Proton and Copper Binding to Humic Acids Analyzed by XAFS Spectroscopy and Isothermal Titration Calorimetry | |
Xu, Jinling1,2 | |
刊名 | Environmental Science & Technology
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2018 | |
卷号 | 52期号:7页码:4099-4107 |
DOI | 10.1021/acs.est.7b06281 |
英文摘要 | Proton and copper (Cu) binding to soil and lignite-based humic acid (HA) was investigated by combining X-ray absorption fine structure (XAFS) spectroscopy, isothermal titration calorimetry (ITC), and nonideal-competitive-adsorption (NICA) modeling. NICA model calculations and XAFS results showed that bidentate and monodentate complexation occurred for Cu binding to HA. The site-type-specific thermodynamic parameters obtained by combining ITC measurements and NICA calculations revealed that copper binding to deprotonated carboxylic-type sites was entropically driven and that to deprotonated phenolic-type sites was driven by entropy and enthalpy. Copper binding to HA largely depended on the site-type and coordination environment, but the thermodynamic binding mechanisms for Cu binding to the specific site-types were similar for the different HAs studied. By comparing the site-type-specific thermodynamic parameters of HA–Cu complexation with those of low molar mass organic acids, the Cu coordination could be further specified. Bidentate carboxylic–Cu complexes made the dominating contributions to Cu binding to HA. The present study not only yields molecular-scale mechanisms of ion binding to carboxylic- and phenolic-type sites of HA but also provides the new insight that the universal nature of site-type-specific thermodynamic data enables quantitative estimation of the binding structures of heavy metal ions to humic substances. |
URL标识 | 查看原文 |
语种 | 英语 |
内容类型 | 期刊论文 |
源URL | [http://ir.iswc.ac.cn/handle/361005/8831] ![]() |
专题 | 水保所2018届毕业生论文 |
作者单位 | 1.University of Chinese Academy of Sciences, Beijing, 100049, P. R. China 2.State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and the Ministry of Water Resources, Yangling, Shaanxi Province 712100, P. R. China |
推荐引用方式 GB/T 7714 | Xu, Jinling. Proton and Copper Binding to Humic Acids Analyzed by XAFS Spectroscopy and Isothermal Titration Calorimetry[J]. Environmental Science & Technology,2018,52(7):4099-4107. |
APA | Xu, Jinling.(2018).Proton and Copper Binding to Humic Acids Analyzed by XAFS Spectroscopy and Isothermal Titration Calorimetry.Environmental Science & Technology,52(7),4099-4107. |
MLA | Xu, Jinling."Proton and Copper Binding to Humic Acids Analyzed by XAFS Spectroscopy and Isothermal Titration Calorimetry".Environmental Science & Technology 52.7(2018):4099-4107. |
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