State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
State Key Laboratory for Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
J Hazard Mater. 2021 Jul 15;414:125505. doi: 10.1016/j.jhazmat.2021.125505. Epub 2021 Feb 24.
Given high selectivity and excellent stability, zirconium oxides are very promising in selective removal of arsenic, fluorine, and phosphorus from water. Nevertheless, it remains challenging to prepare sub-10 nm zirconium oxides of ultra-high adsorptive reactivity. Herein, we prepared hydrated zirconium oxides (HZO) of 4.88 ± 1.02 nm by conducting in-situ precipitation of nanoparticles (NPs) inside the gel-type anion exchanger (GAE). GAE was swollen in water and contained lots of < 10 nm swollen pores, restricting excess growth of HZO NPs. In comparison, the NPs formed inside the macroporous anion exchanger (MAE) possessed an average diameter of 30.91 ± 8.98 nm. XPS O1s analysis indicated that the oxygen sites in the gel-type nanocomposite (HZO@GAE) possessed a much higher proportion (48.9%) of reactive terminal oxygen (-OH) than the macroporous nanocomposite (HZO@MAE, 21.2%). Thus, HZO@GAE exhibited significantly enhanced adsorption reactivity toward As(V)/As(III) than HZO@MAE. The exhausted HZO@GAE could be fully regenerated by alkali treatment for repeated use without any loss in decontamination efficiency. In column assays, the HZO@GAE column successively produced ~2400 bed volume (BV) clean water ([As]<10 μg/L) from synthetic groundwater, exceeding twice the amount produced by the HZO@MAE column. This study may shed new light on developing highly efficient nanocomposites for water decontamination.
鉴于氧化锆具有高选择性和优异的稳定性，因此非常有希望从水中选择性地去除砷、氟和磷。然而，制备亚 10nm 的超高吸附反应性氧化锆仍然具有挑战性。在此，我们通过在凝胶型阴离子交换剂 (GAE) 内原位沉淀纳米颗粒 (NPs) 制备了 4.88±1.02nm 的水合氧化锆 (HZO)。GAE 在水中溶胀，含有大量<10nm 的溶胀孔，限制了 HZO NPs 的过度生长。相比之下，在大孔阴离子交换剂 (MAE) 内形成的 NPs 平均直径为 30.91±8.98nm。XPS O1s 分析表明，凝胶型纳米复合材料 (HZO@GAE) 中的氧位具有更高比例（48.9%）的反应性末端氧 (-OH)，而大孔纳米复合材料 (HZO@MAE 为 21.2%)。因此，HZO@GAE 对 As(V)/As(III) 的吸附反应性明显增强。通过碱处理可以完全再生耗尽的 HZO@GAE，以用于重复使用，而不会降低去污效率。在柱实验中，HZO@GAE 柱从合成地下水中连续产生约 2400 床体积 (BV) 的清洁水 ([As]<10μg/L)，是 HZO@MAE 柱产生量的两倍多。这项研究可能为开发用于水净化的高效纳米复合材料提供新的思路。
