Phosphorus removal by iron–carbon microelectrolysis: A new way to achieve phosphorus recovery

Abstract Iron–carbon microelectrolysis was employed to remove phosphorus in this study. The efficiency, mechanism, influence factors, and feasibility of actual wastewater were investigated. The results showed that iron–carbon microelectrolysis had an excellent phosphorus removal ability. When the initial concentration of PO 4 3 − {\text{PO}}_{4}^{3-} –P was 19.44 mg·L−1, after 120 min reaction time, the remaining PO 4 3 − {\text{PO}}_{4}^{3-} –P in wastewater was 4.65 mg·L−1, and the removal rate was 76.05%. The precipitate formed in the reaction was mainly ferric phosphate (FePO4), which had a high recovery value. There was a linear correlation between initial phosphorus concentrations and phosphorus removal velocity. As to actual wastewater, 88.37 ± 0.44%, 89.78 ± 1.88%, and 94.23 ± 0.16% phosphorus removal rates were achieved in the influent of municipal wastewater treatment plant, effluent of secondary sedimentation tank, and actual high salinity wastewater, respectively, after 120 min reaction time. This study provides a new method for phosphorus removal and recovery from wastewater. Graphical abstract Iron–carbon microelectrolysis has an excellent phosphorus removal ability. The precipitate formed in the reaction was mainly ferric phosphate (FePO4) which had a high recovery value.