钠基膨润土吸附酸性品红的动力学与热力学

Thermodynamics and Kinetics of Adsorption of the Acid Red by Na-bentonite

用膨润土作为吸附剂,以酸性品红为模拟染料废水,考察了吸附剂的投加量、吸附时间、温度和pH值等因素对酸性品红染料吸附效果的影响,并研究了其在膨润土上的吸附平衡和吸附动力学。实验结果表明:用300目的钠基膨润土,pH 6,室温振荡50 min,其吸附量达256.41 mg/g,且吸附量随温度的升高而增大;通过计算不同温度下的热力学参数ΔG0,ΔH0和ΔS0,证实吸附为一自发的吸热过程;等温吸附平衡符合Langmuir模型;吸附动力学更适合准二级反应方程。

The dyestuff waste water is China＇s currently one of the main harmful and difficult processing industrial waste waters.Na-bentonite was used as an adsorbent to adsorb Acid Red from aqueous solution at various contact time,initial pH and temperature,and the results showed that in the conditions of pH6 and reaction time 50 min,the adsorption capacity was 256.41mg·g^-1 at the room temperature,and it became much bigger with the temperature hoisted.The adsorption process was spontaneous and endothermic by calculating thermodynamic parameters ΔG^0,ΔH^0 and ΔS^0 in the different temperatures.The adsorption isotherms fit for the Langmuir model accurately.The adsorption reaction was found to obey a second-order rate.