凹凸棒石纳米铁复合材料的制备及应用探讨

通过对凹凸棒石进行湿法提纯和酸处理改性提高凹凸棒石的纯度、比表面积和吸附性能;将提纯改性后的凹凸棒石作为载体,以硼氢化钾作为还原剂,在氩气保护下采用离子交换法制备凹凸棒石纳米铁复合材料,解决纳米铁稳定性差、容易凝聚成团的问题,从而增大纳米铁与污染物反应的有效面积。与纳米铁相比,凹凸棒石纳米铁复合材料较稳定,易于保存。以地下水中常见的硝酸盐为目标污染物,探讨了将凹凸棒石纳米铁复合材料应用到可渗透反应墙技术、抽出处理技术及注入修复技术中的方法。应用研究成果表明,经上述技术处理后,地下水硝酸盐浓度可得到有效去除。

Preparation and Application of Palygorskite/Nano-iron Composite

The purity, specific surface area and adsorption properties of palygorskite were improved through wet purification and acid modification. The modified palygorskite was used as a carrier and KBH₄ as a reducing agent to prepare palygorskite/nano-iron composite material using ion exchange method under the protection of argon gas. Hence, the stability of nano-iron could be enhanced, iron-nano particles were prevented from condensing into groups, and the effective area of the nano-iron reacting with pollutants could be increased. Compared with nano-iron, palygorskite/nano-iron composite is more stable and easier to store. Furthermore, with nitrate as target contaminant in groundwater for example, the usage of palygorskite/nano-iron composite in permeable reactive barrier technology, extraction processing technology and injection processing technology in removing nitrate was discussed. Treated by these techniques, the nitrate concentration in groundwater can be effectively degraded.