Treatment of coating plant effluent with an ultrafiltration membrane

Membrane filtration is being used to treat E-stage bleach plant effluent. T his paper describes research efforts to develop ultrafiltration membranes f or the treatment of coating plant effluent. Membranes of different pore siz es were made from polyethersulfone polymer by phase-inversion technique. Th e membranes were then tested in the laboratory using feed solutions contain ing various concentrations of cloy and styrene butadiene (SBR) solutes. Sep arations of both cloy and SBR were close to 100%. However, a sharp flux red uction was observed immediately after start of each experiment for all the membranes studied. Flux reduction increased with increasing feed concentrat ion. For 0.1 wt% feed concentration, flux reduction during the first 15 min of run was in the range of 25-50% while it was 95-97% for the 30 wt% feed concentration. Flux was substantially higher when SBR was not present in th e feed. Flux reduction was attributed to pore blocking and coke layer forma tion over the membrane. Scanning electron microscopy of membrane cross-sect ions showed a distinct foyer of foulants at the membrane surface.