(Invited) Bioelectrochemical Systems for Resource Recovery and H2 Production from Wastewater

Abstract

Wastewaters contain abundant nutrients and energy, which can be recovered by using proper bioelectrochemical systems. We developed a three-chamber resource recovery microbial fuel cell (RRMFC) to treat synthetic urine-containing wastewater with various organic pollutants and simultaneously recover nutrients (e.g., N, P, and S). Over one cycle (∼3 days), 99% of urea, 97% of COD, 99% of histidine, 91% of creatinine, 99% of sodium acetate, 98% of SO4 2−, and 99% of PO4 3− were removed from the wastewater, and simultaneously 42% of total nitrogen, 37% of PO4 3−, 59% of SO4 2−, and 33% of total salts were recovered from the wastewater. We also developed a solar microbial electrolysis cell (solar-MEC) with a Fe2O3 photoanode, a bioanode, and a black-silicon (b-Si) photocathode for H2 production from wastewater without external bias. The solar-MEC had a maximum current density of 0.8 mA/cm2 and an average H2 production rate of 5.1 µmol/h/cm2 under one sun irradiation.