Disposal of phenol waste water by CoFe2O4&AA activated peroxydisulfate

The pathological changes caused by phenolic wastewater discharged from various industries has attracted extensive attention in recent years. In this study, a novel sulfate-radical-based advanced oxidation process (SR-AOP) was used to dispose the target pollutant – phenols. Firstly, a solid-phase active catalyst – cobalt ferrite (CoFe2O4) was prepared from a sol–gel process with the innovative addition of ascorbic acid (AA). Then the original AOP was modified by using a novel CoFe2O4/AA/PDS combined system (PDS: peroxydisulfate).CoFe2O4 was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and H-M magnetic hysteresis loops. The influence factors on degradation in the new system were determined. It was found the activated PDS (S2O82−) generated a strong oxidizer sulfate radical (SO4·) and the phenol removal process basically obeyed the pseudo-first-order kinetics. The phenol degradation rate maximized to 98.00% under the following optimal conditions: CoFe2O4 preparation temperature at 500°C, initial phenol concentration at 50.00 mg/L, PDS dosage of 4.20 mM, CoFe2O4 dosage of 1.00 gL−1, and AA dosage of 0.42 mM. The new system had a high phenol degradation performance in a wide range of pH 3-7.The easy oxidization of metal ion solutions in a homogeneous system and the application limitation of pH range were well solved. The synergistic effect of the novel CoFe2O4/AA/PDS combined system on activated PDS was verified. The separation and reuse of CoFe2O4 were improved owing to its magnetism. These findings will underlie the practical application of CoFe2O4 into disposal of phenol waste water.