Per- and Polyfluoroalkyl Substances in Landfill Leachate: Patterns, Time Trends, and Sources

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• 作者：Jonathan P. Benskin ; Belinda Li ; Michael G. Ikonomou ; John R. Grace ; Loretta Y. Li
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：November 6, 2012
• 年：2012
• 卷：46
• 期：21
• 页码：11532-11540
• 全文大小：448K
• 年卷期：v.46,no.21(November 6, 2012)
• ISSN：1520-5851

文摘

Concentrations and isomer profiles for 24 per- and polyfluoroalkyl substances (PFASs) were monitored over 5 months (February鈥揓une, 2010) in municipal landfill leachate. These data were used to assess the role of perfluoroalkyl acid (PFAA) precursor degradation on changes in PFAA concentrations over time. The influence of total organic carbon, total suspended solids, pH, electrical conductivity (EC), leachate flow rates, and meteorological data (precipitation, air temperature) on leachate PFAS concentrations was also investigated. Perfluoropentanoate and perfluorohexanoate were typically the dominant PFASs in leachate, except for March鈥揂pril, when concentrations of perfluorooctane sulfonate, perfluorooctanoate, and numerous PFAA-precursors (i.e., (N-alkyl) perfluorooctane sulfonamides and fluorotelomer carboxylic acids) increased by a factor of 2鈥?0 (4 渭g/L to 36 渭g/L 危PFASs). During this time, isomer profiles of PFOA became increasingly dominated by the linear isomer, likely from transformation of linear, telomer-manufactured precursors. While 危PFAA-precursors accounted for up to 71% of 危PFASs (molar basis) in leachate from this site, leachate from a second landfill displayed only low concentrations of precursors (<1% of 危PFASs). Overall, degradation of PFAA-precursors and changes in leachate pH, EC, and 24-h precipitation were important factors controlling PFAS occurrence in leachate. Finally, 8.5鈥?5 kg/yr (mean 16 kg/yr) of 危PFASs was estimated to leave the landfill via leachate for subsequent treatment at a wastewater treatment plant.