Mechanistic Model Describing the Uptake of Chemicals by Aquatic Integrative Samplers: Comparison to Data and Implications for Improved Sampler Configurations
Mechanistic Model Describing the Uptake of Chemicals by Aquatic Integrative Samplers: Comparison to Data and Implications for Improved Sampler Configurations
复制标题
描述水生综合采样器吸收化学品的机制模型：数据比较以及改进采样器配置的意义
DOI：
10.1021/acs.est.8b06225
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Vermeirssen ELM
中科院分区：
文献类型：
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作者：
Endo S;Matsuura Y;Vermeirssen ELM
水生综合被动采样器用于确定极性有机污染物的水溶液浓度，但其吸收机制知之甚少。我们介绍了一个一维模型来模拟被动采样器，Chemcatcher吸收。该模型认为，通过一系列的水边界层（ABL），膜过滤器（MF），和吸附剂磁盘与并发吸附矩阵的MF和磁盘的分子扩散的吸收。在一周和一个月内测量的1020种极性化学物质的吸收曲线被准确地建模。该模型很好地解释了滞后相、线性和曲线吸收以及平衡行为等特征行为。由于该模型是机械的基础上，它是能够显示的MF/水（KMF/W）和磁盘/水（Kdisk/W）分配系数，扩散系数和ABL厚度的采样率的综合影响。在模型结果的基础上，我们提供了三个具体的建议，以实现测量时间加权平均浓度所需的线性吸收：（i）使用不会显著吸附化学品的MF（例如，logKMF/w< 3）以避免滞后期，（ii）使用具有强吸附性能的吸附剂（例如，logKdisk/w> 6）以有效地将化学品捕获在盘顶层上，以及（iii）使ABL和/或MF更厚，使得朝向盘的扩散减慢。
Aquatic integrative passive samplers are used to determine aqueous concentrations of polar organic pollutants, yet their uptake mechanisms are poorly understood. We introduce a one-dimensional model to simulate uptake by a passive sampler, Chemcatcher. The model considers the uptake as molecular diffusion through a series consisting of the aqueous boundary layer (ABL), the membrane filter (MF), and the sorbent disk with concurrent sorption by matrix of the MF and the disk. Uptake profiles of ∼20 polar chemicals measured over a week and a month were accurately modeled. Characteristic behaviors such as lag phases, linear and curved uptake, and equilibrating behavior were explained well by the model. As the model is mechanistically based, it was able to show the combined influences of the MF/water (KMF/w) and disk/water (Kdisk/w) partition coefficients, diffusion coefficients, and the ABL thickness on the sampling rates. On the basis of the model results, we offer three concrete recommendations for achieving the linear uptake needed for measuring time-weighted average concentrations: (i) use a MF that does not significantly sorb chemicals (e.g., logKMF/w< 3) to avoid lag phases, (ii) use a sorbent with strong sorption properties (e.g., logKdisk/w> 6) for effective trapping of chemicals on the disk top layer, and (iii) make the ABL and/or the MF thicker so that the diffusion toward the disk slows.