Dissertations / Theses on the topic 'Pollution and contamination'
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MacDougall, Kenneth Alasdair. "Groundwater contamination : a risk based approach." Thesis, University of Strathclyde, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366814.
Full textKortbaoui, Ziad S. "The sea shore contamination of the Lebanese coast /." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27537.
Full textSome 125 samples were then analyzed for the presence of Cadmium and Mercury by atomic absorption spectrophotometry. Cadmium content, holding a mean 0.77 $ mu$g/L, was generally low for most areas with only a few elevated readings in Tripoli (1.89 $ mu$g/L), Checca (1.83 $ mu$g/L), Kaslik (0.79 $ mu$g/L), Beirut (1.19 $ mu$g/L) and Ramlet Al-Bayda (1.77 $ mu$g/L). Mercury content, holding a mean value of 0.06 mg/Kg (wet weight), was below the accepted tolerance limit of 0.5 mg/Kg for all sampling sites.
Some 128 samples were then analyzed for fecal coliforms (Escherichia coli and Streptococcus feacalis). Approximately, 50% of the sampling stations showed satisfactory results (less than 100 colonies/100 ml). High counts of fecal coliforms, over 500 colonies/100 ml, collected at Dora, Ramlet Al-Bayda and Antelias, reveal poor sea water quality and a public health hazards to swimmers and fishermen.
Some 36 samples were collected and analyzed for dissolved oxygen (DO), pH, salinity and temperature. For all sites sampled, DO averaged 4.03 mg/L, pH averaged 7.97, salinity averaged 38.77 ppt and temperature averaged 27.9$ sp circ$C.
The degree of pollution was found to be related to population density, industrial and human activity, continental runoffs and hydrological and meteorological conditions.
Trowsdale, Sam A. "The depth of penetration of contamination in urban groundwater." Thesis, University of Sheffield, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269320.
Full textBurton, Susan Mary. "Evaluation of stream meiofauna as a monitor of trace metal contamination." Thesis, University of Plymouth, 1998. http://hdl.handle.net/10026.1/2168.
Full textHalstead, John Michael. "Managing ground water contamination from agricultural nitrates." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54787.
Full textPh. D.
Harrison, Adrian Briscoe. "Hydrocarbon pollution of soil : effects on microbial populations and biomediation methods." Thesis, University of York, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362025.
Full textPrintes, Liane Biehl. "The value of acetylcholinesterase activity in Daphnia as a biomarker of environmental contamination." Thesis, University of Reading, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288746.
Full textPayne, Rosara Faith. "Investigation of radiological contamination of soil samples from Idaho National Laboratory." Diss., Online access for everyone, 2006. http://www.dissertations.wsu.edu/Dissertations/Summer2006/r%5Fpayne%5F053106.pdf.
Full textChoi, Chung-ming. "Land contamination and its remediation methods : a case study in Hong Kong /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B14709156.
Full textWeemees, Ilmar Andrew. "Development of an electrical resistivity cone for groundwater contamination studies." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28730.
Full textApplied Science, Faculty of
Civil Engineering, Department of
Graduate
Tu, Wai-ki Alex. "Hong Kong marine sediment contamination with Tributyltin and its impacts /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22285180.
Full textOtt, Cindy Lee. "Groundwater and surface water contamination by fire retardants at Abbotsford Airport." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24893.
Full textGraduate and Postdoctoral Studies
Graduate
Casper, Susan Theresa. "Contamination, bioavailability and speciation of metals from copper processing industry in the Churnet River valley, Staffordshire, UK." Thesis, University of Derby, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270033.
Full textO'Shea, Francis Timothy. "Assessment of diffuse pollution originating from estuarine historical landfills." Thesis, Queen Mary, University of London, 2016. http://qmro.qmul.ac.uk/xmlui/handle/123456789/12995.
Full textMa, Kit-cheong James. "Hong Kong Government criteria for assessing contamination levels of dredged marine sediments /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22264474.
Full textBuco, Stéphanie. "Métrologie de la contamination des sols par les hydrocarbures aromatiques polycycliques." Aix-Marseille 3, 2001. http://www.theses.fr/2001AIX30098.
Full textThe Polycyclic Aromatic Hydrocarbons (PAHs) are proven to be major pollutants because of their mutagenic and carcinogenic properties. These compounds raised up many "on-site" or laboratory methods developments. The in situ methods are used for a rapid screening of contaminated soils and can be completed by laboratory analyses to give more accuracy. The aim of this study was to develop new methods with the minimization of the "on-site" and laboratory methods drawbacks which are respectively low accuracy, cost and analysis time. It appears from our laboratory study that the Curie-point pyrolysis-gas chromatography/mass spectrometry (Cpp-GC/MS) is an efficient alternative method for the PAHs determination. We obtained similar results compared to classical methods, with short operating time and without solvent consumption. The in situ methodology is based on a "on-site" extractor, developed during this work and UV spectrophotometric measurements (Pastel-UV). This methodology has proved to be a fast, quantitative and qualitative screening of contaminated soils by PAHs. The results show that our "on-site" extractor is more efficient than the usual "hand shaking" methods. A correlation was established between laboratory and "on-site" results to near to real PAHs concentration
Harries, Julie Elizabeth. "A study of the extent of estrogenic contamination of English inland waters." Thesis, Brunel University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336703.
Full textMontague, David Joel. "Managing agricultural contamination of ground water: the institutional framework." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43408.
Full textPaisse, Sandrine. "Etude de la réponse d’une communauté bactérienne de sédiments côtiers à une contamination pétrolière." Pau, 2009. http://www.theses.fr/2009PAUU3015.
Full textCoastal zones are highly productive environments chronically exposed to hydrocarbon contamination. Bacterial communities inhabiting these ecosystems play key role in biogeochemical processes and often form microbial mats in which microorganisminteractions are enhanced. In order to characterize the modifications occurring in the bacterial community during oil spill, the bacterial community response of Etang-de-Berre coastal sediment to oil contamination was studied based on in situ analysis of natural bacterial communities as well as on microcosm experiments. First the investigation of the in situ natural bacterial communities inhabiting sediments in a gradient of hydrocarbon concentrations revealed an important adaptation of the bacterial community to the oil contamination. We then explored the early response of the bacterial community to cope with the oil contamination. Analyses based on 16S rRNA genes and their transcripts revealed structural modifications occurring in the first hours and the first days following the contamination. The diversity and the expression of functional genes involved in hydrocarbon degradation such as alkane monooxygenase and naphthalene dioxygenase were investigated. These genes were immediately expressed in response to the oil addition while concomitantly high rates of hydrocarbon biodegradation were observed. Thus these results indicated important adaptative mechanisms during the first two days following the contamination. In order to further characterize this mechanism at the whole bacterial community level, we then performed the identification of genes repressed and/or overexpressed in response to oil addition
Svendsen, Claus. "Earthworm biomarkers in terrestrial ecosystems." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326956.
Full textLucas, Jean-Paul. "Contamination des logements par le plomb : prévalence des logements à risque et identication des déterminants de la contamination." Nantes, 2013. http://archive.bu.univ-nantes.fr/pollux/show.action?id=ee1e7f1b-e1e9-455c-afa8-ea7f68143c8e.
Full textResidential lead levels were estimated for the first time in mainland France. For this, tools of the theory of survey sampling were applied to the data of the Plomb-Habitat survey (2008-2009). A sample of 484 dwelling was drawn to study the population (N = 3 581 991) of the main residences (as opposed to second home) where at least one child aged 6 months to 6 years was present. Approximately 2. 9% of housing units have a lead concentration in tap water higher or equal than the regulatory threshold (RT) of 10 µg/L; in approximately 0. 21% of dwellings and in 4. 1% of common areas the American RT of 430 µg/m² (40 µg/ft²) was exceeded for interior floor dust lead; 1. 4% of exterior play area soils exceed the American RT of 300 mg/kg of lead; 24. 5% of housing units have still lead-based paint. Lead in floor dust was pointed out as the main predictor of blood lead level in children. A multilevel model with 2 levels was fitted to explain the floor dust lead loadings of the 1834 rooms as level-1 units investigated in the homes considered as level-2 units. No weights was used in the estimation method (pseudolikelihood) used for this kind of modeling on survey data. Dust of the landing of an apartment is the main contributor to the contamination of dust by lead. A simulation study was carried out from our data to compare the different weights for the level-2 units of a multilevel model. Its result enabled us to confirm the fitting of an unweighted model to explain the dust lead loadings. Until now, only the level-1 weights had been studied in the literature for this kind of model
Leeming, Rhys, and n/a. "Coprostanol and related sterols as tracers for feacal contamination in Australian aquatic environments." University of Canberra. School of Resource, Environmental & Heritage Sciences, 1996. http://erl.canberra.edu.au./public/adt-AUC20060816.172519.
Full textCosson, Richard P. "Influences des pratiques agricoles sur la contamination des écosystèmes aquatiques par les métaux lourds : approche écotoxicologique." Paris 11, 1987. http://www.theses.fr/1987PA112209.
Full textLarno, Valérie. "Réponses génétiques et physiologiques de populations de Chevaine (Leuciscus cephalus) à la contamination chimique dans le bassin du Rhône." Lyon 1, 2004. http://www.theses.fr/2004LYO10241.
Full textShuping, Likentso Sylvia. "Biomonitoring of metal contamination in the lower Diep River, Milnerton, Western Cape." Thesis, Cape Peninsula University of Technology, 2008. http://hdl.handle.net/20.500.11838/786.
Full textThe lower Diep River is a major freshwater ecosystem in the Western Cape. The river is surrounded by many possible sources of metal pollution such as an oil refinery, industries, a sewage treatment plant and a landfill site. However, metal contamination levels have not been monitored in this river. The aim of the study was therefore to monitor the degree of metal pollution in the lower Diep River, over a period of one year, and to investigate the use of the sedge Bolboschoenus maritimus, as biomonitor species. Three sampling sites were used. Site I was located in the vicinity of landfill sites and farm areas. Site 2 was located I km upstream from a wetland reserve, surrounded by heavy industrial activity and continuous residential developments. Site 3 was located downstream of the wetland reserve, 2 km from the river mouth. The following metals were investigated: aluminium, cadmium, chromium, cobalt, copper, iron, lead, manganese, nickel and zinc. Water and sediment samples were collected every two months for a period of one year. Plant specimens (roots, leaves and stems) were collected seasonally from site I and site 3. Samples were acid digested and metal analysis was done using an ICP - AES (Inductively Coupled Plasma- Atomic Emission Spectrophotometer). Statistical analyses were done to investigate possible differences between the sites, sampling occasions and various plant components.
Williams, Benjamin Deeter. "Uranium contamination of vadose zone sediments from the Hanford U single shell tank farm." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/B_Williams_112709.pdf.
Full textTitle from PDF title page (viewed on Jan. 26, 2010). "School of Earth and Environmental Sciences." Includes bibliographical references (p. 48-51).
Korre, Anna. "A methodology for the statistical and spatial analysis of soil contamination in GIS." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266111.
Full textLafabrie, Céline. "Utilisation de Posidonia oceanica (L. ) Delile comme bio-indicateur de la contamination métallique." Corte, 2007. http://www.theses.fr/2007CORT3098.
Full textThe coastal zone of the continental shelf contains a high ecological richness. However, this zone is very fragile towards xenobiotics ; the pollution of this environment can be damaging to the structure of the biocenoses and to the productivity of the ecosystems. Metals, contrarily to numerous contaminants, are normal constituents of the environment at a trace level, but are all toxic above a certain threshold. At the end of the 1970s, several researchers proposed the use of organims to evaluate the quality of the marine environment ; it is in this context that the bio-indicator concep arises. The seagrass Posidonia oceanica (L. ) Delile, endemic of the Mediterranean Sea, has been the subject of several work proposing to use this species to determine the metal concentrations of the environment. However, most studies carried out explorative research in order to qualify this species as bio-indicator. The results of this work validate the use of Posidonia oceanica as a reliable tool for the evaluation of metal contamination of coastal ecosystems. Inded, this work allowed : ( i ) to better understand the trace metals accumulation processes by Posidonia oceanica (influence of age and growth of foliar tissues in the metal accumulation ); (ii) to confirm the high sensitivy of this species as a tracer of metal contamination (identification of metal inputs associated to the previous asbestos mine of Canari and evaluation of the extent of the impact of this previous exploitation) ; (iii) to confirm its reliability as bio-indicator of metal contamination (same trends observed for this species and the bio-indicator Mytilus galloprovincialis Lamark,1819). Therefore, Posidonia oceanica appears as an interesting tool in the frame of setting up biomonitoring networks at the scale of the Mediterranean Sea. A technique, which consists in collecting only the blades of the adult leaves is proposed insofar as it will allow to carry out trace metals analyses without inducing the mortality of the plant (protected species in numerous Mediterranean countries) and conserving its integrity. Preliminary scales to interpret the level of metal contamination in the environment have equally been proposed for cadmium, mercury, nickel and lead (priority subtances ; Decision N° 2455/2001/EC ; EC, 2001). Finally, this work shows equally the possible use of Posidonia oceanica as a "tracer" of the past mercurial contamination thanks to the lepidochronology technique
Ginnever, Rhoda C. "Soil and plant contents of lead and other trace elements with special reference to the influences of parent rock and pollution." Thesis, Aberystwyth University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324309.
Full textBrostrom, Kathleen A. "Are Fecal Sterols a Possible Alternative Indicator of Human Waste Contamination in Hawaiian Recreational Waters?" Thesis, Water Resources Research Center, University of Hawaii at Manoa, 2005. http://hdl.handle.net/10125/22259.
Full textBensoussan, Hélène. "Effets d'une contamination à l'uranium sur le système cholinergique : approches in vivo et in vitro." Paris 11, 2009. http://www.theses.fr/2009PA11T073.
Full textSuvornmongkhol, Narumon. "Uptake of radionuclides by wheat roots with respect to location of contamination below the surface." Thesis, Online version, 1996. http://ethos.bl.uk/OrderDetails.do?did=2&uin=uk.bl.ethos.321557.
Full textDubé, Jean-Sébastien. "Modifications hydrodynamiques du comportement des métaux lourds dans un sol hétérogène présentant une contamination résiduelle en NAPL : étude sur la contamination mixte des sols." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ65448.pdf.
Full textLang, Cassandra C., and University of Lethbridge Faculty of Arts and Science. "Identification and metabolic characterization of host-specific enterococci for use in source-tracking faecal contamination." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2005, 2005. http://hdl.handle.net/10133/265.
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Tayab, Muhammad Rehan. "Environmental impact of heavy metal pollution in natural aquatic systems." Thesis, Brunel University, 1991. http://bura.brunel.ac.uk/handle/2438/5503.
Full textDupuy, Alain. "Simulation de la contamination diffuse des eaux souterraines par les nitrates à l'échelle du bassin versant." Poitiers, 1997. http://www.theses.fr/1997POIT2306.
Full textGhosn, Micheline. "Chemical contamination in different marine organisms along the Lebanese coast : Environmental implications and health risks." Thesis, Littoral, 2019. http://www.theses.fr/2019DUNK0552.
Full textGlobal food fish consumption has been in continuous increase and fishery products have become some of the most traded items in the world. However, the quality of these products is becoming an issue of concern to human health with the increase of anthropogenic activities threatening marine coastal ecosystems. Therefore, despite the well-known health benefits of fishery products, their consumption may be a route of human exposure to different kinds of chemical contaminants including trace elements. In this context, evaluating the contamination levels in these products and the risks they may engender to human health proves to be a necessity in the absence of local guidelines and monitoring programs. Thus, the thesis has 2 main objectives: i) the evaluation of environmental quality through marine organisms and, ii) the assessment of health risks related to the consumption of a selection of fishery products.The first objective was to study the levels of metallic contaminants (20 trace elements) in six marine species from different trophic levels of a food web (algae, mussel, shrimp and fish), representative of Lebanese coastal waters. The results showed that species accumulated metals differently underlining the importance of a multi-specific approach to reflect the contamination level of a certain site. Inter-site variations have been found mainly during the rainy period of the year while they were less prominent during the dry season, highlighting the effect of land-based sources and riverine effluents on the marine coastal area. Levels of trace elements in the muscles and edible tissues in species from our study, were similar to the ones reported in the Eastern Mediterranean (Levantine Basin) whereas livers showed higher levels compared to other studies suggesting that the Lebanese coast is exposed to strong environmental pressure. The second objective was to evaluate the health risks related to the consumption of different fishery products sampled along the Lebanese coast. In this prospect, five commonly consumed local species belonging to different compartments of the food chain, (1 bivalve, 1 crustacean and 3 fish species) sampled from three sites with different levels of anthropogenic pressures were selected. The samples were all analyzed for their content of trace elements. Metals such as mercury (Hg) are found in several chemical forms, the most toxic form being methylmercury (MeHg). The main route of human exposure to MeHg is the consumption of fishery products. That’s why, a method for the speciation of mercury in fishery products by HPLC-ICP-MS was optimized and validated based on an accuracy profile. The results showed that the levels of trace elements and MeHg in the selected species were all below the allowed maximum levels set by the European commission and so their consumption is not likely to cause any adverse effects to human health
Nigar, Meher. "Studies on the interaction between arsenic (As) and rice varieties which differ in arsenate (As(V)) tolerance." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=33413.
Full textNordstrom, Jeanne McDonald 1957. "The utility of using matched weight PVC filters during air sampling for particulates." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276824.
Full textRandima, Livhuwani Priscilla. "Rhizosphere microbial diversity in PAH's contaminated and uncontaminated soil." Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-11302009-195201/.
Full textAponte, Carmen Alicia. "Process inventory and pollution prevention overview for the citrus industry." FIU Digital Commons, 2000. http://digitalcommons.fiu.edu/etd/1298.
Full textAbella, Justine Marie. "Implication des intégrons dans l’adaptation des communautés bactériennes." Thesis, Pau, 2015. http://www.theses.fr/2015PAUU3051/document.
Full textIntegrons are bacterial genetic elements. Recently discovered in the clinical context, they are present in the genome of a number of bacteria from a variety of environments. They are composed of a gene encoding an integrase and a succession of gene cassettes. The activity of integrase allows the acquisition, loss or rearrangement of cassettes. Furthermore, a promoter allows expression reading frames contained in the gene cassettes. Thus, integrons are both reservoirs of genes and these gene expression systems. In the clinical context, they are known to be involved in the adaptation of pathogenic bacteria. They are able to acquire and disseminate genes conferring a selective advantage over the pressure exerted by the use of antibiotics and biocides, and also being mobilized to be transferred horizontally. Some studies have focused on integrons outside of clinical environments. They have characterized many gene cassettes, without however reaching the diversity, from bacteria or bacterial communities coming from environments with different levels of contamination. However, the diversity of integrase has been little studied, because the majority of studies are limited to clinical integron sequences. Thus, environmental integrons are still poorly characterized and their diversity are little understood. The objectives of my thesis were to characterize the diversity of environmental integrate with a particular focus on integrase, from environments with varying chemical contamination, to evaluate the possible role of integrating in adapting bacteria face environmental disturbances. In this work, approximately 800 different integrase sequences, mostly unknown, were obtained from various freshwater and coastal water sediments. Field studies and microcosms of freshwater or coastal environments, with different types and levels of pollutants allowed to demonstrate an impact of environmental contaminations on the integron diversity, whether on the integrase or the gene cassettes, independently to the bacterial community structure. Finally, in this thesis the characterization of a potentially adaptive integron facing an oil pollution were performed. This integron carrying the intIOPS sequence highlighted and named by Lionel Huang during his thesis. Finally, the results obtained in this thesis provide further elements which support our main hypothesis that environmental integrons would be involved in the adaptation of bacterial communities in response to the presence of contaminants in non- clinical settings
Tapie, Nathalie. "Contamination des écosystèmes aquatiques par les PCB et PBDE : application à l'estuaire de la Gironde." Bordeaux 1, 2006. http://www.theses.fr/2006BOR13325.
Full textDue to the recent re-evaluation of their toxic properties, the study of environmental distribution of Polychlorobiphenyls (PCBs) has regained a great interest. At the same time, concentration of similar compounds with similar properties, such as Polybromodiphenyl-ethers (PBDEs), seems to increase in environment. In order to understand transfer phenomenon of PCBs and PBDEs in aquatic ecosystems, fast and reliable analytical methods using ASE (Accelerated Solvent Extraction) and MAE (Microwave Extraction) have been developed. These protocols allow handling a lot of samples per day and managing environmental study and field experiment at large scale. Field experiments on different trophic status (algae (Isochrysis galbana), mussels (Mytilus edulis) and fishes (Sparus aurata)) were realised in order to understand the mechanisms of bioaccumulation or depuration of organic compounds (PCB 77, PCB 153, PBDE 47, PBDE 153, Bap, Fluoranthene, Chrysene). At the same time, Gironde estuary has been selected as a specific study area to study transfer of PCBs and PBDEs in aquatic ecosystems. The contamination of pelagic food web was evaluated by analysing water, particles, crustaceans and fishes. To compare Gironde estuary contamination to other French Atlantic coast estuaries (Seine, Ster, Loire, Vilaine and Gironde), flounder was selected as a model specie and its levels of contamination were characterised. Results show a relatively low contamination of French estuaries by PBDEs, but PCB contamination is still important and could be problematic particularly if we consider level of contamination of eel in Gironde estuary
Tlili, Ahmed. "Signification écologique de la tolérance acquise des communautés microbiennes des biofilms de rivières à une contamination d’origine anthropique." Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10293/document.
Full textChanges in structure and diversity of biological communities within ecosystems subjected to disturbances are generally synonymous of the scarcity, loss and/or the emergence of new tolerant species or by the proliferation of other species already present but at low density. This leads to a decrease in the overall sensitivity of the community toward the substance(s) responsible for this change of community structure and diversity. The evaluation (and if possible the quantification) of tolerance towards a toxicant may therefore enable us to reveal a posteriori the exposure of a biological community to this toxicant (its exposure history), and demonstrate the specific link between pressure and impact on the biotic compartment of an ecosystem and, more generally, on the ecosystem. Despite numerous studies in this area, there are still many gaps in scientific understanding of the pollution induced-tolerance. The biological model that we used is the lotic biofilm (or periphyton) whose biological and ecological characteristics make it a very interesting tool for study. This work has shown firstly that the integration of the acquired tolerance concept as a complementary tool in the environmental assessment systems would allow more ecological relevance and ecotoxicological specificity to the current set of used bio-indicators. Furthermore, the PICT is also a conceptual approach at the community level, which confirms the interest to address ecotoxicology from the viewpoint of the ecologist that is more holistic than the toxicologist one. Indeed, measures of pollution-induced tolerance, by taking into account the functional diversity of biofilms, and the associated taxonomic analysis, allowed to have a better understanding of resistance and resilience of the ecosystem submitted to chemical perturbations. Our works enabled us to tackle the concept of ecological thresholds of resistance and resilience, and to highlight the fact that enhanced tolerance to a given stress, could result in the displacement of communities from an initial state to an « alternative » stable state, even after the stress removal. These ecological thresholds and the alternative stable state mean that the disappearance of the most sensitive species (as a process explaining the PICT) does not affect the functions of the community until reaching a threshold of resistance. Thus the PICT could correspond to a reduction in diversity or changes in species composition, without having a negative effect on the functioning of the community. However, the ability of communities to be tolerant toward disturbance can have negative consequences on the resilience and resistance of ecosystems. Consequently, we addressed in our work the concept of "negative co-tolerance between species" and costs of tolerance
Tu, Wai-ki Alex, and 杜偉麒. "Hong Kong marine sediment contamination with Tributyltin and its impacts." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31254780.
Full textHamel, Hélène. "Étude de l’évolution du trichlorure d’azote et des trihalométhanes dans l’eau et l’air des piscines chlorées : exploration des voies de réduction de cette contamination." Rennes 1, 2007. http://www.theses.fr/2007REN1S066.
Full textChlorination of swimming pool water generates various disinfection by-products like trihalomethanes and nitrogen trichloride, arising from the reaction between organic compounds released by the swimmers and chlorine. These compounds are of great volatility and also contaminate indoor air of swimming pools. This work brings on the one hand useful information on trihalomethane levels in pool water and indoor air, which are poorly documented, and highlights the important contributors to this contamination. Given the great concern for public health authorities caused by exposure of the population to disinfection by-products, this work explores on the other hand two ways of reduction of this contamination. UV treatment of pool water was first studied and particularly its impact on trihalomethane levels. We also developed a promising lab-scale to remove nitrogen trichloride from water
Choi, Chung-ming, and 蔡頌明. "Land contamination and its remediation methods: a case study in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B3125312X.
Full textReese, Ronald S. "Characterization of organic contamination of groundwater in a mining area, Globe, Arizona." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277240.
Full textRAMBERT, ALECSANDRA. "Etude de l'interaction particules-ecoulement : applications a l'analyse de la contamination aerienne en bioclimatologie et en pollution urbaine." Paris 11, 1998. http://www.theses.fr/1998PA112412.
Full textEl-Osmani, Racha. "Étude de la contamination des eaux et des sédiments par les pesticides." Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10165/document.
Full textSince the explosion of the chemical industry in the twentieth century and the use of synthetic products, increasing amounts of chemicals, have continued to be released into the environment. However, in recent decades, there has been a growing concern about the fate of these chemicals that threaten water resources. Increased knowledge on the analytical performance and toxicological data on active products has led authorities in industrialized and developing countries to impose various restrictions. Monitoring of contaminants in aquatic environments has been put in place to achieve good ecological state of the environment. Among the most dangerous and the most commonly detected in aquatic organic pollutants, polycyclic aromatic hydrocarbons, their derivatives and pesticides. These contaminants present in trace amounts in aquatic environments. Analyzes require appropriate analytical methods to be both specific and sensitive. The objective of this thesis is to develop analytical methods for the extraction of several families of organic contaminants (pesticides, hydrocarbons ...) in water and sediment. A mathematical model Umetrics was used to study the influence of each interest parameter. Compared to conventional methods, this model reduces the number of experiments, and have very good yields. The optimized methods were then applied to study the natural environment in France and Lebanon