Treatment of rayon grade pulp drain effluent by upflow anaerobic fixed packed bed reactor (UAFPBR)

The Rayon grade pulp (RGP) drain effluent of pulp and paper mill was studied to find out pollutant loading and its control measures by low cost and efficient treatment method. Upflow anaerobic fixed packed bed reactor (UAFPBR) with brick ballasts as packing material was used for this purpose. This was compared with conventional anaerobic treatment method. The digested slurry was taken as inoculum from the active cow dung biogas plant. After stabilization of the reactors the reduction in pollutant loading was found to be higher in UAFPBR than conventional anaerobic reactor (CAR). Hydraulic retention time (HRT) of 12 hr was optimum for the treatment of effluent when 74.5% COD and 81% BOD reduction was obtained. 30% inoculum concentration was best for the anaerobic treatment of RGP colour drain effluent. The maximum biogas production (1.37 l l(-1) of effluent) was when the effluent was inoculated with 30% seeding material. Thus, UAFPBR system was very efficient in terms of BOD, COD, TSS and TDS removal from RGP drain of paper mills in ambient environmental conditions.