Dyes are recalcitrant compounds that resist conventional biological treatments. The degradation of three textile dyes (Indigo, RBBR and Sulphur Black), and the dye-containing liquid effluent and solid waste from the Municipal Treatment Station, Americana, São Paulo, Brazil, by the cyanobacteria Anabaena flos-aquae UTCC64, Phormidium autumnale UTEX1580 and Synechococcus sp. PCC7942 was evaluated. The dye degradation efficiency of the cyanobacteria was compared with anaerobic and anaerobic–aerobic systems in terms of discolouration and toxicity evaluations. The discoloration was evaluated by absorption spectroscopy. Toxicity was measured using the organisms Hydra attenuata, the alga Selenastrum capricornutum and lettuce seeds. The three cyanobacteria showed the potential to remediate textile effluent by removing the colour and reducing the toxicity. However, the growth of cyanobacteria on sludge was slow and discoloration was not efficient. The cyanobacteria P. autumnale UTEX1580 was the only strain that completely degraded the indigo dye. An evaluation of the mutagenicity potential was performed by use of the micronucleus assay using Allium sp. No mutagenicity was observed after the treatment. Two metabolites were produced during the degradation, anthranilic acid and isatin, but toxicity did not increase after the treatment. The cyanobacteria showed the ability to degrade the dyes present in a textile effluent; therefore, they can be used in a tertiary treatment of effluents with recalcitrant compounds.

R E S U M OOs pesticidas utilizados na agricultura para combater pragas e doenças têm causado contaminação dos recursos hídricos cujas consequências são alterações nos ecossistemas e prejuízos à saúde, sobretudo quando as águas são utilizadas para consumo humano. A contaminação ocorre principalmente em áreas próximas aos locais de aplicação por deflúvio superficial ou contaminação do lençol freático. Alguns fatores que afetam o transporte para o meio aquático são as propriedades do agente químico e variáveis ambientais, como tipo de solo, declividade, presença de cobertura vegetal e clima; alguns desses fatores, como relevo planáltico e solo quartzoso, estão presentes em grande parte do país fazendo com que a poluição do meio aquático seja acentuada. A adoção de práticas agrícolas mais racionais pelos agricultores e medidas como proteção das matas ciliares, podem prevenir a contaminação por pesticidas dos recursos hídricos, sendo a forma mais eficiente de controle da poluição agrícola nas condições locais.Main aspects of the pollution in Brazilian rivers by pesticides A B S T R A C T Pesticides, which are used in agriculture for pest and disease control, has caused contamination of water resources. The consequences are changes in ecosystems and damage to health, especially when the waters are used for human consumption. The contamination occurs mainly in areas near the application site by surface runoff or groundwater contamination. Some factors affecting transport to the aquatic environment are the properties of the chemical and environmental conditions, such as soil type, slope, land cover and climate. Some factors such as plateau relief and quartzose soil are present in the most part of the country, causing the water pollution more severe. The adoption of more rational agricultural practices by farmers and measures for protection of riparian forests can prevent pesticide contamination of water resources, which consists in the most efficient control practice for agricultural pollution in the tropical regions. Palavras IntroduçãoPesticidas são um dos grupos mais representativos de poluentes no ambiente devido ao seu uso intensivo na agricultura (Choudhury et al., 2008). O Ministério do Desenvolvimento Agrário, MDA (2012) e a Agência Nacional de Vigilância Sanitária, ANVISA (2013) mostram que o Brasil é o maior consumidor e produtor de agrotóxicos do mundo, desde 2009. O mercado desses produtos cresceu aproximadamente 176% na última década sendo quatro vezes maior que a média mundial (ANVISA, 2013).O impacto do aumento da produção de bens agrícolas no ambiente é notado pela perda da biodiversidade e da qualidade dos recursos hídricos. Os estudos de monitoramento de resíduos de agrotóxicos têm aumentado ano a ano e sinalizado que resíduos de agroquímicos estão presentes nos alimentos (ANVISA, 2013), na atmosfera (Moreira, et al., 2012), nas precipitações secas e úmidas, como chuvas (Nogueira et al., 2012) e águas superficiais e subterrâneas .A ocupação desordenada do solo origina a supressão da vegetação compact...

ABSTRACT

The Americana Municipal Treatment Station, Sa˜o Paulo, Brazil, manages 400 l of effluent s )1 , from domestic and textile origin, which produces an average of 20 t of sludge per day. The decolourization of the effluent and sludge by three strains of Pleurotus (Pleurotus sajor-caju F2, F6 and Pleurotus ostreatus) was evaluated. The strains of P. sajorcaju F2 and F6 were able to decolourize the sludge, while P. ostreatus was less efficient. Detoxification was appraised with three bioassays comprising the cnidarian Hydra attenuata, the alga Selenastrum capricornutum and lettuce seeds. After exposure to fungi, effluent toxicity decreased but not that of its sludge. Strain P. sajor-caju F6 presented signs of toxicity shown by electron microscopy in the presence of the effluent. The three strains produced high amounts of manganese-peroxidase (Mn-P) and laccase in the presence of the sludge. Although P. ostreatus produced large amount of Mn-P and laccase enzymes, these enzymes did not result in decolourization of the sludge, suggesting that other factors are likely to be involved. Carbon content decreased only in the treatment with P. ostreatus.

ABSTRACT:We examined the possibility of adapting the LuminoTox, a recently-commercialized bioanalytical testing procedure initially developed for aqueous samples, to assess the toxic potential of sediments. This portable fluorescent biosensor uses photosynthetic enzyme complexes (PECs) to rapidly measure photosynthetic efficiency. LuminoTox testing of 14 CRM (Certified Reference Material) sediments was first undertaken with (1) a ''solid phase assay'' (Lum-SPA) in which PECs are in intimate contact with sediment slurries for a 15 min exposure period and (2) an elutriate assay (Lum-ELU) in which PECs are exposed for 15 min to sediment water elutriates. CRM sediment toxicity data were then compared with those generated with the Microtox Solid Phase Assay (Mic-SPA). A significant correlation (P < 0.05) was shown to exist between Lum-SPA and Mic-SPA, indicating that both tests display a similar toxicity response pattern for CRM sediments having differing contaminant profiles. The sediment elutriate Lum-ELU assay displayed toxicity responses (i.e. measurable IC 20 s) for eight of the 14 CRM sediments, suggesting that it is capable of determining the presence of sediment contaminants that are readily soluble in an aqueous elutriate. Lum-SPA and Mic-SPA bioassays were further conducted on 12 natural freshwater sediments and their toxicity responses were more weakly, yet significantly, correlated. Finally, Lum-SPA testing undertaken with increasing mixtures of kaolin clay confirmed that its toxicity responses, in a manner similar to those reported for the Mic-SPA assay, are also subject to the influence of grain size. While further studies will be required to more fully understand the relationship between Lum-SPA assay responses and the physicochemical makeup of sediments (e.g., grain size, combined presence of natural and anthropogenic contaminants), these preliminary results suggest that LuminoTox testing could be a useful screen to assess the toxic potential of solid media.