Air-soil exchange of semi-volatile organic compounds (SOCs) in the UK
Air-soil exchange of semi-volatile organic compounds (SOCs) in the UK
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DOI：
10.1016/s0269-7491(98)00069-4
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发表时间：
1998-01-01
影响因子：
8.9
通讯作者：
Jones, KC
中科院分区：
文献类型：
--
作者：
Cousins, IT;Jones, KC
本文描述了(1)一项野外实验，其中测量了一系列多氯联苯(PCbs)和多环芳烃(PAHs)的大气-土壤交换；(2)利用逸度商概念提供了关于多氯联苯、多环芳烃和多氯二苯并-对二恶英(PCDDs)在英国空气和土壤之间平衡分配的信息。在野外试验中，将装有薄层(类似于5毫米)的尖峰土壤和未尖峰土壤的铝箔托盘放置在气象站定制的遮蔽物下，并将其暴露在室外空气中长达9个月(281天)。在这9个月期间，定期采集土壤和空气样本，并对其进行多氯联苯和多环芳烃分析。实验结果表明，土壤中的多氯联苯和多环芳烃正向平衡分配条件迁移。大多数多氯联苯/多环芳烃化合物在添加添加剂的土壤中发生了显著的损失。挥发被认为是主要的损失机制。在实验开始时，未添加添加剂的土壤中的多氯联苯与空气接近平衡，因此，在9个月的暴露期间，它们的浓度几乎没有变化。对于多环芳烃，在试验期间，未添加添加剂的土壤中的浓度也只有很小的变化，尽管在统计上有显著的损失。土壤/空气逸度商是利用野外实验中测量的空气和土壤浓度以及我们的英国空气和土壤调查数据数据库计算出来的。计算的土壤/空气逸度商与田间试验结果相结合，表明土壤和空气对多氯联苯的吸附接近平衡。然而，这项研究提供的证据表明，土壤现在可能是大气中一些较轻的多环芳烃的来源，而它似乎仍然是较重的多环芳烃和多氯二苯并二恶英的长期汇。(C)1998爱思唯尔科学有限公司。保留所有权利。
This paper describes (1) a field experiment in which the air-soil exchanges of a range of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were measured and (2) the use of the fugacity quotient concept to provide information on the equilibrium partitioning of PCBs, PAHs and polychlorinated dibenzo-p-dioxins (PCDDs) between the air and soil in the UK. In the field experiment aluminium foil trays containing thin layers (similar to 5 mm) of spiked and unspiked soil were placed under custom-built shelters at a meteorological station and exposed to outdoor air for periods of up to 9 months (281 days). Soil and air samples were taken periodically throughout the 9-month period and analysed for PCBs and PAHs. The results from the experiment showed that the PCBs and PAHs in the soils were moving towards equilibrium partitioning conditions. Statisitically significant losses of the majority of PCB/PAH compounds occurred in the spiked soils. Volatilisation was hypothesised to be the dominant loss mechanism. The PCBs in the unspiked soils were close to equilibrium with the air at the start of the experiment and there was, therefore, little change in their concentrations during the 9 months of exposure. For the PAHs there was also only a small change in the concentrations in the unspiked soils during the experiment, although there was a statistically significant loss of acenaphthene, fluorene and phenanthrene. Soil/air fugacity quotients were calculated using the air and soil concentrations measured in the field experiment and also using our database of UK air and soil survey data. The calculated soil/air fugacity quotients, together with the findings of the field experiment, indicate that the soil and air are close to equilibrium for PCBs. However, this study provides evidence that the soil may now be a source of some lighter weight PAHs to the atmosphere, whereas it appears to be still acting as a long-term sink for the heavier weight PAHs and the PCDDs. (C) 1998 Elsevier Science Ltd. All rights reserved.