Interactions and Reductive Reactivity in Ternary Mixtures of Fe(II), Goethite, and Phthalic Acid Based on a Combined Experimental and Modeling Approach
Interactions and Reductive Reactivity in Ternary Mixtures of Fe(II), Goethite, and Phthalic Acid Based on a Combined Experimental and Modeling Approach
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基于实验和建模相结合的方法，Fe(II)、针铁矿和邻苯二甲酸三元混合物中的相互作用和还原反应性
DOI：
10.1021/acs.langmuir.9b00538
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发表时间：
2019
期刊：
影响因子：
3.9
通讯作者：
Zhang Huichun
中科院分区：
文献类型：
--
作者：
Huang Jianzhi;Wang Qihuang;Wang Zimeng;Zhang Huichun
有机配体Fe（II）和铁氧化物之间的相互作用在地球化学氧化还原过程中是重要的。邻苯二甲酸（PHA）的还原反应性的Fe（II）与针铁矿的影响进行了研究，采用批量吸附和动力学研究，衰减全反射？傅里叶变换红外光谱（ATR？FTIR）和表面络合建模（SCM）。PHA显著抑制Fe（II）/针铁矿的还原反应性，对氰基硝基苯的准一级还原速率常数（k）可作为定量指标。k值从1.68？0.03 0.338？0.14你好吗1在pH 6.0时，随着PHA浓度从0增加到1000？M.研究了Fe（II）和PHA在针铁矿上的共吸附对抑制效果的影响，探讨了其抑制机理。吸附实验表明，Fe（II）略有增强PHA吸附，而PHA不影响Fe（II）的吸附，这表明抑制不是由于不同的Fe（II）吸附量。ATR？吸附的PHA在三元混合物中的FTIR光谱表明，主要的表面物种是外球物种，与少量的内球复合物形成。SCM结果表明，PHA（L）的存在导致A型三元物种（（？）FeOFe+）2？？L2？）在针铁矿表面，减少了丰富的反应物种（？FeOFeOH）。PHA在针铁矿表面的吸附可能会阻断反应中心，抑制Fe（II）与针铁矿之间的电子转移，从而降低反应活性。总的来说，这些研究结果提供了新的见解表面吸附的Fe（II）的反应机制，这将有助于开发新的技术，现场修复和更准确的风险评估。
The interactions between organic ligands, Fe(II), and iron oxides are important in biogeochemical redox processes. The effect of phthalic acid (PHA) on the reductive reactivity of Fe(II) associated with goethite was examined using batch adsorption and kinetic studies, attenuated total reflectance?Fourier transform infrared spectroscopy (ATR?FTIR), and surface complexation modeling (SCM). PHA significantly inhibited the reductive reactivity of Fe(II)/goethite, as quantified by the pseudo-first-order reduction rate constants (k) ofp-cyanonitrobenzene. Thekvalue decreased from 1.68 ? 0.03 to 0.338 ? 0.14 h?1at pH 6.0 as the PHA concentration increased from 0 to 1000 ?M. The effects of the co-adsorption of Fe(II) and PHA onto goethite were then investigated to study the inhibition mechanism. The adsorption experiments showed that Fe(II) slightly enhanced PHA adsorption, whereas PHA did not affect Fe(II) adsorption, suggesting that the inhibition was not due to different amounts of Fe(II) adsorbed. The ATR?FTIR spectra of the adsorbed PHA in the ternary mixtures demonstrated that the major surface species was outer-sphere species, with minor inner-sphere complexes formed. SCM results showed that the presence of PHA (L) led to the formation of a type A ternary species ((?FeOFe+)2???L2?) on the goethite surface, decreasing the abundance of the reactive species (?FeOFeOH). Moreover, the adsorption of PHA on the surface of goethite might block the reactive sites and inhibit the electron transfer between Fe(II) and goethite, thus decreasing the reactivity. Overall, these findings provided new insights into the reaction mechanisms of surface-adsorbed Fe(II), which will facilitate the development of new technologies for site remediation and more accurate risk assessment.