State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; China Meteorological Administration Key Laboratory of Cities' Mitigation and Adaptation to Climate Change (Shanghai Meteorological Bureau), IESD, Tongji University, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Center for Applied Geoscience, University of Tübingen, Hölderlinstrasse 12, Tübingen 72074, Germany.
J Hazard Mater. 2021 May 15;410:124646. doi: 10.1016/j.jhazmat.2020.124646. Epub 2020 Nov 20.
It is a great challenge to accurately estimate chemical activity of hydrophobic organic contaminants in field soils. Ex-situ and in-situ determinations were developed for this purpose based on low-density polyethylene (LDPE) passive sampling and non-equilibrium correction by release of performance reference compounds (PRCs) previously spiked to the samplers. This work investigated kinetic processes of target contaminants' uptake into and PRCs' release from the sampler in an ex-situ soil suspension incubated for 100 days. A close agreement of kinetic parameters for pyrene's (target) uptake into and deuterated pyrene's (PRC) release from LDPE indicated their similar exchange kinetics. Three kinetic models were developed to correct uptake of target compounds in non-equilibrium conditions via release processes of PRCs. The second-order kinetic model was recommended for ex-situ measurements. The PRC-based non-equilibrium corrections were further applied to in-situ static passive sampling from several weeks to months in a PAH-contaminated field site. Two-weeks' deployments were sufficient for quantifying lighter PAHs (logK < 8.0), but not recommended to accurately estimate heavier PAHs (logK > 9.0), even if over four months. Concentration estimates from the in-situ and ex-situ passive samplings were comparable in order of magnitude with traditional estimation from equilibrium partitioning models considering both organic and black carbon fractions.
准确估计野外土壤中疏水性有机污染物的化学活性是一项巨大的挑战。为此，开发了基于低密度聚乙烯（LDPE）的被动采样和通过先前添加到采样器中的性能参考化合物（PRC）的释放进行非平衡校正的原位和异位测定。本工作研究了在 100 天孵育的土壤悬浮液中，目标污染物进入和 PRC 从采样器中释放的动力学过程。芘（目标）进入 LDPE 和氘化芘（PRC）释放的动力学参数非常吻合，表明它们具有相似的交换动力学。开发了三种动力学模型，通过 PRC 的释放过程来校正非平衡条件下目标化合物的吸收。建议将二级动力学模型用于异位测量。基于 PRC 的非平衡校正进一步应用于多周至数月的多环芳烃污染现场的原位静态被动采样。两周的部署足以量化较轻的 PAHs（logK < 8.0），但不建议用于准确估计较重的 PAHs（logK > 9.0），即使超过四个月。原位和异位被动采样的浓度估计与传统的平衡分配模型考虑有机和黑碳分数的估计在数量级上是可比的。
