咖啡壳吸附亚甲基蓝和碱性品红的性能研究

Adsorptive Performance of Coffee Shell on Methylene Blue and Basic Fuchsin in Aqueous Solution

研究了咖啡壳对亚甲基蓝和碱性品红的吸附性能,考察了咖啡壳的粒径、投加量、溶液p H、吸附时间、温度等条件对吸附效果的影响。应用准一级动力学方程和准二级动力学方程模拟了咖啡壳吸附亚甲基蓝和碱性品红的动力学过程,结果表明准二级动力学方程适合描述整个吸附过程。文中计算了吉布斯自由能(ΔG0)、焓变(ΔH0)、熵变(ΔS0)等热力学参数,ΔG0、ΔH0均小于0、ΔS0大于0,说明此吸附过程是一个自发的无序的放热过程。

This paper mainly focuses on the absorptive properties of coffee shell on methylene blue and basic fuchsine. And it investigated how adsorption capacities was affected by coffee shell size, adsorbent content, pH, absorption time and temperature. Quasi-order kinetic equation and quasi-second-order equation were used separately to simulate the kinetics process of absorptive properties of coffee shell to methylene blue and basic fuchsin. The results showed that the pseudo-second kinetic equation was suitable for describing the whole adsorption process. The thermodynamic parameters of Gibbs free energy （ΔG^0）, enthalpy （ΔH^0） and entropy change （ΔS^0） were calculated and ΔG^0〈0, ΔH^0〈0 and ΔS^0〉0 were abtained, which indicating that this adsorption process is a spontaneous, disorderly and exothermic process.