Water and Steam Chemistry Division, BARC Facilities, Kalpakkam, Tamil Nadu, India.
J Hazard Mater. 2011 Jul 15;191(1-3):110-7. doi: 10.1016/j.jhazmat.2011.04.046. Epub 2011 Apr 16.
Separation and isolation of radioactive cobalt ((60)Co), one of the main contributors towards the activity build up in nuclear reactors, is essential for radioactive waste volume reduction during nuclear reactor decontamination procedures. In this context, sorption of free and complexed Co(II), Cu(II) and nitrilotriacetic acid (NTA) on the biosorbent, chitosan was studied. A detailed investigation on the role of pH on sorption of Co(II), Cu(II) and NTA was done. Uptake capacities of the metal ions and NTA were measured within pH range of 2.0-7.0. At pH above 5, the NTA uptake capacities were found to be higher in presence of the metal ions than in their absence. Effect of NTA was found to be more pronounced on copper uptake than on cobalt uptake. Significant change in selectivity of chitosan towards metal ion uptake from NTA medium was observed with respect to change in pH. At pH 2.9, the uptake of cobalt was found to be more than that of copper, while the selectivity was reversed at pH 6.0. The respective selectivity coefficient (k(Co/Cu)) values were found to be 2.06 and 0.072.
放射性钴（(60)Co）的分离和隔离是核反应堆去污过程中减少放射性废物体积的关键，因为钴是导致反应堆活性增加的主要物质之一。在这种情况下，研究了螯合剂氮川三乙酸（NTA）和游离态及络合态的钴(II)、铜(II)在生物吸附剂壳聚糖上的吸附作用。详细研究了 pH 值对钴(II)、铜(II)和 NTA 吸附的影响。在 2.0-7.0 pH 值范围内测量了金属离子和 NTA 的吸附容量。在 pH 值高于 5 的情况下，发现存在金属离子时 NTA 的吸附容量高于不存在金属离子时的吸附容量。与钴相比，NTA 对铜的吸附影响更为显著。随着 pH 值的变化，壳聚糖对 NTA 介质中金属离子的吸附选择性发生了显著变化。在 pH 值 2.9 时，钴的吸附量大于铜的吸附量，而在 pH 值 6.0 时，选择性则相反。相应的选择性系数 (k(Co/Cu)) 值分别为 2.06 和 0.072。
