Treatment of coating plant effluent with an ultrafiltration membrane

Membrane filtration is being used to treat E-stage bleach plant effluent. This paper describes research efforts to develop ultrafiltration membranes for the treatment of coating plant effluent. Membranes of different pore sizes were made from polyethersulfone polymer by phase-inversion technique. The membranes were then tested in the laboratory using feed solutions containing various concentrations of cloy and styrene butadiene (SBR) solutes. Separations of both cloy and SBR were close to 100%. However, a sharp flux reduction was observed immediately after start of each experiment for all the membranes studied. Flux reduction increased with increasing feed concentration. 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 the feed. Flux reduction was attributed to pore blocking and coke layer formation over the membrane. Scanning electron microscopy of membrane cross-sections showed a distinct foyer of foulants at the membrane surface.