铁酸盐
吸附
化学
吸附
溶解有机碳
砷
离子强度
氧烷
环境化学
解吸
稻草
有机质
无机化学
核化学
光谱学
有机化学
水溶液
量子力学
物理
作者
Aminu Darma,Yichen Liu,Xing Xia,Yihao Wang,Lin Jin,Jianjun Yang
出处
期刊:Chemosphere
[Elsevier]
日期:2024-03-01
卷期号:352: 141372-141372
标识
DOI:10.1016/j.chemosphere.2024.141372
摘要
The mobility of arsenic (As) specie in agricultural soils is significantly impacted by the interaction between ferrihydrite (Fh) and dissolved organic carbon (DOC) from returning crop straw. However, additional research is necessary to provide molecular evidence for the interaction of toxic and mobile As (As(III)) specie and crop straw-based organo- Fh coprecipitates (OFCs). This study investigated the As(III) sorption behaviours of OFCs synthesized with maize or rape derived-DOC under various environmental conditions and the primary molecular sorption mechanisms using As K-edge X-ray absorption near edge structure (XANES) spectroscopy. According to our findings, pure Fh adsorbed more As(III) relative to the other two OFCs, and the presence of natural organic matter in the OFCs induced more As(III) adsorption at pH 5.0. Findings from this study indicated a maximum As(III) sorption on Ma (53.71 mg g⁻1) and Ra OFC (52.46 mg g⁻1) at pH 5.0, with a sharp decrease as the pH increased from 5.0 to 8.0. Additionally, As K-edge XANES spectroscopy indicated that ∼30% of adsorbed As(III) on the OFCs undergoes transformation to As(V) at pH 7–8. Functional groups from the DOC, such as O–H, COOH, and CO, contributed to As(III) desorption and its oxidation to As(V), whereas ionic strength analysis revealed inner complexation as the dominant As(III) sorption mechanism on the OFCs. Overall, the results indicate that the interaction of natural organic matter (NOM) with As(III) at higher pH promotes As(III) mobility, which is crucial when evaluating As migration and bioavailability in alkaline agricultural soils.
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