膨胀石墨对碱性嫩黄和聚乙二醇的竞争吸附性能

Adsorption and competitive adsorption of auramine lake yellow O and poly ethylene glycol on expanded graphite

以硫酸为插层剂,高锰酸钾为氧化剂制备了膨胀石墨(EG)吸附剂.以聚乙二醇PEG(相对分子质量为10 000)和染料碱性嫩黄-O(ALYO)为吸附质,研究了其在EG上的吸附、竞争吸附热力学及动力学性能.研究表明:1)EG对ALYO和PEG都有一定吸附能力,ALYO和PEG在EG上的吸附及竞争吸附等温线均为I型;2)在2组分共存竞争吸附中,第2种吸附质的存在会降低第1种吸附质在EG上的吸附量,ALYO和PEG在EG相同结构位点上存在竞争吸附;3)竞争吸附中EG对2种组分的总吸附量高于单组分体系中单个组分的吸附量,ALYO和PEG可以分别吸附在EG的不同结构位点上;4)吸附和竞争吸附过程均可以用准二级模型来描述,吸附速率常数随吸附过程温度的升高而增大;5)吸附作用以物理吸附为主.

Expanded graphite（EG） adsorbent was prepared with KMnO4 as oxidant,H2SO4 as inserting reagent.Poly ethylene glycol（PEG） with a molecular weight of 10 000 and Auramine lake yellow O（ALYO）were used as adsorbates,and theirs adsorption,competitive adsorption kinetics and thermodynamic capacities on EG were investigated.The results are： 1） EG has adsorption capacity for both PEG and ALYO,the adsorption and competitive adsorption isotherms are all type I;2） In the competitive adsorption,the existence of the other component would decrease the adsorbance of EG for single component,which might be caused by the competition of PEG and ALYO for the same adsorbing site;3） The total adsorbances for PEG and ALYO in competitive adsorption are higher than the adsorbance of PEG or ALYO in single system,these adsorbates can also be adsorbed on different adsorbing site;4） No matter adsorption or competitive adsorption of PEG and ALYO on EG,the kinetic models can all be described with pseudo second-order kinetic model,and adsorption rate increases with the increase in temperature;5） Physical adsorption is the main action.