Comparative Performance Analysis of Constructed Wetland-Microbial Fuel Cells Operated under Batch and Continuous Mode for Treating Wastewater with RO Concentrate

Comparative analysis of hybridized microbial fuel cell (MFC) with constructed wetland systems (CW) as continuous and batch flow in with/without plant setups has been done. The sewage-generated WW was spiked with reverse osmosis (RO) concentrate [1:1] and was used as the substrate. The effects of RO-induced salinity and efficiency of wastewater (WW) biomass conversion to energy have been analyzed. The analysis was based on the removal of chemical oxygen demand (COD), total suspended solids (TSS), total dissolved solids(TDS), voltage generation, and energy recovery (NERs) to find out the performance efficiency of the four systems. Systems consisted of two batch setups with the downflow regime, batch setup with plant (BWP) and batch setup without plant (BWOP) and two continuous setups with the upflow regime, continuous setup with plant (CWP) and continuous setup without plant (CWOP). The maximum COD removal and energy recoveries in BWP, BWOP, CWP, and CWOP were 91.66%, 86.45%, 90.62%, and 83.33% and 6.20, 1.98, 0.98, and 0.72 W·h/kgCOD, respectively. The incorporation of RO concentrate positively influenced the performance of CW-MFCs by its induced salinity specifically in presence of Canna indica, thus increasing the energy output as indicated by the voltage generation and energy recoveries.