MEMBRANE FILTRATION OF TEXTILE DYEHOUSE WASTE-WATER FOR TECHNOLOGICALWATER REUSE

Polish textile industry demands big amounts of water and produces wast ewater having high load of contaminants. The continued increase in the costs of chemicals, energy and water makes their recovery more import ant today than it was years ago when separation techniques by membrane filtration were first introduced to the textile industry. The aim of introducing membrane filtration is not only to reduce water consumptio n and wastewater streams. Membrane filtration also reduces the consump tion of energy as the warm water can be recovered. While the filtratio n techniques applied for textile wastewater treatment and water recove ry have been used at only few installations, these installations have been reported as successful and have been able to save enough to repay the recovery process in one to two years [1]. The paper describes the results of research works and implementation project concerning clean er technology and water reuse in textile dyehouse. The goal of the res earch was application of membrane filtration to reuse water after dyei ng of cotton and polyester fabrics. The Textile Research Institute in Lodz, Poland, together with the Danish partners, the Technical Univers ity of Denmark, the Institute for Product Development and RINSE has ca rried out this research. The research was sponsored by Danish Environm ental Protection Agency DEPA. Membrane filtration has been tested in l ab and pilot scale. The experiments were done with selected two membra nes for nanofiltration and one for reverse osmosis. All membranes were manufactured by Desalination Systems and made of proprietary polysulp hone. The lab tests investigated membrane performance using chemicals selected from real process wastewater. The pilot scale tests were done to prove membrane performance in industrial use and determine dimensi oning parameters for full-scale system. The results of lab and pilot s cale tests have shown that membranes can be used with the rinsing wate r from dyeing of cotton and polyester fabrics. As the result of the pi lot scale tests two full scale systems were proposed: nanofiltration s ystem producing permeate which can be used in limited technological pr ocesses and reverse osmosis system producing permeate of the same qual ity as technological water.