An air-cathode MFC-adsorption hybrid system, made from earthen pot was designed and tested for simultaneous wastewater treatment and energy recovery. Such design had demonstrated superior characteristics of low internal resistance (29.3Ω) and favor to low-cost, efficient wastewater treatment and power generation (55mW/m(3)) with average current of 2.13±0.4mA. The performance between MFC-adsorption hybrid system was compared to the standalone adsorption system and results had demonstrated great pollutants removals of the integrated system especially for chemical oxygen demand (COD), biochemical oxygen demand (BOD3), total organic carbon (TOC), total volatile solids (TVS), ammoniacal nitrogen (NH3-N) and total nitrogen (TN) because such system combines the advantages of each individual unit. Besides the typical biological and electrochemical processes that happened in an MFC system, an additional physicochemical process from the activated carbon took place simultaneously in the MFC-adsorption hybrid system which would further improved on the wastewater quality.

A B S T R A C TA cost effective single-chamber microbial fuel cell (MFC) integrated with adsorption system was tested under different operating temperatures to observe pH profiles, organics, solids, nutrients, color and turbidity removal and power density generation. The optimum operating temperature range was found to be $25-35 C with majority of the removals achieved at $35 C. Maximum power density recorded was 74 AE 6 mW/m 3 with coulombic efficiency (CE) of 10.65 AE 0.5% when operated at 35 C. Present studies had successfully demonstrated the effectiveness of a hybrid system in removing various types of pollutants in POME at optimum temperature and able to fulfill the stringent effluent discharge limit. Chemical oxygen demand (COD), total solids (TS) and turbidity removals increase linearly with temperatures with removal efficiency of 0.5889% C À1 , 1.0754% C À1 and 0.7761% C À1, respectively. The temperature coefficient (Q 10 ) is found to be 1.06, 1.45 and 1.09, respectively. Besides, MFC-adsorption hybrid system had demonstrated superior stability over a wide range of operating temperatures in terms of COD removal as compared to the non-integrated MFC system.

ACFF: activated carbon fiber felt; APHA: American Public Health Association; CE: Coulombic efficiency; COD: chemical oxygen demand; ECG: electrocardiogram; GAC: granular activated carbon; GFB: graphite fiber brush; MFC: microbial fuel cell; MFC-AHS: microbial fuel cell integrated with adsorption hybrid system; MFC-GG: microbial fuel cell integrated with graphite granules; POME: palm oil mill effluent; PTFE: polytetrafluoroethylene; SEM: scanning electron microscope.