DOI: | 10.2172/1009764
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报告号: | PNNL-20136
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报告题名: | Tc-99 Adsorption on Selected Activated Carbons - Batch Testing Results |
作者: | Mattigod, Shas V.; Wellman, Dawn M.; Golovich, Elizabeth C.; Cordova, Elsa A.; Smith, Ronald M.
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出版年: | 2010
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发表日期: | 2010-12-01
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国家: | 美国
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语种: | 英语
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中文主题词: | 碳
; 挥发性有机化合物
; 硝酸盐
; PH
; PH值
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主题词: | CARBON
; VOLATILE ORGANIC COMPOUNDS
; NITRATE
; PH
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英文摘要: | CH2M HILL Plateau Remediation Company (CHPRC) is currently developing a 200-West Area groundwater pump-and-treat system as the remedial action selected under the Comprehensive Environmental Response, Compensation, and Liability Act Record of Decision for Operable Unit (OU) 200-ZP-1. This report documents the results of treatability tests Pacific Northwest National Laboratory researchers conducted to quantify the ability of selected activated carbon products (or carbons) to adsorb technetium-99 (Tc-99) from 200-West Area groundwater. The Tc-99 adsorption performance of seven activated carbons (J177601 Calgon Fitrasorb 400, J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, J177612 Norit GAC830, J177613 Norit GAC830, and J177617 Nucon LW1230) were evaluated using water from well 299-W19-36. Four of the best performing carbons (J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, and J177613 Norit GAC830) were selected for batch isotherm testing. The batch isotherm tests on four of the selected carbons indicated that under lower nitrate concentration conditions (382 mg/L), Kd values ranged from 6,000 to 20,000 mL/g. In comparison. Under higher nitrate (750 mg/L) conditions, there was a measureable decrease in Tc-99 adsorption with Kd values ranging from 3,000 to 7,000 mL/g. The adsorption data fit both the Langmuir and the Freundlich equations. Supplemental tests were conducted using the two carbons that demonstrated the highest adsorption capacity to resolve the issue of the best fit isotherm. These tests indicated that Langmuir isotherms provided the best fit for Tc-99 adsorption under low nitrate concentration conditions. At the design basis concentration of Tc 0.865 Âľg/L(14,700 pCi/L), the predicted Kd values from using Langmuir isotherm constants were 5,980 mL/g and 6,870 mL/g for for the two carbons. These Kd values did not meet the target Kd value of 9,000 mL/g. Tests conducted to ascertain the effects of changing pH showed that at pH values of 6.5 and 7.5, no significant differences existed in Tc-adsorption performance for three of the carbons, but the fourth carbon performed better at pH 7.5. When the pH was increased to 8.5, a slight decline in performance was observed for all carbons. Tests conducted to ascertain the temperature effect on Tc-99 adsorption indicated that at 21 ÂşC, 27 ÂşC, and 32 ÂşC there were no significant differences in Tc-99 adsorption for three of the carbons. The fourth carbon showed a noticeable decline in Tc-99 adsorption performance with increasing temperature. The presence of volatile organic compounds (VOCs) in the source water did not significantly affect Tc-99 adsorption on either of two carbons tested. Technetium-99 adsorption differed by less than 15% with or without VOCs present in the test water, indicating that Tc-99 adsorption would not be significantly affected if VOCs were removed from the water prior to contact with carbon. |
URL: | http://www.osti.gov/scitech/servlets/purl/1009764
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Citation statistics: |
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资源类型: | 研究报告
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标识符: | http://119.78.100.158/handle/2HF3EXSE/39609
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Appears in Collections: | 过去全球变化的重建 影响、适应和脆弱性 科学计划与规划 气候变化与战略 全球变化的国际研究计划 气候减缓与适应 气候变化事实与影响
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1009764.pdf(999KB) | 研究报告 | -- | 开放获取 | | View
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Recommended Citation: |
Mattigod, Shas V.,Wellman, Dawn M.,Golovich, Elizabeth C.,et al. Tc-99 Adsorption on Selected Activated Carbons - Batch Testing Results. 2010-01-01.
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