Proton binding to humic substances. 1. Electrostatic effects
Proton binding to humic substances. 1. Electrostatic effects
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DOI：
10.1021/es00047a004
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发表时间：
1993-09
影响因子：
11.4
通讯作者：
Jo de Wit;W. V. van Riemsdijk;L. Koopal
中科院分区：
文献类型：
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作者：
Jo de Wit;W. V. van Riemsdijk;L. Koopal
离子与腐殖质的结合受化学异质性和腐殖质的可变电荷行为的影响。在本文中，我们主要研究可变电荷效应。为了研究这些影响，分析了11种腐殖质在一系列盐分水平下的酸碱滴定数据。在一阶方法中，有机物分子被处理为一定大小的不透水的圆柱形或球形小颗粒的集合，表面电荷密度随pH和盐浓度的变化而变化。利用这种粒子的双层模型，可以很好地描述静电对质子结合的影响。当腐殖质的密度被用作约束时，球体或圆柱体的半径是模型中唯一可调的参数
Ion binding to humic substances is influenced by the chemical heterogeneity and by the variable charge behavior of the humics. In this paper, we concentrate on the variable charge effects. To study these effects, acid/base titration data of 11 humic substances measured at a series of salt levels are analyzed. In a first-order approach, the organic matter molecules are treated as an ensemble of small rigid and impermeable cylindrical or spherical particles of a certain size and a variable surface charge density depending on pH and salt concentration. With double-layer models for such particles, the electrostatic effects on the proton binding can be described reasonably well. When the density of the humic material is used as a constraint, the radius of the spheres or the cylinders is the only adjustable parameter in the model