摘要
采用间歇试验研究白陶土对Pb(Ⅱ)的吸附特性,考虑了吸附剂用量、初始溶液pH、离子强度、反应时间、温度及铅初始浓度等因素的影响.间歇试验结果表明,吸附剂用量、pH、离子强度等因素对铅去除影响显著,温度对白陶土吸附能力影响相对较小.在20℃、pH0=5.5、初始浓度200 mg/L、吸附剂用量1g/L下,白陶土对Pb(Ⅱ)的吸附量可达136.33mg/g.动力学试验结果表明,白陶土对Pb(Ⅱ)的吸附为快速反应,10min时的吸附量为最大吸附量的80%,180min内即达到吸附平衡,伪二级动力学模型对白陶土吸附Pb(Ⅱ)的过程拟合较好.Langmuir模型可较好地预测白陶土对Pb(Ⅱ)的等温吸附.热力学试验结果表明,白陶土对Pb(Ⅱ)的吸附为自发与吸热反应,升温有利于吸附反应的进行.白陶土对Pb(Ⅱ)的吸附机制为离子交换、静电吸附与络合反应.
Batch experiments were conducted to study the adsorption behaviors of Pb（Ⅱ）on white pottery clay.Several experimental conditions,including dosage of adsorbent,initial solution pH, ionic strength,contact time,temperature and initial concentration of lead,were investigated.The experimental results indicate that the lead removal is strongly dependent on dosage of adsorbent,pH and ionic strength.The temperature has a negligible effect on the adsorption capacity of white pottery clay.The maximum adsorption of Pb（Ⅱ）on white pottery clay is 136.33 mg/g at 20 ℃,with an initial concentration of 200 mg/L,pH0 =5.5 and dosage of adsorbent of 1 g/L.The kinetics＇ experimental results show that the adsorption of Pb（Ⅱ）on white pottery clay is a fast process and could reach equilibrium within 180 minutes.More than 80% of the maximum adsorption capacity can be reached in 10 minutes.The adsorption process of Pb（Ⅱ）on white pottery clay is well described by the pseudo-second order kinetic model.Langmuir model is found to be applicable to the prediction of isothermal adsorption of Pb （Ⅱ）on white pottery clay.The thermodynamics＇ experimental results show that the adsorption of Pb（Ⅱ）on white pottery clay is a spontaneous and endothermic process. Raising temperature makes for the adsorption process.The adsorption mechanism mainly involves ion exchange,electrostatic interaction and complexation.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2016年第4期396-405,共10页
Journal of Dalian University of Technology
基金
国家自然科学基金资助项目(51179023)
关键词
白陶土
铅
吸附
平衡
动力学
热力学
机制
white pottery clay
lead
adsorption
equilibrium
kinetic
thermodynamic
mechanism
