Combined electrocoagulation/flotation technique and membrane desalination for textile wastewater reuse

Abstract

A novel integrated system that combined electrocoagulation/flotation (ECF) technique with membrane desalination was used for textile wastewater treatment to reduce the environmental pollution of textile wastewater. Two scenarios were examined: the first is ECF followed by membrane desalination; the second is the application of membrane desalination for treatment of raw wastewater. Iron electrodes were used in batch-wise tests to examine the effects of electrolysis time and current intensity on percentage removals. The SiO2/PA(TFC) membrane was used to treat raw wastewater and ECF effluents. As the current intensity increased from 50 mA to 600 mA, the color elimination was improved from 94 % to 99 % and the COD elimination improved from 59.1 % to 81.5 %. The findings demonstrate the efficacy of ECF in removing color and COD, although the treated wastewater sample's TDS increased from 4200 mg/L to 19,400 mg/L (raw textile wastewater sample). The SiO2/PA(TFC) membrane displays the salt rejection and water flux reduction of the raw wastewater samples 95 %, and 22 (L/m2.h). Corresponding results for ECF treated wastewater were 94, 93, 91 % and 13, 11.5, and 10 (L/m2.h), respectively. The SiO2/PA(TFC) membrane displays the reduction of COD from 760 mg O2/L (raw) and 310 mg O2/L (ECF effluent) to zero%. Also, it proves the capabilities of SiO2/PA(TFC) membrane for the removal of TDS, COD and color. This integrated system can provide sustainable source for fresh water supply used for landscape, irrigation, industry and various purposes.