Cost benefit analysis of integrated constructed wetland microbial fuel cell system for sustainable and economic domestic wastewater treatment

Abstract

Wastewater treatment with integrated constructed wetland–microbial fuel cell technology has attracted serious attention from researchers. The economic sustainability of any potential technology is the key to its commercialization from laboratory to field application, which is fulfilled through an exhaustive assessment of the related costs and benefits. This article presents a comparative cost-benefit analysis of three reactors: constructed wetland (R1), integrated CW-MFC (R2), and unplanted CW-MFC (R3) for domestic wastewater treatment and economic sustainability assessment. The study was conducted with 36 h and 24 h hydraulic retention times of the reactors and the respective cost-benefit ratio was determined. Results revealed that R2 was the most sustainable option with maximum economic benefits during Phase 1 and Phase 2 without effluent disinfection. With effluent disinfection in place, R1 emerged with the best cost-benefit ratio due to less investment cost and low revenue from electricity production in R2 and R3. Sensitivity analysis with net investment cost, power density, electrode area, effective reactor volume, and hydraulic retention time; showed power density was the most influential parameter affecting the cost-benefit ratio. Revenue from wastewater treatment was found essential for economic sustainability which shows the importance of producing high-quality effluent and greater power density to make CW-MFC technology economically attractive.