斜发沸石对模拟核素Co^(2+)的吸附/解吸动力学研究

Study on Adsorbing & Desorbing Kinetics of Simulated Nuclide Co^(2+) on Clinoptilotite

以Co(NO3)2.6H2O为核素源、新疆某地所产斜发沸石为吸附剂,研究斜发沸石对Co2+的动力吸附/解吸效果。探讨了吸附时间、K+初始浓度与吸附量的关系。用pH值为6的水溶液对饱和吸附了Co2+的斜发沸石进行解吸。结果表明:斜发沸石对Co2+的吸附在2 h能达到最大吸附率的99.5%,Freundlich吸附等温式能对吸附曲线进行很好的描述,单位质量沸石对Co2+的最大吸附量为31.34 mg/g,以阳离子交换吸附为主。4.5 h后解吸率为5.76%,解吸速率远小于吸附速率,解吸量与解吸时间的自然对数呈明显线性关系,用Elovich方程对解吸曲线进行拟合,R=0.9995,拟合方程为:qt=0.23893+0.30056lnt。理论上将15%的Co2+解吸出来约需1943天。该斜发沸石固Co2+能力很强,对于处理含Co2+放射性废液具有重要的意义。

With Co（NO3）2.6HzO for nuclide source, clinoptilotite in Xinjiang for adsorbent, kinetic adsorption and desorption effect of clinoptilotite forCO^2＋ was studied. The relationship between adsorption time, CO^2＋ initial concentration and the adsorption quantity was discussesed. With pH=6 water in solution, clinoptilotite that saturated adsorption of CO^2＋ was desorbed. The results showed that the adsorption of clinoptilotite to CO^2＋ in 2 h can achieve maximum absorption 99.5%. Adsorption curve fits Freundlich isotherm very well. The maximum adsorption capacity is 31.34 mg/g, and adsorption was cation exchange adsorption principally. After 4.5 h, desorption rate is 5.76 %. Desorption speed rate is far less than that of adsorption rate. Desorption capacity and the natural logarithms of desorption time has obvious linear relation. Elovich equation was used for fitting desorption curve, R=0.9995, the regression equation is q1=0.23893＋0.300561nt. Desorption out 15 % CO^2＋, theoretically the time is 1943 days. The clinoptilotite having the strong ability of fixation CO^2＋, for treating of CO^2＋radioactive waste liquid has the vital significance.