Análise comparativa da capacidade de remoção do corante direct blue 71 em solução pelos fungos Phanerochaete chrysosporium e Aspergillus oryzae
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Data
2011-04-12
Autores
Santos, Graziely Cristina dos [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Entre as questões ambientais mais discutidas pela sociedade, está a poluição pelos diversos ramos da indústria. As indústrias têxteis estão entre os responsáveis pela contaminação, pois, muitas vezes, eliminam seus efluentes sem tratamento adequado nos mananciais, portanto, sem a completa remoção dos corantes. Os corantes azóicos são os mais utilizados pela indústria têxtil e são caracterizados pela presença de grupos azo (N=N). Dos vários métodos de tratamento de efluentes existentes, o tratamento biológico tem sido amplamente estudado. Buscando uma maneira de melhorar o tratamento biológico, o presente trabalho teve como objetivo comparar a capacidade de biossorção e biodegradação do corante azóico Direct Blue 71 em solução pelos fungos Phanerochaete chrysosporium e Aspergillus oryzae, na forma paramorfogênica. Para isso utilizou-se uma solução de corante DB71 a 100 μg/mL. Foram realizados testes de biossorção, por um período de 2 horas, com cinco diferentes concentrações de biomassa e três valores de pH, 2.5, 4.5 e 6.5, sendo que o pH 2.5 proporcionou a melhor condição para a biossorção. A adsorção do corante pela parede celular de ambos os fungos foi avaliado com o auxílio das isotermas de Freundlich, modelo seguido por P. chrysosporium, e Langmuir, seguido por A. oryzae. Para os testes de biodegradação, por 240 horas, utilizou-se apenas uma concentração de biomassa. Com espectrofotometria UV-VIS foi possível determinar porcentagem de descoloração e absorbância relativa do corante após realização dos testes de biossorção e biodegradação, respectivamente. Análises de FTIR permitiram a identificação de moléculas presentes na solução antes e após a biodegradação. Com A. oryzae obteve-se os melhores resultados de biossorção e biodegradação. Contudo, P. chrysosporium também se mostrou eficiente para os tratamentos...
Among many environmental issues discussed in society, all sorts of pollution from industrial branches arise as an important matter. Textile industries are responsible by such contamination, since they often eliminate their effluents in the environment without proper treatment, therefore, without complete dye removal. Azo dyes are frequently used in textile industry and characterized by the presence of azo groups (N = N). Of the various methods of wastewater treatment available, biological treatment has been extensively studied. Thus, to improve biological treatment in textile industries, this study aimed to compare the ability of biosorption and biodegradation of Azo dye Direct Blue 71 solution by Phanerochaete chrysosporium and Aspergillus oryzae fungi in paramorfogenic form. In order to achieve this, a 100 μg/mL DB7 dye solution was used. Biosorption tests were performed within two hours with five different biomass concentrations and three pH values, 2.5, 4.5 and 6.5. It was observed that pH 2.5 solutions presented best biosorption conditions. The dye adsorption through studied fungi cell wall was evaluated with the Freundlich isotherm model for P. chrysosporium, and Langmuir for A. oryzae. For the biodegradation tests in 240 hours, it was used only one biomass concentration. Through an UV-VIS spectrophotometry the percentage of relative absorbance and dye discoloration was determined after biosorption and biodegradation tests respectively. FTIR analysis allowed molecular compounds identification in solution before and after biodegradation. The best results were obtained with A. oryzae in both biosorption and biodegradation. Yet even then P. chrysosporium was also efficient in all treatments. Hence, both A. oryzae and P. chrysosporium have great potential of dye removal in wastewaters. These results may contribute to improve effluent treatment systems in textile industries.
Among many environmental issues discussed in society, all sorts of pollution from industrial branches arise as an important matter. Textile industries are responsible by such contamination, since they often eliminate their effluents in the environment without proper treatment, therefore, without complete dye removal. Azo dyes are frequently used in textile industry and characterized by the presence of azo groups (N = N). Of the various methods of wastewater treatment available, biological treatment has been extensively studied. Thus, to improve biological treatment in textile industries, this study aimed to compare the ability of biosorption and biodegradation of Azo dye Direct Blue 71 solution by Phanerochaete chrysosporium and Aspergillus oryzae fungi in paramorfogenic form. In order to achieve this, a 100 μg/mL DB7 dye solution was used. Biosorption tests were performed within two hours with five different biomass concentrations and three pH values, 2.5, 4.5 and 6.5. It was observed that pH 2.5 solutions presented best biosorption conditions. The dye adsorption through studied fungi cell wall was evaluated with the Freundlich isotherm model for P. chrysosporium, and Langmuir for A. oryzae. For the biodegradation tests in 240 hours, it was used only one biomass concentration. Through an UV-VIS spectrophotometry the percentage of relative absorbance and dye discoloration was determined after biosorption and biodegradation tests respectively. FTIR analysis allowed molecular compounds identification in solution before and after biodegradation. The best results were obtained with A. oryzae in both biosorption and biodegradation. Yet even then P. chrysosporium was also efficient in all treatments. Hence, both A. oryzae and P. chrysosporium have great potential of dye removal in wastewaters. These results may contribute to improve effluent treatment systems in textile industries.
Descrição
Palavras-chave
Fungos, Biodegradação, Corantes, Biossorção, Corantes têxteis, Azo, Forma paramorfogênica, Azo dyes, Biodegradation, Biosorption, Paramorfogenic form
Como citar
SANTOS, Graziely Cristina dos. Análise comparativa da capacidade de remoção do corante direct blue 71 em solução pelos fungos Phanerochaete chrysosporium e Aspergillus oryzae. 2011. 116 f. Dissertação - (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2011.