Bioenergy production and treatment of aquaculture wastewater using saline anode microbial fuel cell under saline condition

Abstract

Saline anode microbial fuel cell (SA-MFC) equipped with carbon felt as anode and cathode, separated by nafion membrane was used to evaluate the aquaculture wastewater treatment efficiency and energy production under saline condition (4%). Operation of SA-MFC was executed at different organic load (OL) from 0.5 gCOD/L to 1.5 gCOD/L under saline condition. TCOD (Total Chemical Oxygen Demand) removal was 75 ± 1.4%, 81 ± 0.9% and 84 ± 1.1% at 0.5, 0.75 and 1 gCOD/L OL respectively. SCOD (Soluble Chemical Oxygen Demand) removal in SA-MFC was 68 ± 1.2%, 75 ± 0.8% and 81 ± 0.5% at 0.5, 0.75 and 1 g COD/L OL. Among the OL used 1.25 gCOD/L recorded high TCOD (92 ± 1.1%), SCOD (91 ± 0.5%) and TSS (Total Suspended Solids) removal (78 ± 0.7%) with a maximum power production (369 mW/m 2 ). Increase in OL to 1.5 gCOD/L revealed decline in TCOD (79 ± 1.3%), SCOD (74 ± 0.8%), TSS (71 ± 1.5%) removal and power production (310 mW/m 2 ). The predominant bacterial strains responsible for aquaculture wastewater treatment and energy production was identified as Ochrobactrum (53%), Marinobacter (22%) and Rhodococcus (15%). The other strains such as Bacillus , Stenotrophomonas , Xanthobacter , Sphingomonas , Pseudomonas and Sedimentibacter also present in the SA-MFC reactor operated under saline condition. • Treatment of aquaculture wastewater in SA-MFC under saline condition (4%). • TCOD and SCOD removal was 92 and 91% at 1.25 gCOD/L OL. • Maximum power density of 369 mW/m 2 at 1.25 OL. • Dominance of Ochrobactrum, Marinobacter and Rhodococcus in SA-MFC.