The Primary Factors Affecting the Efficiency of Two-Chamber Electrochemical Systems in Treating Phosphate-Containing Wastewater

Abstract

The electrochemical crystallization method for recovering phosphorus resources from industrial wastewater has gained widespread attention due to its high efficiency and low cost. However, the strong corrosiveness of the industrial wastewater can affect the components of the electrochemical system, decreasing its performance. This study examines the stability of the two-chamber electrochemical (TCE) system and the service life of its components while recovering phosphate from the chemical polishing (CP) wastewater. An investigation of the phosphate removal rate and power output through the replacement of the system’s components was performed. The results indicated that the TCE system could effectively treat the CP wastewater, achieving a removal rate of up to 99% for phosphate and aluminum ions with a maximum power output of 1.09 mW. However, the strong corrosiveness of the CP wastewater decreased the performance of the TCE system, requiring component replacement every 20 days. The yield of ferrous ions was not the primary limiting factor for phosphate removal due to the effects of both electrochemistry and self-corrosion, but the excessive ferrous ions influenced the solution pH. The solution pH controlled the Fe(II)/P molar ratio in step 1, which subsequently influenced the purity of the vivianite in step 2. The closed circuit promoted an increase in the pH of wastewater. This method not only recovers phosphorus resources but also generates electrical energy, offering a new approach for resource recovery in industrial wastewater, aligning with the national sustainable development goals.