State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing, PR China, 210023.
Environ Sci Technol. 2013 Aug 20;47(16):9347-54. doi: 10.1021/es401710q. Epub 2013 Aug 2.
Here we fabricated a novel nanocomposite HZO-201, an encapsulated nanosized hydrous zirconium oxide (HZO) within a commercial porous polystyrene anion exchanger D201, for highly efficient defluoridation of water. HZO-201 exhibited much higher preference than activated alumina and D201 toward fluoride removal when competing anions (chloride, sulfate, nitrate, and bicarbonate) coexisted at relatively high levels. Fixed column adsorption indicated that the effective treatable volume of water with HZO-201 was about 7-14 times as much as with D201 irrespective of whether synthetic solution or groundwater was the feeding solution. In addition, HZO-201 could treat >3000 BV of the acidic effluent (around 3.5 mg F(-)/L) per run at pH 3.5, compared to only ∼4 BV with D201. The exhausted HZO-201 could be regenerated by NaOH solution for repeated use without any significant capacity loss. Such attractive performance of HZO-201 resulted from its specific hybrid structure, that is, the host anion exchanger D201 favors the preconcentration of fluoride ions inside the polymer based on the Donnan principle, and the encapsulated nanosized HZO exhibits preferable sequestration of fluoride through specific interaction, as further demonstrated by XPS spectra. The influence of solution pH, competitive anions, and contact time was also examined. The results suggested that HZO-201 has a great potential in efficient defluoridation of groundwater and acidic mine drainage.
在这里，我们制备了一种新型纳米复合材料 HZO-201，即将纳米级水合氧化锆（HZO）封装在商业多孔聚苯乙烯阴离子交换剂 D201 内，用于高效除氟水。当共存相对较高水平的竞争阴离子（氯离子、硫酸盐、硝酸盐和碳酸氢根）时，HZO-201 对氟化物去除的偏好性明显高于活性氧化铝和 D201。固定柱吸附表明，无论进料溶液是合成溶液还是地下水，HZO-201 的有效可处理水量约为 D201 的 7-14 倍。此外，HZO-201 可以在 pH 3.5 下处理超过 3000 BV 的酸性废水（约 3.5 mg F(-)/L），而 D201 只能处理约 4 BV。用过的 HZO-201 可以用 NaOH 溶液再生，重复使用而不会有任何明显的容量损失。HZO-201 的这种有吸引力的性能源于其特殊的混合结构，即主体阴离子交换剂 D201 有利于基于 Donnan 原理在聚合物内部预浓缩氟离子，而封装的纳米级 HZO 通过特定相互作用表现出对氟离子的优先螯合，XPS 光谱进一步证明了这一点。还研究了溶液 pH、竞争阴离子和接触时间的影响。结果表明，HZO-201 在地下水和酸性矿山排水的高效除氟方面具有巨大的潜力。
