Long-Term Radiostrontium Interactions and Transport through Sediment

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• 作者：Daniel I. Kaplan ; Todd J. Miller ; David Diprete ; Brian A. Powell
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：August 5, 2014
• 年：2014
• 卷：48
• 期：15
• 页码：8919-8925
• 全文大小：329K
• ISSN：1520-5851

文摘

Radioactive strontium is one of the most common radiological contaminants in groundwater and soil. Objectives of this study were to (1) evaluate Sr transport through an 11-year-long field lysimeter study and (2) quantify secondary aging effects between Sr and sediment that may need to be considered for long-term transport modeling. Batch sorption/desorption tests were conducted with ⁸⁵Sr, ⁸⁸Sr, and ⁹⁰Sr using a sediment recovered from a field lysimeter containing a glass pellet amended with high-level nuclear waste for 24 years. Sr was largely reversibly and linearly sorbed. ⁸⁵Sr sorption coefficients (K_d, concentration ratios of solids/liquids) after a 23-day contact period were about the same as the ⁹⁰Sr desorption K_d values after a 24-year contact period: sorption K_d = 32.1 卤 3.62 mL g^鈥? and desorption K_d = 43.1 卤 11.4 mL g^鈥?. Numerical modeling of the lysimeter ⁹⁰Sr depth profile indicated that a K_d value of 32 mL g^鈥? fit the data best. The K_d construct captured most of the data trends above and below the source term, except for immediately below the source where the model clearly overestimated Sr mobility. ⁹⁰Sr desorption tests suggested that the overestimated mobility may be attributed to a second, slower sorption reaction that occurs over a course of months to decades.