An electrochemical method through hydroxyl radicals oxidation and deposition of ferric phosphate for hypophosphite recovery

Phosphorus is an essential and irreplaceable element of the ecosystem. In this work, phosphorus has been recovered using an electro-Fenton process. The effects of current intensity, initial pH and H2O2 concentration on the recovery of hypophosphite were investigated. When the current intensity, pH value, and H2O2 concentration were 0.2 A, 3.0 and 90 mM, respectively, hypophosphite was completely oxidized to phosphate. Under such conditions, the phosphate was recovered through the generation of deposition. In order to determine the mechanism of hypophosphite recovery, the morphology and microstructure of the deposition were analyzed using X-ray diffraction, scanning electron microscopy, energy dispersive Xray, high resolution transmission electron microscopy, Fourier transform infrared and X-ray photoelectron spectra. The generation of hydroxyl radicals was confirmed using electron spin resonance technique. This method is a clean process for phosphorus recovery, and does not generate hazardous substances. (C) 2018 Elsevier Inc. All rights reserved.