Adsorption and reduction from modified polypyrrole enhance electrokinetic remediation of hexavalent chromium-contaminated soil
Adsorption and reduction from modified polypyrrole enhance electrokinetic remediation of hexavalent chromium-contaminated soil
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DOI：
10.1007/s11356-022-18998-2
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发表时间：
2022-02-09
影响因子：
5.8
通讯作者：
Li, Dongwei
中科院分区：
文献类型：
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作者：
Wang, Jiangyuan;Yu, Qiu;Li, Dongwei
环境中的有毒金属污染物Cr（VI）对动物和人类健康构成严重威胁。本论文通过在PPy结构中掺杂Fe 3 O 4纳米粒子和氨基，制备了Fe3O4@PPy、Arg@PPy和Arg/Fe3O4@PPy复合材料，以增强对Cr（VI）的吸附。通过FTIR、SEM、EDS、BET分析和静态吸附实验研究了它们的特性。并将其作为可渗透反应屏障（PRB）与电动修复（EKR）结合联合收割机对铬污染土壤进行修复。吸附实验结果表明，PPy、Fe3O4@PPy、Arg@PPy和Arg/Fe3O4@PPy对Cr（VI）的最大吸附量分别为60.43 mg/g、67.12 mg/g、159.86 mg/g和141.50 mg/g。它们的吸附行为均符合准二级动力学模型和Langmuir等温吸附模型，且均为单分子层吸附。在EKR/PRB体系中，Fe3O4@PPy、Arg@PPy和Arg/Fe3O4@PPy的存在使阳极附近的Cr（VI）去除率分别比PPy提高了74.60%、26.04%和68.64%。在酸性条件下，EKR修复过程中，阴离子污染物和质子化改性PPy之间存在强烈的静电吸引力，并且Cr（VI）还原为Cr（III）。本研究为改性聚吡咯复合材料应用于有毒金属污染土壤的治理开辟了前景。
Toxic metal pollutant Cr(VI) in the environment will pose a severe threat to animal and human health. In this work, Fe3O4@PPy, Arg@PPy, and Arg/Fe3O4@PPy were prepared to enhance adsorption of Cr(VI) by doping Fe3O4 nanoparticles and amino radicals into the original PPy structure. Their characteristics were investigated by FTIR, SEM, EDS, BET analysis, and batch adsorption experiments. And they were used as permeable reaction barriers (PRB) to combine with electrokinetic remediation (EKR) to remediate Cr-contaminated soil. Adsorption experiment results showed that the maximum adsorption capacities of PPy, Fe3O4@PPy, Arg@PPy, and Arg/Fe3O4@PPy for Cr(VI) were 60.43 mg/g, 67.12 mg/g, 159.86 mg/g, and 141.50 mg/g, respectively. They all followed the kinetic pseudo-second-order model and the Langmuir isothermal model with a monolayer adsorption behavior. In the EKR/PRB system, the presence of Fe3O4@PPy, Arg@PPy, and Arg/Fe3O4@PPy obtained the higher Cr(VI) removal efficiency near the anode than that of the PPy, increasing by 74.60%, 26.04%, and 68.64%, respectively. A strong electrostatic attraction between anion contaminants and protonated modified PPy and a reduction from Cr(VI) to Cr(III) appeared in the EKR remediation process under acid conditions. This study opened up a prospect for applying modified PPy composites to treat toxic metal-contaminated soil.