Color removal of high strength paper and fermentation industry effluents with membrane technology

This paper presents the pilot plant studies on the biologically treated eff luents from the pulp and paper and fermentation industry effluents by using two stage membrane treatment (Ultrafiltration(UF) and reverse osmosis(RO), (brackish water(BW) and seawater(:SW)) membranes). In the first part of th e study, the combination of UF and RO treatment resulted in very high remov als of COD, color and conductivity for the pulp and paper industry effluent s. At the end of one single pass with SW membrane, the initial GOD, colour and conductivity values were reduced to 10-20 mg/l, 0-100 Pt-Co units and 2 00-300 mu s/cm, respectively. The influent, UF permeate, BW permeate and SW permeate conductivities were 6000-6700 mu s/cm, 5500-5900 mu s/cm, 1000-15 00 mu s/cm and 200-300 mu s/cm, respectively. Almost complete colour remova ls were achieved in the RO experiments with SW membranes. RO studies with B W membranes were also performed to the same permeate from the first stage U F study. In the second part of the study, ultrafiltration and reverse osmos is membranes were evaluated for their suitability in separating color and C OD from the different wastewater streams generated by the fermentation indu stry. Three different wastewater stream, including the anaerobic treatment plant effluents of plant A and B, the aerobic treatment plant effluent of p lant B have been tested during the runs. The overall removal efficiencies o f GOD, Color, Conductivity, NH3-N were found as 90-95%, 95-97%, 85-90% and 80-90% respectively with 85-90% recovery after UF and RO membranes for all these wastewater streams. Applying membrane technology to these complex ind ustrial wastewaters, color problems of treatment plant effluents can be sol ved effectively. (C) 1999 Published by Elsevier Science Ltd on behalf of th e IAWQ. All rights reserved.