Treatment of Pulp and paper mill wastewater by column type sequencing batch reactor

Laboratory scale studies were performed on the performance of column type sequencing batch reactor (SBR) for the biodegradation of pulp and paper mill wastewater. SBR of volume 3.46 L was fabricated with Perspex material and was seeded with the aerobic seed sludge obtained from a sewage treatment plant. The sludge was acclimatized with 200 mg/L of phenol for two weeks. Subsequently diluted pulp and paper mill wastewater was fed to the reactor at a 24 hour cycle of operation. After achieving significant COD reduction the organic load of the feed was increased by decreasing the dilution and finally raw wastewater has been fed to the reactor. A COD removal efficiency of 87% was achieved during the last phase of the study. The pH and alkalinity were also within the permissible limits. The settling characteristics of the sludge were improved and the granulation process has just started. There was a significant increase in the concentration of volatile suspended solids within the reactor. The turbidity removal efficiency was around 95%.