Advanced Degradation of Aniline in Secondary Effluent from a Chemical Industry Park by Cobalt Ferrite/Peracetic Acid System

The residual emerging pollutants in secondary effluent from a chemical industry park contain potential risks for natural waters. Herein, the cobalt ferrite/peracetic acid system was employed to destroy aniline, a typical emerging pollutant, with a reaction rate of 0.0147 min−1 at pH 7.0. Singlet oxygen (1O2) served as the predominant reactive species for aniline degradation, with superoxide radicals (O2−) and organic radicals (R-O) acting in secondary roles. The valence transition between Co(II) and Co(III) on the CoFe2O4 surface played a determining role in the reaction progression. The presence of anions and humic acids with low concentrations had minimal impact on aniline removal. Additionally, the CoFe2O4 catalyst demonstrated excellent recyclability, maintaining a pollutant removal rate above 93% over five consecutive cycles. Lastly, the CoFe2O4/PAA system demonstrates effective treatment of typical pollutants, including phenolic compounds, pesticides, antibiotics, and dyes, achieving removal rates of 77.48% to 99.99%. Furthermore, it significantly enhances water quality in the treatment of actual secondary effluent, offering a novel theoretical foundation and practical insights for applying this catalytic system in wastewater treatment.