Abstract
The recovery of caustic soda from textile mercerization wastewater by means of nanofiltration has been investigated in pilot-scale with SelRO MPT-34 membrane. With a brief summary of previously reported lab-scale results concerning membrane performance as well as the proper pretreatment and cleaning methods, the importance of operating temperature is emphasized in this study because it is found to play a crucial role in governing flux. The productivity of the given membrane system is directly determined by flus. It increases with increase in temperature and decrease in caustic soda concentration of feed solution. It is essential to raise the temperature of feed solution to at least 40℃ to maintain permissible flux. From informations obtained by field visits to Banwol and Bisan textile industrial complexes and Alchemie's successful MF system in India, installation of NF membrane system at an environmental company rather than a textile company is finally suggested as the best method for its industrial application in Korea. Since economic benefit and a payback period are significantly dependent on the NaOH concentration of mercerization wastewater, cooperation of textile companies in collecting the higest caustic soda solution with lower volume is needed.
