Treatment of chlorine bleaching effluent using a white-rot fungus

This study was undertaken to better understand the reactions related to fungal treatment of pulp bleaching effluents. Color, COD (chemical oxygen demand), glucose, chloride and ammonium concentration were monitored during the course of treatment of alkali extraction stage liquor (E1) with a white-rot fungus Phanerochaete chrysosporium.The color removal rate was independent on the initial glucose concentration. The earlier used glucose concentration of 10 g l⁻¹ was found to be unnecessary high as the residual glucose accounted for about 50% of the final COD of the effluent. The lowest practical glucose concentration was 2 g l⁻¹. Below this the fungus lost its decolorizing activity in a few days. The lignin-related COD decreased 32% and up to 16.5 mM inorganic chloride was liberated (being 34% increase from the original concentration) from the chlorinated organic material in the effluent in 2 d. The observed rapid depletion of added ammonium nitrogen is believed to indicate a switch of a part of the mycelium to primary growth which leads to higher activity and longer active period of time due to renewal of the cells.