Treatment of Nitrobenzene-Loaded Wastewater via Electrochemical Heterogeneous Catalytic Processes

An electrochemical heterogeneous catalytic process was applied to remove nitrobenzene from wastewater. Three key factors, including applied potential, supporting electrolyte concentration, and pH, were tested for their effects on the nitrobenzene removal. The optimal condition was determined as an applied potential of 40 V, Na₂SO₄ concentration of 500 mg L^-1 and a pH of 10. Under the optimal condition, the nitrobenzene and COD removals were 73.7% and 32.9%, respectively. In addition, the apparent kinetics of nitrobenzene removal could be expressed as a pseudo first-order reaction. A possible mechanism of nitrobenzene degradation was proposed based on the intermediate products.