Effect of Humic Acid on the Sorption and Kinetic Desorption of Radiocaesium Ions on/from Na-Rectorite Studied by the Batch Technique and a Chelating Resin
Effect of Humic Acid on the Sorption and Kinetic Desorption of Radiocaesium Ions on/from Na-Rectorite Studied by the Batch Technique and a Chelating Resin
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DOI：
10.1260/026361706780810294
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发表时间：
2006-09
影响因子：
2.9
通讯作者：
W. Wu;Q. Fan;S. Lu;S. Niu;X. Wang
中科院分区：
文献类型：
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作者：
W. Wu;Q. Fan;S. Lu;S. Niu;X. Wang
在常温下，用间歇法研究了pH值为5.0±0.2的钠累托石对放射性铯离子的吸附。同时考察了腐植酸对Cs+离子吸附的影响。结果表明，腐植酸的存在显著提高了累托石对Cs+的吸附。通过添加螯合树脂，研究了Cs+在裸累托石和HA结合累托石上的动力学解吸行为。结果表明，累托石对Cs+离子的吸附产生了可逆和不可逆两种吸附位置，不可逆吸附位置至少由两种类型组成，即弱吸附和强吸附。随着老化时间的延长，吸附在固体胶体表面的Cs+离子可以从弱位置向强位置移动，而对应于不可逆吸附的Cs+离子不能移动，与老化时间无关。所获得的结果对于评估放射性核素在自然环境中的行为很重要。
The sorption of radiocaesium ions onto Na-rectorite was studied at a pH value of 5.0 ± 0.2 using the batch technique under ambient conditions. The effect of humic acid on the Cs+ ion sorption was also investigated. The results indicated that the presence of humic acid significantly enhanced the sorption of Cs+ ions onto rectorite. The kinetic desorption of Cs+ ions from bare and HA-bound rectorite, respectively, was studied by the addition of a chelating resin. The results obtained indicated that Cs+ ion sorption onto rectorite generated reversible and irreversible sorption sites, with the irreversible sorption sites consisting of at least two kinds, i.e. “weak” and “strong”. With increasing ageing time, surface-sorbed Cs+ ions on solid colloids can move from “weak” sites to “strong” sites, whereas that corresponding to irreversible sorption are incapable of movement irrespective of the length of the aging time. The results obtained are important for the evaluation of the behaviour of radionuclides in the natural environment.