Fast degradation of florfenicol in SiC-Fe0 Fenton-like process: The overlooked role of atomic H* in peroxymonosulfate activation

Herein, the SiC-Fe 0 powders were mechanically synthesized and employed for activation of peroxymonosulfate (PMS) to remove florfenicol (FLO). Compared to Fe 0 /PMS system, up to a 3.97-fold increase in degradation rates of 20 mg/L FLO was observed by 25% ( w / w ) SiC-Fe 0 /PMS system in 5 mins, which could be attributed to the increased specific surface area and electron transfer rate of SiC-Fe 0 . Both the radical and non-radical processes were involved in the SiC-Fe 0 /PMS system, in which 1 O 2 and • O 2 − played the dominant role in the FLO degradation and SO 4 •− as well as • OH also participated in the system. ROSs investigation suggested that 1 O 2 , • O 2 − , SO 4 •− were mainly generated from the decomposition of PMS and • OH was mainly derived from the ZVI (or Fe 2+ )-catalyzed activation of O 2 . Meanwhile, H* has a nonnegligible role in PMS activation or the transformation of iron species. Five intermediates of FLO in SiC-Fe 0 /PMS system were identified and a significant removal of the overall toxicity was observed. The degradation pathways of FLO were proposed to be hydrolysis, hydroxylation and dechlorination. Besides, this SiC-Fe 0 /PMS system shows effective removal rate for 2-chlorophenol, acetaminophen, tetrabromobisphenol A and carbamazepine, and the FLO-polluted surface water and artificial wastewater. Overall, this study demonstrated that SiC-Fe 0 was promising in practical application and provided new insights into the generation mechanisms of ROSs in the ZVI/PMS system.