摘要
自制活性炭电极,并用于不同含量的KCl、CdCl2、CuCl2和FeCl3溶液电吸附行为研究。结果表明,多价离子吸附速率和吸附容量大,但脱附率低;单价离子吸附速率和吸附容量小,但脱附率高;同价态离子,离子半径越小的离子越容易被吸附。各离子在活性炭电极上的电吸附,均符合2级动力学方程,速率常数K与电压U关系符合指数函数,在相同电压下,吸附速率常数K(Fe3+)>K(Cu2+)>K(Cd2+)>K(K+);吸附等温线均符合Langmuir等温式,活性炭电极的最大吸附量qm与操作电压U线性相关,在相同电压下,活性炭电极的最大吸附容量qm(Fe3+)>qm(Cu2+)>qm(Cd2+)>qm(K+)。循环伏安和交流阻抗进一步验证了电吸附试验结果。
In order to study the behavior of different cations, activated carbon electrodes were prepared and several electrosorption experiments were conducted in KCI, CdCl2, CuCl2, FeCl3 solution. The adsorption/desorption performance of different cations were evaluated and the corresponding adsorption dynamics equations and corresponding adsorption isotherm equations were discussed, and cyclic voltammetry and ac impedance were employed to analyse the adsorption of different cations on the activated carbon electrodes. The results showed that： The multivalent cations had a higher adsorption rate and adsorption capacity with a lower desorption ratio; the mono-ion was opposite. For cations with same charge, the one with smaller radius would be more easily adsorpted. The electrosorption of cations on activated carbon electrodes conformed to the secondary dynamic equation, and the relationship between the rate constant K and the potential conformed to the exponential function. Under the same potential the rate constant order of different cations was K（Fe^3＋）〉K（Cu^2＋）〉K（Cd^2＋）〉K（K^＋）. The adsorption isotherm equations all conformed to the Langrnuir isothermal. The largest activated carbon adsorption capacity qm had linear correlation with operating potential. Under the same potential the largest adsorption capacity order was qm（Fe^3＋）〉qm（Cu^2＋）〉qm（Cd^2＋）〉qm（K^＋）. The cyclic voltammetry and ac impedance further verified the results of electrsorption experimenis.
出处
《水处理技术》
CAS
CSCD
北大核心
2010年第4期32-35,40,共5页
Technology of Water Treatment
关键词
活性炭
电吸附
阳离子
activated carbon
electrosorption
cations
