Treatment of Bleaching Effluent of Pulp and Paper Mill by Combined Photocatalytic-aerobic Activated Sludge Processes

The treatment efficiency of bleaching effluent of bagasse pulp treated by photocatalytic-aerobic activated sludge was studied.Effects of pH value,TiO2 dosage and H2O2 concentration on the photocatalytic treatment were investigated by Response Surface Methodology(RSM).The change of intermediates was detected by using GC-MS.The treatment efficiency of bleaching effluent treated by the combined processes was investigated through BOD5/CODCr and biodegradation respiration curve.The results indicated that in the process of photocatalysis,pH value,TiO2 dosage and H2O2 concentration interacts in certain degree,and H2O2 has synergistic effect on UV/ TiO2 system.Dechlorination,transformation or degradation of the organic pollutants in the effluent improves its biodegradability,CODCr of the bleaching effluent decreases from 965 mg/L to 78 mg/L,the removal rates of color and UV254 are 91% and 95% respectively after treating by the combined photocatalytic-aerobic activated sludge processes.The combined processes is proved an effective process for treating high concentration organic waste water which is difficult to be biodegraded.