Performance of Composite Reverse Osmosis Membranes Used in Textile Wastewater Treatment and Reutilization

Textile industry is producing large amounts of wastewater heavily colored with high loading of inorganic salts. Two kinds of composite reverse osmosis membranes aimed for advanced treatment of textile dyeing wastewater were investigated, which made up an effective hybrid membrane separation coupled with coagulation-flocculation, micro filtration(MF)-ultra filtration (UF) and reverse osmosis(RO) dual membrane processes. At first, effect of membrane materials on practical treatment efficiency was discussed and performance of different membrane separation as well as quality of permeates used for industrial recycling was compared. Since ultra filtration combined with coagulation as pretreatment for RO/NF process can remove most turbidity, the rejection for COD and salts in integrated RO membrane process could reach as high as 94% and 97%, respectively. The permeate flux of CPA2 was larger than BW30, but its anti-fouling ability was less than that of BW30. All final RO permeates were colorless, and had a fairly good quality to exceed the Water Quality Standard for Industrial Water Consumption (GB/T 19923-2005) of China, which showed feasibility of integrated membrane process application in industrial textile wastewater reutilization.