凹凸棒与酸化凹凸棒对Pb(Ⅱ)和Zn(Ⅱ)的选择吸附性差异

The Difference of Selective Adsorption Between Palygorskite and Acid-activated Palygorskite for Pb(Ⅱ) and Zn(Ⅱ)

采用批处理吸附技术,研究了Pb(Ⅱ)和Zn(Ⅱ)在凹凸棒及酸化凹凸棒中的竞争吸附特征。结果表明,Pb2+在凹凸棒与酸化凹凸棒上的吸附性均优于Zn2+,但酸化凹凸棒较前者对Zn2+具有更高的选择吸附性。随着温度的升高,凹凸棒对Pb2+,Zn2+的选择吸附性分别逐渐增强和减弱,而酸化凹凸棒对两种金属离子的选择吸附性在40℃分别达到最强和最弱。吸附主导机理不同是导致两种吸附剂的选择吸附性能出现差异的主要原因。

A batch experiment was conducted to study the adsorption of Pb（ Ⅱ） and Zn（ Ⅱ ） by natural and acid-activated palygorskites in single component and binary systems. The results showed that se- lective adsorption of natural and acid activated palygorskites are both prior to Pb2＋ than Zn2＋ , but a higher selective adsorption for Zn2＋ was obtained by acid-activated palygorskite compared with that of palygorskite. Selective adsorption of palygorskite for Pb2＋ and Zn2＋ become stronger and weaker with the increase of temperature, respectively. For acid activated palygorskite, the selective adsorption for Pb2＋ and Zn2＋ become strongest and weakest in 40℃, respectively. The dissimilarity in dominant ad- sorption mechanisms was a main reason resulted in the difference of selective adsorption of the two adsorbents.