Formação de subprodutos do estrona e 17\'beta\'-estradiol na oxidação utilizando cloro e o ozônio em água
Data
2017-11-15
Autores
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Biblioteca Digital de Teses e Dissertações da USP
Universidade de São Paulo
Escola de Engenharia de São Carlos
Universidade de São Paulo
Escola de Engenharia de São Carlos
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Descrição
A poluição dos corpos de água é cada vez maior devido ao lançamento de efluentes, esgotamento sanitário e disposição inadequada de resíduos sólidos. Esse fato causa grande preocupação à comunidade científica, pois à poluição associam-se riscos à saúde causado por poluentes bioativos, compostos químicos orgânicos persistentes e outros compostos que poderiam estar presentes na água. Dentre as substâncias que causam risco à saúde se destacam os desreguladores endócrinos, que são compostos químicos exógenos que interferem na atividade hormonal. Os sistemas de tratamento de água convencionais não removem alguns compostos, tais como pesticidas e hormônios, os quais deveriam ser removidos. O uso do ozônio e cloro vem sendo reportado para tal finalidade, pois atuam como oxidantes que são capazes de oxidar compostos orgânicos, além de serem poderosos desinfetantes. Portanto, o objetivo deste estudo foi avaliar a eliminação e/ou redução dos desreguladores endócrinos - DE em estações de tratamento de água com o uso do ozônio e do cloro. Aliado ao estudo, avaliar qual será a eficiência de remoção de organismos indicadores nas doses utilizadas para oxidação de DE (Coliformes Totais e E.coli) e avaliar a ecotoxicidade em peixes de amostras cloradas contendo 17\'beta\'-estradiol. O cloro e o ozônio foram capazes de remover eficientemente estrona (E1) e 17\'beta\'-estradiol (E2) de águas, contudo a eficiência de remoção diminui em concentrações na ordem de ng/L, necessitando-se de altas doses de ozônio e cloro para a completa remoção dos hormônios estudados. Tanto o cloro como o ozônio foram eficientes na inativação de organismos indicadores nas doses comumente utilizadas em ETAs e nas doses requeridas para a remoção dos contaminantes estudados. Amostras contendo E2 após serem cloradas apresentaram toxicidade crônica a peixes da espécie Danio rerio, o efeito estrogênico foi observado principalmente em machos. Foi necessário uma dose de ozônio de 0,95 e 3,8 mg/L para a remoção de 93 e 98% de E2 e E1 respectivamente (Co = 100 ng/L). Considerando o cloro como oxidante após a aplicação de 1,5 mg/L com tempo de contato de 24 h chegou-se a uma remoção de 99,6 e 97,5% para o E2 e E1 respectivamente (Co = 500 ng/L). Tão importante quanto remover o estrona e o 17\'beta\'-estradiol foi verificar e identificar quais foram os subprodutos formados após a oxidação dos mesmos. Foram identificados vários subprodutos tanto utilizando a degradação por meio do cloro como do ozônio. Alguns destes compostos identificados foram persistentes e recalcitrantes. Para o ozônio a completa remoção foi atingida após 10 mg/L de \'O IND.3\' e 16 mg/L de \'O IND.3\' para os subprodutos do E1 e E2 respectivamente. Considerando o cloro mesmo após um tempo de contato de 16 dias, havia ainda subprodutos da degradação na água.
The pollution of water bodies is increasing due to the release of effluents, sewage and inadequate solid waste disposal. This fact causes great concern to the scientific community, because pollution are associated with health risks caused by pollutants of bioactive compounds and other persistent organic compounds that could be present in water. Among the substances that can cause health risks are the endocrine disrupters, which are exogenous chemicals that interfere with hormonal activity. The conventional water treatment systems does not remove certain compounds, such as pesticides and hormones, which should be removed. The use of ozone and chlorine has been reported for this purpose because it acts as an oxidant that can oxidize organic compounds, and addicionally are powerful disinfectants. Therefore, the aim of this study was the elimination and/or reduction of endocrine disrupters during the water treatment using ozone and chlorine. Allied to the study, evaluate the efficiency of indicator organisms removal in the doses used for the oxidation of endocrine disrupters (coliform and E.coli) and assess the ecotoxicity of fish in chlorinated samples containing 17\'beta\'- estradiol. Chlorine and ozone were able to efficiently remove estrone (E1) and 17\'beta\'-estradiol (E2) of water, but the removal efficiency decreases at concentrations in the ng/L. Complete removal of the hormones was reach with high doses of ozone and chlorine. Both chlorine and ozone were effective in the inactivation of indicator organisms at commonly doses used in water treatment plants and in the doses required for the removal of the pollutants studied. Samples containing chlorinated E2 had chronic toxicity to fish Danio rerio, the estrogenic effect was observed mainly in males, females in some groups estrogenic effect was not observed. The dose of ozone necessary for the removal of 93 and 98% of E1 and E2 (Co = 100 ng/L) were 0.95 and 3.8 mg/L, respectively. The application of 1.5 mg/L of chlorine with a contact time of 24 h achieved removal of 99.6 and 97.5% for E1 and E2 respectively (Co = 500 ng/L) . As important as removing estrone and 17\'beta\'-estradiol was to verify and identify which were the byproducts formed after oxidation. Several byproducts were identified by the degradation using chlorine and ozone. Some of these compounds were identified to be persistent and recalcitrant. The ozone dose required to the complete removal of the byproducts was achieved after 10 mg/L \'O IND.3\' and 16 mg/L \'O IND.3\' for the byproducts of E1 and E2 respectively. The byproducts of chlorine even after a contact time of 16 days persisted in the water.
The pollution of water bodies is increasing due to the release of effluents, sewage and inadequate solid waste disposal. This fact causes great concern to the scientific community, because pollution are associated with health risks caused by pollutants of bioactive compounds and other persistent organic compounds that could be present in water. Among the substances that can cause health risks are the endocrine disrupters, which are exogenous chemicals that interfere with hormonal activity. The conventional water treatment systems does not remove certain compounds, such as pesticides and hormones, which should be removed. The use of ozone and chlorine has been reported for this purpose because it acts as an oxidant that can oxidize organic compounds, and addicionally are powerful disinfectants. Therefore, the aim of this study was the elimination and/or reduction of endocrine disrupters during the water treatment using ozone and chlorine. Allied to the study, evaluate the efficiency of indicator organisms removal in the doses used for the oxidation of endocrine disrupters (coliform and E.coli) and assess the ecotoxicity of fish in chlorinated samples containing 17\'beta\'- estradiol. Chlorine and ozone were able to efficiently remove estrone (E1) and 17\'beta\'-estradiol (E2) of water, but the removal efficiency decreases at concentrations in the ng/L. Complete removal of the hormones was reach with high doses of ozone and chlorine. Both chlorine and ozone were effective in the inactivation of indicator organisms at commonly doses used in water treatment plants and in the doses required for the removal of the pollutants studied. Samples containing chlorinated E2 had chronic toxicity to fish Danio rerio, the estrogenic effect was observed mainly in males, females in some groups estrogenic effect was not observed. The dose of ozone necessary for the removal of 93 and 98% of E1 and E2 (Co = 100 ng/L) were 0.95 and 3.8 mg/L, respectively. The application of 1.5 mg/L of chlorine with a contact time of 24 h achieved removal of 99.6 and 97.5% for E1 and E2 respectively (Co = 500 ng/L) . As important as removing estrone and 17\'beta\'-estradiol was to verify and identify which were the byproducts formed after oxidation. Several byproducts were identified by the degradation using chlorine and ozone. Some of these compounds were identified to be persistent and recalcitrant. The ozone dose required to the complete removal of the byproducts was achieved after 10 mg/L \'O IND.3\' and 16 mg/L \'O IND.3\' for the byproducts of E1 and E2 respectively. The byproducts of chlorine even after a contact time of 16 days persisted in the water.
Palavras-chave
Degradação, Tratamento de água, Subprodutos, Oxidação, Hormônios, Desinfecção, Hormones, Disinfection, Oxidation byproducts, Degradation, Water treatment