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

Saline anode microbial fuel cell (SA-MFC) equipped with carbon felt as anode and cathode, separated by nation 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. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

In the treatment of aquaculture wastewater using Saline Anode Microbial Fuel Cell (SA-MFC), higher organic load and saline condition can effectively enhance the removal efficiency of chemical oxygen demand and suspended solids, with a maximum power output of 369 mW/m(2). However, excessive organic load may lead to a decrease in removal efficiency and power output.