新型铯选择性吸附剂的合成及性能

摘要

A novel inorganic selective adsorbent for cesium,potassium nickel hexacyanofer-rate (KNiFC/Ni)based on the surface of nickel matrix,was synthesized in site by a simple water chemical method.Its surface chemical composition is K1.4 Ni1.3 Fe(CN)6 determined by X-ray photoelectron spectrometry (XPS),and the crystalline structure of KNiFC is face-centered lattice with a=0.9 9 6 0 nm determined by the X-ray diffractometry (XRD),and its thick is about 40-80 nm.The adsorbent is stable in aqueous media.It has high adsorption capacity,rapid adsorption kinetics and high selectivity for Cs+.The distribution coefficient (Kd)for 137 Cs is up to 105 mL/g,and even in the 1.0 mol/L NaNO3 solution,it is still over 103 mL/g.It is found that the adsorbent for 137 Cs is typical ion-exchange mechanism. Because NH+4 ion radius is close to Cs+,NH+4 has the strongest competition as compared to Na+,Sr2+,and H+.The adsorbent is promising for 137 Cs separation and treatment of 137 Cs liquid waste .%在金属镍粉表面原位合成了与金属基体紧密结合的亚铁氰化镍钾(KNiFC/Ni)吸附剂。经分析,其表面为面心立方晶系的亚铁氰化镍钾(KNiFC),厚度约为40~80 nm,晶格参数为0.9960 nm,化学组成可表示为K1.4 Ni1.3 Fe(CN)6。结果表明：该吸附剂不水解,对137 Cs具有较高的吸附容量,非常快的吸附速率,很高的选择性,Cs的吸附分配系数(Kd)可达105 mL/g,即使在1.0 mol/L NaNO3溶液中,Kd 值也大于103 mL/g；该吸附剂吸附137 Cs为典型的离子交换机制,NH+4由于具有和Cs+相近的离子半径所以竞争最为强烈。本吸附剂有望用于含铯废液的处理及137 Cs的分离或提取。