliographical references (leaves 116-139).
Abstract also in Chinese.
ABSTRACT --- p.i
ACKNOWLEDGEMENT --- p.iii
TABLE OF CONTENTS --- p.iv
LIST OF TABLES --- p.viii
LIST OF FIGURES --- p.ix
Chapter CHAPTER ONE --- GENERAL INTRODUCTION --- p.1
Chapter CHAPTER TWO --- LITERATURE REVIEW
Chapter 2.1 --- Introduction --- p.4
Chapter 2.2 --- Heavy metals --- p.6
Chapter 2.3 --- Mechanisms of metal toxicity --- p.9
Chapter 2.4 --- Toxic effects of metals on marine organisms --- p.10
Chapter 2.4.1 --- Cadmium --- p.10
Chapter 2.4.2 --- Chromium --- p.10
Chapter 2.4.3 --- Copper --- p.11
Chapter 2.4.4 --- Lead --- p.12
Chapter 2.4.5 --- Nickel --- p.12
Chapter 2.4.6 --- Zinc --- p.13
Chapter 2.5 --- Metal uptake and elimination in marine organisms --- p.14
Chapter 2.5.1 --- Uptake of metals --- p.14
Chapter 2.5.2 --- Elimination of metals --- p.15
Chapter 2.5.3 --- Metal detoxification system in fish --- p.16
Chapter 2.6 --- Heavy metals in marine fish --- p.17
Chapter 2.7 --- Bioaccumulation --- p.20
Chapter 2.7.1 --- Models of metal accumulation --- p.21
Chapter 2.7.2 --- Compartment model --- p.21
Chapter 2.7.3 --- Physiologically based pharmacokinetic (PB-PK) model --- p.22
Chapter 2.8 --- The influence of environmental factors on bioaccumulation of metals --- p.23
Chapter 2.8.1 --- Temperature --- p.23
Chapter 2.8.2 --- Salinity --- p.23
Chapter 2.8.3 --- Organic matter --- p.24
Chapter 2.8.4 --- pH --- p.25
Chapter 2.8.5 --- Chelators and surfactants --- p.25
Chapter 2.8.6 --- Other metals --- p.26
Chapter 2.9 --- Biological effects of heavy metals on man --- p.26
Chapter 2.10 --- The use of biological indicator organisms for metal pollution --- p.28
Chapter CHAPTER THREE --- HEAVY METAL CONCENTRATIONS IN CULTURED MARINE FISH IN HONG KONG
Chapter 3.1 --- Introduction --- p.31
Chapter 3.2 --- Materials and methods --- p.36
Chapter 3.2.1 --- Sampling --- p.36
Chapter 3.2.2 --- Water analysis --- p.36
Chapter 3.2.3 --- Sediment analysis --- p.39
Chapter 3.2.4 --- Mussel analysis --- p.40
Chapter 3.2.5 --- Fish analysis --- p.40
Chapter 3.2.6 --- Quality control and statistical analysis --- p.41
Chapter 3.3 --- Results --- p.42
Chapter 3.3.1 --- Seawater --- p.42
Chapter 3.3.2 --- Sediment --- p.46
Chapter 3.3.3 --- Mussel --- p.46
Chapter 3.3.4 --- Fish --- p.50
Chapter 3.4 --- Conclusion --- p.67
Chapter 3.4.1 --- "Metal concentration in seawater, sediment, green mussel and fish" --- p.67
Chapter 3.4.2 --- Accumulation of heavy metals in different tissues of cultured fish --- p.69
Chapter 3.4.3 --- Relationship between the body weight and metal accumulation --- p.71
Chapter 3.4.4 --- Heavy metal pollution in fish culture sites --- p.72
Chapter 3.4.5 --- Selection of fish culture site --- p.72
Chapter CHAPTER FOUR --- ACUTE AND SHORT-TERM EFFECTS OF COPPER(II) IONS ON SPARUS SARBA
Chapter 4.1 --- Introduction --- p.76
Chapter 4.2 --- Materials and methods --- p.79
Chapter 4.2.1 --- Experimental animals --- p.79
Chapter 4.2.2 --- Determination of the 96 hour median lethal concentrations --- p.19
Chapter 4.2.3 --- Determination of growth rate --- p.80
Chapter 4.3 --- Results --- p.82
Chapter 4.3.1 --- Determination of the 96 hour median lethal concentrations --- p.82
Chapter 4.3.2 --- Determination of growth rate --- p.82
Chapter 4.3.3 --- Distribution of Cu concentration in whole body and different tissues of S. sarba --- p.82
Chapter 4.4 --- Conclusion --- p.91
Chapter 4.4.1 --- Determination of the 96 hour median lethal concentrations --- p.91
Chapter 4.4.2 --- Determination of growth rate --- p.93
Chapter 4.4.3 --- Distribution of Cu concentration in whole body and different tissues of S. sarba --- p.94
Chapter CHAPTER FIVE --- ACCUMULATION AND ELIMINATION OF COPPER(II) IONS TO SPARUS SARBA
Chapter 5.1 --- Introduction --- p.96
Chapter 5.2 --- Materials and methods --- p.98
Chapter 5.2.1 --- Experimental animals --- p.98
Chapter 5.2.2 --- Uptake and elimination of Cu ion in S. sarba during continuous exposure to waterborne Cu --- p.98
Chapter 5.3 --- Results --- p.100
Chapter 5.4 --- Conclusion --- p.108
Chapter CHAPTER SIX --- GENERAL CONCLUSION --- p.112
CHAPTER SEVEN REFERENCES --- p.116
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Kruger, Taneshka. "Effects of zinc, copper and cadmium on Oreochromis mossambicus free-embryos and randomly selected mosquito larvae as biological indicators during acute toxicity testing." Thesis, 2008. http://hdl.handle.net/10210/1145.
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M.Sc.Aquatic toxicology is the qualitative and quantitative study of toxic effects of pollutants on aquatic organisms. The main goal in toxicity testing is to predict, in combination with other environmental factors, with known accuracy, a concentration of a specific toxicant that will not harm a system and to make this prediction in a responsible and cost effective manner. There are a variety of unique toxicity tests, with fish being one of the most popular organisms to work with, due to being the best-understood organism in the aquatic environment and its commercial importance. Zinc, copper and cadmium are three biologically important heavy metals that are commonly used in various industries. Low concentrations zinc and copper are essential micronutrients for both plants and animals, but in higher concentrations they become toxic to the environment and its biota. Cadmium has a chemical structure similar to that of zinc and is often found in association with it, but it is a very toxic substance. The effects of zinc, copper and cadmium on the free-embryo life stage (yolk sac phase) of Oreochromis mossambicus were examined, for evaluation as a possible ¡§early life stage¡¨ fish lethality assessment. ¡§Fish early life stage tests¡¨ are considered to be relatively quick, comparable and inexpensive screening tools for testing effluents and chemicals. The yolk-sac stage is considered the most sensitive life stage in fish. O. mossambicus free-embryos feed endogenously and are indigenous to southern Africa and are therefore a good choice for lethality testing. The effects of the same metals on randomly selected Culicidae (mosquito) larvae were also tested. The reason for randomly selected larvae was to determine the possibility of doing toxicity testing without a species-specific culture. Mosquitoes are very common and well known due to being vectors of various human diseases. Recommendations towards future studies, to determine the usefulness of both O. mossambicus embryos and Culicidae larvae as biological indicator organisms, were also looked at.
Prof. G.J. Steyn