Siga este link para ver outros tipos de publicações sobre o tema: Water pollution.
Teses / dissertações sobre o tema "Water pollution"
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Veja os 50 melhores trabalhos (teses / dissertações) para estudos sobre o assunto "Water pollution".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Veja as teses / dissertações das mais diversas áreas científicas e compile uma bibliografia correta.
1
Gharib, J. "Water pollution". Thesis, Сумський державний університет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/31047.
Texto completo da fonteResumo:
It is hard to imagine and believe that 75% of the earth is covered with water; and its inhabitants are not satisfied with clean water to drink and other home uses. Some people in Africa travelling hundreds of miles every day to fetch clean water from a hole that was not properly drilled and that with only a bucket that cannot meet daily needs. On the other hand the human body is 70% water too, and when exposed to dirty water, diseases erupt (epidemics) which lead to 3.4million deaths of people each year. And Nearly 99% of deaths occur in developing the countries.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/31047
2
Syrotenko, Sergiy. "Water pollution". Thesis, Видавництво СумДУ, 2007. http://essuir.sumdu.edu.ua/handle/123456789/13086.
Texto completo da fonteResumo:
The urbanization and industrialization create new problems of preservation of pure water. The crude or badly cleared drains of cities are dumped in reservoirs. Security clearing constructions still lags behind development of the industry. Unlike household sewage industrial drains considerably differ on the structure. They contain acids, alkalis, oils both other organic and inorganic connections. Poisons, synthetic and radioactive substances can contain a number of industrial drains.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/13086
3
Huang, Hesha, Mengwei Jiang e Fan Liu. "Water Pollution in China : study on the relationship between economic development and water pollution". Thesis, Högskolan Kristianstad, Sektionen för hälsa och samhälle, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-10861.
Texto completo da fonteResumo:
Purpose/aim The purpose of the research is to analyze the relationship between water pollution (WP) and the economic development in China. We found a vicious cycle that at the same time as China’s economy has developed; the WP has become the focus of attention, and has also caused huge economic losses. Faced with this situation, this topic is really worth to study. Design/methodology/approach The research adopted a quantitative methodology for the exploration, and conducted a survey through questionnaires which were answered by different people. These respondents come from four areas in China. After having conducted the survey, we selected three typical provinces as representative for each area, and surveyed the basic information about these places. The sample information was calculated by the Chi-square test. The results will be analyzed together with the findings below. Findings The findings indicated that through an analysis of GDP, population, the economic development level and the degree of WP, there is relationship between economic development and WP. When people ignore the problem of WP, and just focus on the economy, the relationship shows that the more developing of economy, the more serious the WP becomes. Originality/value The original idea in our dissertation is to discuss the relationship between economic development and WP in China. The water problem and economic development form a vicious circle. And it seriously affects the whole China. The study has a value for the improvement of the environmental awareness of all the people in China, and advocates the government to develop the economy, and at the same time protect the water sources.
4
Tiazhkorob, Y. "How to stop water pollution". Thesis, Sumy State University, 2017. http://essuir.sumdu.edu.ua/handle/123456789/65664.
Texto completo da fonteResumo:
Water pollution is one of the biggest threats to the environment today. The impact of water pollution on wildlife and their natural habitat can be immense. Human activity is destroying our oceans and the life that it contains. While some pollution occurs directly in or at the edge of the ocean from ships and coastal communities, a majority of it comes from land and air pollution that may occur miles and miles away.
5
Magnusson, Albin. "Water Pollution and Economic Growth". Thesis, Umeå universitet, Nationalekonomi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-184578.
Texto completo da fonteResumo:
Water pollution is a cornerstone of environmental issues, where it not only harms human health but also has major economic consequences. This study examines whether there is proof of the inverted U – shape Environmental Kuznets Curve (EKC) between water pollution and GDP per capita for 16 European countries between the years 1992 and 2018. The study is divided into two parts, one part where the focus is on whether there is an EKC for all 16 countries together and the other part examines in which of these 16 countries it is possible to find the EKC. This study uses a dynamic econometric technique, the generalized method of moments (GMM) but also a fixed effects regression model (FEM). Furthermore, an OLS time series analysis has been used to examine the relationship for each country. This study could not find empirical support for the EKC hypothesis between BOD and GDP per capita on European data, but that there is evidence that it exists an inverted U – shape EKC for Albania and North Macedonia.
6
Boyd, Nathan Andrew. "Impact of sediment-water interactions upon overlying water quality in an urban water system". Thesis, Manchester Metropolitan University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366236.
Texto completo da fonte
7
Ng, Kwok-keung Stephen. "Transboundary water pollution : a legal perspective /". Hong Kong : University of Hong Kong, 2002. http://sunzi.lib.hku.hk/hkuto/record.jsp?B25438979.
Texto completo da fonte
8
Frey, Walter C. "Water for life : fighting water pollution in Eastern Europe". Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/45738.
Texto completo da fonte
9
Mzini, Loyiso Lloyd <1975>. "Water De-Pollution: Different Sorbents for Different Water Pollutants". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amsdottorato.unibo.it/8181/1/Mzini_Loyiso%20Lloyd_tesi.pdf.
Texto completo da fonteResumo:
The occurance of emerging contaminants in water had become an environmental concern since global climate change is causing water to become a scarce resource globally. Veternary antibiotic sulfamethoxazole (SMX) is one of emerging pollutants of interest in this study. The main concern with the presence of antibiotics in aquatic environment is that they can provoke antibiotic resistance which bear ecological and human health risks. Hence, investigations on the adsorption capacity of zeolite Y on SMX in the presence of caffeic acid (CA) and vanillin (VNL) were carried out.The experiments were conducted at room temperature in a wide pH range 5-8. Results indicated that CA is marginally adsorbed by zeolite Y at all pH investigated. Whereas SMX and VA were adsorbed by zeolite Y, the adsorption was inversely affected by pH, adsorption increased as the pH decreases. Both compounds demonstrated a quick kinetics, where these compounds were adsorbed within 1 min. Therefore VNL can compete with SMX for zeolite adsorption sites (i.e. pores). However, since the adsorption of SMX is irreversible whilst that of VNL is reversible, therefore SMX should be retained more firmly by the zeolite.
Another water pollutant investigated in this study was heavy metals (Cu and Zn). Water pollution by heavy metals cause both environmental and health problems throughout the world, due to their toxicity and poor biodegradability. The peel waste of banana (BP), orange (OP), pineapple (PP) and potato (PoP) were used as adsorbent. The river water spiked with Cu and Zn were percolated in a 1 g peel glass column. The results indicated that BP adsorbed up to 17.8 and 23.5 mg/g for Cu and Zn, respectively. The eluates of the adsorption experiments were used to grow lettuce on hydroponics. BP eluates significantly obtained higher biomass yield of lettuce leaves and roots compared to tap water.
10
Kambanellas, Chrysostomos Andreou. "Water consumption and recycling of grey water in Cyprus". Thesis, University of South Wales, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333926.
Texto completo da fonte
11
Evans, R. "Water quality requirement for oil industry water injection projects". Thesis, Cranfield University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333540.
Texto completo da fonte
12
Salas, Díaz Lucas Andrés 1980. "Water pollution, cancer and molecular mechanisms". Doctoral thesis, Universitat Pompeu Fabra, 2015. http://hdl.handle.net/10803/459076.
Texto completo da fonteResumo:
Disinfection by-products (DBP) are complex mixtures of toxicants derived from drinking water treatment. Trihalomethanes (THM) and haloacetic acids (HAA) are the most prevalent DBP in chlorinated waters, which are used as surrogates of total DBP in epidemiological studies. Levels of THM in Spain have been among the highest in Europe.
DBP have gained attention during the last years because of their ubiquity, multiple exposure routes involved, and the potential burden of cancer associated. In experimental animals, evidence supports a DBP-cancer association. In humans, chronic exposure to total THM has been consistently related to bladder cancer. However, mechanisms of action remain poorly understood. Epigenetic mechanisms, heritable reversible changes which alter gene expression without DNA sequence changes, may explain this association. Although experimental evidence suggests that this is a plausible mechanism of action, the relationship between acute and chronic DBP exposure and gene expression/epigenetic mechanisms has not been explored in human populations.Los subproductos de la desinfección (DBP) son mezclas complejas de tóxicos producto del tratamiento del agua potable. Los trihalometanos (THM) y los ácidos haloacéticos (HAA) son los DBP más prevalentes en agua clorada, los cuales se usan como sucedáneos de la mezcla de DBP en estudios epidemiológicos. Los niveles de THM en España han estado entre los más altos en Europa. Los DBP han ganado atención durante los últimos años dada su ubiquidad y la potencial carga de cáncer asociada a su presencia. En animales experimentales, la evidencia soporta una asociación DBP cáncer. En humanos, la exposición crónica a THM totales se ha relacionado consistentemente con el cáncer de vejiga. Sin embargo, los mecanismos de acción aún son poco entendidos. Los mecanismos epigenéticos, cambios reversibles que alteran la expresión genética sin alterar la secuencia de ADN, pueden explicar esta asociación. Aunque la evidencia experimental sugiere que este es un mecanismo de acción plausible, la relación entre la exposición aguda y crónica a DBP y los mecanismos de expresión genética/epigenéticos no han sido explorados en las poblaciones humanas.
Els subproductes de la desinfecció del aigua (DBP) són barreges complexes de substàncies tòxiques derivades del tractament de l’aigua potable. Els trihalometans (THM) i els àcids haloacètics (HAA) són els DBP més freqüents en aigües clorades , que s'utilitzen com a substituts dels DBP totals en els estudis epidemiològics. Els nivells de THM a Espanya han estat entre els més alts d'Europa. Els DBP han guanyat importància en els últims anys a causa de la seva ubiqüitat i la càrrega potencial de càncer associat. En els animals d'experimentació, l'evidència dóna suport a una associació DBP-càncer. En els éssers humans, l'exposició crònica als THM totals ha estat consistentment relacionat amb el càncer de bufeta. No obstant això, els mecanismes d'acció segueixen sent poc coneguts. Els mecanismes epigenètics, canvis reversibles hereditàries que alteren l'expressió de gens sense canvis en la seqüència de l'ADN, poden explicar aquesta associació. Encara que l'evidència experimental suggereix que aquest és un mecanisme plausible d'acció, la relació entre l'exposició aguda i crònica DBP i els mecanismes de l'expressió dels gens/epigenètics no ha estat explorada en les poblacions humanes.
13
Chalew, Talia Weinberg Howard. "Chemical indicators of surface water pollution". Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,662.
Texto completo da fonteResumo:
Thesis (M.S.)--University of North Carolina at Chapel Hill, 2006.Title from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Masters of Science in the Department of Environmental Sciences and Engineering." Discipline: Environmental Sciences and Engineering; Department/School: Public Health.
14
Ng, Kwok-keung Stephen, e 吳國強. "Transboundary water pollution: a legal perspective". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31255255.
Texto completo da fonte
15
Patrick, M. J. L. "Discolouration and pipe-water interface studies : an examination of corrosion, deposition and water quality in potable water distribution pipelines". Thesis, University of Hertfordshire, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.276552.
Texto completo da fonte
16
Wong, Wang-wah. "Trace organics pollution in the aquatic environment /". [Hong Kong] : University of Hong Kong, 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13498356.
Texto completo da fonte
17
Mohamed, Ali Sithy Kadija. "Industrial water pollution in a surface water system in Colombo, Sri Lanka". Thesis, Durham University, 1991. http://etheses.dur.ac.uk/1180/.
Texto completo da fonteResumo:
Surface waters are increasingly polluted by the industries in Colombo, Sri Lanka. Among these the food and drink industries are prominent in urban Colombo. To understand the extent of pollution of the inland surface waters a project was undertaken in the San Sebastian canal, which runs through the heart of Colombo, and the connecting waterways. It entailed the chemical and physical monitoring of the surface waters and the waste water discharges of the industries. The results indicated that the San Sebastian canal was a highly polluted canal with a very low dissolved oxygen level. The oxygen sag was very marked at the industrial discharges. Most of the industries, by nature of the highly organic waste waters in addition to being untreated failed to meet the specified standards of discharges into inland surface waters. The rainfall-pollutant and the rainfall-lag analysis indicated the poor dilution of these strong waste waters, and the low assimilative capacity of the highly polluted canal system. Hence, the San Sebastian canal polluted the receiving river Kelani, into which it discharges in the east, and the Beira lake in the west, where the polluted waters are pumped from the canal to maintain the level of the lake.
18
Courtis, Benjamin John. "Water quality chlorine management". Thesis, University of Birmingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289743.
Texto completo da fonte
19
García, Molina Verónica. "Wet oxidation processes for water pollution remediation". Doctoral thesis, Universitat de Barcelona, 2006. http://hdl.handle.net/10803/1526.
Texto completo da fonteResumo:
The main objective of this work was to test the efficiency of wet oxidation processes when treating several types of aqueous wastes. On one side its performance for the abatement of chloro-organic aromatic toxic pollutants, such as 4-chlorophenol and 2,4-dichlorophenol has been studied. On the other hand, wastewater from pulp and paper mills, which has been reported to be an indirect source of entry of chlorophenols in the aquatic environment, has been investigated. More in detail, it has been taken as feed stream for the wet oxidation unit in order to investigate whether this type of waste streams can be treated by this technology or not. Regarding Chlorophenols, special attention was drawn to the degradation of 4-chlorophenol by means of wet oxidation and wet peroxide oxidation. This aromatic compound was taken into investigation due to its harmful properties against the environment and due to its wide presence in the environment. Once it was clear that it could be degraded by these technologies, a research focused on the influence of the operating conditions in the result of the oxidation was carried out. The influence on the wet peroxide oxidation and wet oxidation reactions of the following parameters, initial concentration of the pollutant, temperature and amount of oxidizing agent (oxygen or hydrogen peroxide depending on the process) has been taken under study.
The identification and quantification of the intermediate compounds involved in the wet oxidation of 4-chlorophenol, together with a suggested mechanistic pathway, allowed the obtaining of a kinetic model, which appeared to be a useful tool for the prediction of these compounds throughout the reactions. The evolution of the free chlorine released to the solution from the degraded chlorophenol was also a useful tool when determining the kinetic pathway of the reaction.
Another objective of the work comprised the investigation of the variations of the biodegradability of the samples during the process. The knowledge of evolution of this parameter during the wet oxidation was thought to be of major importance, since high biodegradability enhancements allow the combination of a wet oxidation unit with a biological post-treatment, which is an effective and inexpensive technology to couple the oxidation.
The establishment of a comparison between wet oxidation and the wet peroxide oxidation for the removal of 4-chlorophenol was investigated as well.
Concerning wastewaters from pulp and paper mills, debarking and termo-mechanical pulp process wastewater have been treated by wet oxidation. Both waters were concentrated before oxidation in order to favor the economy of the process. Debarking wastewater was concentrated by evaporation and pulp process water by nanofiltration. The influence of the operating conditions, such as temperature and partial pressure of oxygen, on the results achieved at the end of the wet oxidation were studied and evaluated in order to find the optimum working conditions for each type of wastewater. Special attention was drawn to the evolution of Lipophilic Wood Extractive Compounds throughout the reactions. In addition, kinetic models suggested in the literature were tested to find a suitable one, which allowed the prediction of for instance, the organic load, over the duration of the reactions.
Due to the fact that wet oxidation is more economically viable when the initial waste stream is highly concentrated, a final chapter dedicated to a emerging technique, i.e., membrane technology has been included in this thesis. An investigation regarding the parameters affecting its performance, as well as the general aspects of the process has been conducted.
20
Okuofu, C. A. "The water pollution indicator potential of bifidobacteria". Thesis, University of Newcastle Upon Tyne, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353445.
Texto completo da fonte
21
Borgan, Nawal Sunna'. "Microbial regrowth of water supplies in Amman distribution system and house-hold water storage tanks". Thesis, University of Newcastle Upon Tyne, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245733.
Texto completo da fonte
22
Wararatananurak, Puchong. "Fractionation of chromium toxicity in water". Thesis, University of Aberdeen, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327394.
Texto completo da fonte
23
Holmes, Paul Robin. "The effectiveness of organizations for water pollution control". Thesis, Lancaster University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287125.
Texto completo da fonte
24
Ma, Yik. "Water pollution from metal-finishing industry in Hong Kong /". Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17457828.
Texto completo da fonte
25
Barua, Anamika. "An empirical analysis of water pollution in India". Thesis, University of Leeds, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.507674.
Texto completo da fonte
26
Montero, Juan-Pablo. "Uncertainty and the markets for water pollution control". Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/36315.
Texto completo da fonte
27
Udén, Jonathan. "Pollution transport in the Boden garrison storm water". Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-203039.
Texto completo da fonteResumo:
In 2012, the Swedish fortification agency started an environmental program for their real estate in northern Sweden. For the Boden garrison this meant an evaluation was needed for their storm water handling. The evaluation fell upon Grontmij AB in Boden. This thesis concerns the pollution from the storm water pipes into its recipient Lule River. Its aim was also to evaluate the areas for the event of a bigger oil spill, since there are many mechanical garages within the garrison. The pollution concerning oil was evaluated by calculating the flow in each outlet into the river, with different rain intensities. For other pollutants, the volumes of storm water each year, for every outlet were calculated. With concern for the snow melting process, it was also calculated for which period of the year would be interesting to keep an extra watch for pollutant concentrations and maximum flows. Results showed that for a 50-year period, none of the years would have had their peak flow because of the snow melt. The results for evaluation of an oil spill showed that none of the outlets were equipped for an accident of such sort, should it coincide with a rainfall of a high intensity. The results also showed that one of the outlets had an oil trap only dimensioned for rainfall of the lowest intensity. The calculating of pollutant volumes raises the concern for reliable data, but measures have already been taken to meet this concern.
28
Mikhieiev, O. M., O. V. Lapan, L. H. Ovsiannikova e S. M. Madzhd. "WATER BODIES TREATMENT FROM RADIONUCLIDES AND CHEMICAL POLLUTION". Thesis, ПАЛИВОДА А.В, 2017. http://er.nau.edu.ua/handle/NAU/30497.
Texto completo da fonte
29
Pushkarskaya, Helen N. "NONPOINT SOURCE WATER POLLUTION CONTROL: INCENTIVES THEORY APPROACH". The Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1041607329.
Texto completo da fonte
30
Gough, Mark Adrian. "Characterisation of unresolved complex mixtures of hydrocarbons". Thesis, University of Plymouth, 1989. http://hdl.handle.net/10026.1/461.
Texto completo da fonteResumo:
The hydrocarbons of recent polluted sediments, in-reservoir and laboratory biodegraded crude oils, and certain petroleum products (e.g. lubricating oils) often display 'humps' or Unresolved Complex Mixtures (UCMs) when analysed by gas chromatography (GC). Although widespread and often abundant, to date little is known of their detailed molecular composition. Standard chromatographic methods of isolation of model aliphatic and aromatic hydrocarbon UCMs from lubricating oils followed by conventional methods of analysis provided little compositional detail. Thus GC and GC-electron impact mass spectrometry (GC-EIMS) was limited to an estimate of carbon number ranges and to the identification of certain series of 'biological marker' compounds. However, these were well resolved and were estimated to account for <10% of the total detector response. Further analyses were performed by chemical ionisation-MS (CI-MS), probe distillation EI-MS, field ionisation-MS (FIMS), and elemental analysis; yet the information provided by each was limited to a few 'average' molecular types. In view of the limitations of conventional methods of analysis, alternative methods were adopted. These utilised novel chemical and pyrolytic degradations of the UCM hydrocarbons. Chemical oxidation with Cr03 in glacial acetic acid produced reasonable yields of total recoverable material (40-80%). Furthermore, a high proportion were functionalised (>90%), and many resolved, which allowed their identification by EI and CI GC-MS. Surprisingly, the most abundant products of oxidation of hydrocarbon UCMs were straight chain monocarboxylic acids. This appeared to contradict literature consensus on UCM composition, namely a predominance of highly branched and/or cyclic hydrocarbons. However, from literature reported CrO oxidations of hydrocarbons, potential precursor compounds were proposed. These were monoalkyl substituted 'TO-branched acyclic and monocyclic alkanes for the aliphatic UCM and alkyl 'TO-branched monoaromatic hydrocarbons for the aromatic UCM. Proposed precursor UCM hydrocarbons were confirmed by synthesis and chemical oxidation under the same conditions. Thus each of the synthetic candidate UCM hydrocarbons [7-n-hexylnonadecane, 9-(2-phenylethyl)-heptadecane and 9-(2- cyc 1 ohexyl ethyl j--hep tade cane] produced n-acids on oxidation with Cr03- Further correlations were found for products of other synthetic alkanes and less abundant UCM oxidation products. For example, n-alkan-2-ones. iso alkan-2- ones, and 7-methyl--y-lactones could all be correlated with methyl substituted acyclic alkyl linkages on UCM hydrocarbons. The application of chemical oxidation to aliphatic UCMS of varied origin showed the technique has great potential for fingerprinting such samples. GC-MS analysis of a selected series of resolved product compounds (alkyl ketones, -y-methyl--y-lactones) showed good correlations for samples of the sane origin, yet distinct differences for UCHs from different sources. Biodegradation of the three candidate UCM hydrocarbons alongside acyclic isoprenoid alkanes and normal and monomethyl alkanea showed the UCM hydrocarbons were at least as resistant to microbial degradation as the isoprenoid alkanes. In this context it is therefore concluded that the candidate UCM compounds serve as good molecular models for hydrocarbon UCMs.
31
Butcher, Melissa Rachelle. "Diffuse Nutrient Pollution from Residential Catchments". Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5194.
Texto completo da fonteResumo:
Nonpoint source nutrient pollution is diffuse pollution lacking discrete origin and conveyance. This thesis synthesizes and critically reviews research on residential nitrogen and phosphorus loss to stormwater runoff and leaching. The evaluation pulls from research covering influential socio-demographic indicators, such as use of lawn maintenance services and homeowner fertilizer practices. The extent to which such social and economic factors may influence the prevalence and fate of diffuse nutrients in stormwater runoff from residential areas has not been adequately established. Understanding the source and influencing factors of diffuse nutrient pollution is important in order to effectively protect surface and groundwater resources.
Research based on sampling campaigns of catchments, sampling of controlled turf systems and models of residential catchments were compiled for this review. Based on the compilation reviewed for this thesis, there are wide differences in approaches researchers have taken to attempt to quantify and understand diffuse nutrient pollution from residential and urban areas. There is not consistency in the chemical nitrogen or phosphorus species evaluated or in reported measurements (i.e. concentration vs. loading vs. yield).
This review revealed several important knowledge gaps. Determination of correlation between residential system nutrient loss to the environment and social factors, demographic characteristics, local fertilizer ordinances or nutrient management education programs has not been substantiated. More exploration of nutrient leaching from different soil types and turf grass species is needed to develop a complete understanding of nutrient loss from turf grass systems. Further, other specific management practices such as leaving grass clippings on lawns has not been studied in depth for a variety of soil types and grass species. There is room for improvement in future research and additional studies are needed to guide future policy and implementation of best management practices. Based on these and other findings, I recommend a concerted effort to standardize a portion of the reporting details of future stormwater research and for reevaluation of nutrient/fertilizer education efforts.
32
Spiller, Marc. "EU water policy : pollution source control by water companies in England and Wales". Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/4586.
Texto completo da fonteResumo:
Water management is undergoing a transformation towards integration, source control and ecological thinking. In the EU, the Water Framework Directive can be considered as a driver towards this new approach to water management. Innovations are deemed necessary to deliver this ideal of water management. In this thesis efforts by water sewerage companies in England & Wales to rectify agricultural pollution at source are viewed as an organisational innovation towards more sustainable water management. These source control interventions can help achieving the goals of the Water Framework Directive by reducing diffuse pollution from agriculture, fostering participation in water management and by reducing overall cost of implementation. This thesis contributes to understanding the process of change in water management by developing a model of the innovation-decision process. Insights about how innovation and therefore change can be influenced is generated by applying this model to the process of source control intervention adoption by water and sewerage companies. This research employed a flexible research design using comparative case studies. Each of the 10 water and sewerage companies in England and Wales represented an individual case. Data were collected in two phases using semi-structured interviews with selected water and sewerage company representatives. Thematic analysis, recurrence counts and content analysis were applied to analyse interviews. It was found that water companies are likely to contribute towards integrated approaches to water management, since there is a trend to adopt source control intervention. Change in water management is influenced by the interaction of factors from the domains: ‗Natural-Physical‘, ‗Organisational Characteristics‘, ‗Regulatory- Institutional‘ and ‗Innovation Attributes‘. The rate of change by water and sewerage companies is governed by a combination of asset characteristics, environmental state changes and the funding cycle. Furthermore, innovation is triggered by direct regulation and regulation that requires the gathering of information. Contrary to this flexible or framework regulation performs better in guiding the direction of change.
33
Walsh, Stephen. "Integrated design of chemical waste water treatment systems". Thesis, Imperial College London, 1993. http://hdl.handle.net/10044/1/8603.
Texto completo da fonte
34
Ahmed, Sara. "Questioning participation : culture and power in water pollution control". Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335064.
Texto completo da fonte
35
Knowland, Thomas J. W. "Changing the guard? : institutional change in water pollution control". Thesis, University of East Anglia, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283949.
Texto completo da fonte
36
Ma, Yik, e 馬奕. "Water pollution from metal-finishing industry in Hong Kong". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31253490.
Texto completo da fonte
37
Tijunelyte, Inga. "Development of SERS nanosensor for detection of water pollution". Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCD007/document.
Texto completo da fonteResumo:
La pollution des eaux par des composés organiques constitue un problème mondial majeur. Parmi cescomposés, les molécules aromatiques de faibles masses molaires constituent une famille largementrependue dont la toxicité et la cancérogénicité est avérée et bien documentée. La Directive-CadreEuropéenne sur l’eau (2000/60/EC, 2006/118/EC and 2006/11/EC) établit des normes de qualitéenvironnementales ayant pour objectif d’améliorer la qualité des eaux. Dans ce contexte, ledéveloppement d’outils analytiques robustes, permettant de détecter et de quantifier précisément et insitula présence de polluants dans les eaux est d’une importante primordiale. L’objectif principal de cetteétude est l’élaboration de nanocapteurs sensibles, robustes et réutilisables, permettant l’analyse depolluants organiques dans les eaux grâce à la Spectroscopie Raman Exaltée de Surface (SERS).Tout d’abord, une attention particulière a été portée à la sélection des récepteurs et des différentesstratégies de fonctionnalisation permettant d’élaborer un nanocapteur SERS capable de pré-concentrerles polluants visés. L’utilisation d’antigènes et de fragments d’antigènes (F(ab)2) a montré des résultatsprometteurs pour l’élaboration de nanocapteurs très sélectifs. Une seconde approche basée surl’utilisation de cavitants ou molécules hôtes, telles que les cyclodextrines (CDs), a été développée. Lapré-concentration sélective des polluants grâce à leur taille a été démontrée par spectroscopie Raman etSERS. Enfin, grâce à la possibilité d’identification moléculaire en milieu complexe offerte par laspectroscopie SERS, une approche permettant une pré-concentration non spécifique des polluants a étédéveloppée. Pour ce faire, différents sels de diazoniums (DSs) ont été synthétisés et greffés à la surfacedes nanocapteurs afin de créer une couche hydrophobe permettant la pré-concentration et la détection decomposés apolaires. Les performances de ces nano-capteurs ont été démontrées pour la détection de plusieurs PAHs apolairesEnvironmental water pollution by organic compounds is in continues worldwide concern. Low molecular mass aromatic molecules consisting in benzene rings have received considerable attention due to a documented significant toxicity and carcinogenicity. Within the objectives of the European Water Framework Directives (2000/60/EC, 2006/118/EC and 2006/11/EC) aiming in water quality improvement, the development of analytical tools allowing in-situ accurate and sensitive detection is of primary importance and would be a meaningful innovation. With this regard, the main scope of this study was to design sensitive, reproducible, specific and reusable nanosensor for the detection of organic pollutants in environmental waters using Surface Enhanced Raman Spectroscopy (SERS).During this study the main attention was paid to the selection of suitable receptors and strategies for SERS nanosensor surface functionalisation in order to preconcentrate targeted pollutants. The application of antibodies and antigen binding fragments (F(ab)2) for surface decoration was found to be promising approach for highly selective nanosensor design. Another strategy exploited during this study was related with an application of cyclodextrins (CDs). Using Raman and SERS spectroscopies the size selective encapsulation of analytes was demonstrated. Finally, taking advantage of molecular identification in the complex environments offered by SERS technique, nanosensors providing non-specific molecular pre-concentration was considered. For this purpose several diazonium salts (DSs) were studied and applied to the surface functionalisation to create highly hydrophobic coating layer. The performance of such nanosensor was evaluated by detection of aromatic pollutants
38
Shears, John Richard. "The environmental assessment of oil pollution". Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294005.
Texto completo da fonte
39
Tadesse, Behailu. "Iron and manganese oxides in the soil-water environment". Thesis, Brunel University, 1997. http://bura.brunel.ac.uk/handle/2438/6624.
Texto completo da fonteResumo:
The importance of iron and manganese oxides in soil-water environments and their roles in controlling the availability and mobility of contaminants and nutrients are determined. Sorption is simulated using the synthetic iron and manganese oxides: goethite (a-FeOOH), birnessite (Na4Mn14O27.9H20a) nd magnetite (Fe304) which are analogous to natural soil components. Goethite is investigated in the three possible modes of occurrences in soil: colloidal, aggregate, and as coatings on inert materials. The adsorption of cadmium and cobalt onto goethite occurs in a narrow pH range between 6.5 and 7.5. Metal retention increased with both temperature and contact time. A tenfold decrease in ionic strength has no effect on the adsorption pH. Goethite pellets have a different pattern of adsorption due to reduction in surface area and granulation. The sorbing capacity of goethite coated sand is lower than that of the colloidal goethite but has a similar adsorption curve. The coated material is shown to have potential in industrial applications and notably in effluent treatment. Cobalt and cadmium uptake on to hydrated suspensions of birnessite occur in a pH range (3.0-8.0) with sigmoidal shapes for the percent of adsorption curves. Birnessite uptake capacity increases with increasing pH with a maximum at about 6.4 pH. The pH, contact time and the surface area of the oxide are the main factors that control the uptake. The adsorption of coloured species and organic colloids on magnetite was investigated in which magnetite is used both as an adsorbent and as magnetic material. Colour species and organic colloids adsorbed in acid pH and the adsorption decreases with increasing alkalinity. Dissolutions of the magnetite itself increases in low and high pH conditions. The results of investigations of sorption of contaminants and nutrients onto iron and manganese oxides have been applied to shed light upon the behaviour of contaminants and nutrients in soil in the light of soil resource management. The importance of a detailed understanding of contaminant and nutrient transport behaviour in soil-water systems to achieve effective environmental management is demonstrated. Although soil pollution is of major environmental concern, it is probably the least understood source of pollution in terms of both transport of contaminants and remediation. The studies carried out in this work have indicate the types of information required to permit the development of soil management and remediation protocols that will assist in technical management of issues related to soil resources. Detailed knowledge from experimental work must form the scientific basis for the development of contaminated soil assessment and management in an integrated approach.
40
Jackson, Paul P. "Removal of cadmium from polluted water by immobilized algae". Thesis, Durham University, 1990. http://etheses.dur.ac.uk/6184/.
Texto completo da fonteResumo:
A feasibility study was planned to determine the efficiency of immobilized algal cells growing in a packed bed for removing Cd from commercial effluents. To select appropriate material for an immobilized cell system, twenty-five strains of algae isolated from heavy-metal contaminated environments of known water chemistry were tested for their ability to accumulate Cd. Before accumulation experiments were initiated, ion exchange resin was employed to demonstrate that EDTA in the medium did not complex Cd to a significant degree. Svnechococcus D562 cells subcultured in Cd accumulated the most metal; little was bound to the cell wall. A continuous culture of steady- state Svnechococcus D562 cells tolerated a lower maximum concentration of metal (3.4 mg 1(^-1) Cd) than batch- cultured cells (5 mg 1(^-1) Cd), indicating that metabolic status influences the toxicity of Cd. When flasks of calcium-alginate beads were challenged with Cd, up to 60 % of the added metal was bound within 16 h; however, further incubation did not reduce the pollutant concentration. Two axenic strains which accumulated the metal to a high concentration were then immobilized and tested for their capacity to remove Cd from the circulating medium. A packed-bed reactor containing Mougeotia D536 cells proved more effective at metal removal than Svnechococcus D562, but both species grew to a lower cell density at the effluent end of the column. The medium was then aerated to overcome such growth-limiting conditions, but this treatment inhibited Cd accumulation. Column-immobilized cells reduced Cd levels more effectively than inoculated, alginate beads in stationary flasks or free cells. Energy dispersive X-ray microanalysis located Cd only in particular Svnechococcus D562 polyphosphate bodies (those with a high Ca to K ratio); peaks for Zn, Pb, Fe, Mn and Ba were also detected in algae isolated from the field. Scanning proton microanalysis provided information on the distribution of macro- and micro-elements throughout the two strains of cyanobacteria and two strains of algae selected from the Durham Culture Collection and demonstrated the presence of Cd in Klebsormidium rivulare D537.Detergent-sensitive spheroplasts of Svnechococcus D562 were produced by lysozyme and protease digestion, but were not viable for growth. To observe the extracellular mucilage of this strain by EM, lysozyme digestion proved imperative for effective ruthenium red staining to convert the material into an electron opaque material. From cultures of Svnechococcus D562 grown with or without Cd a 14 kD plasmid was isolated, which contained two Eco RI, two Bam HI and five Hind III restriction sites. A radiolabelled oligonucleotide probe based on part of the nucleotide sequence of a metallothionein from Svnechococcus FCC 6301 did not bind to a genomic and plasmid blot of Svnechococcus D562 DNA. The putative Cd-binding peptides ((yEC)(_n)G's) that were discovered only bound significant quantities of the metal when cells were exposed to 6.17 mg 1(^-1) Cd for 2 days at the end of their log-growth phase. Indigenous peptides failed to bind substantial amounts of the metal and the presence of Cd throughout growth did not influence the quantity of chelated Cd, except for Mougeotia D536. The pH of half displacement for (yEQjp's from this strain is comparable with that of other species. Reversed-phase HPLC of the peptides from Mougeotia D536 generated a thiol profile similar to that recorded for the Cd-binding peptides of Datura innoxia. The Cd-induced ultrastructural distortions that were recorded include potential Ca / P / Cd precipitates in Mougeotia D536, the loss of polyglucoside granules from Calothrix D184 together with a relaxation of its thylakoid packing and a lack of plastoglobuli in Cd-exposed Klebsormidium D537. The space between an immobilized cell and the matrix either represents shrinkage of the matrix during dehydration or mucilage which does not bind electron dense stains. Release of alkaline phosphatase into the medium by Svnechococcus D562, provided suitable material to study the inhibitory effects of Cd upon P hydrolysis. Ultrafiltration membranes proved effective as initial step towards enzyme purification and for the determination of activity under sub-optimal pH conditions. At pH 7.0, the activity of an enzyme concentrate was inhibited when 1 and 10 mg 1(^-1) Cd were added to the assay medium, but the presence of this metal in the growth medium did not reduce activity. One-dimensional SDS PAGE revealed only one protein difference between strains grown with or without Cd; a reduction in the staining intensity of a 17 kD band of Calothrix D184.
41
Black, S. H. "Disinfection by-product formation from swimming pool water disinfection". Thesis, Cranfield University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284924.
Texto completo da fonte
42
Wraige, Emma Jane. "Studies of the synthesis, environmental occurrence and toxicity of unresolved complex mixtures (UCMs) of hydrocarbons". Thesis, University of Plymouth, 1997. http://hdl.handle.net/10026.1/465.
Texto completo da fonteResumo:
The occurrence of unresolved complex mixtures of hydrocarbons (UCMs) in the aliphatic fraction of marine sediments and organisms from areas impacted by petroleum hydrocarbons is well documented and widely accepted as an indication of fossil fuel contamination. In contrast, the presence of an aromatic UCM is often ignored and environmental concentrations of aromatic UCM hydrocarbons in marine biota and sediments are rarely reported. The aims of this study were to establish the quantitative significance of aromatic UCMs in environmental samples and to assess the toxicological significance of both aliphatic and aromatic UCMs. A reproducible method was developed and validated for the analysis and quantification of petroleum hydrocarbons in mussel (Mytilus edulis) tissue. Emphasis was placed upon development of a method which minimized losses of more volatile, lower molecular weight, toxicologically significant hydrocarbons, without compromising recovery of higher molecular weight compounds which are useful for source identification in environmental monitoring schemes. Analysis of mussels from a small number of U. K. coastal locations indicated that aromatic hydrocarbon UCMs may form a significant proportion (ca 20 %) of the total hydrocarbon body burden of mussels from areas contaminated with petroleum hydrocarbons. Aromatic UCM hydrocarbons were not observed in mussels from relatively uncontaminated areas but concentrations of 430 μg g'' (dry wt tissue) were measured in mussels from heavily impacted areas. Aliphatic UCM concentrations ranged from 7- 3445 μg gg' (dry wt tissue). For the purposes of toxicological studies, a low molecular weight model aliphatic UCM hydrocarbon, 4-propyloctane (4-PO) was synthesised. Two low molecular weight model aromatic hydrocarbons 7- cyclohexyltetralin and 7-cyclohexyl-l-propyltetralin were also synthesised using a modification of the Haworth synthesis. All three target compounds and synthetic intermediates were characterised by NMR, MSandIR. Exposure of M. edulis to 4-PO caused a significant reduction in mussel ciliary feeding activity indicating that 4-PO was indeed toxic as measured by this bioassay. The demonstrable narcotic activity of 4-PO is presumably related to the greater aqueous solubility of branched hydrocarbons compared with similar straight chain hydrocarbons. Further experiments investigating the effect of 4- PO over exposure periods up to 120h provided a unique and detailed insight into the relationship between concentration of toxicant in the gills of M. edulis and observed feeding rate. The established method of mussel feeding rate determination was modified in light of this relationship to produce an " improved rapid and reproducible screening technique. Both of the model aromatic UCM hydrocarbons were also found to be toxic to mussel ciliary feeding activity. This appears to be the first report of investigations into the toxicity of the aromatic UCM and suggests that previous studies have ignored an environmental burden of toxicological significance. Estimates of the tissue effective concentration (TEC50) for the model UCM hydrocarbons gave comparable values with those reported for the effect of other narcotic hydrocarbons upon mussel feeding rate, providing support for the theory that non-specific narcosis occurs at a relatively constant tissue concentration of toxicant. The demonstrated narcotic activity of each of the three model UCM hydrocarbons has extended the molecular weight range of narcotic hydrocarbons studied to date. The results presented herein suggest that a small proportion of low molecular weight aliphatic UCMs and perhaps a greater proportion of aromatic UCMs are of toxicological significance.
43
Alharbi, Mohammed Musad Mohammed. "Spatial and temporal variations in trace metal concentrations in sediments, pore water of the Forth estuary, and their potential impact on water quality". Thesis, University of Stirling, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386611.
Texto completo da fonteResumo:
The concentrations of trace metals: cadmium, copper, nickel, lead and mercury, in addition to aluminium, iron and manganese were determined in the sediments and pore water (except aluminium) of the Forth estuary. Organic matter (as loss on ignition), total organic carbon (TOe), total organic nitrogen (TON), particle size and redox potential were also determined in the sediments. In addition, chloride, sulphate, conductivity, alkalinity, pH, dissolved organic carbon, phosphate and nitrate were determined in the sediments pore water. Trace metals in the pore water were determined using a modified preconcentration technique and measurements were carried out by graphite furnace. Mercury was measured using the p.s.a mercury specific fluorescence detector. organic matter (TOC & TON) in the sediments were measured using CHNS/O analyzer. Samples were collected at seasonal intervals for a period of 18 months on board the survey vessel "Forth Ranger". Six stations were selected to represent upper, middle and lower estuary. Sediment cores collected at each station were subjected to centrifugation under nitrogen gas atmosphere to separate the pore water after being sectioned at 2.5 cm intervals for a depth of 10 centimetres. Concentrations of trace metals in the Forth estuary varied from station to station and from one season to another. Mean concentrations for sediments were as follows (mg\kg): lead, 56.9; cadmium, 0.22; copper, 38.9; nickel, 33.7 and mercury, 1.86. For pore water, the mean concentraxxi tions (Jlg\l) were as follows: lead, 3.14; cadmium, 1.86; copper, 31.9; nickel, 24.7 and mercury, 0.075. Measurements of sulphates, nitrates, phosphate, conductivity and dissolved organic carbon were used to examine the processes controlling their distributions in the pore water. The results indicated that the distributions of nutrients (phosphate and nitrate) in the upper 10 cm seemed to be controlled by macro-infaunal irrigation activities and their values varied according to the overlying water conditions. The distributions of trace metals in the sediments were found to be controlled by particle size and organic matter both spatially and temporally. Vertical distribution of trace metals in the pore water were found to be controlled by redox potential variations especially for iron and manganese. Concentrations of trace metals (Pb, Hg, Ni, Cd and CU) in the pore water were found to be higher than that in the overlying water. Enrichment factors were limited to 10-50 fold increase. Lead and mercury were 10 fold higher while 50 fold higher were found for nickel, copper and cadmium. Benthic flux calculations showed a significant flux of trace metals both in the summer and winter. However, flux of copper, nickel and lead tended to increase in the summer. Spatially, the lower estuary showed a higher flux of trace metals than the upper and middle reaches of the estuary.
44
Mariola, Matthew J. "Are Markets the Solution to Water Pollution? A Sociological Investigation of Water Quality Trading". Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1250015222.
Texto completo da fonte
45
Gonçalves, Ana Raquel Calapez. "Multiple-stressor impacts on mediterranean stream communities: responses to water scarcity and water pollution". Doctoral thesis, ISA, 2020. http://hdl.handle.net/10400.5/21198.
Texto completo da fonteResumo:
Doutoramento em Restauro e Gestão Fluviais - Instituto Superior de Agronomia / Faculdade de Arquitetura / Instituto Superior Técnico. Universidade de LisboaFreshwater ecosystems are influenced by diverse anthropogenic stressors and natural disturbances producing interacting effects (synergies and antagonisms) often unpredicted based on their independent effects, and thereby represent a major concern to predict ecological changes and develop effective management and restoration strategies. The aim of this Thesis was to assess different responses of key stream biological elements (i.e., biofilms and macroinvertebrates) to the impact of main stressors acting in concert in Mediterranean rivers related with water scarcity and pollution (i.e., flow velocity reduction/stagnation and sewage contamination/hypoxia), using mesocosm approaches and evidences of a case study. In a first part, the effects of flow reduction and oxygen depletion conditions in two seasons were evaluated in macroinvertebrates behavioural and functional responses, conducting to evidences of changes in drift patterns and loss of trait diversity with potential impacts on ecosystem functioning and services. In a second part was investigated how single and combined effects of water flow stagnation and sewage contamination affect primary producers and primary consumers, showing that while stagnant water had an overall inhibitory effect, sewage inputs increased biological responses. Also, stressors combined effect revealed to be unfavourable for some biofilm assemblages (decreasing bacteria and algae diversity) while advantageous to other (increasing fungi diversity). In the last part, flow and water quality variations were followed over time in a Mediterranean urban stream, leading to observations of an impoverished community with low diversity and high abundance of tolerant taxa and resistance traits, which was associated with multiple-stressors patterns of urban ecosystems. Overall it was showed that the effects of representative multiple-stressor scenarios on Mediterranean stream biota are dependent on water scarcity conditions and that reductions on sewage inputs needs to be given priority by stream managers to prevent further degradation of these aquatic ecosystems
N/A
46
Bentley, James Michael. "Mechanisms of penetration in cartridge filtration of de-ionised water". Thesis, Loughborough University, 1991. https://dspace.lboro.ac.uk/2134/27471.
Texto completo da fonteResumo:
A programme of research has been carried out into the performance of cartridge filters rated from 0.1 to 0.45 micron in response to steady and varying particle concentrations and water flows. It was discovered that pulsing the water flow to these filters often resulted in release of particles which had been previously captured by the filter. For membrane filters the release of particles was instantaneous. However, for one filter with more depth, a considerable time was required for most of the particles released to be detected. This filter was described as a pre-filter rather than a membrane filter.
47
Symon, Carolyn Jane. "A water quality model for the north eastern Irish Sea". Thesis, Lancaster University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305942.
Texto completo da fonte
48
Gardner, Brian. "Atmospheric deposition of polycyclic aromatic hydrocarbons to natural water surfaces". Thesis, Lancaster University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359936.
Texto completo da fonte
49
Dixon, Joanna. "Trace metal-particle water interactions in the western North Sea". Thesis, University of Plymouth, 1998. http://hdl.handle.net/10026.1/1894.
Texto completo da fonteResumo:
The distribution of trace metals (Fe, Mn, Cu, Cd and Pb) has been determined in dissolved and particulate phases, along with relevant hydrographic parameters, from the nearshore coastal zone of the western North Sea (between 52ON and 56ON) during four Land Ocean Interaction Study (LOIS) surveys covering the seasonal cycle (autumn 1994 to summer 1995) The behaviour of the redox-sensitive metals, Fep and Mnp in the western North Sea were strongly correlated (r>0 44 for all seasons, P<0 05) in all surveys and exhibited maximum concentrations in winter (16 mg g -1 and 700 ug g-1 respectively) which progressively decreased throughout the year Distinct seasonal variations were also observed for particulate Cu, Cd and Pb For example, enhanced concentrations of Cup (36 ± 39 ug g-1) and Cdp (0.36 ± 0.42 ug g -1) in the Humber coastal zone during summer were attributed to preferential particulate organic/biogenic-metal interactions. In contrast enhanced, though diffuse, atmospheric inputs of Pb from continental winds were considered to have contributed to the elevated Pbp concentrations (82 ± 27 ug g -1) observed offshore during winter Results from radiotracer incubation experiments suggest that biological activity makes a significant contribution to the removal of dissolved Mn and Cd to the particulate phase. However, a phase lag of two to three months between maximum primary productivity and maximum particulate metal adsorption (KD=2 X 104 & 5 x 102 for Mn and Cd respectively) indicates a decoupling from the spring plankton bloom In general metal distributions in the Humber coastal zone were significantly influenced by freshwater discharge, tidal regime at the mouth of the estuary and prevailing wind conditions Total trace metal fluxes across the mouth of the Humber Estuary were highest during spring (311, 8 96 & 1045 kg day-1, for Cu, Cd and Pb respectively) and lowest during summer (25 7, 1 .12 & 33 4 kg day-1, for Cu, Cd and Pb respectively) They were dominated by variations in freshwater outflow and the tidal range during sampling On an annual basis comparison to estuarine inputs (rivers, industry and sewage sources) suggested retention of Cu (25%) and Cd (56%) Estimates of partitioning (KD) were derived from the dissolved and particulate data for Cu, Cd and Pb over the seasonal cycle Copper was dominated by the particulate phase (73-80%) in all seasons but summer, whilst Cd showed particulate phase dominance (54-70%) in autumn and winter only The Pb distributions were dominated by the particulate phase (94-99%) independent of season Trace metal settling velocities implied that the Humber Plume was acting as a sink for Cu, Cd and Pb in winter and spring However settling velocities calculated for Cd and Pb (flood tide) in summer were similar to background suspended particulate matter (SPM) suggesting long range transport with the residual circulation. Modelling of Pb isotopic ratios in the Humber Plume suggested that on average 32-39% of the extracted Pbp originated from anthropogenic sources The data from this study has given unique information concerning the concurrent seasonal distributions of particulate trace metals in the western North Sea and have yielded new insights into mechanisms affecting trace metal cycling and transport, essential in the development and refinement of coupled hydrodynamic-geochemical models.
50
Bird, Linda Margaret. "The effects of saline pumping water on freshwater invertebrate communities". Thesis, Nottingham Trent University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253693.
Texto completo da fonte