Degradation of bisphenol AF in water by periodate activation with FeS (mackinawite) and the role of sulfur species in the generation of sulfate radicals

© 2020 Elsevier B.V. The heterogeneous catalyst Mackinawite (FeS) was applied to activate periodate (IO4−) to degrade endocrine disruptors bisphenol AF (BPAF). This study investigated the influence of FeS dosage, periodate dosage, BPAF concentration, initial pH value and inorganic ions on BPAF degradation by FeS/IO4− system. The results showed that the BPAF was effectively degraded by FeS/IO4− system. The acidic pH exhibited higher efficiency in BPAF degradation compared with alkaline and neutral conditions. Furthermore, the BPAF degradation was dramatically promoted in the presence of Cl− and SO42−, whereas CO32− inhibited BPAF degradation. The radical scavenging tests and EPR indicated that singlet oxygen (1O2), superoxide radicals (O2[rad]−) and SO4[rad]− were committed to the degradation of BPAF, among which O2[rad]−, 1O2 were predominant radicals. The separate experiments showed that Fe(Ⅱ) participated in the activation of periodate. Furthermore, the effects of sulfur species (including the S2−, SO32−) on BPAF degradation by FeS/IO4− system were studied. The radical quenching tests suggested that S2− and SO32− were responsible for producing SO4[rad]−. The findings of this study elucidated an approach for the removal of micro-pollutants in the water environment through heterogeneous activation of periodate by FeS