Outstanding energy reduction of nitrogen recovery by biohythane concept introduction by 3D-weaved anode network in microbial electrolysis cell

Abstract

This work achieved nitrogen recovery from the wastewater treatment by the bioelectrochemical system with the concept of biohythane generation. In this study, 3D network electrode could improve the biohythane generation to reduce energy consumption of the nitrogen recovery, achieving the highest biohythane production rate at 0.123 m3 m−3 treated wastewater to obtain energy consumption at 0.77 kWh kg−1 N under 0.8 V, significantly lower than other traditional technologies (at about 1.3 to 14 kWh kg−1 N). Further microbial analysis was processed for voltage optimization, and 0.8 V was proved as best voltage for high abundance of Geobacter over Methanosarcina. Correlation factor and heatmap analysis indicated that the suitable voltage could benefit Geobacter growth for higher energy recovery. Furthermore, genera of Bacteroides and Azospirillum were found as key species. This study proved that the biohythane generation concept could outstandingly reduce the energy consumption for higher nitrogen recovery from wastewater treatment.