Biodegradation performance of anaerobic sequencing batch biofilm reactor for oil with polychlorinated biphenyls

 The biodegradability of oil containing polychlorinated biphenyls (PCBs) from electrical transformer by the anaerobic sequencing biofilm batch reactor (ASBBR) with was assessed. 

 Two anaerobic sequencing batch biofilm reactor (ASBBR) containing polyurethane foam cubes as inert support was used. The reactors were operated for 310 days at 35 ± 2°C. The reactors with a total volume of 7 L, 5 L effective volume and 3.5 L for gas production, were operated in a cycle per day. The effect of operational parameters including organic loading rate, PCBs loading rate, co-substrate type, initial PCBs and COD concentration was evaluated. 

 The results point to admirable reactors stability and over 95% efficiency in PCBs removal, with effluent PCBs concentration of lower than 10 mg/L. However, degradation rates increased as the initial concentration of PCBs as increased. The average of COD removal efficiency by two ASBBR reactors was more than 92% that corresponding to > 9 μg/L of effluent COD. In over all operation, average of biogas production in R1 was 5.7 ± 2.2 L/d and maximum produced biogas was 8.02 L/d at 310 day. The kinetic studies revealed that second - order kinetic model described the COD removal by ASBBR reactors from synthetic wastewater better than two other kinetic model. 

 Therefore, this investigation demonstrated that the ASBBR have good potential for biodegradation of oil containing PCBs, despite variation of influent PCBs and organic loading rate (OLR).