Soil Research Centre, Department of Geography and Environmental Science, School of Archaeology, Geography and Environmental Science, University of Reading, Whiteknights, Reading, RG6 6DW, UK.
Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, UK.
Chemosphere. 2018 Oct;209:480-488. doi: 10.1016/j.chemosphere.2018.06.121. Epub 2018 Jun 18.
There is significant current interest in the application of magnetic (magnetite or maghemite) nanoparticles functionalised with chelating agents for the environmental remediation of metal contaminated waters and solutions. Whilst there is a body of knowledge about the potential remediation efficacy of such engineered nanoparticles from studies involving synthetic solutions of single metals, there is relatively little data involving mixed-metal solutions and virtually no studies about nanoparticle performance in chemically complex environmental solutions representing those to which a scaled-up nanoremediation process might eventually be applied. Therefore, we investigated the ability of diethylenetriaminepentaacetic acid (DTPA)-functionalised, silica-coated maghemite nanoparticles to extract potentially toxic (Cd, Co, Cu) and "non-toxic" (Ca, Mg) metals from solution (initial [metal] = 10 mg L; pH range: 2-8) and to extract a wider range of elements (As, Ca, Cd, Co, Cr, Cu, Mg, Na, Pb, Zn) from leachate obtained from 10 different contaminated soils with variable initial pH, (semi-)metal and dissolved organic carbon (DOC) concentrations. The functionalised nanoparticles could extract the potentially toxic metals with high efficiency (in general >70%) from single metal solutions and with efficiencies that were either unaffected or reduced from the soil leachates. K values remained high (>500 L kg), even for the soil leachate extractions. Our findings show that DOC and relatively high concentrations of non-toxic elements do not necessarily reduce the efficiency of metal contaminant removal by DTPA-functionalised magnetic nanoparticles and thus demonstrate the remediation potential of such particles when added to chemically complex soil-derived contaminated solutions.
目前，人们对用螯合剂功能化的磁性（磁铁矿或磁赤铁矿）纳米粒子来修复受金属污染的水和溶液的应用非常感兴趣。虽然有大量关于此类工程纳米粒子在涉及单一金属的合成溶液的研究中具有潜在修复功效的知识，但涉及混合金属溶液的数据相对较少，几乎没有关于纳米粒子在代表可能最终应用于规模化纳米修复过程的化学复杂环境溶液中的性能的研究。因此，我们研究了二亚乙基三胺五乙酸（DTPA）功能化、硅烷涂层的磁赤铁矿纳米粒子从溶液中提取潜在毒性（Cd、Co、Cu）和“非毒性”（Ca、Mg）金属的能力（初始[金属]=10mg L；pH 值范围：2-8），并从 10 种具有不同初始 pH 值、半金属和溶解有机碳（DOC）浓度的受污染土壤的浸出液中提取更广泛的元素（As、Ca、Cd、Co、Cr、Cu、Mg、Na、Pb、Zn）。功能化纳米粒子可以从单一金属溶液中高效地提取潜在毒性金属（一般>70%），并且从土壤浸出液中的提取效率要么不受影响，要么降低。K 值仍然很高（>500 L kg），即使是从土壤浸出液中提取。我们的研究结果表明，DOC 和相对较高浓度的非毒性元素不一定会降低 DTPA 功能化磁性纳米粒子去除金属污染物的效率，因此，当将此类粒子添加到化学复杂的土壤衍生污染溶液中时，证明了它们具有修复潜力。
