Industrial & Engineering Chemistry Research, Vol.51, No.24, 8211-8221, 2012
Optimization of Integrated Electro-Bio Process for Bleaching Effluent Treatment
The technical and economic feasibility of various electrochemical processes as pretreatment step for biological treatment for the management of kraft bagasse pulp bleach effluent has been studied, and the results are compared with that of the conventional chemical coagulation followed by biological treatment. A modeling methodology for integrating processes involving electrochemical and biological methods is proposed. Optimal combinations of operating variables giving a definite completion of pollutant removal are derived from the empirical models of each process. However, both the electrochemical steps as electrocoagulation and electro-oxidation were observed to perform technically better, and the former was noticeably more attractive based on the overall operating cost. The cost of electrocoagulation-biological (EC-Bio) treatment giving 80% COD removal was determined to be US $0.166/m(3). A 41% reduction in the treatment cost was achieved when the conventional chemical coagulation-biological (CC-Bio) methodology replaced by an EC-Bio system. The research revealed the feasibility of electrochemical steps as a primer in the reduction of organic load and improvement in the biodegradability of pulp-bleaching effluent.