Enhanced Total Nitrogen Removal from Wastewater Using a Combined Biological–Electrolytic Process

The total nitrogen (TN) concentration of wastewater effluent treated with a conventional biological process is occasionally higher than required, and nitrate is commonly detected as the dominant TN component. In this work, biological and electrolytic processes were applied to treat synthetic wastewater and actual pesticide wastewater, with activated sludge used as the biological carrier and Fe—Ti/RuSn plates used as electrodes. The results indicated that about 31.37% of ammonia in raw synthetic wastewater was degraded and partly converted to nitrate via the biological process, while about 92.50% of TN could be removed by the combined biological–electrolytic process. The electrolytic process could be selected as an available polishing step to achieve biological denitrification.