标题: Anoxic oxidation of As(III) during Fe(II)-induced goethite recrystallization: Evidence and importance of Fe(IV) intermediate

作者: Hua, J (Hua, Jian); Fei, YH (Fei, Ying-heng); Feng, CH (Feng, Chunhua); Liu, CS (Liu, Chengshuai); Liang, S (Liang, Sheng); Wang, SL (Wang, Shan-Li); Wu, F (Wu, Feng)

来源出版物: JOURNAL OF HAZARDOUS MATERIALS卷:421

DOI: 10.1016/j.jhazmat.2021.126806出版年: JAN 5 2022

摘要: Under anoxic conditions, aqueous Fe(II) (Fe(II)aq)-induced recrystallization of iron (oxyhydr)oxides changes the speciation and geochemical cycle of trace elements in environments. Oxidation of trace element, i.e., As(III), driven by Fe(II)aq-iron (oxyhydr)oxides interactions under anoxic condition was observed previously, but the oxidative species and involved mechanisms are remained unknown. In the present study, we explored the formed oxidative intermediates during Fe(II)aq-induced recrystallization of goethite under anoxic conditions. The methyl phenyl sulfoxide-based probe experiment suggested the featured oxidation by Fe(IV) species in Fe(II)aq-goethite system. Both the Mo center dot ssbauer spectra and X-ray absorption near edge structure spectroscopic evidenced the generation and quenching of Fe(IV) intermediate. It was proved that the interfacial electron exchange between Fe(II)aq and Fe(III) of goethite initiated the generation of Fe(IV). After transferring electrons to goethite, Fe(II)aq was transformed to labile Fe(III), which was then transformed to Fe(IV) via a proton-coupled electron transfer process. This highly reactive transient Fe(IV) could quickly react with reductive species, i.e. Fe(II) or As(III). Considering the ubiquitous occurrence of Fe(II)-iron (oxyhydr)oxides reactions under anoxic conditions, our findings are expected to provide new insight into the anoxic oxidative transformation processes of matters in non-surface environments on earth.

作者关键词: Anoxic oxidation; Electron and atom exchange; Fe(IV) intermediate; Proton-coupled electron transfer; Stable Fe isotope

地址: [Hua, Jian; Wu, Feng] Wuhan Univ, Sch Resources & Environm Sci, Wuhan 430079, Peoples R China.

[Hua, Jian; Liu, Chengshuai] Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550081, Peoples R China.

[Fei, Ying-heng] Guangzhou Univ, Sch Environm Sci & Engn, Guangzhou 510006, Peoples R China.

[Feng, Chunhua; Liang, Sheng] South China Univ Technol, Sch Environm & Energy, Guangzhou 510006, Peoples R China.

[Liu, Chengshuai] Guangdong Acad Sci, Guangdong Inst Ecoenvironm Sci & Technol, Guangzhou 510650, Peoples R China.

[Wang, Shan-Li] Natl Taiwan Univ, Dept Agr Chem, Taipei 10617, Taiwan.

通讯作者地址: Liu, CS (通讯作者)，Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550081, Peoples R China.

电子邮件地址: liuchengshuai@vip.gyig.ac.cn

影响因子：10.588