Activation of Peroxymonosulfate by P-Doped Cow Manure Biochar for Enhancing Degradation of 17β-Estradiol

Abstract

Sulfate radical-based advanced oxidation processes exhibit great potential for the degradation of organic pollutants. In this study, P-doped biochar (PBC500) was successfully synthesized by the pyrolysis of H3PO4-impregnated cow manure waste and was employed to activate peroxymonosulfate (PMS) for the elimination of 17β-estradiol (E2). The characterization results showed that the surface area, defective structure, and functional groups (C=O and phosphorus-containing groups) of biochar increased after H3PO4 modification. PBC500 exhibited high PMS activation activity and excellent E2 degradation capacity; 97.91% of 3 mg/L E2 can be removed within 90 min using 0.2 g/L PBC500 and 1 mM PMS. Based on the quenching experiments and X-ray photoelectron spectroscopy (XPS) analysis, defective structures, C=O, and P-C groups on biochar act as active sites to promote the catalytic oxidation of E2 by generating O2− and 1O2. In addition, PBC500 displayed excellent reusability, achieving 65.15% E2 degradation after three reuse cycles. Overall, this study presented a new technique that supports a high efficiency, environmentally friendly, and low cost treatment method for E2 wastewater and simultaneously provided a new option for the resource utilization of livestock waste.