ZnS/AC复合材料的制备及其对铀酰离子的吸附性能

Preparation of ZnS/AC composites and its adsorption performance of uranyl ions in aqueous solution

摘要:

采用化学沉淀法制备了活性炭负载纳米硫化锌的复合材料ZnS/Ac，利用SEM、EDS、XRD、FTIR、BET等手段对该复合材料进行了表征分析。研究了ZnS/Ac对水溶液中铀酰离子的吸附性能，探讨了吸附时间、初始铀酰离子浓度、pH值、吸附剂投加量、温度等因素对吸附性能的影响，并对吸附过程进行了热力学和动力学模拟，探讨了吸附机理。结果表明：ZnS/Ac的比表面积为201.1961 m2/g，比活性炭的比表面积（165.0240 m2/g）明显增大，平均孔径为4.70 nm，孔容为0.038 cm3/g。在初始质量浓度为35 mg/L，pH=6，吸附时间为120 min，投加量为10 mg，处理温度为50 ℃的条件下，吸附剂对铀酰离子的吸附量为64.4736 mg/g。吸附过程符合准二级动力学方程和Langmuir 吸附等温线模型，热力学参数<0、>0、>0，表明该吸附是一个自发的吸热过程。

Abstract:

The composite ZnS/Ac of nano-zinc sulfide supported on activated carbon was prepared by chemical precipitation method. The composites were characterized by SEM, EDS, XRD, FTIR and BET. The adsorption performance of ZnS/Ac on uranyl ions in aqueous solution was studied. The effects of adsorption time, initial uranyl ion concentration, pH value, adsorbent dosage and temperature on adsorption performance were discussed. Thermodynamic and kinetic simulations explored the adsorption mechanism. The results show that the specific surface area of ZnS/Ac is 201.1961 m2/g, which is significantly higher than that of activated carbon (165.0240 m2/g). The average pore diameter is 4.70 nm and the pore volume is 0.038 cm3/g. At an initial mass concentration of 35 mg/L, pH=6, adsorption time of 120 min, dosage of 10 mg, and treatment temperature of 50 ?C, the adsorption capacity of the adsorbent for uranyl ion is 64.4736 mg/g. The adsorption process conforms to the pseudo second order kinetic equation and the Langmuir adsorption isotherm model. The thermodynamic parameters<0、>0、>0， indicate that the adsorption is a spontaneous endothermic process.