Enhanced Arsenite Removal from Silicate-containing Water by Using Redox Polymer-based Fe(III) Oxides Nanocomposite
Enhanced Arsenite Removal from Silicate-containing Water by Using Redox Polymer-based Fe(III) Oxides Nanocomposite
复制标题
使用基于氧化还原聚合物的 Fe(III) 氧化物纳米复合材料增强含硅酸盐水中亚砷酸盐的去除
DOI：
10.1016/j.watres.2020.116673
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发表时间：
2020
期刊：
影响因子：
12.8
通讯作者：
Pan Bingcai
中科院分区：
文献类型：
--
作者：
Fang Zhuoyao;Li Zhixian;Zhang Xiaolin;Pan Siyuan;Wu Mengfei;Pan Bingcai
从地下水中有效去除亚砷酸盐[As(III)]仍然是一个巨大的挑战。 Fe(III)、Zr(IV) 和 Al(III) 纳米级氧化物可以通过内球络合作用选择性地去除地下水中的砷。然而，由于纳米颗粒表面形成聚硅酸盐涂层，普遍存在的硅酸盐对As(III)的去除产生显着的不利影响。在此，我们提出了一种新策略，通过将纳米级氧化物嵌入氧化还原聚合物主体内来增强纳米级氧化物的硅酸盐抗性。作为概念验证，纳米复合材料 HFO@PS-Cl 用于去除含硅酸盐水中的 As(III)。聚合物主体 (PS-Cl) 含有活性氯，可将 As(III) 氧化成砷酸盐 [As(V)]，并且嵌入的 Fe(III) 氧化物能够对砷进行特异性吸附。在 pH 3-7 条件下，硅酸盐对 HFO@PS-Cl 去除 As(III) 的影响可以忽略不计，但对于 HFO@PS-N 处理的溶液（即嵌入聚合物主体内部且不含活性氯的纳米级 Fe(III) 氧化物），残留砷浓度从 49 µg/L 增加到 166 µg/L。在六次循环净化-再生测定中，HFO@PS-Cl 稳定地将 As(III) 降低到 10 µg/L 以下。然而，对于 HFO@PS-N，第六次运行中残留砷增加至约 57 µg/L。在色谱柱模式下，HFO@PS-Cl 色谱柱从模拟的 As(III) 污染地下水中生成 >3200 床体积 (BV) 的洁净水 ([As]<10 µg/L)。相比之下，As(V) 污染水和 HFO@PS-N 色谱柱的值分别仅为约 650 BV 和约 608 BV。化学计量分析、XPS 和原位 ATR-FTIR 分析表明，As(III) 氧化过程中产生的质子强烈抑制硅酸盐聚合，从而使 HFO@PS-Cl 具有优异的抗硅酸盐性能。
The efficient removal of arsenite [As(III)] from groundwater remains a great challenge. Nanoscale oxides of Fe(III), Zr(IV), and Al(III) can selectively remove arsenic from groundwater through inner-sphere complexation. However, owing to polysilicate coatings formation on nanoparticles surface, the ubiquitous silicate exerts remarkably adverse effects on As(III) removal. Herein, we propose a new strategy to enhance silicate resistance of nanoscale oxides by embedding them inside the redox polymer host. As a proof-of-concept, the nanocomposite HFO@PS-Cl was employed to remove As(III) from silicate-containing water. The polymer host (PS-Cl) contains active chlorine to oxidize As(III) into arsenate [As(V)], and the embedded Fe(III) oxides enabling specific adsorption toward arsenic. Silicate exerts negligible effects on As(III) removal by HFO@PS-Cl in pH 3-7, but increasing the residual arsenic concentration from 49 µg/L to 166 µg/L for the solutions treated by HFO@PS-N,i.e., the nanoscale Fe(III) oxides embedded inside the polymer host without active chlorine. During the six cyclic decontamination-regeneration assays, HFO@PS-Cl steadily reduces As(III) below 10 µg/L. As for HFO@PS-N, however, the residual arsenic increases to ~57 µg/L in the sixth run. In column mode, HFO@PS-Cl column generates >3200-bed volume (BV) clean water ([As]<10 µg/L) from the simulated As(III)-contaminated groundwater. In contrast, the values for As(V)-contaminated water and HFO@PS-N column are only ~650 BV and ~608 BV, respectively. The stoichiometric assays, XPS, andin-situATR-FTIR analysis demonstrate that silicate polymerization is intensively suppressed by the protons produced during As(III) oxidation, thus rendering HFO@PS-Cl with excellent silicate resistant properties.