粉煤灰及膨润土对Ni^(2+),Zn^(2+),Cd^(2+),Pb^(2+)的吸附研究

Study on the Adsorption of Ni^(2+)、Zn^(2+)、Cd^(2+)、Pb^(2+) by Fly Ash and Bentonite

研究了粉煤灰和膨润土对溶液中有毒重金属离子Ni^(2+)、Zn^(2+)、Pb^(2+)、Cd^(2+)的吸附能力。动态吸附试验显示,吸附过程是快速的。试验结果表明:粉煤灰对Zn^(2+)的吸附能力和膨润土相当,对Ni^(2+)、Cd^(2+)的吸附能力均大于膨润土。平衡吸附模型说明在高浓度下,Ni^(2+)、Zn^(2+)、Pd^(2+)在粉煤灰中,Ni^(2+)、Pd^(2+)在膨润土中的吸附符合Langmuir模式。试验还表明:随着吸附剂中Ni^(2+)、Zn^(2+)、Pb^(2+)、Cd含量增加,粉煤灰和膨润土对Ni^(2+)、Zn^(2+)、Pb^(2+)、Cd^(2+)的吸附百分率下降。

Adsorption of Ni^(2+), Zn^(2+), Cd^(2+), Pb^(2+) from aqueous solutions by fly ash and bentonite was investigated. The results of kinetic experiments showed that the adsorption process of Ni^(2+), Zn^(2+), Cd^(2+), Pb^(2+) on fly ash and bentonite was rapid. The adsorption data showed that the uptakes of Ni^(2+), Cd^(2+), Pb^(2+) on fly ash was larger than those of bentonite, while the uptakes of Zn^(2+) on fly ash was equal to that of bentonite. Equilibrium modeling of the adsorption showed that at high concentration, the adsorption of Ni^(2+), Zn^(2+), Pb^(2+) on fly ash and the adsorption of Ni^(2+), Cd^(2+) on bentonite were fitted to a Langmuir isotherm. The results also showed that when Ni^(2+), Zn^(2+), Pb^(2+), Cd^(2+) loading in absorbents increased, the percentage of Ni^(2+), Zn^(2+), Cd^(2+), Pb^(2+) adsorption by fly ash and bentonite decreased.