Reactions of nitrite with goethite and surface Fe(II)-goethite complexes

被引：0

作者：

Dhakal, P. ^{[1
]}

Coyne, M.S. ^{[1
]}

McNear, D.H. ^{[1
]}

Wendroth, O.O. ^{[1
]}

Vandiviere, M.M. ^{[1
]}

D'Angelo, E.M. ^{[1
]}

Matocha, C.J. ^{[1
]}

机构：

[1] Department of Plant and Soil Sciences, University of Kentucky, Lexington,KY,40546, United States

来源：

Science of the Total Environment | 2021年 / 782卷

关键词：

Chemical reduction - Chemodenitrification - Goethite - Infrared: spectroscopy - Nitrite - Nitrite removal - Nitrous oxide - NO $-2$ - Redox transformations - Surface Fe;

D O I：

暂无

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学科分类号：

摘要：

Chemodenitrification-the abiotic (chemical) reduction of nitrite (NO2−) by iron (II)-plays an important role in nitrogen cycling due in part to this process serving as a source of nitrous oxide (N2O). Questions remain about the fate of NO2− in the presence of mineral surfaces formed during chemodenitrification, such as iron(III) (hydr) oxides, particularly relative to dissolved iron(II). In this study, stirred-batch kinetic experiments were conducted under anoxic conditions (to mimic iron(III)-reducing conditions) from pH 5.5–8 to investigate NO2− reactivity with goethite (FeOOH(s)) and Fe(II)-treated goethite using wet chemical and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. Nitrite removal from solution by goethite was more rapid at pH 5.5 than at pH 7 and 8. Spectral changes upon nitrite adsorption imply an inner-sphere surface interaction (monodentate and bidentate) at pH 5.5 based on ATR-FTIR spectra of the nitrite-goethite interface over time. In iron(II)-amended experiments at pH 5.5 with high aqueous Fe(II) in equilibrium with goethite, nitrous oxide was generated, indicating that nitrite removal involved a combination of sorption and reduction processes. The presence of a surface complex resembling protonated nitrite (HONO) with an IR peak near ~1258 cm−1 was observed in goethite-only and iron(II)-goethite experiments, with a greater abundance of this species observed in the latter treatment. These results might help explain gaseous losses of nitrogen where nitrite and iron(II)/goethite coexist, with implications for nutrient cycling and release of atmospheric air pollutants. © 2021 Elsevier B.V.

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