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首页> 外文期刊>Environmental Science & Technology >Improving Predictability of Sediment-Porewater Partitioning Models using Trends Observed with PCB-Contaminated Field Sediments
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Improving Predictability of Sediment-Porewater Partitioning Models using Trends Observed with PCB-Contaminated Field Sediments

机译：利用多氯联苯污染的田间沉积物观察到的趋势，提高沉积物-水分区模型的可预测性

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摘要

More than 1900 sediment-water partitioning coefficients were measured for 58 polychlorinated biphenyi (PCB) congeners in 53 historically contaminated sediments collected from 10 urban and rural waterways in the United States and Canada. Freely dissolved porewater concentrations were determined using passive sampling with polyoxymethylene. Measured total organic carbon (TOC)/water partitioning coefficients, K_(TOC) ranged from one to nearly three orders-of-magnitude higher than typical literature values based on spiking experiments and model predictions. Although total PCB concentrations ranged from 0.08 to 194 mg/kg, the more highly contaminated sediments showed only slightly lower K_(TOC) values than less-contaminated sediments. No correlation was observed between log K_(TOC)values and sediment TOC, black carbon (BC), or BC/TOC fractions (r~2 typically <0.l). Utilizing a two-carbon model incorporating anthropogenic BC did not improve predictions over a one-carbon TOC model. A comparison of models recently validated for field data showed that a coal-tar pory parameter linear-free energy relationship (PP-LFER) and a Raoult's Law model were successful at predicting average log K_(TOC) values, without the need for any calibration or fitting (within a factor of 10 more than 90% of the time, and within a factor of 30 more than 99% of the time). Predictions were further improved by the introduction of a Weathering Factor (WF) that accounts for the relative depletion of lower molecular weight congeners due to weathering. Highly weathered sediments (with a WF near 1) tended to follow the coal-tar PP-LFER and Raoult's Law model the closest. Less-weathered sediments (with WF « 1) sorbed Iess than predicted by these models. Noncalibrated WF inclusive coal-tar PP-LFER and Raoult's Law models performed as well or better than a quantitative-structure activity relationship (QSAR) model calibrated specifically to the data. These recommended partitioning models here can readily be used for all 209-PCB congeners.
机译：在美国和加拿大的10个城市和农村水道中，对53种历史受污染的沉积物中58种多氯联苯（PCB）同类物进行了1900多个沉积物-水分配系数的测量。使用聚甲醛进行被动采样，确定自由溶解的孔隙水浓度。根据峰值实验和模型预测，测得的总有机碳（TOC）/水分配系数K_（TOC）比典型文献值高1到三个数量级。尽管多氯联苯的总浓度范围为0.08至194 mg / kg，但污染程度较高的沉积物的K_（TOC）值仅比污染程度较小的沉积物略低。 log K_（TOC）值与沉积物TOC，黑碳（BC）或BC / TOC分数之间没有相关性（r〜2通常<0.1）。使用结合了人为BC的两碳模型并不能比一碳TOC模型改善预测。最近对现场数据进行验证的模型的比较表明，煤焦油参数线性自由能关系（PP-LFER）和拉乌尔定律模型可以成功预测平均log K_（TOC）值，而无需进行任何校准或拟合（在超过90％的时间的10倍内，在超过30％的99％的时间内）。通过引入风化因子（WF）进一步改善了预测，该因子说明了由于风化而导致的较低分子量同类物的相对消耗。高度风化的沉积物（WF接近1）趋向于遵循煤焦油PP-LFER和拉乌尔定律模型。与这些模型所预测的相比，较少风化的沉积物（WF«1）吸收的Iess值高。未校准的WF包含煤焦油的PP-LFER和Raoult定律模型的性能与针对数据进行校准的定量结构活性关系（QSAR）模型一样好或更好。这些推荐的分区模型可轻松用于所有209-PCB同类产品。

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  • 来源
    《Environmental Science & Technology》 |2011年第17期|p.7365-7371|共7页
  • 作者

    Steven B. Hawthorne; Carol B. Grabanski; David J. Miller; Hans Peter H. Arp;

  • 作者单位

    Energy and Environmental Research Center, University of North Dakota, 15 North 23rd Street, Grand Forks, North Dakota,United States 58203;

    Energy and Environmental Research Center, University of North Dakota, 15 North 23rd Street, Grand Forks, North Dakota,United States 58203;

    Energy and Environmental Research Center, University of North Dakota, 15 North 23rd Street, Grand Forks, North Dakota,United States 58203;

    Department of Environmental Engineering, Norwegian Geotechnical Institute, P.O. Box 3390, Ulleval Stadion, N-0806, Oslo, Norway;

  • 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);
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  • 正文语种 eng
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