Mineralization of aniline in aqueous solution by electrochemical activation of persulfate

• Sulfate radicals are chiefly responsible for mineralization of aniline.
• Sulfate radicals are descended from cathodic reduction of persulfate anions.
• Electrogenerated hydrogen peroxide contributes partially for destruction of aniline.
• Persulfate anions and oxygen are competitively adsorbed on Pt cathode.

Oxidative degradation of aniline in aqueous solution was carried out by coupling electrolysis with persulfate oxidation, in which a synergistic effect occurred. Experiments were performed under a batch-wise mode to evaluate the influence of various operation parameters on the electrolytic behavior, such as acidity of aqueous solution, temperature, electrode potential, persulfate anion concentration and nitrogen/oxygen gas dosage. The aniline pollutants could be almost entirely mineralized by means of electro-activated persulfate oxidation, wherein sulfate radicals were presumed to be principal oxidizing agents. Besides, electrogenerated hydrogen peroxide originated from cathodic reduction of oxygen, supplied chiefly by anodic oxidation of water, would contribute partially for decomposition of aniline. On the whole, the electro-activated persulfate process is a very promising method for treatment of aniline in wastewater.