A novel photoelectrocatalytic reactor with Fenton-like BiFeO3-TNTAs electrode for treatment of reclaiming water

Abstract

The reuse of reclaimed water has been limited by the ecological and human health risks of the residual trace organic pollutants, antibiotic-resistant bacteria and antibiotic resistance genes it often contains. The emerging photoelectrocatalytic technology may be able to break through this bottleneck. Nevertheless, the detailed information about such technology in the reclaiming water treatment has not been fully addressed. A laboratory-scale photoelectrocatalytic purification system was constructed using TiO2 nanotube arrays doped with BiFeO3 nanoparticles as the anode and carbon/polytetra-fluoroethylene as the cathode. The anode was stable with excellent optical and electrochemical properties. About 5.6 log of antibiotic-resistant bacteria were inactivated within 30 min, and 60% of free antibiotic resistance genes were removed within 60 min. The effective removal was mainly due to mutual promotion between photoelectrocatalysis and Fenton reactions which produced abundant active radicals. Low concentrations of effluent organic matter promoted the inactivation. The process was demonstrated in a bench-scale reactor treating 17α-ethinylestradiol and antibiotic-resistant bacteria with high removal rates. The designed photoelectrocatalytic reactor can provide efficient technology for the reuse of reclaiming water.