Mg-Al水滑石的制备及对Cr(VI)阴离子吸附效果研究

Preparation of Mg-Al Hydrotalcite and Its Adsorption Property on Cr(VI) Anion

为了寻求对水体中重金属阴离子具有较好效果的吸附剂,并探讨其最佳的制备条件,笔者研究了Mg-Al型水滑石对Cr(VI)阴离子的吸附,通过平衡吸附的单因素试验和正交试验,考察了Mg/Al离子比、制备过程中的p H、反应温度以及陈化时间等制备条件下Mg-Al-LDHs对Cr(VI)阴离子的吸附效果的影响。结果表明,当Mg/Al离子比为2:1、制备过程中p H保持在10.5左右、反应温度控制在90℃左右以及陈化时间达到24 h及以上时,所制成的Mg-Al-LDHs对Cr(VI)阴离子有较好的吸附效果,其吸附量可以达到10.5 mg/g。该试验确定了具有较好吸附效果的Mg-Al型水滑石的最佳制备条件,对重金属阴离子吸附材料的选择以及Mg-Al型水滑石对Cr(VI)阴离子吸附性能的研究提供了一定的参考。

In order to find a relatively effective adsorbent for water dissolved heavy metal anions,and toexplore the optimal preparation conditions,the adsorption of Mg-Al hydrotalcite on Cr（VI） anion was studied.In the experiment,several factors,including ion ratio of Mg/Al,pH,reaction temperature and aging time,wereinvestigated to analyze the effect of adsorption of Mg-AL-LDHs on Cr（VI） anion by single factor tests andorthogonal experiments of equilibrium adsorption.The results indicated that when the ion ratio of Mg/Al was2：1,the pH during preparation process was 10.5,the reaction temperature was 90℃ and the aging time waslonger than 24 h,as-prepared Mg-Al-LDHs showed best adsorption effect on Cr（VI） with the adsorptionamount up to 10.5 mg/g.In summary,the optimal preparation conditions were determined to fabricate Mg-Alhydrotalcite with effective adsorption capacity,which might provide certain guidance for the choosing of heavymetal anion adsorption material and the research on the adsorption properties of Mg-Al hydrotalcite on Cr（VI）.