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 PVAcoated 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.

Dyeing process wastewater (influent, coagulated water and effluent) was treated by MF, NF and RO. The NF and RO membranes were coated with a neutral PVA polymer. The PVA-coated membranes showed a lower surface charge and roughness than the uncoated ones. The PVAcoated NF and RO membranes reduced fouling significantly. It was possible to use the effluent directly for membrane filtration (NF and RO) compared with the influent and the coagulated wastewater, owing to its lower loading of SS and COD. To use the membrane process successfully, the SS should be removed from the effluent completely by using MF. The PVA-coating of NF or RO membranes, after MF of the effluent, were useful for the reuse of the dyeing process waste-