One-pot preparations of cyclodextrin polymer-entrapped nano zero-valent iron for the removal of p-nitrophenol in water
One-pot preparations of cyclodextrin polymer-entrapped nano zero-valent iron for the removal of p-nitrophenol in water
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DOI：
10.1016/j.cej.2021.133370
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发表时间：
2022-01-06
影响因子：
15.1
通讯作者：
Cai，Xiyun
中科院分区：
文献类型：
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作者：
Yang，Xiaohang;Yu，Shuangfei;Cai，Xiyun
纳米零价铁(NZVI)材料在水中对目标污染物(如对硝基苯酚)和非目标水组分(如硝酸盐和溶解有机物-DOM)的选择性通常较低。本文以环糊精聚合物(CDP)为载体，采用原位浸渍和KBH_4还原FeCl3的方法制备了包埋在CDP基质中的选择性nZVI。NZVI-CDP复合材料具有CDP网络结构，主要是40~80 nm的nZVI颗粒包裹在网络中，300 nm的铁颗粒包覆在网络表面。NZVI具有很高的稳定性，选择性的CDP促进了对硝基苯酚对nZVI的访问，这都是复合材料具有高选择性的原因。NZVI材料的化学降解和吸附共同促进了对硝基苯酚的去除。在不同的硝酸盐、DOM或硫化物水平下，nZVI材料通常表现出相似或更高的对硝基苯酚的去除效果。柱实验表明，nZVI材料完全净化了63柱含对硝基苯酚的地下水，比nZVI和CDP的混合物高6倍。据估计，nZVI材料的潜在性能持续时间平均为109d，表明其在地下水中的长期性能。
Nano zero-valent iron (nZVI) materials usually have low selectivity in water toward target contaminants (e.g.,p-nitrophenol) and nontarget water constituents (e.g., nitrates and dissolved organic matter-DOM). Here we prepared the selective nZVI entrapped in the matrix of cyclodextrin polymer (CDP), usingin situimpregnation and aqueous KBH4reduction of FeCl3in the matrix of CDP. The nZVI-CDP composites feature the network structure of CDP with mainly 40–80 nm nZVI particles entrapped in the network and 300 nm iron particles coated on the network surface. nZVI entrapped displays high stability and selective CDP facilitates the access ofp-nitrophenol to nZVI, both accounting for the high selectivity of the composites. Chemical degradation of the nZVI materials, combined with adsorption, contributed to thep-nitrophenol removal. The nZVI materials usually exhibited similar or higherp-nitrophenol removal at different levels of nitrates, DOM or sulfides. Column experiments showed that the nZVI materials completely decontaminated 63 column volumes of groundwater containingp-nitrophenol, 6-fold higher than mixed nZVI and CDP. The nZVI materials were estimated to have potential performance duration of averaging 109 d, indicating the long-term performance in groundwater.