Specific cation effects on surface reactions of HgCl2 in clay-water systems
Source abstract
Abstract
The significant complexity of the chemical forms and reactions of HgCl 2 in clay-water systems make elucidating the corresponding interaction mechanisms and activities challenging. The specific ion effect and its mechanisms for HgCl 2 adsorption at charged clay surfaces were investigated in this study. Experimental results showed that (1) at a fixed background concentration, the adsorption capacity and adsorption energy of HgCl 2 on montmorillonite surface decreased in the order Li +> > Na + > K +, and HgCl 2 adsorption exhibited a strong specific cation effect. (2) For the same background cation (Li +, Na + or K +), the adsorption capacity and energy of HgCl 2 decreased as the cation concentration increased. An analysis of the origin of the adsorption energy for HgCl 2 showed that this energy linearly increased with the surface electric field strength of montmorillonite. On the basis of orbital asymmetric hybridization theory, we speculated that specific adsorption of the HgCl 2 molecule occurs via “polarization-induced covalent bonding” adsorption between O (clay surface) and Hg (HgCl 2 ) atoms. The adsorption energy linearly increased with the surface electric field strength in the clay-water system. These findings provide useful information on modifying the physical, chemical and biological activities of HgCl 2 in clay-water systems.
Source: expertdata · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Groundwater and Isotope Geochemistry · Clay minerals and soil interactions · Groundwater flow and contamination studies
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
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