Biobleaching of pulp and paper mill effluent using mixed white rot fungi

摘要

In the recent past, white rot fungi have received a considerable attention for the removal of color from pulp and paper mill effluents. Investigation was carried out to compare the biobleaching potential of reported four immobilized whit-rot fungal strains (a) Phanerocheate chrysosporium, (b) Trametes versicolor, (c) Daldella flavida and (d) Pleurotus ostreatus. Also, the most efficient decolorizer was co-immobilized with best Chemical Oxygen Demand (COD) reducer and the suitability of the same was studied. The treated and pre-treated combined effluent samples for the study was collected from Varindra-Agros Paper Mills Ltd., Barnala, Punjab, and stored at 4±1deg C, until further use. Polyurethane Foam (PUF) pieces were used for adsorption and immobilization of white-rot fungi.The study revealed T. versicolorMTCC 138 as the best decoloriser with 87.7% color reduction, while P. chrysosporium BKMF1767 was found to reduce COD up to a maximum of 42.3%, after 72 hours incubation time at 30±1deg C. Themixed immobilized cultures of P. chrysosporium BKMF 1767 and T. versicolorMTCC 138 supported the maximum color reduction of 88.84% and a corresponding COD reduction of 41.60% after 120 hours of incubation at 30±1deg C. The study suggests that co-immobilized system can be more efficient for decolorization and COD reduction of pulp and paper mill effluent and paves a good platform for further investigation of enzymatic remedial processes for the same.