Distribution and Retention of 137Cs in Sediments at the Hanford Site, Washington

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• 作者：James P. McKinley ; Cynthia J. Zeissler ; John M. Zachara ; R. Jeffrey Serne ; Richard M. Lindstrom ; Herbert T. Schaef ; and Robert D. Orr
• 刊名：Environmental Science & Technology
• 出版年：2001
• 出版时间：September 1, 2001
• 年：2001
• 卷：35
• 期：17
• 页码：3433 - 3441
• 全文大小：351K
• 年卷期：v.35,no.17(September 1, 2001)
• ISSN：1520-5851

文摘

¹³⁷Cesium and other contaminants have leaked fromsingle-shell storage tanks (SSTs) into coarse-textured,relatively unweathered unconsolidated sediments.Contaminated sediments were retrieved from beneath aleaky SST to investigate the distribution of adsorbed ¹³⁷Cs⁺across different sediment size fractions. All fractionscontained mica (biotite, muscovite, vermiculatized biotite),quartz, and plagioclase along with smectite and kaolinitein the clay-size fraction. A phosphor-plate autoradiographmethod was used to identify particular sediment particlesresponsible for retaining ¹³⁷Cs⁺. The Cs-bearing particleswere found to be individual mica flakes or agglomeratedsmectite, mica, quartz, and plagioclase. Of these, only themicaceous component was capable of sorbing Cs⁺strongly. Sorbed ¹³⁷Cs⁺ could not be significantly removedfrom sediments by leaching with dithionite citrate bufferor KOH, but a fraction of the sorbed ¹³⁷Cs⁺ (5-22%) wasdesorbable with solutions containing an excess of Rb⁺. Thesmall amount of ¹³⁷Cs⁺ that might be mobilized by migratingfluids in the future would likely sorb to nearby micaceousclasts in downgradient sediments.