Exchangeable cations (Cu2+, Zn2+) effects on unfrozen water content in clay-water system using 1H NMR method

The H-1-NMR method has been applied to study unfrozen water content in three model montmorillonites in their natural state and after ion exchange for Cu2+ or Zn2+ cations, being toxic for the environment. The research indicates statistically significant effect of exchangeable cation type on the variation in unfrozen water content. The proposed empirical models are able to predict the unfrozen water content after the exchange for the Cu2+ or Zn2+ ions using the clay fraction as a soil parameter much better than some of the known models based on the specific surface area and, at the same time, on the specific surface area and the clay fraction.

Automated summary

The study found that the type of exchangeable cations significantly affects the unfrozen water content in montmorillonite, and proposed empirical models that can predict the unfrozen water content after ion exchange.