Resumo O corante Preto Reativo 5 (RB5 - reactive black 5) é um dos corantes reativos sintéticos mais utilizados na indústria têxtil, devido à sua solubilidade em água e a grupos reativos que formam ligações covalentes com a fibra. No processo de tingimento de tecidos, no entanto, estima-se que 12-14% dos corantes sejam liberados para o efluente. O objetivo deste trabalho foi avaliar a biodegradação do corante RB5, adsorvido em espuma de poliuretano, por basidiomicetos (Phanerochaete chrysosporium ATCC 24725, Pleurotus ostreatus e Pleurotus florida). Os resultados foram avaliados considerando a descoloração parcial ou total do meio, a capacidade de adsorção do corante na espuma de poliuretano e a medida respirométrica. Os resultados mostraram que Phanerochaete chrysosporium foi o mais eficicente, sendo capaz de degradar parcialmente RB5 na concentração de 50 mg L-1 em pH 6.0, quando cultivado em pacas de Petri. Quando este microrganismo foi cultivado em cubos de espuma de poliuretano saturada com solução de RB5 (50 mg L-1, pH 6.0) a produção de CO2 atingiu o valor acumulado de 2.16 mg no décimo quinto dia, revelando o crescimento microbiano e a degradação do contaminante, que foi utilizado como fonte de nutrientes.

Abstract Reactive Black 5 (RB5) is one of the synthetic reactive dyes most used in the textile industry, due to its solubility in water and reactive groups which form covalent bonds within the fiber. In the process of dyeing fabrics, however, it is estimated that 12-14% of dyes are released into the effluent. This work evaluated the biodegradation of RB5 dye, adsorbed in polyurethane foam, by basidiomycetes (Phanerochaete chrysosporium ATCC 24725, Pleurotus ostreatus and Pleurotus floridae). Results were evaluated considering the partial- or total medium discoloration, the adsorption capacity of the dye in the polyurethane foam (PUF) and the respirometric measurements. The results showed that Phanerochaete chrysosporium was able to partially degrade 50 mg L-1 of RB5 in pH 6.0, when cultivated in Petri dishes. When this microorganism was cultivated in PUF cubes saturated with RB5 solution (50 mg L-1, pH 6.0), CO2 production reached an accumulated value of 2.16 mg on the fifteenth day, revealing the growth of the microorganism and consequently the contaminant degradation, which was used as the source of nutrients.

Resumo A indústria de papel e celulose está entre as que mais consome água no mundo, gerando grandes volumes de efluentes. O processo Kraft produz efluentes com elevada DBO, DQO, sólidos suspensos, teor de lignina e uma mistura complexa de compostos potencialmente tóxicos, os quais necessitam de tratamento para posterior descarte no meio ambiente. Os processos oxidativos avançados, dentre eles o processo UV/H2O2, têm sido aplicado como alternativa de tratamento pois é capaz de degradar os mais diversos compostos até sua mineralização. No entanto, quando o processo oxidativo é incompleto, podem ser formados produtos intermediários com elevada toxicidade. Este estudo avaliou a toxicidade aguda em Daphnia magna de duas amostras de efluente Kraft (KE1 e KE2) tratadas por processo UV/H2O2. Os efeitos da variação de pH e da concentração do oxidante sobre a redução de COT, área espectral UV-vis e cor aparente foram utilizados para ajustar as condições experimentais com a amostra KE1 diluida. Ambas as amostras foram tratadas em pH 4.0 e com 70 mg L-1 de H2O2 por 40 min, alcançando remoções de até 69,4% na cor aparente, 73,7% de compostos fenólicos e 68,9% de compostos lignínicos. Quando a reação foi aplicada nas amostras não diluídas de efluentes, a toxicidade aguda para Daphnia magna diminuiu para KE1 após 780 min de tratamento, enquanto KE2 tornou-se três vezes mais tóxica. Os dados mostraram que embora o tratamento tenha sido eficiente, considerando os parâmetros físicos e químicos, é necessário acompanhar os processos oxidativos por ensaios ecotoxicológicos para garantir sua segurança, uma vez que cada efluente kraft pode apresentar diferentes níveis de mineralização de seus compostos orgânicos.

Abstract The pulp and paper industry is one of world’s largest water consumers, generating high volumes of effluents. The Kraft process produces effluents with high BOD, COD, suspended solids, lignin and a myriad of potentially toxic compounds, which require treatment before discharge into the aquatic environment. Advanced oxidation processes, such as UV/H2O2, have been applied as treatment alternatives because they can destroy many compounds before they mineralize. However, when the oxidation process is incomplete, occurs could be produced by products with high toxicity. This study evaluated the acute toxicity on Daphnia magna of two effluent samples of Kraft pulp mill (KE1 and KE2) treated by UV/H2O2 process. The effects of the pH variation and oxidant concentration on the removal of DOC, total UV-vis spectral area and apparent color were considered to adjust the experiments’ conditions with diluted effluent KE1. Both samples were treated at pH 4.0 and 70 mg L-1 of H2O2 for 40 min, achieving removals of up to 69.4% in apparent color, 73.7% of phenolic compounds and 68.9% of lignin compounds. When the reaction was applied in undiluted effluent samples, the acute toxicity for Daphnia magna decreased for KE1 after 780 min of treatment, whereas KE2 became four times more toxic. The data showed that although the treatment had been efficient considering physics and chemicals parameters, it is necessary follow the oxidative processes with ecotoxicological bioassays to guarantee their safety, since different effluents of the Kraft pulp mill could present different levels of organic compound mineralization.

A sensitive high-performance liquid chromatography-fluorescence detection method (HPLC-FLD) was developed and validated for 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) determination in wastewater samples. Sample preparation was performed by solid-phase extraction (SPE) on Hypersep C18 cartridges. Conditioning and elution solvents and sample volume were investigated by a 23 factorial design for both analytes. The pre-concentration factor was 2500 times, allowing to quantify 5.0 ng L-1 for both hormones. The SPE-HPLC-FLD method was successfully applied to detect and quantify trace amount of target compounds in raw and treated wastewater samples. E2 was found below limit of quantification in influent and effluent samples. Nevertheless, the recoveries of E2 in standard addition experiments were between 41 and 72%, with relative standard deviations between 4 and 16%. An important matrix effect was observed in the determination of EE2, with fluorescence signal suppression.

In this work, the materials used in the recovery of estrogens from aqueous matrices by filtration and solid phase extraction were evaluated. The results showed that glass-fiber filters allow a recovery and repeatability compatible with this type of analysis, whereas cellulose esters lead to significant losses of the analytes, mainly due to adsorption processes. On the other hand, the transferring of the sample to the extraction cartridges should be carried out with glass or Teflon tubing, since the adsorption observed with other polymeric materials (eg. silicone, Tygon, polyethylene and PVC) dramatically reduces the recovery and repeatability of the extraction process.