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首页> 外文期刊>Environmental Science & Technology >Extremely Slowly Desorbing Polycyclic Aromatic Hydrocarbons from Soot and Soot-like Materials:Evidence by Supercritical Fluid Extraction
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Extremely Slowly Desorbing Polycyclic Aromatic Hydrocarbons from Soot and Soot-like Materials:Evidence by Supercritical Fluid Extraction

机译：从烟灰和烟灰类物质中极缓慢地解吸多环芳烃：超临界流体萃取的证据

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摘要

Combustion-derived PAHs are strongly sorbed to their participate carrier (i.e.,soot,charcoal),and therefore,very slow desorption kinetics of the chemicals might be anticipated.Measurements are however lacking,because conventional methods (Tenax,XAD,gas-purging) fail to accurately determine desorption kinetics due to practical problems.In this study,we used a mild supercritical fluid extraction (SFE) method,which mimics desorption into water and circumvents these problems,to quantify desorption kinetics of 13 native PAHs from pure charcoal,coal,and four types of soot.The results show that generally only very small PAH fractions are released.Desorption behavior was,however,not related to common sorbent/sorbate characteristics.Two-site model-derived "fast desorbing fractions" were <0.01 in the majority of cases,and for the dominant "slow sites",the calculated rate constants for desorption into water measured from 10~(-7) to 10~(-5) h~(-1).These data suggest that desorption of coal and combustion-derived PAHs can be even slower than the "very slow" desorption observed in sediments.Estimated time scales required for removal of pyrogenic PAHs from these extremely slow sites into water amount to several millennia.Our results imply reduced chemical risks for soot and soot-like materials,casting doubts on current risk assessment procedures and environmental quality standards of pyrogenic PAHs.
机译：燃烧衍生的多环芳烃强烈吸附在其参与的载体（即烟灰，木炭）上，因此，化学物质的解吸动力学可能非常缓慢。但是由于常规方法（Tenax，XAD，气体净化），缺乏测量由于存在实际问题，未能准确确定解吸动力学。在这项研究中，我们采用了温和的超临界流体萃取（SFE）方法，该方法模拟了向水中的解吸并规避了这些问题，以量化13种天然木炭，煤中天然多环芳烃的解吸动力学。结果表明，通常仅释放出非常少的PAH组分。然而，解吸行为与常见的吸附剂/山梨酸酯特性无关。两点模型得出的“快速解吸组分”在<0.01在大多数情况下，对于主要的“慢点”，计算出的水中解吸速率常数为10〜（-7）至10〜（-5）h〜（-1）。这些数据表明，煤炭和商业衍生自裂解的PAH甚至比沉积物中观察到的“非常缓慢”的解吸还要慢。从这些极慢的位置将热解PAHs除去到水中所需的估计时间长达几千年。我们的结果表明减少了烟灰和烟灰的化学风险相似的材料，使人们对目前热原多环芳烃的风险评估程序和环境质量标准产生怀疑。

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  • 来源
    《Environmental Science & Technology》 |2005年第20期|p.7889-7895|共7页
  • 作者

    MICHIEL T.O.JONKER; STEVEN B.HAWTHORNE; ALBERT A.KOELMANS;

  • 作者单位

    Institute for Risk Assessment Sciences,Utrecht University,P.O.Box 80176,3508 TD Utrecht,The Netherlands,Energy and Environmental Research Center,University of North Dakota,P.O.Box 9018,Grand Forks,North Dakota 58202,and Aquatic Ecology and Water Qual;

    Institute for Risk Assessment Sciences,Utrecht University,P.O.Box 80176,3508 TD Utrecht,The Netherlands,Energy and Environmental Research Center,University of North Dakota,P.O.Box 9018,Grand Forks,North Dakota 58202,and Aquatic Ecology and Water Qual;

    Institute for Risk Assessment Sciences,Utrecht University,P.O.Box 80176,3508 TD Utrecht,The Netherlands,Energy and Environmental Research Center,University of North Dakota,P.O.Box 9018,Grand Forks,North Dakota 58202,and Aquatic Ecology and Water Qual;

  • 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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