Heavy Metal Removal by Electrocoagulation Integrated Membrane Bioreactor

Abstract

This study investigates the performance of electrocoagulation integrated membrane bioreactor (EMBR) in treating synthetic wastewater enriched with heavy metals (Cu, Cr, and Zn). This hybrid system was compared with a conventional membrane bioreactor (MBR). The results suggest that it is superior to conventional MBR in terms to chemical oxygen demand removal, flux improvement, fouling reduction, and metal removal. The metal removal efficiencies in both MBR and EMBR followed the sequence Cr > Cu > Zn. The average removal efficiencies in MBR were 60.90, 53.24, and 48.22% for Cr, Cu, and Zn, respectively, while for the EMBR 98.60, 97.53, and 93.52% could be achieved, respectively. The mixed liquor suspended solids (MLSS) concentration was also found to affect the metal removal potential of the MBR. In MBR, metal removal and MLSS concentration showed significant relationship, while in EMBR, this correlation was found to be less. The specific energy consumption for removing each metal by EMBR was calculated and found to be 6.62, 6.94, and 6.69 kWh/kg removed for Cr, Zn, and Cu, respectively.