累托石对钾离子的吸附/解吸动力学研究

以KCl为钾源，研究了湖北钟祥累托石对钾离子的吸附和解吸动力学行为。结果表明：累托石对K⁺的吸附速度很快，吸附动力学过程符合ExpAssoc模型，吸附平衡时间约为30 min；累托石对K⁺的等温吸附过程符合Langmuir等温吸附模式，饱和吸附量为14.588 mg/g；pH=5的HCl溶液对K+的解吸量最小，Ca²⁺+Mg²⁺混合溶液对K⁺的解吸量随着Ca²⁺+Mg²⁺浓度的提高而提高，Elovich模型和指数模型（双常数模型）可较好地描述 K⁺的解吸过程；累托石是较好的钾元素缓释载体，环境中Ca²⁺+Mg²⁺浓度越低，缓释效果越好。

Research of Dynamic Adsorption/Desorption of Rectorite to Potassium Ion

By using KCl as potassium source，the dynamic adsorption and desorption property of Zhongxiang rectorite in Hubei Province to Potassium ion was studied.The results indicated that the adsorption of K⁺ on rectorite was fast，and the process of the dynamic adsorption matched the ExpAssoc model with the equilibrium adsorption time for 30 min.And the adsorption fit Langmuir isotherm adsorption model with the adsorption quantity of 14.588 mg/g as well.The desorption quantity of K⁺ by HCl solution in pH 5 was minimum and the desorption quantity by Ca²⁺+Mg²⁺ increased with the increasing of (Ca²⁺+Mg²⁺) concentration.The desorption fits Elovich equation and exponential equation(Double constant equation) well.Because rectorite is a good potassic fertilizer sustained-release carrier，so the lower concentration of (Ca²⁺+ Mg²⁺) in the soil is，the better effect of sustained-release is.