Enhanced Accessibility of Polycyclic Aromatic Hydrocarbons (PAHs) and Heterocyclic PAHs in Industrially Contaminated Soil after Passive Dosing of a Competitive Sorbate
Enhanced Accessibility of Polycyclic Aromatic Hydrocarbons (PAHs) and Heterocyclic PAHs in Industrially Contaminated Soil after Passive Dosing of a Competitive Sorbate
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DOI：
10.1021/acs.est.7b01198
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发表时间：
2017-07-18
影响因子：
11.4
通讯作者：
Loibner, Andreas P.
中科院分区：
文献类型：
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作者：
Humel, Stefan;Schmidt, Stine N.;Loibner, Andreas P.
为了评估多环芳烃（PAHs）的暴露，重要的是要了解特定的土壤成分和有机污染物之间的结合机制。在这项研究中，吸附生物可及性提取（SBE）应用于量化的可访问PAH馏分在工业污染的土壤与被动剂量的竞争性山梨酸盐。SBE实验揭示了41 +/- 1%的可获得的PAH部分（Sigma 16 US EPA PAH + 5另外的PAH）。低于其饱和水平的甲苯的被动剂量显示竞争性结合，并导致可接近部分平均增加至49 +/-2%，由此主要影响较高分子量多环芳烃的可接近性（log K-ow > 6）。竞争性结合进行了验证，使用相同的土壤，只有解吸阻力多环芳烃存在。在该实验中，被动投加甲苯导致13 +/- 0.4%的PAH解吸。我们解释增加PAH解吸后，通过竞争吸附到高亲和力的吸附位点，同时承认甲苯可以另外增加PAH的流动性在土壤基质中的甲苯。研究结果表明，在受污染的场地存在的copollutants值得特别考虑，因为这些可能会增加可访问性，从而暴露和流动性的多环芳烃。
To assess the exposure to polycyclic aromatic hydrocarbons (PAHs) it is important to understand the binding mechanisms between specific soil constituents and the organic pollutant. In this study, sorptive bioaccessibility extraction (SBE) was applied to quantify the accessible PAH fraction in industrially contaminated soil with and without passive dosing of a competitive sorbate. SBE experiments revealed an accessible PAH fraction of 41 +/- 1% (Sigma 16 US EPA PAHs + 5 further PAHs). The passive dosing of toluene below its saturation level revealed competitive binding and resulted in an average increase of the accessible fraction to 49 +/- 2%, whereby primarily the accessibility of higher molecular weight PAHs (log K-ow > 6) was affected. Competitive binding was verified using the same soil with only desorption-resistant PAHs present. In this experiment, passive dosing of toluene resulted in desorption of 13 +/- 0.4% PAH. We explain increased PAH desorption after addition of toluene by competitive adsorption to high-affinity sorption sites while acknowledging that toluene could additionally have increased PAH mobility within the soil matrix. Findings suggest that the presence of copollutants at contaminated sites deserves specific considerations as these may increase accessibility and thereby exposure and mobility of PAHs.