亚铁氰化镍对铯离子的吸附机理研究

摘要

The nickel hexacyanoferrate (KNiFC) compound is often applied for the ion adsorption of cesium and strontium in low-level radioactive wastewater treatment .In this work , the co-precipitate method was used for the preparation of KNiFC using K4 Fe(CN)6 and Ni(NO3 )2 as raw materials .Then this compound was added into the aqueous solution of CsCl with a certain molar ratio .The mixture was shaken with an oscillator for completely adsorbing cesium ions in KNiFC .The morphology ,structure , adsorption stoichiometry and molar ratio of KNiFC before and after cesium ion adsorp-tion were analyzed with transmission electron microscope (TEM ) ,atomic adsorption spectrophotometer (AAS ) ,X-ray diffraction (XRD ) ,X-ray fluorescence (XRF ) and Mossbauer spectrum .The results indicate that the obtained KNiFC has a 15-20 nm crys-tal size and ellipsoidal shape .Cs+ is adsorbed mainly by exchanging with the K + in KNiFC .The phase structure of KNiFC is obviously changed after adsorption ,but still maintains a good symmetry .%亚铁氰化镍（KNiFC ）配合物常用于对放射性废水中铯、锶等放射性离子的吸附。本文以Ni（NO3）2和K4 Fe（CN）6为原料通过共沉淀法制备KNiFC配合物，将配合物与CsCl溶液按一定比例混合以吸附溶液中的Cs＋，通过TEM、原子吸收分光光度计、XRF、XRD、穆斯堡尔谱等手段对KNiFC吸附Cs＋前后的形貌、结构、吸附化学计量学及各元素的摩尔比进行表征来探讨KNiFC对Cs＋的吸附机制。结果表明：KNiFC具有粒径约为15～20 nm的椭球形特征，且溶液中的Cs＋主要通过与KNiFC中的K＋交换而达到吸附效果；吸附后，KNiFC晶体结构发生了较大变化，但依旧保持了良好的对称性。