Evidence for Dynamic Air-Water Exchange of PCDD/Fs: A Study in the Raritan Bay/Hudson River Estuary

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• 作者：Rainer Lohmann ; Eric Nelson ; Steven J. Eisenreich ; and Kevin C. Jones
• 刊名：Environmental Science & Technology
• 出版年：2000
• 出版时间：August 1, 2000
• 年：2000
• 卷：34
• 期：15
• 页码：3086 - 3093
• 全文大小：299K
• 年卷期：v.34,no.15(August 1, 2000)
• ISSN：1520-5851

文摘

The first detailed evidence for dynamic air-waterexchange of polychlorinated dibenzo-p-dioxins and furans(PCDD/Fs) is presented. Samples of air (340-380 m³)and water (33-60 L) were taken simultaneously duringJuly 1998 at two sites in the lower Hudson River Estuary,NY. The atmospheric gas and particulate phases andthe aqueous dissolved and particulate phases were analyzedfor di- to octa-CDD/Fs. All the homologue groups wereroutinely detected by HRGC-HRMS, with detection limitsfor the homologue groups ~1 pg/sample. Cl₂DDs, OCDD, andCl₂DFs were the most abundant homologues in thewater, and the Cl₂DDs were the most abundant in the air (4.3-7.6 pg/m³). The Cl₂DD/Fs and Cl_7/8DD/Fs were 25-53%and 78-99% associated with the water particulate phase,respectively. The likelihood of sampling artifacts influencingthe apparent dissolved/particulate partitioning of the higherchlorinated congeners is discussed. Water concentrationswere constant over the sampling period, while atmosphericconcentrations varied with air mass origin. The fugacityratios between the dissolved phase in water and thegas phase in air were usually >1, implying a net volatilizationflux. Evidence for outgassing of the lower chlorinatedhomologues, obtained by the simultaneous measurementof air over adjacent land and water, provided further supportfor the outgassing of the lower chlorinated homologuesfrom the water body.