Cow Manure Biochar for Activation of Peroxymonosulfate to Degrade 17Β-Estradiol: Performance and Mechanism

Estrogens are widely detected in the environment and can strongly disrupt the endocrine systems of humans in extremely minute concentrations. Therefore, it is imperative to address possible 17β-estradiol (17β-E2) pollution and explore resourceful utilization methods from cow manure, which contains estrogen. In this study, cow manure biochar (CBC) was successfully prepared and used for the activation of peroxymonosulfate (PMS), attaining a 17β-E2 degradation rate exceeding 90 % within a mere 10 min. Optimal degradation performance was achieved at 2 mg/L 17β-E2 concentration, 2 mM PMS concentration, and 0.2 g/L CBC concentration. Furthermore, the influence of biochar-activated PMS on estrogen degradation was thoroughly explored under various environmental factors. The key reactive oxygen species were identified as O2– and 1O2 by conducting quenching experiments and delayed experiments. This study elucidated the occurrence of direct electron conduction and the generation of reactive oxygen species to degrade 17β-E2. Furthermore, the phenol group on the benzene ring and the hydroxyl group on the cyclopentane in 17β-E2 as the susceptible reaction sites during the degradation process were predicted using density functional theory (DFT). This study presents promising opportunities for the resourceful utilization of cattle manure and the mitigation of environmental pollution by endocrine disruptors.