Ammonium–Potassium–Calcium Exchange on Vermiculite and Hydroxy-aluminum Vermiculite
2002
Evangelou, V. P. | Lumbanraja, J.
Binary and ternary cation-exchange reactions involving NH⁺ ₄, K⁺, and Ca²⁺ on vermiculite and hydroxy-Al interlayered vermiculite (HIV) were investigated. In the case of vermiculite, NH₄-Ca exchange was nearly indistinguishable from the nonpreference isotherm while HIV exhibited preference for NH⁺ ₄ The presence of K⁺ had significant suppressing impact on the apparent NH⁺ ₄ selectivity in NH₄-Ca exchange in HIV most likely because of retardation of Ca²⁺ diffusion in the interlayer. For vermiculite, the presence of K⁺ in the NH₄-Ca system induced apparent high affinity sites for NH⁺ ₄ most likely because of interlayer collapse. The overall study demonstrated that cation-exchange selectivity coefficients in vermiculite and HIV are dependent on number and type of cations present.
显示更多 [+] 显示较少 [-]