K^+浓度对潮土和褐土钾吸附动力学的影响  

K^+ ADSORPTION KINETICS OF FLUVO-AQUIC AND CINNAMON SOIL UNDER DIFFERENT K^+ CONCENTRATIONS

作　　者：龙怀玉[1] 李韵珠[2] 蒋以超[2] 

机构地区：[1]中国农业科学院土壤肥料研究所,北京100081 [2]中国农业大学资源和环境学院,北京100094

出　　处：《土壤学报》2001年第2期226-234,共9页Acta Pedologica Sinica

基　　金：龙怀玉在中国农业大学土壤系完成的博士论文的部分内容;国家自然科学基金"华北平原节水农业应用基础研究"(49391600)资助

摘　　要：研究了潮土、褐土在五种Ｋ十浓度下吸附Ｋ＋的动力学，结果表明：不同浓度下的表观吸附过程均可用一级反应动力学方程描述；表观吸附速率常数ｋａ及其与表观平衡吸附量ｑ∞的乘积与淋洗液Ｋ＋浓度之间均表现为极显著的直线正相关；表观平衡吸附量与浓度之间的关系符合Ｌａｎｇｍｕｉｒ或Ｆｒｅｕｎｄｌｉｃｈ等温吸附公式。依据试验结果对土壤钾吸附动力学进行了讨论与推导，找到四个动力学参数ｎ、ｋ１、Ｋ２、ｑｍａｘ，通过这些动力学参数可以计算表观吸附动力学参数Ｋａ、ｑ∞和平衡常数Ｋ及吸附过程中的自由能变△Ｇ，在一定条件下，还可以用来判断等温吸附的类型、估算等温吸附参数。The K+ adsorption kinetics of Fluvo-aquic soil and Cinnamon soil under different K+ concentration were studied. The results showed: (1) adsorption rate decreased with the increase in adsorption, and the relationship between them could be described with significant linear regressive equations, indicating the adsorption were fit for the first order equations; (2) the apparent adsorption rate constant ka and the product of ka multiplied by the apparent equilibrium adsorption q∞ were significantly linearly correlated to K+ concentration C: (3) the relationship between q∞ and C conformed to Langmuir and Freundlich isothermal adsorption equations. Based on those results the K+ adsorption kinetics was deduced, leading to four kinetics parameters n、 k1、K2、qmax independent of C. With n、 k1、K2、qmax the apparent parameters and free energy change △G of adsorption could be worked out, and under certain conditions n、 k1、K2、qmax could also be used to judge isothermal adsorption and reckon its parameters.

关 键 词：钾浓度 吸附动力学 等温吸附 潮土 褐土 钾吸附 

分 类 号：S153[农业科学—土壤学]