光致Fenton氧化-混凝耦合工艺的镍皂废水 有机物去除特性

A nickel soap wastewater-based photocatalytic Fenton oxidation-coagulation coupling process was developed to enhance the removal efficiency of organic pollutants and overcome the limitations of conventional Fenton processes. The process was combined the coagulation effect of iron salts with the ligand-to-metal charge transfer(LMCT) process to achieve efficient and continuous removal of organic contaminants. The removal efficiency and influencing factors of the process were investigated, and the H₂O₂ decomposition utilization rate was calculated to determine the proportion of four H₂O₂ activation pathways. Electron paramagnetic resonance(EPR) and chemical probe techniques were employed to identify and quantify the free radicals in each system. Finally, the supernatant and flocs formed in the process were characterized by X-ray photoelectron spectroscopy(XPS). The results showed that with iron salt dosage of 10 mmol/L, H₂O₂ dosage of 80 mmol/L, and initial pH of 3, the process achieved COD removal rate of 75.9% within 60 minutes, with H₂O₂ utilization rate as high as 99%, significantly outperforming the removal efficiency of conventional Fenton process. Additionally, the process efficiently reduced Fe³⁺ to Fe²⁺ through the LMCT cycle induced by visible light, continuously activating H₂O₂ to generate a large number of hydroxyl radicals(·OH), which further removed oxidation intermediates through the coagulation effect of iron salts. A comparison with peroxymonosulfate(PMS) and persulfate(PDS) revealed that the photocatalytic Fenton oxidation-coagulation coupling process had a broad applicability, demonstrating its potential in treating high COD and high salinity organic wastewater, which provided a new technical approach for the effective treatment of industrial wastewater.