Journal Article

Effectiveness of constructed wetland integrated with microbial fuel cell for domestic wastewater treatment and to facilitate power generation

Yadav, Anamika, Jadhav, Dipak A., Mitra, Arunabha, Ghangrekar, Makarand M.

2022

Overview

Constructed wetlands (CWs) have gained a lot of attention for wastewater treatment due to robustness and natural pollutant mitigation characteristics. This widely acknowledged technology possesses enough merits to derive direct electricity in collaboration with microbial fuel cell (MFC), thus taking advantage of microbial metabolic activities in the anoxic zone of CWs. In the present study, two identical lab-scale CWs were selected, each having 56 L capacity. One of the CW integrated with MFC (CW-MFC) contains two pairs of electrodes, i.e., carbon felt and graphite plate. The first pair of CW-MFC consists of a carbon felt cathode with a graphite plate anode, and the second pair contains a graphite plate cathode with a carbon felt anode. The other CW was not integrated with MFC and operated as a traditional CW for evaluating the performance. CW-MFC and CW were operated in continuous up-flow mode with a hydraulic retention time of 3 days and at different organic loading rates (OLRs) per unit surface area, such as 1.45 g m −2  day −1 (OLR-1), 2.43 g m −2  day −1 (OLR-2), and 7.25 g m −2  day −1 (OLR-3). The CW-MFC was able to reduce the organic matter, phosphate, and total nitrogen by 92%, 93%, and 70%, respectively, at OLR of 1.45 g m −2  day −1 , which was found to be higher than that obtained in conventional CW. With increase in electrochemical redox activities, the second pair of electrodes made way for 3 times higher power density of 16.33 mW m −2 as compared to the first pair of electrodes in CW-MFC (5.35 mW m −2 ), asserting carbon felt as a good anode material to be used in CW-MFC. The CW-MFC with carbon felt as an anode material is proposed to improve the electro-kinetic activities for scalable applications to achieve efficient domestic wastewater treatment and electricity production. Graphical abstract

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V
• Subject: Anodes / Aquatic Pollution / Artificial wetlands / Biochemical fuel cells / Carbon / Cathodes / constructed wetlands / Domestic wastewater / Earth and Environmental Science / Ecotoxicology / Electric power generation / Electricity / electricity generation / Electrochemistry / Electrode materials / Electrodes / Environment / Environmental Chemistry / Environmental Health / Environmental science / Fuel cells / Fuel technology / graphene / Graphite / Green Energy for Environmental Sustainability / Hydraulic retention time / Loading rate / microbial fuel cells / Microorganisms / Organic loading / Organic matter / phosphates / Pollutants / Pollution control / power generation / Redox properties / Retention time / sewage treatment / surface area / total nitrogen / Waste Water Technology / Wastewater treatment / Water Management / Water Pollution Control / Water treatment / Wetlands