Enhanced Removal of Antimony and Aniline from Wastewater by Combining Electrocoagulation with Peroxymonosulfate

Antimony (Sb) and aniline are typical pollutants in printing and dyeing wastewater. This study explored the simultaneous removal of Sb and aniline by combining electrocoagulation (EC) with peroxymonosulfate (PMS) and systematically studied the underlying reaction mechanisms. The results showed that at the optimal conditions of aluminum and iron electrodes, current density 20 A/m², PMS 2.5 mM, NaCl 0.1 mol/L, and initial pH 8.0, 80% of the two contaminants were removed in the first 5 min. When the concentration of PMS is sufficient, Sb and aniline can be completely removed after 20 minutes of reaction. The removal efficiency is higher than exclusively using PMS or EC. It was found that PMS facilitated the formation of iron flocs, leading to the improved removal of Sb. In addition, the results of electron paramagnetic resonance (EPR) analysis and quenching experiments demonstrated that PMS promoted the generation of ¹O₂, •OH, and SO₄^•−, which accelerated the oxidation of aniline. Overall, this study demonstrated that the EC/PMS system could remove heavy metals and organic substance simultaneously from water. The results are of great significance to the application of wastewater treatment.