Multi-Ratio Equilibrium Passive Sampling Method to Estimate Accessible and Pore Water Concentrations of Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls in Sediment

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• 作者：Foppe Smedes ; L. Alexander van Vliet ; Kees Booij
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：January 2, 2013
• 年：2013
• 卷：47
• 期：1
• 页码：510-517
• 全文大小：391K
• 年卷期：v.47,no.1(January 2, 2013)
• ISSN：1520-5851

文摘

The freely dissolved concentration (C_w,0) in the pore water and the accessible (releasable) concentration in the sediment (C_as,0) are important parameters for risk assessment. These parameters were determined by equilibrating contaminated sediments and passive samplers using largely differing sampler鈥搒ediment ratios. This method is based on the principle that incubations at low sampler/sediment ratios yield the concentration in the pore water (minor depletion of the sediment phase) and incubations at high sampler/sediment ratios yield the accessible concentration in the sediment (maximum depletion of the sediment phase). It is shown that equilibration was faster in dense suspensions and at high sampler/sediment ratios when compared to low sampler/sediment ratios. An equilibrium distribution model was used to estimate C_w,0 and C_as,0 by nonlinear least-squares regression. The method was evaluated for three sediments (harbor, estuarine, marine). Accessible concentrations of 13 PAHs were 2 (low K_ow) to 10 (high K_ow) times lower than the total concentrations (three sediments). By contrast, the accessible concentrations of 15 PCBs were about 1.2 times lower than the total concentrations and displayed no trend with K_ow (one sediment). Implications for risk assessment and considerations for application of multi-ratio equilibrium passive sampling with other sediments are discussed.