Wu Jianfeng, Xu Qichu, Bai Tao
Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an, Shan'Xi 710024, China.
Appl Radiat Isot. 2007 Aug;65(8):901-9. doi: 10.1016/j.apradiso.2007.04.004. Epub 2007 Apr 13.
The equilibrium and kinetic properties of Am(III), Eu(III) and Cs(I) ions adsorption by three weathered coals (WCs) from China, have been investigated in batch stirred-tank experiments. The effects of contact time, solution acidity and initial sorbate concentration on the adsorption of Am(III), Eu(III) and Cs(I) by Yuxian(YX) Tongchuan (TC) and Pingxiang (PX) WC were evaluated. The radionuclide ions are able to form complex compounds with carboxylic and phenolic groups of WCs and they are also bounded with phenolic groups even at high acidity reaction solution (>0.1 mol/L). Mechanisms including ion exchange, complexation and adsorption to the coal surface are possible in the sorption process. The acidity of the solution played an important role in the adsorption. Even acidity as high as 0.1 mol/L, 60% of Am(III) or Eu(III), 40% of Cs(I) were found to be sorbed on the YX WC, which had the best adsorption capacity for Am(III) and Eu(III). Our batch adsorption studies showed the equilibrium adsorption data fit the linear Langmuir and Freundlich adsorption isotherm. The maximum equilibrium uptake of Eu(III) were 0.412, 3.701, 5.446 mmol/g for JXWC, TCWC and YXWC, respectively.
通过间歇搅拌槽实验，研究了中国三种风化煤（WC）对镅（III）、铕（III）和铯（I）离子的吸附平衡和动力学性质。评估了接触时间、溶液酸度和初始吸附质浓度对蔚县（YX）、铜川（TC）和平乡（PX）风化煤吸附镅（III）、铕（III）和铯（I）的影响。放射性核素离子能够与风化煤的羧基和酚基形成络合物，即使在高酸度反应溶液（>0.1mol/L）中，它们也与酚基结合。吸附过程中可能存在离子交换、络合和吸附到煤表面等机制。溶液酸度在吸附过程中起重要作用。即使酸度高达0.1mol/L，仍发现60%的镅（III）或铕（III）、40%的铯（I）被吸附在对镅（III）和铕（III）具有最佳吸附能力的蔚县风化煤上。我们的间歇吸附研究表明，平衡吸附数据符合线性朗缪尔和弗伦德利希吸附等温线。JXWC、TCWC和YXWC对铕（III）的最大平衡吸附量分别为0.412、3.701、5.446mmol/g。
