Treatment of Paper and Pulp Mill Effluent using Sequential Batch Reactor

The manufacture of paper generates significant quantities of waste water; which can have deleterious effects on the receiving waters; therefore there is a need to find a treatment process which can minimize these effects considerably. The raw wastewater from paper and board mills can be potentially very polluting. This paper reveals the results of laboratory experiments using a sequential batch reactor(SBR) at different operating conditions, including mixed liquor suspended solid concentration, volumetric exchange rate, aeration time, temperature and daily operation cycle on biological treatment of the pulp and paper mill effluent. Removal efficiencies of COD and BOD were as high as 93.85% & 92.45% at the loading rate of 1.35 kg COD/m per day. The average TDS and TSS removal efficiencies were above 71% at the loading rate of 6.67 kg COD/m day. The COD, BOD5, TDS and TSS removal efficiencies of SBR system were about 84%, 83%, 85% and 88% respectively under retention time of 24 hours. The treatment performance of organic removal by the SBR system reached 80±4.5%. The common problems like sludge bulking were almost deficient. The effluent quality was satisfied with the discharge standard set by the local authority. Keywords-Sequencing Batch Reactor, Activated sludge, Paper and pulp mill, Wastewater treatment.