合成了一种成本低,制备工艺简单的沸石分子筛Zeolite-A,并对其吸附重金属离子的性能以及吸附的最佳条件(包括溶液的pH值,金属离子的浓度以及吸附过程的时间等)作了系统研究.除了具有天然沸石的优越吸附性能之外,根据扫描电镜图可见合成的Zeolite-A沸石分子筛还具有洁净的晶体表面,均匀的粒度,规则的形状且不存在胶体或无定形物质的优点.根据试验,Zeolite-A沸石分子筛的吸附效率随金属水合离子的半径的增加而减小.在所试验的金属离子[Fe(Ⅱ、Ⅲ),Cr(Ⅲ),Pb2+,Mn2+,Cu2+,Mg2+,Zn2+,Ni2+及Cd2+]中,Pb2+的水合离子半径最小,故其吸附效率最高,且随溶液pH的升高和吸附过程时间的增加,Pb2+的吸附效率也随之增加.试验中,所用金属离子的浓度为2×103mg·L-1.在此条件下,Pb2+的吸附率达99.6%,合成的Zeolite-A沸石分子筛可用于清除水体中重金属离子的污染.用过的Zeolite-A沸石分子筛置于0.1 mol·L-1 HCl中浸泡可使重金属离子从沸石上解吸.

An adsorbent of low production cost and simple synthesis technology,named Zeolite-A,was synthesized and its adsorption behavior towards heavy metals,and optimum conditions of the adsorption reaction (including pH of solution,concentration of the metal ions,time of adsorption process and etc.) were studied systematically. Besides possessing the prominent adsorptivity of natural Zeolite,the synthetic Zeolite-A was proved to have clean surface of its crystals,homogeneous grainity,regular shape and without the presence of any colloidal or amorphous substances,as shown by its scanning electron micrograph. It was found that efficiency of adsorption by Zeolite-A was dependent on the magnitude of radii of hydrated ions of heavy metals. Among the metal ions studied [Fe(Ⅱ、Ⅲ),Cr(Ⅲ),Pb2+,Mn2+,Cu2+,Mg2+,Zn2+,Ni2+ and Cd2+],Pb2+ ion showed the best adsorptivity;and the efficiency of adsorption of Pb2+ ion was increased with the raise of pH of solution and with the increase of time of adsorption process. The experiments were done in a solution having the concentration of metal ions of 2×103mg·L-1,and the adsorptivity of Pb2+ ion achieved to a value of 99.6%. It was proposed that the synthetic Zeolite-A is suitable to be used in the removal of heavy metals from waters. Desorption of metal ions from Zeolite-A could be effectively done by soaking in a 0.1 mol·L-1 HCl solution.