摘要
研究了717载硫脲树脂对Pd2+的吸附热力学、动力学及脱附特性,考察了吸附时间、pH值、温度等因素对树脂吸附Pd2+的影响。结果表明:在pH=1—5时,吸附能力最好;等温吸附服从Freundlich经验式,在303—313 K条件下,Pd2+吸附量(质量比)为60—80 mg/g的吸附焓变为-29.24—-23.98 kJ/mol,自由能变为-8.00—-7.65 kJ/mol,吸附熵变为-70.10—-52.17 J/(K.mol)。吸附动力学符合Lagergren一级速率方程,303 K时吸附速率常数为0.022 min-1,颗粒内扩散是速率控制步骤之一,膜扩散也共同影响着吸附过程。303 K下树脂静态累积饱和吸附量为144.2 mg/g。用质量分数8%硫脲-1 mol/L HCl混合液可以将树脂上的Pd2+完全解吸。
The adsorption thermodynamics,kinetics and desorption properties of Pd2＋ on the 717 carried thiourea resin were studied.The influences of various factors such as adsorption time,pH value and temperature on the adsorption of Pd2＋ were discussed.The experimental results show that the maximum adsorption ability of the carried thiourea resin occurs at pH=1-5;the adsorption behavior of Pd2＋ on the carried thiourea resin obeys the Freundlich isotherm;at 303-313 K and the amount adsorbed of Pd2＋ of 60-80 mg/g（mass ratio）,the adsorption enthalpy is-29.24——23.98 kJ/mol,the free energy is-8.00——7.65 kJ/mol,the entropy of adsorption is-70.10——52.17 J/（K·mol）.The adsorption kinetics data fit well in with the Lagergren pseudo-first order rate equation,and the adsorption rate constant is 0.022 min-1 at 303 K.Besides the intra-particle diffusion,other processes such as film diffusion also simultaneously affect the rate of adsorption.The statically saturated adsorption capacity of resin is 144.2 mg/g at 303 K.Pd2＋ loaded resin can be completely eluted with 1 mol/L HCl solution containing mass fraction 8% thiourea.
出处
《化学工程》
CAS
CSCD
北大核心
2010年第9期6-10,共5页
Chemical Engineering(China)
基金
广西自然科学基金资助项目(0991285)
玉林师院高层次人才科研基金资助项目
关键词
载硫脲树脂
Pd2+
吸附
脱附
carried thiourea resin
Pd2＋
adsorption
desorption
