Membrane Filtration of Wastewater Split Flows originating from Paper Industry and Biological Wastewater Treatment of the generated Membrane Concentrates

Wastewater effluents from deinking- and TMP processes were taken and were concentrated in 2 stages consisting of ultra- and nanofiltration. Futher more, the concentrates were biologically treated with a single aerobic and a hybrid anaerobic-aerobic process. With a continuous anaerobic reactor and an aerobic SBR reactor experiments were conducted to study the variations in hydraulic retention time (HRT), food to biomass ratio (F/M) and wastewater concentrate. For the deinking wastewater concentrate, an overall average COD elimination of 51 % and 57 % was achieved for aerobic and anaerobic-aerobic treatment, respectively. Single stage aerobic treatment of TMP wastewater concentrate had an mean COD elimination efficiency of 61 % and the hybrid anaerobic-aerobic treatment yielded 73 %. The temperature in the aerobic biological SBR reactor was kept stable at 30?°C with an F/M ratio between 0.01 and 0.5 gBOD5/(gSS · d).