Strong Sorption of Native PAHs to Pyrogenic and Unburned Carbonaceous Geosorbents in Sediments

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• 作者：Gerard Cornelissen ; Gijs D. Breedveld ; Stavros Kalaitzidis ; Kimon Christanis ; Anne Kibsgaard ; and Amy M. P. Oen
• 刊名：Environmental Science & Technology
• 出版年：2006
• 出版时间：February 15, 2006
• 年：2006
• 卷：40
• 期：4
• 页码：1197 - 1203
• 全文大小：166K
• 年卷期：v.40,no.4(February 15, 2006)
• ISSN：1520-5851

文摘

It has recently been shown that the presence ofcarbonaceous geosorbents (CG, including black carbon(BC), unburned coal, and kerogen) can cause strong sorptionof polycyclic aromatic hydrocarbons (PAHs) in sediments.We studied sorption of native PAHs in four Norwegianharbor sediments of which high fractions (21-56%) of thetotal organic carbon (TOC) consisted of CG carbon(CGC), as shown by organic petrography. PAH sorptioncoefficients were 1-2 orders of magnitude above predictionsbased on amorphous organic carbon partitioning alone.In recent studies, such strong sorption was attributed solelyto BC sorption under the implicit assumption that sorptionis linear for coal and kerogen. The most importantresult of the present study is that total sorption is betterexplained by considering all three nonlinearly sorbing CGCmaterials than by only considering BC. In addition, itwas evaluated whether activated carbon (AC) amendmentscould be effective in reducing the freely dissolved porewater concentrations (C_W) and thus the environmental risksof the PAHs in such strongly sorbing sediments. Theresults indicated that an addition of 2 weight % AC reducedthe C_W by factors of 21-153 for the four sediments(average values for all PAHs). It was shown that phenanthrenesorption to AC was, on average, reduced by a factor of6 in sediment-AC mixtures compared to pure AC.