Experimental Study Of Mesoporous Carbon Materials In Adsorpting Bisphenol A

Carbon aerogel is one kind of structure controllable porous carbon materials in nanometer scale, it has continuous three-dimensional network structure, abundant porosity and large surface area, therefore, it has an wide application prospect in separation,adsorption, catalysis etc.In this paper, phenolic resin based carbon aerogels were prepared through acid catalyzed sol-gel method, through the comparison with ordinary commercial activated carbon in the removal of bisphenol A in water, the author found that carbon aerogel shows an obvious superiority. In order to clarify the mechanism on adsorption of bisphenol A, the activated carbon was modified by nitric acid oxidation process. After the characterization of activated carbon and carbon aerogels, their adsorption properties were studied through adsorbent dosage, initial concentration,pH temperature and adsorption time, etc. In addition, the adsorption mechanism were also studied by using the kinetics and thermodynamics model fitting.The ordinary activated carbon, activated carbon modified by nitric acid oxidation and carbon aerogels were characterized by SEM, BET. The results showed that the ash on activated carbon was greatly reduced by acid oxidation, the surface of modified activated carbon is smooth, and a large number of unequal size, irregular pores has been introduced. After modification, the surface area of activated carbon was reduced from400.8162m2/g to357.1521m2/g; Carbon aerogels have a large amount porosity, its surface area is586.539m2/g. The surface area which is formed by micropore accounted for40.3%. Adsorption experiments showed that the adsorption capacity of bisphenol A of the modified activated carbon was improved greatly, under the same conditions, the adsorbing capacity was increased from the original3.72mg/g to5.78mg/g, and the adsorption capacity of carbon aerogels of bisphenol A increased much and reached to11.93mg/g.The kinetic and thermodynamic analysis showed that the solution temperature has a greater influence on the adsorption, the adsorption capacity of activated carbon decreased with the increasing temperature, the adsorption capacity of carbon aerogels increased with the increase of temperature; pseudo second order kinetics model can describe the adsorption process of active carbon and carbon aerogel on bisphenol A well; Langrauir isotherm equation was more suitable for describing the adsorption properties of these two kinds of adsorbents on adsorpting bisphenol A; under acidic conditions, phenolic resin based carbon aerogel has an better effect on the desorption of bisphenol A.