Degradation of estriol (E3) and transformation pathways after applying photochemical removal processes in natural surface water.

Steroidal hormones such as estriol (E3), are resistant to biodegradation; hence their removal by conventional treatment systems (aerobic and anaerobic) facilities is limited. These substances are detected in surface water, and present risks to the aquatic ecosystem and humans via potential biological activity. Photochemical treatments can be used to remove E3; however, just a few studies have analyzed the kinetics, intermediates, and E3 degradation pathways in natural surface water. In this study, the behavior of E3 under ultraviolet irradiation associated with H2O2, O3 or TiO2 was investigated to determine the degradation potential and the transformation pathways in reactions performed with a natural surface water sample. E3 degradation kinetics (200 ppb) fitted well to the pseudo-first-order kinetics model, with kinetic constant k in the following order: kUV/O3 > kUV/TiO2 > kUV/H2O2 > kUV. The mechanism of degradation using different advanced oxidative processes seemed to be similar and 12 transformation byproducts were identified, with 11 of them being reported here for the first time. The byproducts could be formed by the opening of the aromatic ring and addition of a hydroxyl radical. A possible route of E3 degradation was proposed based on the byproducts identified, and some of the byproducts presented chronic toxicity to aquatic organisms, demonstrating the risks of exposure.

Assessment of phytoremediation potencial of Allium cepa L. in raw sewage treatment / Avaliação do potencial de fitorremediação da Allium cepa L. no tratamento do esgoto bruto

Abstract Whereas the effects of the substances found in domestic sewage on live organisms is important to evaluate the use of plants to remove pollutants from the environment. The objective of this study was to assess the phytoremediation activity of Allium cepa L. (onion) roots exposed to raw sewage, as well as the acute toxic activity of this effluent for the bioindicators A. cepa, through a cytotoxicity test, and Artemia salina L., through a mortality/immobility test. The physicochemical assessments of the sewage were conducted in two scenarios: immediately after collection and after being in contact with onion roots (phytoremediation) for 24 hours. The physicochemical data indicate there was a reduction in nitrogen and phosphorus levels and in biochemical oxygen demand in sewage treated. The results from the cytotoxicity test with A. cepa indicated a reduction in the mitotic cell divisions of the onions treated with the raw sewage. The mortality/immobility test with A. salina indicated that the concentrations with 50 and 100% of raw sewage induced the mortality of the nauplii. Thus, the data suggest new studies that seek greater efficiency, efficacy and viability of onion phytoremediation.

Resumo Considerando os efeitos das substâncias encontradas no esgoto doméstico em organismos vivos, é importante avaliar o uso de plantas para remover poluentes do meio ambiente. O objetivo deste trabalho foi avaliar a atividade de fitorremediação de raízes de Allium cepa L. (cebola) expostas ao esgoto bruto, bem como a atividade tóxica aguda desse efluente para os bioindicadores A. cepa, através de um teste de citotoxicidade, e Artemia salina L., através de um teste de mortalidade/imobilidade. As avaliações físico-químicas do esgoto foram realizadas em dois cenários: imediatamente após a coleta e após contato com raízes de cebola (fitorremediação) por 24 horas. Os dados físico-químicos indicam que houve redução nos níveis de nitrogênio e fósforo e na demanda bioquímica de oxigênio no esgoto tratado. Os resultados do teste de citotoxicidade com A. cepa indicaram uma redução nas divisões celulares mitóticas das cebolas tratadas com o esgoto bruto. O teste de mortalidade/imobilidade com A. salina indicou que as concentrações com 50 e 100% de esgoto bruto induziram a mortalidade dos náuplios. Assim, os dados sugerem novos estudos que busquem maior eficiência, eficácia e viabilidade de fitorremediação das cebolas.

Assessment of phytoremediation potencial of Allium cepa L. in raw sewage treatment.

Whereas the effects of the substances found in domestic sewage on live organisms is important to evaluate the use of plants to remove pollutants from the environment. The objective of this study was to assess the phytoremediation activity of Allium cepa L. (onion) roots exposed to raw sewage, as well as the acute toxic activity of this effluent for the bioindicators A. cepa, through a cytotoxicity test, and Artemia salina L., through a mortality/immobility test. The physicochemical assessments of the sewage were conducted in two scenarios: immediately after collection and after being in contact with onion roots (phytoremediation) for 24 hours. The physicochemical data indicate there was a reduction in nitrogen and phosphorus levels and in biochemical oxygen demand in sewage treated. The results from the cytotoxicity test with A. cepa indicated a reduction in the mitotic cell divisions of the onions treated with the raw sewage. The mortality/immobility test with A. salina indicated that the concentrations with 50 and 100% of raw sewage induced the mortality of the nauplii. Thus, the data suggest new studies that seek greater efficiency, efficacy and viability of onion phytoremediation.

Assessment of phytoremediation potencial of Allium cepa L. in raw sewage treatment

Abstract Whereas the effects of the substances found in domestic sewage on live organisms is important to evaluate the use of plants to remove pollutants from the environment. The objective of this study was to assess the phytoremediation activity of Allium cepa L. (onion) roots exposed to raw sewage, as well as the acute toxic activity of this effluent for the bioindicators A. cepa, through a cytotoxicity test, and Artemia salina L., through a mortality/immobility test. The physicochemical assessments of the sewage were conducted in two scenarios: immediately after collection and after being in contact with onion roots (phytoremediation) for 24 hours. The physicochemical data indicate there was a reduction in nitrogen and phosphorus levels and in biochemical oxygen demand in sewage treated. The results from the cytotoxicity test with A. cepa indicated a reduction in the mitotic cell divisions of the onions treated with the raw sewage. The mortality/immobility test with A. salina indicated that the concentrations with 50 and 100% of raw sewage induced the mortality of the nauplii. Thus, the data suggest new studies that seek greater efficiency, efficacy and viability of onion phytoremediation.

Resumo Considerando os efeitos das substâncias encontradas no esgoto doméstico em organismos vivos, é importante avaliar o uso de plantas para remover poluentes do meio ambiente. O objetivo deste trabalho foi avaliar a atividade de fitorremediação de raízes de Allium cepa L. (cebola) expostas ao esgoto bruto, bem como a atividade tóxica aguda desse efluente para os bioindicadores A. cepa, através de um teste de citotoxicidade, e Artemia salina L., através de um teste de mortalidade/imobilidade. As avaliações físico-químicas do esgoto foram realizadas em dois cenários: imediatamente após a coleta e após contato com raízes de cebola (fitorremediação) por 24 horas. Os dados físico-químicos indicam que houve redução nos níveis de nitrogênio e fósforo e na demanda bioquímica de oxigênio no esgoto tratado. Os resultados do teste de citotoxicidade com A. cepa indicaram uma redução nas divisões celulares mitóticas das cebolas tratadas com o esgoto bruto. O teste de mortalidade/imobilidade com A. salina indicou que as concentrações com 50 e 100% de esgoto bruto induziram a mortalidade dos náuplios. Assim, os dados sugerem novos estudos que busquem maior eficiência, eficácia e viabilidade de fitorremediação das cebolas.