Catalytic performance of rGO-Zeolite modified anode in clay biophotovoltaics system for effective urine treatment

Abstract

Low power output due to poor anode kinetics is minimized by modifying the anode with rGO-Zeolite to improve the electrochemical redox reactions in biophotovoltaics (BPV). Higher power production and N/P- recovery is successfully achieved in horizontal Torch separator-based urine fed BPV modified with rGO-Zeolite anodes than bare graphite anode. Among the two variants of anodes, modified anode results in power of 146.88 mW/m2, redox current of 18.9 mA, Phosphorous (88 ± 0.3%), NH4+–N (49 ± 0.5%), and Coulombic efficiency of 15.16 ± 0.3%. Improvement in power output is due to the higher electroactive surface area provided by rGO-Zeolite anode for electron transfer. Recovery of clear catholyte (8 ml/day) during human-urine treatment and energy recovery for operating the hygro-clock are the main key features of low-cost BPV. Thus, BPV with modified anodes serves as a sustainable technology for recovering energy and resources from human urine and makes it suitable to use for onsite urine treatment and sanitation applications.