Not only in South Africa, but also all over the world, pollution is threatening the quality of water resources. More than 100,000 chemicals are produced worldwide and some of these chemicals enter into the aquatic environment, posing a potential threat to humans, animals as well as other organisms. Therefore, determining the quality of water is of great importance. The testing of the toxicity of water samples are either based on a biological model or chemical model. In the biological model, organisms are utilized as indicators for toxicity of a particular sample, this sample may then be cytotoxic to the cells of the organism. In the chemical model the amount of a specific chemical present in water samples are predicted. Although, within the biological model there are many cytotoxicity screening assays (also called bioassays) that assess quality of water, there is a need for a fast, efficient and cost-effective cell culture system that may act as first screening procedure in a range of tests. Of particular importance in the context of this thesis, are bioassays that measure specific biochemical parameters, e.g. the Uridine uptake bioassay, MTT (3-(4,5¬dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide) assay and the bioluminescent assay. An important advantage of these assays are their sensitivity and the fact that the tests are principally based on cell mortality as a consequence of membrane damage or influence on cell metabolism. Researchers at the Highveld Biological Laboratory in South Africa have the past few years paid particular attention to the MTT assay, originally developed by Mosmann, and have modified this assay. In this thesis the adjusted method is referred to as the Modified Highveld Biological assay. There were, however, still a few adjustments to be made in order to use this modified method to its full potential. The Bioluminescent assay, also were thought to have potential to be modified as water quality screening test. Therefore, the hypotheses investigated in the current thesis were: • The original Mosmann MTT method can be modified successfully to provide a sensitive, reproducible mass screening method for determining chemical cytotoxicity and water quality, by using the K-562 cell line. • Sensitivity of the assay can be increased by utilizing a 3 phase medium cycle (Medium type 1-3) instead of the previously used single culture medium. • Furthermore, this cytotoxicity assay can be successfully utilized to determine whether any chemical solution or water sample is cytotoxic. Thus information was needed to determine whether cytotoxicity correlates with real life toxicity. This requires time-consuming epidemiological surveys unless results can be correlated with previous surveys. The research in this thesis attempted to indicate that the obtained cytotoxicity can be used to predict toxicity of a water sample, and that the cytotoxicity findings of this dissertation may indeed be meaningful. The culturing conditions of the Modified Highveld Biological MTT assay were modified successfully and could thus be utilized as the first assay in a battery of tests to determine overall cytotoxicity by utilising K¬652 cells in culture. Due to successful modification of the assay, this MTT assay now reduces assay duration, thereby saving important resources. An attempt was also made to optimise the Bioluminescent assay. This method is based on the fact that adenosine triphosphate (ATP) is present in all living cells. The method utilizes an enzyme, firefly luciferase, which catalyses the formation of light from ATP and luciferin. The emitted light intensity is linearly dependent on the ATP . concentration and is measured using a luminometer. The following problems were, however, identified that renders this method unsatisfactory as cytotoxicity indicator for water samples. • The luciferase enzyme is too sensitive to too many different substances used in the cell culture medium and in the preparation procedures of the cells (ions, salts etc.) which makes it less suited for usage for fast, effective testing of water toxicity. • This method will probably function better when luciferase can be carried into the cells or form part of the cells' genetic material. • We therefore suggest that, the Bioluminescent assay might possibly be a method to determine cytotoxicity, if the sensitivity of the luciferase enzyme could be further investigated. Thus it could be concluded that luminescence is not suitable for assaying complex mixtures because it is possible for unknown non~toxic agents, present in test samples, to interfere with the process of light emission (quenching). Lastly, known chemical solutions as well as unknown water samples were screened using the adjustments to the Modified Highveld Biological Method proposed in this thesis. The cytotoxicity of unknown water samples and chemical solutions were successfully determined and different cytotoxic effects were obtained, e.g. synergism, antagonism, additive effects and neutral effects. It was also possible to reduce or remove the cytotoxicity of certain water samples by applying pre~treatment with either Na2CO3 (removing possible toxic divalent and polyvalent metals) or SepPak cartridge clean up (removing organic toxicants). Results indicated that the method is very sensitive and can detect even low traces of toxicants. Thus, it can be concluded that the method was successfully adjusted to be useful as a first screening assay for toxicity analysis of a series of environmental water samples. / Dissertation (MSc (Anatomy))--University of Pretoria, 2006. / Anatomy / unrestricted

This master´s thesis is focused on the occurrence of phosphorus and nitrogen in effluents and methods of their determination. In the theoretical part of the thesis describes methods for the determination of nitrogen and phosphorus in waste waters, their selection and optimization methods including mobile analytics. Experimental section is devoted to the abstraction of wastewater from selected wastewater treatment plants and their analysis methods including mobile analytics and comparing them with the presentation of their results. The conclusion is drawn evaluate the content of nitrogen and phosphorus in wastewater influent and effluent from wastewater treatment plants and compared the variation of these values during the one-month study and compared with published data.

In my thesis I focused on the problem of removal of some heavy metals from water. Heavy metals cause deterioration of quality of water sources and bring about a need of complicated water treatment technologies. In particular it is the case of mercury, arsenic, cadmium, lead, chromium and nickel. This diploma thesis focuses on the utilization of adsorption using suitable adsorption materials to reduce concentrations of nickel in drinking water. At the same time it investigates the effectiveness of these materials in the process of removing iron and manganese from water. The first part of my thesis presents an overview of these metals. I write about their occurrence, its forms, properties and significance. The second part of the work focuses on the laboratory observations of the effectiveness in removing iron, manganese and nickel from water. The description of the used sorptive materials is also included.

A field investigation of the pollution existing in the Roanoke River within the Roanoke Metropolitan district was carried out from June, 1940 to May, 1941 by various departments of the Virginia Polytechnic Institute with the material aid of several other interested groups. Studies of the chemical and bacteriological conditions, and of the microscopic life existing in the stream were made by P. H. McGauhey and H. F. Eich, of the Department of Civil Engineering. The invertebrate and vertebrate life of the stream, as well as the toxicity of viscose wastes to fishes, was investigated by H. W. Jackson and Croswell Henderson, of the Department of Biology. Monthly mineral analyses of water were made by F. H. Fish and others of the Department of Chemistry, and data relative to certain industrial wastes were furnished by R. A. Fisher and Dudley Thompson, of the Department of Chemical Engineering. / Master of Science

Thesis (MPhil)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: A farm in Zimbabwe (Farm A) obtains its water for tbe poultry operations from tbe Makavusi River that is heavily contaminated with bacteria and performance results are thereby reduced. Anolyte is a Russian invention that claims to have bactericidal effects that could be beneficial to broilers. The aim of this research is to investigate the effect of Anolyte on production profits of broilers given water of poor quality by carrying out a number of trials. Trials that were conducted are basic in vitro tests on Anolyte within the laboratory, water analysis on water supply to the broiler section (both chemical and bacteriological), and a detailed trial within an experimental trial site comparing broiler performance results with different chemical water treatments and different dilutions of Anolyte. Broiler chicks from different hatcheries (Hatchery A and Hatchery B) were also compared. Performance results were based on growtb rate, mortality, feed conversion ratios (FCR), performance efficiency factors (PEF) and profit margin comparisons. Results showed that in tbe laboratory, Anolyte had an antibacterial activity. In the broiler performance trial on Hatchery B broilers, the live weights at forty two days of age in broilers given 15% Anolyte differed from other treatments (P<0.05) other than 10% Anolyte (P > 0.05). However, the FCR and mortalities did not differ (P > 0.05) between treatments. In the trial on Hatchery A broilers to 42 days of age, growth rates in broilers given 15% Anolyte differed from tbe control, Chematron and 20% Anolyte (P < 0.05). However, the FCR and mortalities did not differ between (P>0.05) treatments. In comparing chicks from different hatcheries, Hatchery B broilers differed (P < 0.05) from Hatchery A broilers in live weights at 42 days on 10% Anolyte, 15% Anolyte and on Chematron treatments. However, tbe cumulative mortalities and FCR did not differ (P > 0.05) between the Hatchery B and Hatchery A on any treatment. When comparing profitability, tbe treatment that had the greatest margin in comparison to tbe control (untreated drinking water) was 15% Anolyte for both tbe Hatchery B and Hatchery A trials. / AFRIKAANSE OPSOMMING: 'n Plaas in Zimbabwe, (Plaas A) verkry water, vir hul pluimvee bedryf vannuit die Makavusi rivier. Die rivier is swaar besmet met bakterië en as gevolg daarvan verhoed dit dat hulle hul volle opbrengs potential bereik. Anolyte is 'n Russiese uitvindsel wat aanspraak maak daarop dat dit bakteriëdodende effekte besit wat tot die bevordering van slaghoenders kan lei. Die doel van die navorsing is om Anolyte op proef te stel aangaande produksie profyt op slaghoenders waaraan swak kwaliteit water verskaf is. Verskeie toetse is uitgevoer n1. 'n basiese 'in vitro' toets in samewerking met die laboratorium, water ontleding op water wat aan die slaghoender seksies verskaf is (beide chemikalies and bakterieologies) asook 'n intensiewe proefnemeing waarin die verskeie obrengs resultate, van chemikaliese behandelde water en verskillende verdunnings van Anolyte, met mekaar vergely is, in 'n experimetele navorsings eenheid. Slaghoender kuikens van twee verskillende broeihuise (n1. Broeihuis A en Broeihuis B) is ook met mekaar vergelyk. Die resultate is gabasseer op groei tempo, sterftes, voer omsettings verhouding, opbrengs geskikthied faktore asook vergelykings op wins. Laboratorium navorsing het bevestig dat Anolyte wel antibakteriese aktiviteit getoon het. Terwyl in die proefneming op Broeihuis B slaghoenders, het die lewende gewig van hoenders, op 42 dae van ouderdom, waaraan 15% Anolyte verskaf is, verskil van ander behandelings (P<0.05) met die uitsondering van 10% Annolyte (P>0.05). Alhoewel die voer omsetting verhoudings en sterftes nie in die verskillende behandelings verskil het nie. In die proefnemeing op Broeihuis A slaghoenders tot 42 dae van ouderdom, het die ontwikkeling van slaghoenders, waaraan 15% Anolyte verskaf is, verskil van die kontiole, Chematron en 20% Anolyte. Die voer omsettings verhoudings en sterftes het egter geen verskil getoon tussen die verskeie behandelings nie. Resultate van die vergelyking tussen die kuikens uit die twee verskillende broeihuise, het getoon dat die Broeihuis A en Broeihuis B lewensgewigte, op 42 dae van ouderdom, wel met mekaar verskil het met 10% Anolyte, 15% Anolyte sowel as die Chematron behandelings. Daar was egter geen verskil, (P>O.05) tussen die twee tipes aangaande elke tipe se saamgestelde sterftes en die voer omsettings verhoudings, in welke behandeling nie. Die vergelykings op wins het getoon dat die behandeling met die grootste brulo marge, die was van 15% Anolyte in vergelyking met die kontiole (onbehandelde drinkwater) vir beide die Broeihuis A en die Broeihuis B proefnemings.

M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology, 2016 / Natural organic matter if not removed from water used for electricity generation has dire consequences that affect the long term plant health. The main problem is that organic matter at higher temperature and pressure disintegrate into smaller organic acids and carbon dioxide. This causes the cycle water and steam to be acidic and this can result in corrosion of the plant. The raw water from the Komati (Arnot power station) and Usutu (Kriel power station) scheme were analysed to determine the organic profile and seasonal variation. There was a noticeable variation in the quality of the water with an increase in DOC during rainy season. The water was found to be containing hydrophobic as well as hydrophilic molecules that could be quantified with a liquid chromatography organic detector (LC-OCD). Current water treatment processes employed at the two stations, Arnot and Kriel, has demonstrated the capability of removing organics to just over 50 percent at the pre-treatment section. The water treatment plant includes demineralisation plant that was able to produce water that met Eskom’s target specifications of less than 250 ppb DOC values. Qualitative and quantitative analysis of the steam-condensate water was done by use of an ion chromatography method. The determined organic anions were found to be acetates, formats and lactates.

A study has been conducted for the qualitative and Quantitative analysis of chlorinated organic compounds in water. The study included the adaptation of Amberlite XAD macroreticular resin techniques for the concentration of municipal wastewater samples, followed by GC/MS analysis. A new analytical method was developed for the determination of volatile halogenated organics using liquid-liquid extraction and electron capture gas chromatography. And, a computer program was written which searches raw GC/MS computer files for halogen-containing organic compounds.

Este trabalho teve como objetivo principal a utilização de duas variantes da técnica analítica de fluorescência de raios X, dispersiva em energia - EDXRF e reflexão total TXRF, na determinação de Pb em amostras de águas superficiais e subterrâneas, e em sedimentos em suspensão e de fundo. Cinco amostras de cada matriz foram coletadas em uma área contaminada, nas proximidades da desativada fábrica de baterias Indústria Acumuladores Ajax Ltda., localizada no km 229 da rodovia Jaú-Ipaussu, em Bauru, SP. As variantes EDXRF com pré-concentração com APDC e medida direta por TXRF mostraram resultados satisfatórios na determinação de Pb em soluções-padrão e amostra certificada de água natural SRM1640, produzida pelo NIST, obtendo-se concentrações compatíveis com os valores esperados. A primeira técnica resultou em limite de detecção da ordem de 0,70 mg L-1, com tempo de análise de 300 s, melhor que a segunda técnica (4,46 mg L-1), em 200 s. Estas duas variantes também foram utilizadas para outros elementos químicos, como o Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn e Br, onde a EDXRF mostrou também melhores limites de detecção para todos os elementos. Para Ni, Cu e Zn, importantes na indústria de baterias, foram encontrados os limites de 0,34 - 0,27 e 0,24 mg L-1, respectivamente, enquanto que por TXRF foram encontrados os valores ao redor de 1 mg L-1. Na validação destas duas metodologias para análise de água, a EDXRF mostrou resultados mais próximos aos valores esperados, enquanto que por TXRF foram superestimados na maioria das vezes, com exceção para As, Se e Pb. Este erro foi devido a uma interferência espectral ocasionada provavelmente pela presença dos elementos Ti ao Zn nos componentes metálicos do arranjo experimental, ausentes no suporte refletor de quartzo, colimador do detector ou solução do padrão interno. Sem a eliminação dessa interferência, os resultados obtidos por TXRF para estes elementos, com exceção para As, Se e Pb, só podem ser utilizados como qualitativos. Para análise de sedimentos em suspensão foi utilizada a técnica de EDXRF, assumindo a amostra como filme fino, atingindo limite de detecção da ordem de 2 mg g-1 para Pb, enquanto que para o Cu e Zn o limite de detecção foi da ordem de 5 mg g-1, em 300 s. Para sedimento de fundo foi utilizada a mesma técnica, mas admitindo a amostra como espessa, corrigindo-se o efeito matriz através do fator de absorção, validando-a pela análise de amostras certificadas de sedimento (SRM1646a/NIST) e solo (SRM2711/NIST). O limite de detecção para Pb ficou em torno de 2 mg g-1, e para outros elementos os limites foram de 3,07 mg g-1 para Ni, 2,12 mg g-1 para Cu e 1,50 mg g-1 para Zn, em 500 s. Com base nos valores máximos permitidos para Pb, estabelecidos pela Portaria 1469/00 e Resolução 20/1986 CONAMA, duas amostras de água mostraram-se contaminadas pelos resultados obtidos pela variante EDXRF, e quatro pelos resultados da TXRF. Para os outros elementos, apesar da interferência na TXRF, por esta técnica uma amostra de água ultrapassou o limite permissível para Cu e todas as cinco para Zn, e pela EDXRF uma amostra para Ni e Cu em água, e três para Zn. Na legislação brasileira não há limite máximo permitido para Pb e outros elementos em solos e sedimentos, e portanto foram adotados os limites TEL (Threshold Effect Level, nível limiar do efeito) e PEL (Probable Effect Level, nível provável do efeito), utilizados pela Agência Ambiental Canadense. As amostras de sedimento em suspensão mostraram concentrações de Pb menores que o limite de detecção, e das cinco amostras de sedimento de fundo, uma amostra apresentou valor acima do limite TEL, e outra, coletada num ponto bem ao lado da fábrica, acima do limite PEL. Para os outros elementos Ni, Cu e Zn, nenhuma das amostras de sedimento em suspensão ou de fundo não ultrapassaram os limites TEL. / This study had as main objective the use of two variants of the analytical technique of X-ray fluorescence, energy dispersive - EDXRF and total reflection - TXRF, for the determination of Pb in superficial and underground water and in suspended and bottom sediment samples. Five samples of each matrix were collected in a contaminated area near the closed battery plant, Indústria de Acumuladores Ajax Ltd., located on km 229 of the Jaú-Ipaussu highway, near the city of Bauru in São Paulo State, Brazil. The two variants – EDXRF with preconcentration with APDC and TXRF direct measurement – had shown satisfactory results in the determination of Pb in standard solutions and certified natural water sample SRM1640/NIST, obtaining compatible concentrations with the expected values. The first technique resulted in a 0.70 mg L-1 limit of detention, with 300 s analysis time, and the second one 4.46 mg L-1 in 200 s. These two variants were also used for other chemical elements, such as Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn and Br. EDXRF also showed better limits of detection for all the elements. For Ni, Cu and Zn, important in the industry of batteries, the limits of 0.34, 0.27 and 0.24 mg L-1, respectively, were found, while with TXRF the values of around 1 mg L-1 were achieved. In the validation of these two methodologies for water analysis, the EDXRF showed results nearer to the expected values, while with TXRF the results were overestimated most of the times, with the exceptions of As, Se and Pb. This error was due to a spectral interference caused probably by the presence of the elements Ti to Zn in the metallic parts of the experimental arrangement, absent in the quartz reflecting support, detector collimator or internal standard solution. Without the elimination of this interference, the results for TXRF for these elements, with the exceptions of As, Se and Pb, can only be used as qualitative results. For analysis of suspended sediments, the EDXRF technique was used, assuming the sample as thin film, the limit of detection of around 2 mg g-1 for Pb was reached, while that for Cu and Zn was around 5 mg g-1, in 300 s. For bottom sediments the same technique was used, but admitting the sample as thick, the matrix effect through the absorption factor was corrected, validating it for the analysis of certified samples of sediment (SRM1646a/NIST) and soil (SRM2711/NIST). The limit of detention for Pb was around 2 mg g-1 and for other elements the limits were 3.07, 2.12 and 1.50 mg g-1 for Ni, Cu and Zn, respectively, in 500 s. On the basis of the Brazilian allowed maximum values for Pb, established by Decree 1469/00 and Resolution 20/1986 CONAMA, two water samples were shown to be contaminated by the results gotten with variant EDXRF, and four by the results of TXRF. For the other elements from the TXRF results (despite the interference) one water sample exceeded the permissible limit for Cu and all the five for Zn, and for the EDXRF results one sample for Ni and Cu and three for Zn. In the Brazilian legislation there is no maximum limit allowed for Pb and other elements in soils and sediments; therefore, TEL (Threshold Effect Level) and PEL (Probable Effect Level) limits from the Canadian Environment Agency were adopted. The suspended sediment samples showed Pb concentrations lesser than the limit of detection. From the five bottom sediment samples, one sample presented a value above the TEL limit, and another one, collected in a point very close to the plant, above the PEL limit. For the other elements, Ni, Cu and Zn, none of the suspended or bottom sediment samples exceeded the TEL limits.

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-05-30T18:32:50Z No. of bitstreams: 1 LUCIANA ROCHA DE LIMA - DISSERTAÇÃO PPGSA PROFISSIONAL 2017..pdf: 983248 bytes, checksum: 57452632c520590aad123ff5ddc65a52 (MD5) / Made available in DSpace on 2018-05-30T18:32:50Z (GMT). No. of bitstreams: 1 LUCIANA ROCHA DE LIMA - DISSERTAÇÃO PPGSA PROFISSIONAL 2017..pdf: 983248 bytes, checksum: 57452632c520590aad123ff5ddc65a52 (MD5) Previous issue date: 2017-06-20 / O consumo de água utilizado nas instituições de Educação Infantil pública do município de Aparecida, Estado da Paraíba, é proveniente de fontes como: poços profundos, abastecimento de água por carro pipa, bem como pelo uso de água proveniente de cisternas. Com o objetivo de analisar a qualidade da água utilizada nessas escolas, e verificar até que ponto essas águas podem ou não causar doenças veiculada por uso de água de baixa potabilidade, optou-se em fazer esse estudo, bem como, estabelecer a que ponto a falta de utilização de meios de informações e proteção, manutenção dos mananciais e possíveis doenças relacionadas e veiculadas com o uso e consumo de água às vezes imprópria para consumo humano, pode causar ao ser humano, em especial as crianças, e sabendo que a água é um elemento essencial a vida, mas que pode trazer riscos à saúde humana se houver comprometimento de sua qualidade. Pensando nisso o estudo abrange as escolas públicas de educação infantil do Município de Aparecida, sertão paraibano. Nesse aspecto as crianças são as que mais sofrem com os problemas da ingestão de água contaminada, uma vez que são mais vulneráveis devido à imaturidade de seu sistema imunológico. Nesse contexto destaca a importância de um levantamento da qualidade da água para consumo em instituições do ensino infantil, uma vez que a escola representa um importante ambiente no qual está inserida a criança. Foram coletadas amostras em reservatórios de água em nove escolas e duas creches municipais, nos seguintes pontos: reservatórios, bebedouros, torneira da cozinha e ponto de entrada da água, as amostras foram coletadas no período de estiagem, de julho a agosto do ano de 2016, e posteriormente, transportadas e analisadas no Laboratório de Microbiologia e de Análises de Solos, Água e Plantas, ambos do Campus de Sousa do Instituto Federal de Educação, Ciência e Tecnologia da Paraíba - IFPB. O presente trabalho objetivou- se analisar os padrões físico-químicos e microbiológicos da água utilizadas nas escolas e creches da Educação Infantil do ensino público do município de Aparecida, Sertão paraibano. Com os resultados, verificou-se ser imprópria para consumo humano, de acordo com os parâmetros microbiológicos analisados da água, com presença de Coliformes e Encheria Coli. A pesquisa serviu para fornecer informações para comunidade escolar da real situação da potabilidade, destacando a importância de evitar consumir água imprópria, bem como, orientar a respeito da conservação dos recursos hídricos no processo de Educação Ambiental. / The consumption of water used in public infant education institutions in the city of Aparecida, State of Paraíba, comes from sources such as: deep wells, water supply by car kite, as well as the use of water from cisterns. In order to analyze the quality of the water used in these schools, and to verify the extent to which these waters may or may not cause illnesses caused by the use of low drinking water, it was decided to do this study, as well as to establish the Lack of use of means of information and protection, maintenance of water sources and possible related diseases and transmitted with the use and consumption of water sometimes unfit for human consumption, can cause to the human being, especially the children, and knowing that the water is An element essential to life, but which can pose risks to human health if its quality is compromised. With this in mind, the study covers the public schools of early childhood education in the Municipality of Aparecida, in the Sertão of Paraíba. In this aspect, children are the ones who suffer most from the problems of drinking contaminated water, since they are more vulnerable due to the immaturity of their immune system. In this context it highlights the importance of a survey of the quality of drinking water in institutions of early childhood education, since the school represents an important environment in which the child is inserted. Samples were collected in water reservoirs in nine schools and two municipal nurseries, in the following points: reservoirs, drinking fountains, kitchen faucet and water entry point, samples were collected during the dry season, from July to August, 2016 , And later transported and analyzed in the Laboratory of Microbiology and Analysis of Soils, Water and Plants, both of the Campus de Sousa of the Federal Institute of Education, Science and Technology of Paraíba - IFPB. The objective of this study was to analyze the physicochemical and microbiological patterns of water used in the schools and kindergartens of the Early Childhood Education in the city of Aparecida, Sertão, Paraíba. With the results, it was found to be unfit for human consumption, according to the microbiological parameters analyzed of the water, with presence of Coliformes and Encheria Coli. The research served to provide information to the school community about the real situation of drinking water, highlighting the importance of avoiding the consumption of inappropriate water, as well as guiding the conservation of water resources in the process of Environmental Education.

This thesis examines geomorphic processes that impact thermal stratification within floodplain lakes. Previously, thermal stratification was not thought prevalent in these numerous small water bodies, despite being found in small reservoirs. Thermal stratification leads to long term anoxia in the bottom waters and the release of metals and nutrients from the sediments. This can result in water quality problems such as algal blooms (including potentially toxic cyanobacteria), loss of fish habitat and deterioration of wetland habitat. Four floodplain lakes of the Macdonald River Valley NSW were profiled and tested over 3?? years to assess to what extent, under what conditions, and with what chemical and physical effects, they thermally stratified and destratified. The morphometry, bed facies, vegetation, hydrology and local weather patterns for each lake were also investigated. Physical and chemical analyses found elevated nutrients in all four lakes and higher concentrations of total phosphorous and total nitrogen in the bottom waters. These results were not dependant on stable thermal stratification and long-term anoxia in the bottom waters. Inflow samples had much higher concentrations of nutrients than the lake samples, so the catchment is the likely source. Samples were analysed for phytoplankton and significant populations of potentially toxic cyanobacteria were present. Stratification depended upon whether the lake was "sheltered" from wind stirring or from incident radiation, either topographically by steep slopes surrounding the lakes, or by submerged and emergent vegetation. Aquatic vegetation limits the amount of transfer of turbulent kinetic energy from wind shear and the amount of incident radiation received. At one lake, sheltered areas reached temperatures much higher than less sheltered areas. Topographic sheltering can make a difference of up to three degrees Celsius across the lake surface. Destratification depended on wind speed, wind direction and orientation of the lake to the dominant wind direction. An extension to the classification of fluvial lakes (from Timms 1992) is presented, with further subdivisions to describe the lakes as "sheltered" or "open" and the type of sheltering (vegetation or topography) present.