Dyeing process wastewater treatment using fouling resistant nanofiltration and reverse osmosis membranes

Fouling resistant membranes (NF and RO membranes) were prepared by coating a neutral polyvinyl alcohol (PVA membrane). The PVA-coated membranes showed a lower surface charge and roughness. By using the NF and RO membranes, dyeing process wastewater (influent, coagulated water and effluent) was recycled. The PVA-coated NF and RO membranes reduced fouling significantly. The effluent was feasible for membrane filtration compared with the influent and the coagulated wastewater, owing to the lower loading of suspended solids (SS) and COD. The PVA-coated NF or RO membranes after microfiltration of the effluent were useful for the reuse of the dyeing process wastewater in terms of water quality and the problems in membrane fouling.