Oxi-Bioremediation of Hazardous Biosludge from Integrated Pulp and Paper Mill

The present study establishes the feasibility of decomposition of hazardous biosludge from an integrated pulp and paper mill with ozone and subsequent biodegradation of disintegrated biomass in the activated sludge process (ASP). The 16.0 ± 0.5% solubization of mixed liquor volatile suspended solids and 22.6 ± 2.3% dechlorination of AOX compounds of biosludge were observed at an ozone dosage of 43–47 mg O3/g dry solid. More than 90% PCDD and PCDF compounds were degraded. The recycling of disintegrated sludge to ASP did not affect the performance of the process in terms of reduction in total organic carbon, CODs, color and AOX. The proliferation of filamentous organisms was controlled by ozone treatment of sludge. The biomass yield was only 0.06 g with ozone treatment, whereas the same was 0.31 g/g of CODs removal in control reactor.