Assessment of the Air鈥揝oil Partitioning of Polycyclic Aromatic Hydrocarbons in a Paddy Field Using a Modified Fugacity Sampler

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• 作者：Yan Wang ; Chunling Luo ; Shaorui Wang ; Junwen Liu ; Suhong Pan ; Jun Li ; Lili Ming ; Gan Zhang ; Xiangdong Li
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：January 6, 2015
• 年：2015
• 卷：49
• 期：1
• 页码：284-291
• 全文大小：403K
• ISSN：1520-5851

文摘

Rice, one of the most widely cultivated crops, has received great attention in contaminant uptake from soil and air, especially for the special approaches used for its cultivation. The dry鈥搘et alternation method can influence the air鈥搒oil partitioning of semivolatile organic compounds (SVOCs) in the paddy ecosystem. Here, we modified a fugacity sampler to investigate the air鈥搒urface in situ partitioning of ubiquitous polycyclic aromatic hydrocarbons (PAHs) at different growth stages in a suburban paddy field in South China. The canopy of rice can form a closed space, which acts like a chamber that can force the air under the canopy to equilibrate with the field surface. When we compared the fugacities calculated using a fugacity model of the partition coefficients to the measured fugacities, we observed similar trends in the variation, but significantly different values between different growing stages, especially during the flooding stages. However, the measured and calculated fugacity fractions were comparable when uncertainties in our calculations were considered, with the exception of the high molecular weight (HMW) PAHs. The measured fugacity fractions suggested that the HMW PAHs were also closed to equilibrium between the paddy field and atmosphere. The modified fugacity sampler provided a novel way of accurately determining the in situ air鈥搒oil partitioning of SVOCs in a wet paddy field.