Research on square wave pulsed electrochemical phosphate recovery technology by Pt graphene foam metal electrode

Abstract

Currently, using electrochemical precipitation techniques for phosphate removal and recovery in hydroxyapatite (HAP) or calcium phosphate (CaP) form is widely used, while the high energy consumption of electrochemical precipitation is a major obstacle to its application. In this study, a square wave pulsed electrochemical phosphate precipitation method was developed, which achieved phosphate pollution control and phosphate resource recovery and reuse at the same time. The square wave pulsed electrochemical phosphate recovery system was constructed and a Pt-rGO/CuF electrode was synthesized and evaluated. This result indicated that the Pt-rGO/CuF electrode had the highest electrocatalytic activity, the better electrical conductivity, and the smallest electron transport barrier. Under optimal operation conditions, the phosphate removal efficiency and specific energy consumption of Pt-rGO/CuF were 64.2% and 21.49 kWh kg−1, respectively. The Pt-rGO/CuF electrode demonstrated the best electrochemical precipitation reaction performance. The Pt-rGO/CuF electrode was applied to multiple types of actual wastewater, and the results showed that it has better application prospects in both low (7.75 mg L−1) and high (66 mg L−1) phosphate concentration wastewater, the phosphate removal efficiency was 75.5% and 59.1%, respectively. Compared with traditional chemical precipitation, the electrochemical precipitation method saved $2.88 per kg P and $57.57 per kg P, respectively.