活性炭对苯胺、对硝基苯胺共吸附性能的研究

Co-adsorption of Aniline and p-Nitroaniline on Activated Carbon

文章采用静态吸附法研究活性炭对苯胺和对硝基苯胺混合溶液中各组分的共吸附过程。研究结果表明,在吸附开始阶段,活性炭对各组分的吸附速率均较大,随着吸附时间的延长,其吸附速率减慢。活性炭对两组分吸附的动力学行为均遵循Bangham速率方程,且由于苯胺的分子极性较小,活性炭对苯胺的吸附速率比对硝基苯胺对大。对于不同浓度比的混合溶液,吸附质浓度越大,活性炭对其吸附量越大。混合溶液中对硝基苯胺的浓度越大,活性炭的总吸附速率和吸附量越大。当pH值为4～5时活性炭对苯胺的吸附性能优,而pH值对活性炭对对硝基苯胺的吸附量影响较小。活性炭对两组分的吸附量和吸附速率都随着温度的升高而增加,说明吸附反应为吸热反应。活性炭对苯胺的吸附反应活化能为24.21kJ/mol,对对硝基苯胺的吸附反应活化能为54.98kJ/mol,温度升高更有利于活性炭对对硝基苯胺的吸附。

Co-adsorptive process of aniline and p-nitroaniline on activated carbon was studied in the lab using static adsorption method. The experimental result showed the adsorption velocity decreased for each of the components with the elapse of the adsorption time; the adsorptive behavior followed Bangham velocity equation and moreover, adsorption velocity of aniline is higher that of p-nitroaniline due to the smaller molecular polarity of aniline. As to p-nitroaniline, the adsorptive velocity and amount are proportional to its concentration in the solution. It has been proven that the adsorption is a kind of endothermic reaction in terms of co-adsorptive process of aniline and p-nitroaniline on activated carbon. Affecting parameters such as pH and temperature were also investigated regarding their influences on the activated carbon＇s adsorption capacity.