Evaluation of the biotreatability of bleach pulp mill effluent by aerobic and anaerobic process

The bleaching pulp mill effluent presents, in addition to high concentrations of organic matter in terms of Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD) and color, compounds with high toxicity, which makes the treatment of these effluents difficult. The aim of this article is to evaluate the biotreatability of acid and alkaline bleach effluents from kraft pulp by aerobic and anaerobic processes through characterization using conventional and collective parameters. The results of inert COD, aerobic and anaerobic biodegradability, molecular weight distribution, soluble microbial products and extracellular polymeric substances showed a low biotreatability of the effluents.