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首页> 外文期刊>Environmental Science & Technology >Arsenic(Ⅴ) Removal from Groundwater Using Nano Scale Zero-Valent Iron as a Colloidal Reactive Barrier Material
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Arsenic(Ⅴ) Removal from Groundwater Using Nano Scale Zero-Valent Iron as a Colloidal Reactive Barrier Material

机译：纳米零价铁作为胶体反应性阻隔材料去除地下水中的砷（Ⅴ）

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摘要

The removal of As(Ⅴ), one of the most poisonous groundwater pollutants, by synthetic nanoscale zero-valent iron (NZVI) was studied. Batch experiments were performed to investigate the influence of pH, adsorption kinetics, sorption mechanism, and anionic effects. Field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM),X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Moessbauer spectroscopy were used to characterize the particle size, surface morphology, and corrosion layer formation on pristine NZVI and As(Ⅴ)-treated NZVI. The HR-TEM study of pristine NZVI showed a core-shell-like structure, where more than 90% of the nano-particles were under 30 nm in diameter. Moessbauer spectroscopy further confirmed its structure in which 19% were in zero-valent state with a coat of 81% iron oxides. The XRD results showed that As(Ⅴ)-treated NZVI was gradually converted into magnetite/maghemite corrosion products over 90 days. The XPS study confirmed that 25% As(Ⅴ) was reduced to As(Ⅲ) by NZVI after 90 days. As(Ⅴ) adsorption kinetics were rapid and occurred within minutes following a pseudo-first-order rate expression with observed reaction rate constants (k_(obs)) of 0.02-0.71 min~(-1) at various NZVI concentrations. Laser light scattering analysis confirmed that NZVI-As(Ⅴ) forms an inner-sphere surface complexation. The effects of competing anions revealed that HCO_3~-, H_(4~-) SiO_4~-, and H_2PO_4~(2-) are potential interfering agents in the As(Ⅴ) adsorption reaction. Our results suggest that NZVI is a suitable candidate for As(Ⅴ) remediation.
机译：研究了合成纳米级零价铁（NZVI）去除最具毒性的地下水污染物之一的砷（Ⅴ）。进行批处理实验以研究pH值，吸附动力学，吸附机理和阴离子效应的影响。使用场发射扫描电子显微镜（FE-SEM），高分辨率透射电子显微镜（HR-TEM），X射线衍射（XRD），X射线光电子能谱（XPS）和Moessbauer光谱来表征粒径原始NZVI和经As（Ⅴ）处理的NZVI的表面形貌和腐蚀层形成。原始NZVI的HR-TEM研究显示出核壳状结构，其中90％以上的纳米粒子的直径均在30 nm以下。 Moessbauer光谱进一步证实了其结构，其中19％处于零价状态，被覆81％的氧化铁。 X射线衍射结果表明，经As（Ⅴ）处理的NZVI在90天内逐渐转变为磁铁矿/磁铁矿腐蚀产物。 XPS研究证实90天后NZVI将25％的As（Ⅴ）还原为As（Ⅲ）。 As（Ⅴ）的吸附动力学很快，并在假一级反应表达式后的数分钟内发生，在各种NZVI浓度下观察到的反应速率常数（k_（obs））为0.02-0.71 min〜（-1）。激光散射分析证实NZVI-As（Ⅴ）形成内球表面络合物。竞争阴离子的影响表明，HCO_3〜-，H_（4〜-）SiO_4〜-和H_2PO_4〜（2-）是As（Ⅴ）吸附反应中的潜在干扰剂。我们的结果表明NZVI是As（Ⅴ）修复的合适候选者。

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  • 来源
    《Environmental Science & Technology》 |2006年第6期|p.2045-2050|共6页
  • 作者

    SUSHIL RAJ KANEL; JEAN-MARK GRENECHE; HEECHUL CHOI;

  • 作者单位

    Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712, Korea;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 环境化学;
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