Carbonate effects on hexavalent uranium adsorption by iron oxyhydroxide.
Carbonate effects on hexavalent uranium adsorption by iron oxyhydroxide.
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DOI：
10.1021/es034166m
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发表时间：
2003-07
影响因子：
11.4
通讯作者：
M. Wazne;G. Korfiatis;Xiaoguang Meng
中科院分区：
文献类型：
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作者：
M. Wazne;G. Korfiatis;Xiaoguang Meng
碳酸盐显著影响铀（U（VI））在铁氢氧化物上的吸附及其在自然环境中的移动性。批试验，zeta电位测量，傅立叶变换红外光谱（FTIR）的研究被用来表征U（VI）吸附在水铁矿的性质。吸附等温线表明，pH > 6时，碳酸盐对U（VI）在水铁矿上的吸附有负面影响。Zeta电位的测量表明，U（VI）被吸附为阳离子物种（SO-UO 2+）的情况下，碳酸盐和阴离子U（VI）的存在下，在中性pH值的碳酸盐络合物。吸附的U（VI）的FTIR光谱测量表明，它被保留在碳酸铀酰络合物的存在下。碳酸根浓度的增加导致铀酰（UO 2（2+））U-O键的反对称伸缩振动向低波数方向移动，表明吸附的碳酸根效应增强。成功地将吸附的U（VI）物种纳入表面络合模型来描述人工溶液和污染水中的U（VI）的水铁矿吸附。
Carbonate dramatically affects the adsorption of uranium (U(VI)) onto iron hydroxides and its mobility in the natural environment. Batch tests, zeta potential measurements, and Fourier transform infrared (FTIR) spectroscopic studies were utilized to characterize the nature of U(VI) adsorption on ferrihydrite. Adsorption isotherms demonstrated that carbonate had a negative effect on U(VI) adsorption on ferrihydrite at pH > 6. Zeta potential measurements indicated that U(VI) was adsorbed as a cationic species (SO-UO2+) in the absence of carbonate and as anionic U(VI) complexes in the presence of carbonate at neutral pH. FTIR spectroscopic measurement of adsorbed U(VI) suggested that it was retained as uranyl carbonate complexes in the presence of carbonate. An increase in carbonate concentration caused a shift in the antisymmetric stretching vibration of the uranyl (UO2(2+)) U-O bond toward lower wavenumbers, which indicated an increasing carbonate effect in the adsorbed uranyl carbonate complexes. The adsorbed U(VI) species were successfully incorporated into a surface complexation model to describe the adsorption of U(VI) by ferrihydrite from artificial solutions and contaminated water.