An Integrated Electrochemical System for Synergistic Cathodic Nitrate Reduction and Anodic Sulfite Oxidation
Bing Cui,
Shizhao Wang,
Xiaofu Guo,
Yingying Zhao,
Sohrab Rohani
Affiliations
Bing Cui
Tianjin Key Laboratory of Chemical Process Safety, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Engineering Research Center of Seawater Utilization of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
Shizhao Wang
Tianjin Key Laboratory of Chemical Process Safety, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Engineering Research Center of Seawater Utilization of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
Xiaofu Guo
Tianjin Key Laboratory of Chemical Process Safety, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Engineering Research Center of Seawater Utilization of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
Yingying Zhao
Tianjin Key Laboratory of Chemical Process Safety, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Engineering Research Center of Seawater Utilization of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
Sohrab Rohani
Department of Chemical and Biochemical Engineering, Western University, London, ON N6A 5B9, Canada
Electrochemical reduction of nitrate has broad application prospects. However, in traditional electrochemical reduction of nitrate, the low value of oxygen produced by the anodic oxygen evolution reaction and the high overpotential limit its application. Seeking a more valuable and faster anodic reaction to form a cathode–anode integrated system with nitrate reaction can effectively accelerate the reaction rate of the cathode and anode, and improve the utilization of electrical energy. Sulfite, as a pollutant after wet desulfurization, has faster reaction kinetics in its oxidation reaction compared to the oxygen evolution reaction. Therefore, this study proposes an integrated cathodic nitrate reduction and anodic sulfite oxidation system. The effect of operating parameters (cathode potential, initial NO3−–N concentration, and initial SO32−–S concentration) on the integrated system was studied. Under the optimal operating parameters, the nitrate reduction rate in the integrated system reached 93.26% within 1 h, and the sulfite oxidation rate reached 94.64%. Compared with the nitrate reduction rate (91.26%) and sulfite oxidation rate (53.33%) in the separate system, the integrated system had a significant synergistic effect. This work provides a reference for solving nitrate and sulfite pollution, and promotes the application and development of electrochemical cathode–anode integrated technology.
