基于海泡石制备的含镁纳米复合材料对Cr(Ⅲ)去除的研究

Study on removal of Cr(Ⅲ)by magnesium-containing composites derived from sepiolite

粘土矿物由于其比表面积大、价格低廉和易于获取,而被广泛地用作水体重金属吸附剂.然而,其自身所具有的局限性,如低的载荷能力、对金属相对低的结合常数和低的选择性限制了它的应用.本研究中,以海泡石为原材料,通过对其进行连续的酸-碱处理,制备含镁纳米复合材料,并系统研究了复合材料对Cr(Ⅲ)的去除性能.结果显示,基于海泡石制备的含镁纳米复合材料对Cr(Ⅲ)表现出优异的去除性能,其对Cr(Ⅲ)的最大去除容量约为411.1mg/g,远大于海泡石原样对Cr(Ⅲ)的去除容量(2.8mg/g).通过对海泡石进行简单的酸-碱改性,极大地提高海泡石对重金属的去除容量.由于此改性工艺的简易性,以及改性后所制备的纳米复合材料对重金属去除的优异效果,基于海泡石制备的纳米含镁复合材料在水体重金属去除领域展现出良好的应用前景.

Clays are widely used as adsorptive materials to capture metal ions from aqueous solution,due to their high specific surface areas,low cost,and ubiquitous occurrence in most soil and sediment environments.However,the low loading capacity,relatively small metal ion binding constants,and low selectivity to the type of metal are their inherent limitations.In this study,magnesium-containing nanocomposite was prepared by facile sequential treatment of raw sepiolite with acid and alkali,and its removal ability to Cr(Ⅲ)was studied systematically.The removal capacity of the magnesium-containing nanocomposite is ca.411.1 mg/g,much higher than that of raw sepiolite(2.8 mg/g).The results indicate that the loading capacity of raw sepiolite to Cr(Ⅲ)is greatly enhanced after the modification with acid and alkali.Taking into account of the facile modification method and excellent removal ability to heavy metals,the magnesium-containing nanocomposite derived from sepiolite has real potential for applications in water treatment.