Metastable nano-zirconium phosphate inside gel-type ion exchanger for enhanced removal of heavy metals
Metastable nano-zirconium phosphate inside gel-type ion exchanger for enhanced removal of heavy metals
复制标题
凝胶型离子交换器内的亚稳态纳米磷酸锆可增强重金属的去除
DOI：
10.1016/j.jhazmat.2021.127158
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发表时间：
2021-09-21
影响因子：
13.6
通讯作者：
Pan, Bingcai
中科院分区：
文献类型：
--
作者：
Pan, Siyuan;Shen, Jialin;Pan, Bingcai
纳米技术为水中痕量重金属的净化提供了新的机会，但相对较差的酸性稳定性仍然是纳米吸附剂的主要障碍，因为酸处理经常被用来再生重金属饱和的吸附剂。尽管磷酸锆主要通过非特异性静电吸引与重金属相互作用，但由于其绝对不溶性，因此在水处理方面具有很好的应用前景。在此，我们在市售的凝胶型阳离子交换剂(N001)，即磺化聚(苯乙烯-二乙烯基苯)微珠中制备了超细的ZrP(类似于3.9 nm)。与大孔阳离子交换剂D001内部形成的层状α-ZrP不同，所得到的纳米复合材料中含有非晶态纳米颗粒(NPs)，其结构以亚稳态的γ-ZrP为主。XPS分析表明，ZrP@N001对重金属离子具有较强的吸附亲和力，可以通过内球配位方式选择性吸附重金属。在铅(II)污染水的批式和柱式吸附实验中，ZrP@N001的吸附性能均优于ZrP@D001。吸附后，耗尽的ZrP@N001用酸处理充分刷新，进行5个循环的吸附-再生运行，并保持恒定的去除效率。本研究为高效净水器的合理设计提供了一条途径。
Nanotechnology has provided a new opportunity for water decontamination from trace heavy metals, yet the relatively poor acidic stability remains a major obstacle for the nano-adsorbents, given that acidic treatment is frequently used to regenerate the heavy metal-saturated adsorbents. Zirconium phosphate (ZrP) is very promising for water treatment due to its absolute insoluble nature, though it interacts with heavy metals mainly through the non-specific electrostatic attraction. Herein, we prepared the ultrafine ZrP (similar to 3.9 nm) inside the commercially available gel-type cation exchanger (N001), i.e., the sulfonated poly(styrene-co-divinylbenzene) bead. The resultant nanocomposite ZrP@N001 contained the amorphous nanoparticles (NPs) with metastable gamma-ZrP structure as the main phase, unlike the layered alpha-ZrP formed inside the macroporous cation exchanger D001 (referred to as ZrP@D001). As a result, ZrP@N001 could selectively adsorb heavy metals through inner sphere coordination, possessing a much stronger adsorption affinity than ZrP@D001, as confirmed by XPS analysis. In both batch and column assays on the Pb(II)-polluted water, ZrP@N001 exhibited superior adsorption performance over ZrP@D001. After adsorption, the exhausted ZrP@N001 was fully refreshed by acidic treatment for a 5-cyclic adsorption-regeneration run with constant removal efficiencies. This study may open a door for the rational design of highly efficient water purifiers for heavy metal control.