Processo fotocatalitico combinado com sistemas biologicos no tratamento de efluentes texteis

AUTOR(ES)
DATA DE PUBLICAÇÃO

1999

RESUMO

Combined photochemical and biological processs were applied to the treatment of textile industry effluents. Photochemical processes corresponding to heterogeneous photocatalytic systems, were based on UV light and free and immobilized semiconductors (TiO2 and ZnO). Several white-rot fungi (P .chrysosporium, T. villosa, T. versicolor, L. edodes), brown-rot fungi (G. trabeum) and bacterials (A. vinelandii, P. fluorescence) with high capacity to produce ligninolytic enzymes (lignin peroxidase, manganese peroxidase and laccase) and siderophores were applied. Experiments with free and immobilized enzymes were carried out. The efficiency of single and combined processes was evaluated by measuring several experimental parameters: total organic carbon content, color and toxicity were the most relevant. The analytical control of the processes were carried out by high performance liquid chromatography and gel permeation chromatography, while the toxicity by using bioassays involving Escherichia coli and Scenedesmus subspicatus was evaluated. The degradation efficiency for the photochemical processes using isolated dyes, was observed during four hours of reaction times. The efficiency of biological processes was influenced by chemical structure of dyes. The best results were obtained on degradation processes using L. edodes which decolored several dyes in six days. High degradation efficiency was observed for the textile effluent using immobilized semiconductor in Raschig rings. Complete decoloration and TOC reduction (50 %) were observed in 1 hour. Biological treatment using G. Trabeum and L. edodes was effective for decoloration in four days. Better efficiency was observed with combinated treatments, especially when photochemical / ozone / biological processes were used.

ASSUNTO(S)

industria textil

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