Application of electro-membrane bioreactor in the treatment of pharmaceutical wastewater

Abstract

In the present study, the integrated process of an electro-membrane bioreactor (EMBR) with conventional membrane bioreactor (MBR) was used for wastewater treatment. The removal rates of chemical oxygen demand (COD), phosphate (PO43-), turbidity, diclofenac (DCF), and UV254 were investigated in both reactors, which operated with a sludge retention time (SRT) of 60 d and a hydraulic retention time (HRT) of 24 h. The assessment of the current density effect on DCF removal in an electrocoagulation reactor indicated that 0.5 mA/cm² was an appropriate current for the operation of the EMBR. The results of conventional pollutant removal showed that applying an electric current to the MBR approximately increased COD removal by 1.1 times, PO43- removal by 1.56 times, UV254 removal by 1.26 times, and turbidity removal by 1.11 times compared to the conventional MBR. The DCF removal efficiency increased from 43.90 % in the MBR process to 76.46 % in the EMBR. Membrane fouling was investigated through transmembrane pressure (TMP) monitoring, and the findings showed an increase in membrane usage time in EMBR compared to conventional MBR. Finally, the results explained that the application of current to MBR improves the removal of contaminants, mitigates membrane fouling, and reduces the residual DCF concentration.