摘要
研究了钠基凹凸棒土对重金属Co(Ⅱ)离子吸附行为。考察了接触时间、吸附剂浓度、p H值、离子强度、不同电解质离子、腐植酸(FA)和温度等因素对吸附率的影响。结果表明,凹凸棒土对重金属Co(Ⅱ)离子的吸附在较短时间内即可达到平衡且吸附过程较好地符合假二级动力学方程,体系pH值和离子强度是影响吸附过程的主要因素;离子交换和表面络合是主要的反应机理。通过热力学参数(△G°、△S°和△H°)的计算,证明钠基凹凸棒土对重金属Co(Ⅱ)离子的吸附是一个自发的吸热过程,较高的温度有利于反应的进行;实验数据能较好地符合Langmuir热力学模型。
The sorption effect of Na-attapulgite on heavy metal ion of Co(II)was studied.The experimental factors such as contact time,solid content,pH value,ionic strength,foreign ions,FA and temperature on the adsorption ratio were investigated.The results indicate that the sorption of Na-attapulgite on Co(II)ions achieves equilibration rapidly and can be described well by pseudo-second-order model.pH and ionic strength are the main impact factors and the sorption effect of Na-attapulgite on Co(II)ions is mainly dominated by ion exchange and/or outer-sphere surface complexation.The thermodynamic parameters(△G°,△S°,△H°)calculated from the temperature-dependent sorption isotherms indicated that the sorption of Na-attapulgite on Co(II)is an endothermic and spontaneous process and Langmuir model simulated the experimental data very well.
作者
张万旭
Zhang Wanxu(Sinopec Nanjing Chemical Industry Corporation Ltd.,Nanjing 210048,China)
出处
《煤炭与化工》
CAS
2018年第9期148-154,共7页
Coal and Chemical Industry
关键词
钠基凹凸棒土
重金属离子
吸附
热力学
动力学
废水
Na-attapulgite
heavy metal ion
sorption
thermodynamics
kinetics
wastewater
