Adsorption behavior of soil fulvic acid on crystal faces of kaolinite and goethite: Described by CD-MUSIC model

文献类型： 外文期刊

第一作者： Chen, Hongfeng

作者： Chen, Hongfeng;Hou, Mingxia;He, Zhouyang;Chen, Hongfeng;Hou, Mingxia;He, Zhouyang;Liang, Yu;Xu, Jinling;Tan, Wenfeng

作者机构：

关键词： Fulvic acid; Kaolinite; Goethite; CD-MUSIC model; Isothermal titration calorimetry; Molar adsorption enthalpy

期刊名称：SCIENCE OF THE TOTAL ENVIRONMENT （ 影响因子：9.8； 五年影响因子：9.6 ）

ISSN： 0048-9697

年卷期： 2023 年 903 卷

页码：

收录情况： SCI

摘要： The interaction between organic matter (OM) and minerals has significant impacts on the mineralization process and rate of OM, and can protect part of organic carbon in soils. In this study, the complex species of fulvic acid (FA) on the surface of minerals (kaolinite and goethite) and the corresponding thermodynamic characteristics were investigated with the CD-MUSIC model and isothermal titration calorimetry. With increasing pH, the adsorption of kaolinite for FA increased at pH < 5.5 and decreased at pH > 5.5, which might be due to the binding of carboxyl groups of FA onto the positively charged sites of O-face and edge-face. However, that of goethite consistently decreased with increasing pH from 3.5 to 9.0 due to an increase in electrostatic repulsion. The fraction of FA was mainly adsorbed on the edge-face and O-face to form inner sphere complexes on kaolinite and outer sphere complexes on goethite. Molar adsorption enthalpies indicated that FA was adsorbed through two site types on kaolinite, while that was one site type on goethite. In addition, the molar enthalpy was more closely associated with inner sphere complexation for kaolinite, while with outer sphere complexation for goethite. The findings shed new light on the adsorption behavior and complexation mechanism of OM on the crystal faces of mineral-water interface.

分类号：

  • 相关文献
作者其他论文 更多>>

微信小程序