Studies on biobleaching of kraft pulp using <i>Phanerochaete chrysosporium</i>

Abstract

White-rot fungi <i>Phanerochaete chrysosporium </i>can degrade residual lignin (bleach) of kraft pulp maximum 69.59 percent within 7 days (optimum digestion time) with 20 percent inoculum concentration (optimum) of 7 days old aged (optimum) fungus with 1.0 percent (<i>wlw </i>percent of pulp) (optimum) of glucose and 0.10 percent (<i>w/w </i>percent of pulp) (optimum) of <i>l</i>-asparagine at <i>p</i>H 4.5 and temperature 35°C. COD, BOD and colour of the effluents (filtrate after digestion with microbe) at optimum conditions are very lower. Average COD, BOD and colour values of effluents after bleaching for optimum dose are 320 mg/L, 545 mg and 0.23 (OD at 465 nm) respectively. The increase percentage of brightness, tear index, urst index, tensile index and breaking length of bleached pulp for optimum

dose are 89.35, 38.93, 47.46 , 68.17 and 66.97 respectively.