Anaerobic treatment of agricultural residue based pulp and paper mill effluents for AOX and COD reduction

Abstract

Black liquor and bleach effluent from an agroresidue based pulp and paper mill were treated anaerobically to reduce their high chemical oxygen demand (COD) and adsorbable organic halide (AOX) contents. Addition of 1% w:v glucose yielded 80% methane from black liquor with concomitant reduction of COD by 71%, while bleach effluent generated 76% methane and produced 73 and 66% reductions in AOX and COD, respectively. In the absence of glucose, black liquor and bleach effluent produced only 33 and 27% methane with COD reductions of 43 and 31%, respectively.