PILOT-SCALE MEMBRANE SEPARATION OF ELECTROPLATING WASTE-WATER BY REVERSE-OSMOSIS

Electroplating waste water containing copper was treated by means of r everse osmosis (RO) membrane separation on a pilot scale. The copper c oncentration in the untreated waste water was 340 ppm. After the treat ment, the concentration in the treated water was below 4 ppm which is the Hong Kong government discharge limit. It is shown that, by increas ing transmembrane pressure drop, metal concentrations in the treated w ater can be further reduced. This study suggests that larger scale ope rations on treating electroplating waste water by RO membrane separati on is possible and effective. Effects of operating variables including transmembrane pressure drop and temperature on membrane separation pe rformance were studied and explained based on the solution-diffusion m odel. The present study is part of the recent investigation of industr ial waste water management sponsored by the Hong Kong Government. The purpose of this project is to provide guidelines to the local industri es for waste minimization which is closely monitored by the Hong Kong legislature.