(南京理工大学 化工学院,南京 210094)
摘 要: 通过静态吸附实验,研究了Pb2+在001×7强酸性阳离子交换树脂上的吸附行为,并从热力学和动力学方面对吸附过程进行了分析,用红外光谱的方法探讨了001×7树脂吸附Pb2+的机理。结果表明:在所研究的浓度范围内,Pb2+在001×7树脂上的吸附平衡数据符合Freundlich等温吸附方程,吸附为自发进行的放热过程;液膜扩散为Pb2+在001×7树脂上吸附速率的主要控制步骤,随着振荡频率的增加,吸附速率会逐渐增大;最佳的吸附pH在4左右,用3 mol/L的硝酸对饱和树脂进行洗脱再生,洗脱率可达98%以上;298 K温度下树脂的静态饱和吸附容量为414 mg/g(湿树脂)。
关键字: 铅;强酸性阳离子交换树脂;吸附;热力学;动力学;机理
(School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China)
Abstract:The adsorption behavior of Pb2+ on 001×7 strong-acid cation exchange resin was studied with the static method and the adsorption process was analyzed from thermodynamics and kinetics aspect. The adsorption mechanism of Pb2+ on 001×7 resin was discussed by IR spectra. The experimental results show that, in the studied concentration range, the equilibrium adsorption data fit to Freundlich isotherms. Adsorption is an exothermic process running spontaneously. Kinetic analysis show that the adsorption rate is mainly governed by liquid film diffusion and with the increment of surge frequency, the adsorption rate will increase. The pH value of best adsorption condition is 4. Saturated resin can be regenerated by 3 mol/L nitric acid, the elution percentage is over 98%. The maximal static saturated adsorption capacity is 414 mg/g (wet resin) in 298 K.
Key words: lead; strong-acid cation exchange resin; adsorption; thermodynamics; kinetics; mechanism