Preparation of Fe/Mn/Cu/tourmaline Fenton-like catalyst and the mechanism for degrading organic phosphorous scale inhibitors in simulated electroplating wastewater

Abstract

In Fenton-like reaction process, stable and efficient catalysts are very important to improve the degradation efficiency of refractory organic pollutants. In this study, Fe/Mn/Cu tourmaline Fenton-like catalyst were synthesized using an impregnation calcination method, and hydroxyethylene diphosphate (HEDP) in simulated electroplating wastewater was degraded using the synthesized catalyst. The physicochemical properties of the synthesized catalysts were analyzed by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller nitrogen adsorption desorption. The effects of parameters such as pH, catalyst addition, hydrogen peroxide concentration, and reaction temperature on the efficiency of HEDP removal were investigated using a single-factor method and central composite response surface methodology. Under optimal conditions, the conversion efficiency of organic to inorganic phosphorous was 86.79 %. The electron paramagnetic resonance results indicated that active oxygen species, such as hydroxyl and superoxide radicals, in the reaction system are the primary determinants of the efficient degradation of HEDP. Subsequently, the recovery effects of different coagulants (iron chloride and calcium chloride) on phosphate after simulated wastewater degradation were investigated. Iron-based coagulants showed better recovery effects (pH 7.5, 93.71 %). These results show that Fe/Mn/Cu/tourmaline Fenton-like catalyst have good reusability, high catalytic activity, and broad application prospects in wastewater treatment.