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Freshwater resources are threatened by the presence and increase of harmful algal blooms (HABs) all over the world. The HABs are sometimes a direct result of anthropogenic pollution entering water bodies, such as partially treated nutrient-rich effluents and the leaching of fertilisers and animal wastes. Microcystis species are the dominant cyanobacteria (algae) that proliferate in these eutrophic waters. The impact of HABs on aquatic ecosystems and water resources, as well as their human health implications are well documented. Countermeasures have been proposed and implemented to manage HABs with varying levels of success. These control measures include the use of flocculants, mechanical removal of hyperscums and chemical algicides. The use of flocculants such as PhoslockTM is effective in reducing the phosphates in a water body thus depriving nutrients that are available to cyanobacteria. The mechanical option entails the manual removal of hyperscums thus reducing the numbers of cyanobacteria cells that may be the inoculum of the next bloom. The major disadvantage of these two measures is cost. Copper algicides have been used successfully to control HABs in raw water supplies intended for potable purposes. The major disadvantages are copper toxicity and release of microcystins from lysed cyanobacteria cells. Algicides accumulate in the sediments at concentration that are toxic to other aquatic organisms and may also cause long-term damage to the lake ecology. In some studies, microcystins have been implicated in the deaths of patients undergoing haemodialysis. Therefore there is an increasing need to reduce the use of chemicals for environmental and safety reasons. Thus, the development of environmentally friendly; safe non-chemical control measures such as biological control is of great importance to the management of HABs. Some papers, describe bacteria, which were isolated from eutrophic waters, such as Sphingomonas species with abilities to degrade microcystins and Saprospira albida with abilities to degrade Microcystis cells. Further research is required to evaluate whether these bacteria are antagonistic towards cyanobacteria. Ideally, a combination of strategies should be introduced; that is, combine predatory bacteria that directly lyse the cyanobacteria with microcystin degrading bacteria that then ‘mop up’ the released microcystins. The major objective of this study was to isolate organisms that have a similar antagonistic properties; determine their mechanism of action and then develop a model to account for the interaction between the predator and prey as the basis for the development of a biological control agent. During the screening for lytic organisms from eutrophic waters of Hartbeespoort dam, seven bacterial isolates were obtained. Based on electron microscope observation, two of the isolates were found aggregated around unhealthy Microcystis cells. These were identified as Pseudomonas stutzeri strain designated B2 and <i.Bacillus mycoides strain designated B16. Based on efficiency and efficacy experiments B. mycoides B16 was a more effective antagonist than P. stutzeri B2. Furthermore the <i.B. mycoides B16: Microcystis critical ratio was found to be 1:1 in 12 days. Thus altering the predator-prey ratio by increasing the predator bacteria numbers reduced the Microcystis lysis time to six days. The B. mycoides B16 managed to reduce the population of alive Microcystis cells by 85% under turbulent conditions and 97% under static conditions in six days. The increase in predator bacteria numbers coincided with a decrease in growth of Microcystis. The study on the interactions of Microcystis aeruginosa and Bacillus mycoides B16 indicated a series of morphological and ultrastructural changes within the cyanobacteria cell leading to its death. These are summarised in a conceptual model that was developed. The predatory bacteria, B. mycoides B16 attached onto the Microcystis cell through the use of fimbriae and or exopolymers. During this attachment the bacteria released extracellular substances that dissolved the Microcystis cell membrane and interfered with the photosynthesis process. The presence of numerous bacterial cells that aggregated around Microcystis cell provided a ‘shade’ that reduced the amount of light (hv) that reached the Microcystis cell. In response to these adverse conditions, the Microcystis cell did the following: It expanded its thylakoid system, the light harvesting system, to capture as much light as possible to enable it to carry out photosynthesis and it accumulated storage granules such as phosphate bodies, glycogen and cyanophycin and swollen cells. Other researchers have also reported the swelling phenomenon prior to cell lysis but did not account for what might be the cause. During the course of the lysis process the Microcystis cell underwent a transition stage that involved changes from alive (with an intact membrane) to membrane compromised (selective permeability), to death (no membrane) and eventual cell debris. Due to the depleted Microcystis cells, the B. mycoides B16 (non-motile, non-spore former) formed chains, i.e., exhibited rhizoidal growth in search of new Microcystis cells to attack. In conclusion, the present evidence in this study suggests that B. mycoides B16 is an ectoparasite (close contact is essential) in its lysis of Microcystis aeruginosa under laboratory conditions. These findings that B. mycoides B16 is a predatory bacterium towards Microcystis aeruginosa need to be further evaluated under field conditions in mesocosm experiments (secluded areas in a lake) to determine the possibility of using this organism as a biological control agent. The study on the interactions of Microcystis aeruginosa and Bacillus mycoides B16 indicated a series of morphological and ultrastructural changes within the cyanobacteria cell leading to its death. These are summarised in a conceptual model that was developed. The predatory bacteria, B. mycoides B16 attached onto the Microcystis cell through the use of fimbriae and or exopolymers. During this attachment the bacteria released extracellular substances that dissolved the Microcystis cell membrane and interfered with the photosynthesis process. The presence of numerous bacterial cells that aggregated around Microcystis cell provided a ‘shade’ that reduced the amount of light (hv) that reached the Microcystis cell. In response to these adverse conditions, the Microcystis cell did the following: It expanded its thylakoid system, the light harvesting system, to capture as much light as possible to enable it to carry out photosynthesis and it accumulated storage granules such as phosphate bodies, glycogen and cyanophycin and swollen cells. Other researchers have also reported the swelling phenomenon prior to cell lysis but did not account for what might be the cause. During the course of the lysis process the Microcystis cell underwent a transition stage that involved changes from alive (with an intact membrane) to membrane compromised (selective permeability), to death (no membrane) and eventual cell debris. Due to the depleted Microcystis cells, the B. mycoides B16 (non-motile, non-spore former) formed chains, i.e., exhibited rhizoidal growth in search of new Microcystis cells to attack. In conclusion, the present evidence in this study suggests that B. mycoides B16 is an ectoparasite (close contact is essential) in its lysis of Microcystis aeruginosa under laboratory conditions. These findings that B. mycoides B16 is a predatory bacterium towards Microcystis aeruginosa need to be further evaluated under field conditions in mesocosm experiments (secluded areas in a lake) to determine the possibility of using this organism as a biological control agent. The study on the interactions of Microcystis aeruginosa and Bacillus mycoides B16 indicated a series of morphological and ultrastructural changes within the cyanobacteria cell leading to its death. These are summarised in a conceptual model that was developed. The predatory bacteria, B. mycoides B16 attached onto the Microcystis cell through the use of fimbriae and or exopolymers. During this attachment the bacteria released extracellular substances that dissolved the Microcystis cell membrane and interfered with the photosynthesis process. The presence of numerous bacterial cells that aggregated around Microcystis cell provided a ‘shade’ that reduced the amount of light (hv) that reached the Microcystis cell. In response to these adverse conditions, the Microcystis cell did the following: It expanded its thylakoid system, the light harvesting system, to capture as much light as possible to enable it to carry out photosynthesis and it accumulated storage granules such as phosphate bodies, glycogen and cyanophycin and swollen cells. Other researchers have also reported the swelling phenomenon prior to cell lysis but did not account for what might be the cause. During the course of the lysis process the Microcystis cell underwent a transition stage that involved changes from alive (with an intact membrane) to membrane compromised (selective permeability), to death (no membrane) and eventual cell debris. Due to the depleted Microcystis cells, the B. mycoides B16 (non-motile, non-spore former) formed chains, i.e., exhibited rhizoidal growth in search of new Microcystis cells to attack. In conclusion, the present evidence in this study suggests that B. mycoides B16 is an ectoparasite (close contact is essential) in its lysis of Microcystis aeruginosa under laboratory conditions. These findings that B. mycoides B16 is a predatory bacterium towards Microcystis aeruginosa need to be further evaluated under field conditions in mesocosm experiments (secluded areas in a lake) to determine the possibility of using this organism as a biological control agent. / Thesis (PhD (Water Resource Management))--University of Pretoria, 2008. / Microbiology and Plant Pathology / PhD / Unrestricted

Disertační práce Změny zátěže ekosystému v podélném profilu antropogenně ovlivněného toku Kateřina Kohušová Changes of ecosystem load in longitudinal profile of antropogenically influenced river ABSTRACT To determine anthropogenic load of the Bílina river ecosystem we monitored concentrations of selected heavy metals (As, Cd, Hg, Pb, V, Zn) and specific organic substances (PAH, PCB, HCH, HCB, DDT) in three different matrices: surface water, biofilms and sediments. In the longitudinal profile of the river, four sampling profiles were determined (B1 - B4), mapping different parts of the river. The monitoring took place from 2005 to 2008. Concentrations of the substances monitored in surface water showed a decrease in load compared to the values from ten years ago. The concentrations found in surface water showed clear tendency of pollution in the longitudinal profile; the load increased downstream and profiles B3 and B4 mid- and downstream had the highest concentration. In the case of some concentrations of substances in surface water there is a trend of the majority of values being below the detection limit by the given methods of analysis. This shows a decrease of load in the river but the positive trend was invalidated by variations in maximum concentrations. Even though these variations were rare and...

Osek stream has two antagonistic torrents between its spring and its junction with Loučenský stream. These torrents differ a lot. These differences are evoked mainly by human activity. Attention is paying especially to influence of river-bed modification to life in the stream and around it. Attention is also paying to water pollution caused by people, industry and agriculture

Made available in DSpace on 2015-04-22T22:02:12Z (GMT). No. of bitstreams: 1 Paulo Renan.pdf: 1587343 bytes, checksum: 5a08e797bff6ad2f7e370d3d94651720 (MD5) Previous issue date: 2012-08-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Fractionation of the metals Fe, Mn, Zn, Cu and Ni in sediments was performed for samples collected from ten locations from igarapé Educandos sub-basin, in Manaus AM, north Brazil. From air dried sediment particles was made a sequential extraction procedure proposed by the European Community Bureau of Reference (BCR). In general, the speciation study revealed that Mn, Zn, Cu and Ni have high mobility due to their high contents in the exchangeable/acid soluble fraction, while Fe is less mobile. Principal component analysis (PCA) clearly separated the metals in groups, due to different distributions of the metals in the various fractions, in sediments from different locations. The enrichment factor (EF) obtained for each metal showed the intense anthropogenic influence in the region. Based on the risk assessment code (RAC), Mn, Zn and Ni posed a very high risk to the ecosystem (RAC > 50%), Cu pose a high risk (RAC > 31%) and Fe a low risk (RAC < 10%). / O fracionamento dos metais Fe, Mn, Zn, Cu e Ni em sedimentos de fundo foi realizado para amostras coletadas de dez locais na sub-bacia do igarapé Educandos, na cidade de Manaus Brasil. Nas partículas de sedimento seco ao ar, foi feito um procedimento de extração sequencial proposto pela European Community Bureau of Reference (BCR). De maneira geral, o estudo de especiação revelou que Mn, Zn, Cu e Ni possuem alta mobilidade devido aos seus altos conteúdos na fração solúvel em ácido/trocável, enquanto que Fe é o menos móvel. A análise de componentes principais (PCA) aplicada para as diferentes frações do procedimento BCR claramente separou os metais dentro de grupos, devido as diferentes distribuições dos metais nas várias frações. O fator de enriquecimento (FE) obtido para cada metal mostrou a intensa influência antrópica na região. Baseado no código de avaliação de risco (RAC), Mn, Zn e Ni representam um risco muito alto para este ecossistema (RAC > 50%), Cu representa um risco alto (RAC > 31%) e Fe um risco baixo (RAC < 10%).

In this thesis, water quality and the assessment of anthropogenic pollution in the sediments of the middle course of the Elbe River oxbow lakes Kozelská and Vrť were studied. It is widely accepted that the oxbow lakes are extremely significant ecosystems, However, a large amount of contaminated material may deposit in these lakes. The pollution probably comes from industrial sources of contamination from the second half of the 20th century. In addition, the oxbow lakes show the development of the riverbed, and contribute to the stability of the river ecosystem. The research of Lake Kozelská was chosen especially to its proximity to the chemical factory Spolana in Neratovice, which used to be the biggest source of pollution of the Elbe River. The research included bathymetric measurements, regular observations of hydrological regime, monthly analysis of chemical and physical parameters of water in the period from December 2016 to November 2017, and marginally microscopic analyses of phytoplankton and zooplankton species too. The next part of this research included grain analysis and determination of metal and arsenic concentrations in the sediment fraction of 20µm using Aqua Regia leaching and total decomposition as well. Concerning water quality assessment, these lakes were characterized by higher...

La Directive Cadre sur l'Eau exige le retour au bon état des cours d'eau en Europe. Ces cours d'eau reçoivent en effet différentes pollutions liées aux différentes activités économiques des populations installées le long de leurs rives. On s'intéresse souvent de façon isolée à des types particuliers de pollution: pollution agricole dues aux pesticides, engrais et résidus d'élevage en milieu rural, pollution spécifique d'une industrie (sidérurgie, papeterie, etc.), pollution domestique plus ou moins bien traitée, etc. Or dans de nombreux cas, on a affaire à un mélange de polluants. Dans le cas de la Moselle, la pollution générée par les activités humaines dans la partie française du bassin versant de la Moselle impacte la qualité des eaux de surface en aval, et donc celle du Rhin. Notre but est de contribuer à caractériser l’état de certains affluents de la Moselle (Madon, Meurthe, Vologne et Fensch) en fonction de leurs pressions anthropiques et de proposer une stratégie pour calculer les flux des polluants le long de ces cours d’eau. Dans ce contexte des compagnes de prélèvement avec un pas spatial fin. Outre les paramètres habituels de caractérisation de l’état des masses d’eau (conductivité, pH, carbone organique dissous, azote ammoniacal, nitrates, etc.) une attention particulière a été portée aux propriétés optiques (absorbance UV-visible, fluorescence synchrone) de la matière organique dissoute afin de mieux comprendre son origine. Les spectres de fluorescence synchrone ont été étudiés par déconvolution ou par analyse en composantes principales. En outre une méthode a été développée, basée sur la spectroscopie de fluorescence synchrone, pour détecter la présence des azurants optiques. Enfin une méthodologie a été mise au point appliquée au Madon pour calculer les flux journaliers moyens de pollution à chaque station d'échantillonnage pour chaque période d'échantillonnage à partir de données géographiques. Cette méthode permet ensuite d’évaluer les flux de pollution / The Water Framework Directive demands a return to good condition for rivers in Europe. These rivers receive different types of pollution related to various economic activities of populations installed along their banks. We are often interested in an isolated manner to particular types of pollution: pollution due to agricultural pesticides, fertilizers and livestock waste in rural areas, pollution due to a specific industry (steel, paper mill, etc.), more or less well treated domestic pollution, etc. But in many cases, we are dealing with a mixture of pollutants. In the case of the Moselle, the pollution generated by human activities in the French part of the Moselle watershed impacts surface water quality downstream and therefore the Rhine. Our goal is to characterize the state of some tributaries of the Moselle (Madon, Meurthe, Vologne and Fensch) versus anthropogenic pressures and propose a strategy to calculate the flow of pollutants along these rivers. In this context, sampling campaigns with a dense spatial stations have been organized. In addition to the usual parameters characterizing water quality (conductivity, pH, dissolved organic carbon, ammonia nitrogen, nitrate, etc.) a particular attention has been given to optical properties (UV-visible absorbance, synchronous fluorescence) of dissolved organic matter in order to understand its origin. Synchronous fluorescence spectra were studied by deconvolution or by principal components analysis. A method has been developed, based on the synchronous fluorescence spectroscopy, to detect the presence of optical brighteners. Finally, a methodology has been developed in Madon watershed in order to calculate the mean daily pollution flux at each sampling station for each sampling period from geographic data

Šiuo metu pagal plitimo greitį aplinkoje ir ribas bei koncentracijos didėjimą vienais iš pavojingiausių žmonėms ir gyvūnams laikomi antropogeninės kilmės teršalai - sunkieji metalai. Tyrimui atlikti buvo panaudoti Kauno miesto nuotekų valyklos laboratoriniai duomenys apie nuotekose ir nuotekų dumble susikaupusius sunkiuosius metalus: cinką (Zn), šviną (Pb), nikelį (Ni), gyvsidabrį (Hg), chromą (Cr), kadmį (Cd), varį (Cu). Naudojant susistemintus laboratorinius duomenis buvo nustatyta, kad didesnės sunkiųjų metalų koncentracijos žiemą buvo 2002 – 2003 metais, o 2004 – 2006 metais – rudenį ir pavasarį. Tyrimo rezultatai parodė, kad sunkiųjų metalų koncentracijų kaitą įtakoja krituliai, nustatyti vidutinio stiprumo ryšiai. Pagal taršą sunkiaisiais metalais (Cr, Cu, Cd, Zn, Ni, Hg) Kauno miesto nuotekų valyklos dumblas yra II kategorijos, o pagal Pb atitinka I kategoriją. III kategorijos dumblo iš viso nebuvo rasta, todėl nuotekų dumblas gali būti naudojamas laukų tręšimui bei sąvartynų uždengimui. Tyrimo metu buvo įvertinta galimybė Kauno miesto nuotekų dumblą panaudoti Lapių buitinių atliekų sąvartyno uždengimui. Dumble esančios sunkiųjų metalų koncentracijos nepablogintų sąvartyno filtrato kokybės, tačiau dėl fizikinių savybių (dumblas slysta, technika klimpsta) nėra tinkamas Lapių sąvartyno uždengimui. Dumblo naudojimas energetinių želdinių tręšimui taip pat yra nepalankus nuotekų dumblą tvarkančioms įmonėms dėl mažų tręšimo normų. / Heavy metals are anthropogenic pollutants which are toxic and mostly widespread in nowadays environment. For the research there were used Kaunas wastewater plant laboratorial data about heavy metals in wastewater and sewage sludge, such as chromium (Cr), copper (Cu), cadmium (Cd), zinc (Zn), nickel (Ni), mercury (Hg), plumbum (Pb). By using the systemized laboratorial data it was determined that the biggest concentrations of heavy metals in winter season were in the year 2002 – 2003, but in the year 2004 – 2006 – in autumn and spring. The results of the research showed that precipitation influences heavy metals concentrations to change; there were determined middle strength connections. According to the pollution of heavy metals in the year 2002 – 2006 treated sludge of Kaunas wastewater plant corresponded second category, just plumbum corresponded first category. There was no treated sludge of third category that is why sewage sludge can be used to utilize the fields and cover the landfills. During the research it has been estimated the possibility to use sewage sludge to cover the landfill of Lapes. The concentration of heavy metals in the sludge wouldn‘t make worse the quality of the landfill’s leachate, but still it is not practicable for the covering the Lapes landfill because of the physical characteristics (sludge is slippery, technical equipment is sinking). Because of the low utilising rates the usage for utilizing short rotation forest is not suitable as well for... [to full text]

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