Electrochemical Degradation of Ammonia Nitrogen in Mariculture Wastewater Using an Activated Carbon Fiber Composite Anode

Abstract

This work studied the electrochemical degradation of \({\text{NH}}_{4}^{ + }\)-N in mariculture wastewater using an activated carbon fiber composite anode. The effects of the operating parameters and by-products were investigated. Based on the analysis of the removal rate of \({\text{NH}}_{4}^{ + }\)-N, energy consumption, and current efficiency under various operating conditions, the optimal conditions were ascertained as follows: an initial \({\text{NH}}_{4}^{ + }\)-N concentration of 40 mg/L, a current density of 1.4 mA/cm², a pH value of 8, no extra electrolyte, an electrode gap of 17 mm and the degradation rate of \({\text{NH}}_{4}^{ + }\)-N could reach 94% after 90 min of electrolysis. At the same time, the energy consumption needed in the whole reaction process was extremely low and by-product mass generated from the reaction was negligible. In addition, dynamic fitting indicates the degradation procedure was in accordance with the first-order kinetic model.