TY - JOUR
T1 - Overlooked Role of Fe(IV) and Fe(V) in Organic Contaminant Oxidation by Fe(VI)
AU - Zhu, Jiahui
AU - Yu, Fulu
AU - Meng, Jiaoran
AU - Shao, Binbin
AU - Dong, Hongyu
AU - Chu, Wenhai
AU - Cao, Tongcheng
AU - Wei, Guangfeng
AU - Wang, Hejia
AU - Guan, Xiaohong
N1 - Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/8/4
Y1 - 2020/8/4
N2 - Fe(VI) has received increasing attention since it can decompose a wide range of trace organic contaminants (TrOCs) in water treatment. However, the role of short-lived Fe(IV) and Fe(V) in TrOC decomposition by Fe(VI) has been overlooked. Using methyl phenyl sulfoxide (PMSO), carbamazepine, and caffeine as probe TrOCs, we observed that the apparent second-order rate constants (kapp) between TrOCs and Fe(VI) determined with the initial kinetics data were strongly dependent on the initial molar ratios of TrOCs to Fe(VI). Furthermore, the kapp value increases gradually as the reaction proceeds. Several lines of evidence suggested that these phenomena were ascribed to the accumulation of Fe(IV) and Fe(V) arising from Fe(VI) decay. Kinetic models were built and employed to simulate the kinetics of Fe(VI) self-decay and the kinetics of PMSO degradation by Fe(VI). The modeling results revealed that PMSO was mainly degraded by Fe(IV) and Fe(V) rather than by Fe(VI) per se and Fe(V) played a dominant role, which was also supported by the density functional theory calculation results. Given that Fe(IV) and Fe(V) have much greater oxidizing reactivity than Fe(VI), this work urges the development of Fe(V)/Fe(IV)-based oxidation technology for efficient degradation of TrOCs.
AB - Fe(VI) has received increasing attention since it can decompose a wide range of trace organic contaminants (TrOCs) in water treatment. However, the role of short-lived Fe(IV) and Fe(V) in TrOC decomposition by Fe(VI) has been overlooked. Using methyl phenyl sulfoxide (PMSO), carbamazepine, and caffeine as probe TrOCs, we observed that the apparent second-order rate constants (kapp) between TrOCs and Fe(VI) determined with the initial kinetics data were strongly dependent on the initial molar ratios of TrOCs to Fe(VI). Furthermore, the kapp value increases gradually as the reaction proceeds. Several lines of evidence suggested that these phenomena were ascribed to the accumulation of Fe(IV) and Fe(V) arising from Fe(VI) decay. Kinetic models were built and employed to simulate the kinetics of Fe(VI) self-decay and the kinetics of PMSO degradation by Fe(VI). The modeling results revealed that PMSO was mainly degraded by Fe(IV) and Fe(V) rather than by Fe(VI) per se and Fe(V) played a dominant role, which was also supported by the density functional theory calculation results. Given that Fe(IV) and Fe(V) have much greater oxidizing reactivity than Fe(VI), this work urges the development of Fe(V)/Fe(IV)-based oxidation technology for efficient degradation of TrOCs.
UR - https://www.scopus.com/pages/publications/85089612464
U2 - 10.1021/acs.est.0c03212
DO - 10.1021/acs.est.0c03212
M3 - 文章
C2 - 32644801
AN - SCOPUS:85089612464
SN - 0013-936X
VL - 54
SP - 9702
EP - 9710
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 15
ER -