Effect of Feed Temperature on the DCMD Performances in Treating Synthetic Textile Wastewater

Abstract

This article discussed the effect of feed temperature on the performance of direct contact membrane distillation (DCMD) in treating synthetic textile wastewater containing dissolved dye and salt. The DCMD experiments were conducted using an in-house made composite hollow fiber membrane made of organic polyvinylidene fluoride (PVDF) and inorganic Cloisite 15A. Prior to dyeing solution treatment process, the influence of feed temperature on membrane permeability was first investigated using deionized water. Then, the membrane was tested using synthetic solution containing 50 mg L-1 acid red 1 and 60 g L-1 sodium chloride. The inlet temperature of the feed solution was varied in the range of 50 to 90°C while the temperature of permeate solution was kept constantly at 20°C. The results showed that the vapor fluxes of membrane increased with increasing the feed temperature and maximum flux (Jv = 20.88 kg m-2 h-1) was obtained at 90°C.This is mainly due to the higher water vapor pressure sensitivity at the feed side of a higher operating temperature. With respect to separation performance, it is reported that DCMD process could easily achieve excellent rejection for both dye compound and dissolved salts, recording more than 99% rejection.