A study on novel coupled membrane bioreactor with electro oxidation for biofouling reduction

Abstract

The present study focuses on a novel method to integrate the electro-oxidation process with membrane bioreactor to reduce biofouling and increase the biodegradability index. Here, we used electro-oxidation as pretreatment with membrane bioreactor operating at a current density of 1.5 mA/cm2 with hydraulic retention time at six h. The mixed liquor suspended solids concentration was maintained constant at 3,200 mg/L throughout the experiment for 30 days. The results obtained were promising with the percentage removal of COD, TOC, total nitrogen, and chlorides were in the range of 97%, 90%, 94%, and 15%, respectively, which was comparatively higher than the existing membrane bioreactor. The biodegradable index of treated water was higher, reaching a maximum of 0.6, which is remarkably high compared with 0.3 in a membrane bioreactor. The integrated electro-oxidation process was efficient for the complete removal of pollutants from wastewater, which was confirmed using gas chromatography. In addition, the phytotoxicity test showed a significantly higher quality of treated water compared with that of raw tannery effluent. Hence, our proposed integrated electro-oxidation process can be used to decrease biofouling with increased biodegradability index as a replacement for MBR.