A new hybrid treatment system of bioreactors and electrocoagulation for superior removal of organic and nutrient pollutants from municipal wastewater

This paper evaluated a novel pilot scale hybrid treatment system which combines rotating hanging media bioreactor (RHMBR), submerged membrane bioreactor (SMBR) along with electrocoagulation (EC) as post treatment to treat organic and nutrient pollutants from municipal wastewater. The results indicated that the highest removal efficiency was achieved at the internal recycling ratio as 400% of the influent flow rate which produced a superior effluent quality with 0.26 mgBOD5 L−1, 11.46 mgCODCr L−1, 0.00 mg NH 4 + -N L−1, and 3.81 mgT-N L−1, 0.03 mgT-P L−1. During 16 months of operation, NH 4 + -N was completely eliminated and T-P removal efficiency was also up to 100%. It was found that increasing in internal recycling ratio could improve the nitrate and nitrogen removal efficiencies. Moreover, the TSS and coliform bacteria concentration after treatment was less than 5 mg L−1 and 30 MPN mL−1, respectively, regardless of internal recycling ratios and its influent concentration.