In fresh waters where cyanobacteria (blue-green algae) flourish, dense growths known as blooms occur. Such blooms present a threat to human and animal health as many of these cyanobacteria produce toxins. One such group of toxins are the microcystins which are hepatotoxic resulting in haemoraging and tumour promotion in the liver. There have been several reports of human poisonings resulting from the presence of cyanotoxins in potable waters, some of which have resulted in fatalities. The most frequently cited cyanotoxin in these poisonings has been microcystin-LR, which has prompted the World Health Organisation (WHO) to set a guideline for the recommended safe level of this toxin in drinking water of 1 mgl-1. Removal of microcystin-LR from potable waters has proven to be inefficient using conventional water treatment techniques such as coagualtion, filtration and chemical oxidation using chlorine. While activated carbon adsorption and membrane filtration have been shown to physically remove microcystin-LR from water the toxin is not destroyed. Recently the use of photocatalysis was shown to rapidly degrade microcystin-LR even at high concentrations. The process involves the illumination of a titanium dioxide catalyst with ultraviolet (UV) light to produce highly oxidising hydroxyl radicals in solution. While several researchers have demonstrated the process's effectiveness in degrading the toxin none have determined the fate of the compound, or if the toxicity related to microcystin-LR has been removed. This study was carried out to determine if photocatalytic oxidation of microcystin-LR was suitable as a treatment method for potable water supplies. Analysis of treated toxin samples by high performance liquid chromatography (HPLC) with photo-diode array detection (PDA) and mass spectroscopy established that the toxin was not completely degraded during photocatalysis. A simple toxicity assessment however indicated that by-products were non-toxic. Using the data from this work a proposed pathway for toxin destruction was produced giving the speculative identity of some of the by-products. The use of hydrogen peroxide to enhance UV mediated destruction of microcystin-LR has been previously reported. There have also been reports of the enhancement of photocatalytiC reaction in the presence of this oxidant. The work carried out in this study demonstrated that the destruction of microcystin-LR by photocatalysis was both more rapid and more efficient when hydrogen peroxide was present in the system. The use of a fixed film flow reactor was also investigated for microcystin-LR destruction. While degradation of the toxin occurred it was demonstrated that batch reactors were more efficient as a treatment method. The effectiveness of the photocatalytic process on microcystin-RR, -LW and -LF was also investigated. While destruction of a" the variants occurred during photocatalytic treatment each microcystin demonstrated different rates and efficiencies of photooxidation. It was concluded from this study that photocatalysis is a promising treatment method for the removal of microcystin-LR and other variants from potable waters. Further research however is required to assess if the tumour promoting effects of microcystin-LR are rendered inactive and to determine the behaviour of the toxins degradation in natural water supplies. The study also allowed for speculation as to how the degradation of the toxin occurred during the photocatalytic process.

No description available.

Cyanobacterial blooms are of great concern to the drinking water treatment industry due to their capacity to produce microcystins and other cyanotoxins that are deadly to humans, livestock, pets, and aquatic life at low doses. Unfortunately, the strategies currently employed for cyanotoxin detection involve laborious analyses requiring significant expertise or bioassay kits that are subject to numerous false positives and negatives. These methods are incapable of providing rapid, inexpensive, and robust information to differentiate between the >80 cyanotoxin variants potentially present in an aqueous sample. The use of Raman spectroscopy for identification and quantification of the ubiquitous cyanotoxin microcystin-LR (MC-LR) was examined. Raman spectra readily reflect minute changes in molecular structure, spectra can be collected through water or glass, portable Raman spectrometers are increasingly available, and through surface enhanced Raman spectroscopy (SERS) it is possible to achieve femto or picomolar detection limits for a variety of target species. Drop coating deposition Raman (DCDR) was successfully implemented for quantitation of 2-100 ng of MC-LR deposited in 2 ?L of aqueous sample, even without the use of a specifically designed DCDR substrate or Raman signal enhancements. Reproducible MC-LR Raman spectra were observed for both fresh and aged DCDR samples, and the MC-LR Raman spectrum remained identifiable through a matrix of >80% DOM by mass. DCDR methods show tremendous potential for the rapid, simple, and economical detection of cyanotoxins in environmental matricies at environmentally relevant concentrations. / Master of Science

A oferta de água vem se tornando cada vez mais diminuta à medida que a população, a indústria e a agricultura se expandem. A contaminação dos mananciais gerada pelo descarte de efluentes domésticos e industriais leva a eutrofização, processo pela qual grande aporte de nutrientes, particularmente fosfatos, leva ao crescimento excessivo de algas. As cianobactérias são microrganismos procariontes, que vivem nos ambientes mais adversos. A floração dessas algas quando presente em mananciais destinados ao consumo humano gera sérios problemas à saúde humana, pois algumas dessas algas podem gerar toxinas, conhecidas como hepatotoxinas, neurotoxinas e dermatotoxinas, de acordo com sua ação farmacológica. Dentre as hepatotoxinas encontramos a microcistina, um heptapeptídeo cíclico que pode levar à morte em horas ou dias. O objetivo desse estudo foi viabilizar a técnica HPLC, já proposta por outros autores, para quantificar microcistinas-LR em reservatórios de água, em escala empresarial para ser implementada em laboratórios de análise de águas. Para o desenvolvimento da técnica, foram utilizadas amostras de uma lagoa com floração de Microcystis. Para determinar a eficiência da técnica cromatográfica, foram realizados estudos com outro método, através do kit ELISA. Nessa etapa do trabalho, verificou-se que a técnica HPLC é mais sensível e viável para a quantificação das microcistinas. Nos experimentos realizados com a cromatografia líquida, observou-se que a coluna C-18 LiChrosorb (25 cm) 7 Sm utilizada no método, e o solvente metanol apresentaram grande influência nos resultados. À medida que os experimentos foram executados, verificou-se o decréscimo da sensibilidade da coluna. Os resultados foram satisfatórios apenas após a limpeza realizada na coluna, onde os padrões apresentaram uma curva de correlação igual a 0,92. Este fato leva a concluir que as colunas precisam ser renovadas para análises mais sensíveis, como no caso das microcistinas. As amostras extraídas com metanol apresentaram resultados relevantes, isto é, quanto maior a concentração de metanol utilizado na extração, maior a concentração de microcistina-LR obtida nos resultados, concluindo o metanol ser o solvente apropriado para a extração. Por fim, conclui-se que o método desenvolvido é viável, apresentando algumas dificuldades para sua implantação em escala empresarial. / The water supply has been decreasing more and more as the population, industry and agriculture expand. The contamination of the water sources generated by the domestic and industrial effluents discharges leads to the eutrophization, process where the large presence of nutrients, particularly phosphates, causes excessive increase of algae. The cyanobacteria are procaryote microorganisms which live in the most diverse environments. The florescence of the algae when present in sources directed to human consumption generates serious problems to the human health, for some of them may produce toxins known as hepatotoxins, neurotoxins and dermotoxins, according to their pharmacological action. Among the hepatotoxins, the microcystin, a cyclic heptapeptide that can lead to death in hours or days, is found. The objective of this study was to make feasible the use of the HPLC technique, already proposed by other authors, to quantify microcystins-LR in water reservoirs, in enterprise scale to be implemented in water analysis laboratories. In order to develop the technique, samples of water from a pond with Microcystis florescence were utilized. To evaluate the efficiency of the chromatographic technique, studies were performed with another method, through the ELISA kit. In this phase of the work, it was verified that the HPLC technique is the most sensible and viable for the quantification of the microcystins. It was observed, in the experiments performed with the liquid chromatography, that the column C-18 LiChrosorb (25 cm) 7 Sm utilized in the method and the methanol solvent presented great influence in the results. As the experiments were realized, the decrease of the sensibility of the column was verified. The results were satisfactory only after the column being cleaned, when the patterns presented a curve of correlation equal to 0.92. This fact leads to the conclusion that the columns need to be renewed for more sensible analysis, like in the case of the microcystins. The samples extracted with methanol presented relevant results, that is, the greater the concentration of the methanol utilized, the higher the concentration of microcystin-LR obtained in the results, leading to the conclusion that methanol was the solvent adequate to the extraction. Finally, it was concluded that the method developed is feasible, presenting some difficulties concerning its implantation in enterprise scale.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-04-27T14:14:48Z No. of bitstreams: 1 PDF - Natássya Nyuska Cabral de Lima.pdf: 1817457 bytes, checksum: c20885f87efcfd4edcd9466b67b55e64 (MD5) / Made available in DSpace on 2016-04-27T14:14:48Z (GMT). No. of bitstreams: 1 PDF - Natássya Nyuska Cabral de Lima.pdf: 1817457 bytes, checksum: c20885f87efcfd4edcd9466b67b55e64 (MD5) Previous issue date: 2015-11-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The occurrence of cyanobacterial blooms in water sources used for public supply, is increasingly common. Some genera of cyanobacterial have species potentially producing cyanotoxins, which can affect human health by direct contact through the skin or by ingestion of contaminated water or food. Classified according to their pharmacological action, cyanotoxins, are known as hepatotoxins, neurotoxins and dermatotoxins. Among the hepatotoxins we found the microcystin, a cyclic heptapeptide which can lead to death in hours or days. During the treatment of water for human consumption it is important to consider a technique to remove intact cells of cyanobacteria, since the use of oxidizing agents promotes cell lysis which can cause the release of toxins into the water. The Activated Carbon (AC) is presented as one of the best alternatives to the removal of organic and inorganic compounds due to its high power of adsorption. Aimed the fulfillment the current drinkability ordinance, as the concentration of extracellular cyanotoxins the present study sought to evaluate on a bench scale, the microcystin-LR removal efficiency study of water by adsorption on Activated Carbon (AC). The water study of was prepared with addition of lysed cells Microcystis aeruginosa cultivation. Were evaluated different pH values and the results confirmed that MC-LR adsorption was more efficient at acidic pH close to 5,0. Kinetic studies of adsorption were performed, analyzed according to the models of pseudo-first and pseudo-second order, getting the best fit the model of pseudo-first order, and adsorption isotherms to determine the adsorptive capacity of CA in relation to microcystins. The data of the isotherms were modeled according to the Langmuir isotherm and Freundlich, with best fit to the Langmuir model.The analytical method used during research to determine the concentration of microcystin-LR, after completion of kinetic experiments and isotherm was the High Performance Liquid Chromatography Coupled with Mass Spectrometry (HPLC-MS). The adsorption by AC palm coconut shell proved to be an efficient process for the removal of MC-LR, since averages toxin removal efficiencies above 90% were observed. / A ocorrência de florações de cianobactérias, em mananciais utilizados para abastecimento público, é cada vez mais frequente. Alguns gêneros de cianobactérias possuem espécies potencialmente produtoras de cianotoxinas, que podem afetar a saúde humana pelo contato direto através da pele ou por ingestão de água ou alimento contaminado. Classificadas de acordo com sua ação farmacológica, as cianotoxinas, são conhecidas como hepatotoxinas, neurotoxinas e dermatotoxinas. Dentre as hepatotoxinas encontramos a microcistina, um heptapeptideo cíclico que pode levar a morte em horas ou dias. Durante o tratamento de água para consumo humano é importante considerar uma técnica que remova células intactas de cianobactérias, pois o uso de agentes oxidantes promove a lise celular a qual pode causar a liberação de toxinas na água. O Carvão Ativado (CA) se apresenta como uma das melhores alternativas para a remoção de compostos orgânicos e inorgânicos devido a seu alto poder de adsorção. Visando o cumprimento da portaria de potabilidade vigente, quanto à concentração de cianotoxinas extracelulares o presente trabalho buscou avaliar em escala de bancada, a eficiência de remoção de microcistina-LR da água de estudo por meio de adsorção em Carvão Ativado (CA). A água de estudo foi preparada com adição de cultivo de células lisadas de Microcystis aeruginosa. Foram avaliados diferentes valores de pH e os resultados confirmaram que a adsorção de MC-LR se mostrou mais eficiente em pH ácido próximo a 5,0. Foram realizados estudos cinéticos de adsorção, analisados de acordo com os modelos de pseudo-primeira e pseudo-segunda ordem, obtendo-se melhor ajuste ao modelo de pseudo- primeira ordem, e isotermas de adsorção para determinar a capacidade adsortiva do CA em relação às microcistinas. Os dados das isotermas foram modelados segundo as isotermas de Langmuir e Freundlich, com melhor ajuste ao modelo de Langmuir. O método analítico utilizado durante a pesquisa para determinação da concentração de microcistina-LR, após a finalização dos experimentos de cinética e isoterma foi o Cromatógrafo Líquido de Alta Eficiência Acoplado a Espectrometria de Massas (CLAE-EM). A adsorção por CA de casca de coco de dendê se mostrou um processo eficiente para a remoção de MC-LR, visto que eficiências médias de remoção da toxina acima de 90% foram observadas.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-04-27T14:30:56Z No. of bitstreams: 1 PDF - Aluízio Gonçalves da Silva.pdf: 2861910 bytes, checksum: fec467664bbab2d62bb600299f8e0d10 (MD5) / Made available in DSpace on 2016-04-27T14:30:56Z (GMT). No. of bitstreams: 1 PDF - Aluízio Gonçalves da Silva.pdf: 2861910 bytes, checksum: fec467664bbab2d62bb600299f8e0d10 (MD5) Previous issue date: 2015-11-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Algal blooms and toxic cyanobacteria in fountains intended for human supply has been reported in many countries in recent decades due to impacts and human actions in the most diverse ecosystems on the planet. The presence of lineages of cyanobacteria producing cyanotoxins has negative effects on water bodies in particular in the intendend to the public supply due to the harmful effect of these substances on human health and animals. In general, cyanotoxins are not removed by conventional purifying water technologies. This study aimed to evaluate the efficiency of advanced oxidation process with the Fenton reagent in the oxidation of microcystin-LR water for public supply using conventional treatment steps coagulation, flocculation and sedimentation. The study water was prepared by adding the lysed cell cultivation Microcystis aeruginosa dechlorinated with potable water. Oxidation steps were performed, coagulation, flocculation and sedimentation JarTest programmed with rapid mixing -1 time of 10 s, rapid mixing gradient of 1000 s , flocculation time 20 min, flocculation gradient -1 -1 30 s and sedimentation velocity 1,4 cm.min . Different pH ranges were tested (2,0, 4,5 and + 7,0) and different concentrations of the Fenton reagent in the proportion of 1/3 H2O/Fe . The obtained results showed the oxidation of microcystin-LR in the treatments with pH 2,0; 4,5; and 7,0. By scanning the ions in the mass spectrometer it was possible to identify the peaks of mass/charge (m/z) fragments of enabling confirmation of oxidation by the presence of oxidation by products. Furthermore, after sedimentation the Fenton reagent enables significant removal being treatment T2 in time of 15 minutes the best for include percentage removal of turbidity 0,07 uT, true color 2,61 uH, COD 7,7 mg.L and MC-LR 0,07 μg.L. / Florações de algas e cianobactérias tóxicas em mananciais destinados ao abastecimento humano tem sido relatado em vários países nas últimas décadas devido aos impactos e ações do homem nos mais diversos ecossistemas do planeta. A presença de linhagens de cianobactérias produtoras de cianotoxinas tem efeitos negativo nos corpos hídricos em particular nos destinados ao abastecimento público devido ao efeito nocivo dessas substâncias à saúde humana e de animais. Em geral as cianotoxinas não são removidas pelas tecnologias convencionais de potabilização de água. O presente trabalho buscou avaliar a eficiência do processo de oxidação avançada com o reagente Fenton na oxidação da microcistina-LR de água destinada ao abastecimento público utilizando as etapas de tratamento convencional de coagulação, floculação e sedimentação. A água de estudo foi preparada com adição de cultivo de células lisadas de Microcystis aeruginosa com água potável desclorada. Foram realizadas as etapas de oxidação, coagulação, floculação e sedimentação em JarTest programado com tempo de -1 mistura rápida de 10 s, gradiente de mistura rápida 1000 s , tempo de floculação 20 min, -1 -1 gradiente de floculação 30 s e velocidade de sedimentação de 1,4 cm.min . Foram testados diferentes faixas de pH (2,0, 4,5, e 7,0) e diferentes concentrações do reagente Fenton na 2+ proporção de 1/3 de H2O/Fe . Os resultados obtidos mostraram a oxidação da microcistina-LR nos tratamentos com pH 2,0; 4,5; e 7,0. Através da varredura dos íons no espetrômetro de massas foi possível identificar os picos de massa/carga (m/z) dos fragmentos possibilitando a confirmação da oxidação através da presença dos subprodutos da oxidação. Além disso, após a sedimentação o reagente Fenton possibilitou a remoção significativa sendo tratamento T2 no tempo de 15 minutos o melhor por abrangir percentuais de remoção de turbidez 0,07 uT, cor verdadeira 2,61 uH, COD 7,7 mg.L e MC-LR 0,07 µg.L.

Nanofiltration (NF) membrane technology is effective for removal of natural organic matter (NOM) and Disinfection By-Product (DBP) precursors from treated surface water (Allgeier et al., 1995, Chellam et al., 2000, Smith et al., 2002). However, there is a need to control other micropollutants, such as compounds released from algal blooms. In this research, the feasibility of using NF for removal of cyanobacterial exudates was evaluated as a polishing process for conventionally treated surface water. Screening tests were conducted to compare the performance of four NF membranes, Filmtec's NF90 and NF270, and Hydranautics's LFC1 and NTR7450, for removal of NOM and cyanobacterial exudates. The source water for the experiments was derived from Lake Manatee (FL) following full scale treatment by enhanced coagulation and dual media filtration. Water samples were amended with low levels of three cyanobacterial exudates: microcystin-LR, geosmin and 2-Methylisoborneol (MIB). The rapid bench scale membrane test (RBSMT) protocol was used to test NF at four recoveries of 50%, 70%, 85% and 95%. Bulk organics (TOC and UV254) and inorganics (conductivity, total and calcium hardness) were monitored along with other operating parameters during the setting and recovery tests. Spike tests were performed by spiking microcystin-LR (9.5 to 12.0 micro g/L), geosmin (45 to 220 ng/L) and MIB (45 to 225 ng/L). Three NF membranes (NF90, NF270 and LFC1) were effective for over 90% rejection of TOC and associated disinfection by-product formation potential (DBPFP). Due to NF treatment, the bromide:TOC ratio increased resulting in a shift towards higher levels of brominated DBPFPs. Similarly, these three NF membranes (NF90, NF270 and LFC1) were effective for removal of microcystin-LR to below the World Health Organization (WHO) guideline of 1 micro g/L. Only two of the NF membranes tested (NF90 and LFC1), were capable of removing geosmin and MIB to levels below the taste and odor threshold. These membranes removed greater than 92% of the geosmin and MIB. Based on these bench scale tests, further testing of NF on a pilot scale is warranted.

A oferta de água vem se tornando cada vez mais diminuta à medida que a população, a indústria e a agricultura se expandem. A contaminação dos mananciais gerada pelo descarte de efluentes domésticos e industriais leva a eutrofização, processo pela qual grande aporte de nutrientes, particularmente fosfatos, leva ao crescimento excessivo de algas. As cianobactérias são microrganismos procariontes, que vivem nos ambientes mais adversos. A floração dessas algas quando presente em mananciais destinados ao consumo humano gera sérios problemas à saúde humana, pois algumas dessas algas podem gerar toxinas, conhecidas como hepatotoxinas, neurotoxinas e dermatotoxinas, de acordo com sua ação farmacológica. Dentre as hepatotoxinas encontramos a microcistina, um heptapeptídeo cíclico que pode levar à morte em horas ou dias. O objetivo desse estudo foi viabilizar a técnica HPLC, já proposta por outros autores, para quantificar microcistinas-LR em reservatórios de água, em escala empresarial para ser implementada em laboratórios de análise de águas. Para o desenvolvimento da técnica, foram utilizadas amostras de uma lagoa com floração de Microcystis. Para determinar a eficiência da técnica cromatográfica, foram realizados estudos com outro método, através do kit ELISA. Nessa etapa do trabalho, verificou-se que a técnica HPLC é mais sensível e viável para a quantificação das microcistinas. Nos experimentos realizados com a cromatografia líquida, observou-se que a coluna C-18 LiChrosorb (25 cm) 7 Sm utilizada no método, e o solvente metanol apresentaram grande influência nos resultados. À medida que os experimentos foram executados, verificou-se o decréscimo da sensibilidade da coluna. Os resultados foram satisfatórios apenas após a limpeza realizada na coluna, onde os padrões apresentaram uma curva de correlação igual a 0,92. Este fato leva a concluir que as colunas precisam ser renovadas para análises mais sensíveis, como no caso das microcistinas. As amostras extraídas com metanol apresentaram resultados relevantes, isto é, quanto maior a concentração de metanol utilizado na extração, maior a concentração de microcistina-LR obtida nos resultados, concluindo o metanol ser o solvente apropriado para a extração. Por fim, conclui-se que o método desenvolvido é viável, apresentando algumas dificuldades para sua implantação em escala empresarial. / The water supply has been decreasing more and more as the population, industry and agriculture expand. The contamination of the water sources generated by the domestic and industrial effluents discharges leads to the eutrophization, process where the large presence of nutrients, particularly phosphates, causes excessive increase of algae. The cyanobacteria are procaryote microorganisms which live in the most diverse environments. The florescence of the algae when present in sources directed to human consumption generates serious problems to the human health, for some of them may produce toxins known as hepatotoxins, neurotoxins and dermotoxins, according to their pharmacological action. Among the hepatotoxins, the microcystin, a cyclic heptapeptide that can lead to death in hours or days, is found. The objective of this study was to make feasible the use of the HPLC technique, already proposed by other authors, to quantify microcystins-LR in water reservoirs, in enterprise scale to be implemented in water analysis laboratories. In order to develop the technique, samples of water from a pond with Microcystis florescence were utilized. To evaluate the efficiency of the chromatographic technique, studies were performed with another method, through the ELISA kit. In this phase of the work, it was verified that the HPLC technique is the most sensible and viable for the quantification of the microcystins. It was observed, in the experiments performed with the liquid chromatography, that the column C-18 LiChrosorb (25 cm) 7 Sm utilized in the method and the methanol solvent presented great influence in the results. As the experiments were realized, the decrease of the sensibility of the column was verified. The results were satisfactory only after the column being cleaned, when the patterns presented a curve of correlation equal to 0.92. This fact leads to the conclusion that the columns need to be renewed for more sensible analysis, like in the case of the microcystins. The samples extracted with methanol presented relevant results, that is, the greater the concentration of the methanol utilized, the higher the concentration of microcystin-LR obtained in the results, leading to the conclusion that methanol was the solvent adequate to the extraction. Finally, it was concluded that the method developed is feasible, presenting some difficulties concerning its implantation in enterprise scale.

No description available.

No description available.