标题: Insight into the effect of natural organic matter on the photooxidation of arsenite induced by colloidal ferric hydroxides in water

作者: Wu, Y (Wu, Yi); Huang, XY (Huang, Xingyun); Xu, J (Xu, Jing); Huang, WY (Huang, Wenyu); Li, JJ (Li, Jinjun); Mailhot, G (Mailhot, Gilles); Wu, F (Wu, Feng)

来源出版物: WATER RESEARCH 卷: 232 文献号: 119683 DOI: 10.1016/j.watres.2023.119683 提前访问日期: FEB 2023 出版年: APR 1 2023

摘要: Surface complexation of arsenite (As(III)) on colloidal ferric hydroxide (CFH) plays an important role not only in the adsorptive immobilization of As(III) but also in the subsequent oxidation of As(III) to arsenate (As(V)) through light-induced ligand-to-metal charge transfer (LMCT) in water at near-neutral pH. However, the effects of natural organic matter (NOM), especially humic substances (HSs) and low molecular weight carboxylic acids (CAs), on the photochemistry of the CFH-As(III) system have not been sufficiently understood. In this work, the inhibition of photooxidation of As(III) in terms of the observed apparent rate constant (kobs) by six HSs (below 16 mg L-1) and seven CAs (below 2.5 mM) has been observed in water containing 66 mu M Fe(III) and 5 mu M As(III) at pH 7 under simulated solar irradiation consisting of UVA (lambda max 365 nm) and UVB (lambda max 313 nm) lights. Total inhibition factors (T) have been determined from the combined effect of light-screening factor (S) and competitive complexation factor (C), wherein both S and C varied with NOM concentration. S was obtained by determining the absorbance of NOM, and C was obtained by fitting modified Langmuir or Freundlich models to the amount of As(III) desorbed from CFH upon the addition of NOM. Statistical analysis between the experi-mental Texp and the calculated one according to Tcal = S x C showed that the Freundlich model (RMSE for HS 0.1609 and for CA 0.1771) was better than the Langmuir model and was statistically robust (Q2LOO= 0.691 > 0.5). This work provided an estimation method for the effects of NOM on As(III) photooxidation in the presence of CFH as well as a deeper understanding of the transformation of arsenic species in sunlit water.

作者关键词: Colloidal ferric hydroxide; Arsenic species; Natural organic matter; Photooxidation; Light-screening; Competitive complexation

地址: [Wu, Yi; Huang, Xingyun; Li, Jinjun; Wu, Feng] Wuhan Univ, Sch Resources & Environm Sci, Hubei Key Lab Biomass Resource Chem & Environm Bio, Wuhan 430079, Peoples R China.

[Xu, Jing] Wuhan Univ, State Key Lab Water Resources & Hydropower Engn Sc, Wuhan 430072, Peoples R China.

[Huang, Wenyu] Guangxi Univ, Sch Resources Environm & Mat, 100 Daxue East Rd, Nanning 530004, Peoples R China.

[Mailhot, Gilles] Univ Clermont Auvergne, Inst Chim Clermont Ferrand, CNRS, Clermont Auvergne INP, F-63000 Clermont Ferrand, France.

通讯作者地址: Wu, F (通讯作者)，Wuhan Univ, Sch Resources & Environm Sci, Hubei Key Lab Biomass Resource Chem & Environm Bio, Wuhan 430079, Peoples R China.

Xu, J (通讯作者)，Wuhan Univ, State Key Lab Water Resources & Hydropower Engn Sc, Wuhan 430072, Peoples R China.

Huang, WY (通讯作者)，Guangxi Univ, Sch Resources Environm & Mat, 100 Daxue East Rd, Nanning 530004, Peoples R China.

电子邮件地址: jingxu0506@whu.edu.cn; huangwenyu@gxu.edu.cn; fengwu@whu.edu.cn

影响因子：13.4