含铯废水中亚铁氰化物的粒径分布及组成分析

Particle size distribution and composition analysis of ferrocyanide in wastewater containing cesium ions

亚铁氰化物是处理含Cs^(+)离子放射性废水的一种重要方法。为了研究亚铁氰化物处理Cs^(+)离子时的置换机理以及基础性质,本文按照M^(2+)/Fe(CN)64-=1.33的比例投加共沉淀剂(其中M^(2+)代表了Ni^(2+)、Cu^(2+)、Co^(2+)、Cd^(2+)),在不同的模拟水样中制备了亚铁氰化物。利用激光粒度分布仪器考察了M(NO_(3))_(2)与亚铁氰化钾形成共沉淀物的粒径分布。利用高氯酸和加热装置对制备的亚铁氰化物进行溶解以分析其组成。结果表明:共沉淀物的粒径几乎全部处于0.1~10μm;Cs^(+)和Mg^(2+)离子主要取代K^(+)和部分取代M^(2+)离子,Na^(+)离子只取代K^(+)离子;对1.00 mg/L Cs^(+)离子的去除率高于99%;对其吸附容量高达310mg/g以上。总之,亚铁氰化物粒径较小,Na^(+)和Mg^(2+)存在不会影响亚铁氰化物对Cs^(+)离子的去除。

Ferrocyanide is an important water treatment method for radioactive Cs^(+)-containing wastewater.To explore the replacement mechanism and the basic properties of ferrocyanide when treating Cs^(+)ions,ferricyanide was produced in different simulated solutions by the addition of a co-precipitant at a ratio of M^(2+)/Fe(CN)_(6)^(4-)=1.33(where M^(2+)is Ni^(2+),Cu^(2+),Co^(2+),or Cd^(2+)).The particle size distribution of the co-precipitates formed by M(NO_(3))_(2)and potassium ferrocyanide was examined using a laser particle size distribution instrument.The obtained ferrocyanides were dissolved in perchloric acid and a heating device to analyze their composition.The results showed that the particle size of the co-precipitate is almost in the range of 0.1~10μm.Cs^(+)and Mg^(2+)ions primarily replaced K^(+)ions and partially replaced M^(2+)ions in the co-precipitate,and Na^(+)ions only replaced K^(+)ions.The re-moval rate of 1.00 mg/L Cs^(+)ions is higher than 99%,and the adsorption capacity is above 310 mg/g.In conclusion,the particle size of ferricyanide is small,and the existence of Na^(+)and Mg^(2+)does not influence the removal of Cs^(+)ions by ferricyanide.