铵饱和沸石对几种重金属离子的吸附解吸特性影响研究

通过室内分析的方法比较了天然沸石及铵饱和沸石对重金属离子Cd2+、Zn2+、Cu2+、Pb2+的吸附及解吸特性。研究结果表明:铵饱和沸石对4种重金属离子的吸附量大小顺序依次为Pb>Cu>Zn>Cd,而解吸量和解吸率的大小顺序为Cd>Zn>Cu>Pb,这主要与四种金属离子的水合离子半径和水合能密切相关。与天然沸石相比,铵饱和沸石一方面增加了对4种重金属离子的吸附,同时又降低了其解吸率。原因是铵饱和沸石的阳离子交换量和比表面积有所增加,同时铵饱和沸石的孔穴和通道也较天然沸石更加均一和畅通。因此,铵饱和沸石在农业生产实践中,特别是土壤污染治理方面具有广阔的应用前景。

Adsorption and Desorption of Heavy Metal Ions by Ammonium Saturated Zeolite

Influence of natural zeolite and ammonium saturated zeolite on the adsorption and desorption of Cd2 ,Zn2 ,Cu2 and Pb2 was studied.Results showed that the maximum adsorption amounts of the four heavy metal ions decreased in the order of Pb2 >Cu2 >Zn2 >Cd2 on ammonium saturated zeolite,whereas the desorption amount and desorption ratio were in the order of Cd2 >Zn2 >Cu2 >Pb2 .The ammonium saturated zeolite not only enhanced the adsorption capacity of Cd2 ,Zn2 ,Cu2 ,and Pb2 ,but also reduced the relevant desorption ratio.Compared with natural zeolite,the specific surface area and CEC of ammonium saturated zeolite were larger,and also the interspaces channels were more uniformed.Hence,ammonium saturated zeolite had a broad application prospect in agricultural practices,especially in the soil contaminated by heavy metals.