Abstract
Advanced oxidation processes (AOPs) based on sulfate radicals (SO4 center dot-) is being actively investigated as an effective technology for aqueous organic pollutants degradation. In this work, a novel iron-doped graphitic biochar (Fe@GBC), which was synthesized by one-step method using biomass-derived biochar as precursor and potassium ferrate (K2FeO4) as activator, was applied to activate persulfate (PS) for the degradation of 17 beta-estradiol (E2). The characterizations indicated that Fe@GBC was successfully doped with iron particles and possessed a porous graphitic carbon structure. In order to evaluate the applicability of Fe@GBC, the effects of various reaction parameters, such as initial pH, catalyst dosage, PS concentration, as well as the reusability and stability of Fe@GBC were systematically investigated. With the synergistic effect of doped iron particles and porous graphitic carbon structure, Fe@GBC exhibited a high activity for PS activation and great degradation capacity to E2 (almost 100% degradation efficiency within 90 min). Through radical quenching experiments and electron spin resonance (ESR) analysis, it found that both SO4 and OH were responsible for the degradation of E2, while SO4 center dot- played a dominant role. Moreover, Fe@GBC/PS also exhibited good degradation performance in complex water matrices. Overall, the facile one-step synthetic strategy and superior performance make Fe@GBC an alternative catalyst for persulfate activation and aqueous pollutants degradation.