液固体系NH_4^+和PO_4^(3-)离子吸附反应的Gibbs自由能与化学势变  

Changes in Gibbs free energy and chemical potential of NH_4^+ and PO_4^(3-) ion adsorption reactions in liquid/solid systems

作　　者：李莲芳[1] 吴晓芙[1] 黄中子[2] 马群[1] 

机构地区：[1]中南林业科技大学环境科学与工程研究所,湖南长沙410004 [2]上海工程技术大学,上海201620

出　　处：《中南林业科技大学学报》2011年第3期111-117,共7页Journal of Central South University of Forestry & Technology

基　　金：国家环保部项目(200909066);国家林业局项目(2010-43);湖南省教育厅重点学科与重点实验室项目

摘　　要：选用天然砩石和红壤作为吸附剂,NH4+和PO43-离子作为测试离子进行了水溶液体系平衡离子吸附试验。试验结果证明建立的Gibbs自由能变与化学势变方程可应用于描述阳离子与阴离子的吸附反应。反应体系Gibbs自由能变在所有检测的点上均为负值,说明在本试验条件下测试的吸附反应为自发反应。吸附反应化学势变具有极限的特性为确定吸附容量p值提供了有效的方法,由本试验确定的天然砩石吸附NH4+离子和红壤吸附PO43-离子的p值分别为2.75和2.20 mg/g。Experiments of equilibrium adsorption of NH4^＋ and PO4^3- ions from aqueous solution onto,respectively,natural zeolite and red soil have been conducted to test the applicability of the developed equations for calculating the change in Gibbs free energy and chemical potential of adsorption reactions.The obtained results indicate that the presented equations can be well used to describe the adsorption reactions for both the tested cationic and anionic ions.The calculated values of the change in the Gibbs free energy were negative at all tested points,which confirms the spontaneous nature of the conducted adsorption reactions under the tested conditions.The nature of the presence of an upper limit of the change in chemical potential of the adsorption reaction provides an effective way for determination of the adsorption capacity of the adsorbent（p）.The p value for the natural zeolite sample to adsorb NH4^＋ and that for the red soil to adsorb PO4^3- ions was found to be 2.75 and 2.20mg/g,respectively.

关 键 词：液固吸附体系 Gibbs自由能 化学势 吸附容量 NH4+ PO43- 天然砩石 红壤 

分 类 号：X131.2[环境科学与工程—环境科学]