镅在北山地下水中赋存形态及溶解度分析

Abstract

Abstract: Based on the thermodynamic datapublished by OECD/NEA and the estimated saturation indices for the precipitation of secondary minerals, the influence of pH, calcite, CO₂, and humic acid (HA) on the speciation distribution and solubility of Americium (Am) in Beishan groundwater were investigated using PHREEQC software. The results indicated that Am mainly occurred as AmCO⁺₃ and AmSiO(OH)²⁺₃ at nearly neutral condition, whereas AmOHCO₃·0.5H₂O(cr) and Am(OH)₃(cr) became predominantly at alkaline condition. Therefore, alkaline Beishan groundwater is favorable for the retardation of Am. Calcite exhibited a complex effect on the solubility and mobility of Am. At pH 6—8, it can decrease the solubility of Am slightly; at pH 8—9.7, the formation of anionic Am(CO₃)^-₂ was favorable thus the solubility and mobility of Am increased in presence of calcite; whereas as pH increased to 9.7—11, calcite can decrease the solubility of Am because of the formation of AmOHCO₃·0.5H₂O(cr). When pH was fixed at 7.56, the solubility of americium decreased firstly and then increased subsequently with increasing CO₂ pressure, and reached a minimum value at 10^-2.25bar. The results also indicated that humic acid had strong affinity towards americium, and from nearly acidic to alkaline conditions it could increase the solubility and hence the mobility of americium.

Key words: geological disposal of high-level radioactive waste, americium, speciation distribution, solubility, humic acid

CLC Number:

TL942+.1

Guo Hui, Kang Mingliang, Chen Wanliang, Long Junchen, Zhao Zhun. Speciation and solubility of americium in Beishan groundwater[J].RADIATION PROTECTION, 2016, 36(1): 40-46.

References

[1] 国防科工委,科技部,环保总局, 科工二司[2006]145号. 高放废物地质处置研究开发规划指南[S]. 2006.
[2] 王驹,范显华,徐国庆. 中国高放废物地质处置研究十年进展[M]. 北京:原子能出版社,2004.
[3] 章英杰,冯孝贵,梁俊福,等. 地质环境中Am(Ⅲ)的化学行为研究进展[J]. 核科学与工程,2009, 29 (3):278-288.
[4] Vitorge P,Capdevila H. Thermodynamic data for modelling actinide speciation in environmental waters[J]. Radiochimica Acta,2003,91(11):623-631.
[5] Metz V,Kienzler B,Schussler W. Geochemical evaluation of different groundwater-host rock systems for radioactive waste disposal[J]. Journal of Contaminant Hydrology,2003,61(1-4): 265-279.
[6] De Windt L,Schneider H,Ferry C,et al. Modeling spent nuclear fuel alteration and radionuclide migration in disposal conditions[J]. Radiochimica Acta,2006,94(9-11):787-794.
[7] 吕跃进,史维浚,周文斌. 锕系元素(Am)在水溶液中存在形式模拟计算[J]. 华东地质学院学报,1996,19(1):48-84.
[8] 贯鸿志,张振涛,苏锡光,等. 北山地下水中Am的形态分布计算[J]. 核化学与放射化学,2009,31(2):121-124.
[9] 黄支刚,王永利,陆春海,等. 地下水中Am的形态分布及影响因素[J]. 环境化学,2012,31 (2):168-174.
[10] Guillaumont R,Fanghanel T,Fuger J,et al. Update on the chemical thermodynamics of uranium, neptunium, plutonium, americium and technetium[M]. OECD Nuclear Energy Agency/Elsevier: Amsterdam,2003.
[11] 窦顺梅,陈繁荣,杨永强,等.花岗岩地区水-岩反应次生矿物的沉淀饱和指数估算[J].地球化学,2010,39 (4):326-336.
[12] 周佳,王驹,苏锐,等. 还原氛围下U等元素的存在形式及矿物饱和指数的研究[G]// 第二届废物地下处置学术研讨会论文集. 2008.
[13] 康明亮,蒋美玲,杨颛维,等. 铀在北山地下水中的种态分布及溶解度分析[J]. 核化学与放射化学,2013,35 (3): 160-166.
[14] Li C,Liu XY,Chen T,et al. The influence of pH on the sorption and diffusion of ⁹⁹TcO^-₄ in Beishan granite[J]. Radiochimica Acta,2012,100(7):449-456.
[15] 章英杰,冯孝贵,陈靖,等. Am(III)在花岗岩上的吸附行为[J]. 原子能科学技术,2009,43 (3): 215-220.
[16] 郭永海,王驹,吕川河,等. 高放废物处置库甘肃北山野马泉预选区地下水化学特征及水-岩作用模拟[J]. 地学前缘,2005,12:117-123.
[17] Merkel BJ,Paner-Friedrich B. 地下水地球化学模拟的原理及应用[M]. 朱义年,王焰新,译. 北京:中国地质大学出版社,2005.
[18] 史英霞,郭亮天. 腐殖酸胶体对超铀核素存在形态的影响研究[J]. 核化学与放射化学,2003,25 (1):22-25.
[19] 陶澍,武会先,张宗敏. 水生腐殖酸分子量研究[J]. 环境科学学报,1990,10(1): 90-95.
[20] Czerwinski KR, Kim JI,Rhee DS,et al. Complexation of trivalent actinide ions (Am³⁺, Cm³⁺) with humic acid : The effect of ionic strength[J]. Radiochimica Acta,1996,72:179-187.
[21] Artinger R,Kienzler B,SchüBer W,et al. Effects of humic substances on the ²⁴¹Am migration in a sandy aquifer: column experiments with Gorleben groundwater sediment systems [J]. Journal of Contaminant Hydrology,1998,35:261–275.
[22] Hökmark H,Fälth B. Thermal dimensioning of the deep repository: Influence of canister spacing, canister power, rock thermal properties and nearfield design on the maximum canister surface temperature [R]. SKB TR-03-09. 2003.
[23] Bennett DG,Gens R. Overview of European concepts for high-level waste and spent fuel disposal with special reference waste container corrosion [J]. Journal of Nuclear Materials,2008,379 (1-3):1-8.

Speciation and solubility of americium in Beishan groundwater

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