Comparative studies of ClO2, H2O 2 and O2 treatment of Bamboo pulp on the formation of chlorinated phenolics in the bleach effluent

Elemental chlorine and chlorine compounds are commonly used in the developing countries for bleaching of pulp. The study deals with the bleaching of Bamboo pulp with chlorine, chlorine dioxide, peroxide and O2 treatment and identification of various chlorophenolics compounds. The results show that quantity of the total chlorophenolic compounds formed decreases up to 82% at 100% replacement of chlorine by chlorine dioxide in C stage. A 40% reduction in effluent COD and 79% reduction in color value of CEH effluent indicate a significant drop in pollution load. There is a reduction of 54% in total chlorophenolic compound in the CEH effluent when E stage is changed to Ep. The COD and color values are reduced by 35% and 33% respectively as E stage is changed to Ep stage. Oxygen delignification stage (prebleaching stage) reduced the formation of chlorophenolic compounds by 74%. The effluent COD is reduced by 30% and the color value is reduced by 46% during this stage.