Assessing the potential contributions of additional retention processes to PFAS retardation in the subsurface.
Assessing the potential contributions of additional retention processes to PFAS retardation in the subsurface.
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DOI：
10.1016/j.scitotenv.2017.09.065
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发表时间：
2018-02-01
期刊：
影响因子：
--
通讯作者：
Brusseau ML
中科院分区：
文献类型：
--
作者：
Brusseau ML
全面了解全氟烷基物质和多氟烷基物质在地下的迁移和去向对于准确的风险评估和设计有效的补救行动至关重要。提出了一个多过程滞留模型来解释源区PFAS传输的潜在的附加延迟过程。这些包括分配到土壤大气、在空气-水界面的吸附、分配到被捕获的有机液体(NAPL)以及在NAPL-水界面的吸附。初步评估了两种主要关注的全氟辛烷磺酸(全氟辛烷磺酸)和全氟辛酸(全氟辛酸)以及一种示例性前体(氟调聚体醇)的保留过程的相对程度和重要性。该说明性评价是使用代表沙质包气带土壤的测量的多孔介质特性进行的。从文献中收集的数据被用来确定相关分布系数的测量值或估计值，这些值又被用来计算模型系统的延迟因子。结果表明，空气-水界面的吸附是全氟辛烷磺酸和全氟辛烷磺酸保留量的主要来源，在所用条件下约占总保留量的50%。对NAPL-水界面的吸附和对主体NAPL的分配也被证明是保留的重要来源。NAPL分配是FTOH保留的主要来源，约占总延迟的98%。这些结果表明，在某些情况下，这些额外的过程可能是全氟辛烷磺酸地下运输的重要滞留来源。个别保留过程的具体程度和重要性将取决于所关注的特定系统的性质和条件(例如，全氟辛烷磺酸的组成和浓度、多孔介质、水化学、流体饱和度、共污染物)。在这些额外的保留过程很重要的情况下，来源地区对全氟辛烷磺酸的延迟可能比通常根据固相吸附作为唯一保留机制的标准假设所估计的要大。这对于准确确定地下水的迁移潜力和质量通量的大小，以及计算存在于源区的污染物质量具有重大影响。这两项研究对人类健康风险评估都有重要影响。
A comprehensive understanding of the transport and fate of per- and poly-fluoroalkyl substances (PFAS) in the subsurface is critical for accurate risk assessments and design of effective remedial actions. A multi-process retention model is proposed to account for potential additional retardation processes for PFAS transport in source zones. These include partitioning to the soil atmosphere, adsorption at air-water interfaces, partitioning to trapped organic liquids (NAPL), and adsorption at NAPL-water interfaces. An initial assessment of the relative magnitudes and significance of these retention processes was conducted for two PFAS of primary concern, perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), and an example precursor (fluorotelomer alcohol, FTOH). The illustrative evaluation was conducted using measured porous-medium properties representative of a sandy vadose-zone soil. Data collected from the literature were used to determine measured or estimated values for the relevant distribution coefficients, which were in turn used to calculate retardation factors for the model system. The results showed that adsorption at the air-water interface was a primary source of retention for both PFOA and PFOS, contributing approximately 50%, of total retention for the conditions employed. Adsorption to NAPL-water interfaces and partitioning to bulk NAPL were also shown to be significant sources of retention. NAPL partitioning was the predominant source of retention for FTOH, contributing ~98%, of total retardation. These results indicate that these additional processes may be, in some cases, significant sources of retention for subsurface transport of PFAS. The specific magnitudes and significance of the individual retention processes will depend upon the properties and conditions of the specific system of interest (e.g., PFAS constituent and concentration, porous medium, aqueous chemistry, fluid saturations, co-contaminants). In cases wherein these additional retention processes are significant, retardation of PFAS in source areas would likely be greater than what is typically estimated based on the standard assumption of solid-phase adsorption as the sole retention mechanism. This has significant ramifications for accurate determination of the migration potential and magnitude of mass flux to groundwater, as well as for calculations of contaminant mass residing in source zones. Both of which have critical implications for human-health risk assessments.
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影响因子：
11.4
作者：
Brusseau, Mark L.;Narter, Matt;Janousek, Hilary
通讯作者：
Janousek, Hilary
影响因子：
5.4
作者：
Brusseau, ML;Peng, S;Costanza-Robinson, MS
通讯作者：
Costanza-Robinson, MS
影响因子：
5.4
作者：
BRUSSEAU, ML
通讯作者：
BRUSSEAU, ML
测量不饱和多孔介质中空气-水界面面积的新方法。
影响因子：
8.8
作者：
Brusseau ML;El Ouni A;Araujo JB;Zhong H
通讯作者：
Zhong H
影响因子：
11.4
作者：
Brusseau, Mark L.;Peng, Sheng;Murao, Asami
通讯作者：
Murao, Asami