| Aromatic organic compounds such as benzene, toluene are toxic, carcinogenic, and penetrating into water are difficult to degrade, remove these organic pollutants from the water is critical, select the appropriate adsorbent to remove such pollutants in water is currently one of the most important methods used. However, due to the shortcomings of the present adsorbents, small pore volume, wide pore distribution, low specific surface area and poor selectivity, the adsorptive removal of pollutants is limited. Aerogel is recognized as the world’s lightest material, with good adsorption properties.However,aerogel itself has a certain defect, leading to its practical application is blocked. Therefore, the preparation of composite aerogel to improve its performance,so that the application of a broader perspective.This paper used tetraethoxysilane(TEOS) and graphene oxide(GO),carbon nanotubes(CNTs-COOH),graphene oxide/carbon nanotubes oxide(GO/CNTs-COOH) as the raw materials.Graphene/silica aerogels(GS), carbon nanotubes/silica aerogels(CS), grapheme/carbon nanotubes/silica aerogels(GCS) with different content of GO,CNTs-COOH,GO/CNTs-COOH were synthesized via sol-gel method, combined with surface modification, ambient drying process and high temperature reduction. Through the consider of the density and the specific surface area,etc. The best GS,CS,GCS was obtained and the adsorption of benzene and toluene solution was studied compared with the activated carbon and SiO2 aerogel.The results show that the specific surface area of the silica gel improved greatly by the addition of 3% GO, 3% CNTs-COOH and 3% GO/CNTs-COOH ,which made the porousand homogeneous structure.The density is 180 kg/m3, 160 kg/m3, 250 kg/m3 respectively,the specific surface area and pore diameter are 1039 m2/g, 16.56 nm, 1021 m2/g, 15.39 nm,1030 m2/g and 16.10 nm, respectively. The specific surface area of SiO2 aerogels was 979 n /g, which was obviously improved. The adsorption of benzene and toluene reaches 180 mg/g and 210 mg/g, respectively, approximately 2.5 times of the amount of activated carbon adsorption. The adsorption process was in accordance with the Langmuir isotherm model.PH 3 and pH 7, the adsorption of benzene and toluene was better than pH 11. As in acidic and neutral conditions, the composite aerogel dispersion is better, compared to the adsorption under alkaline conditions, but little effect. In addition, the adsorption of toluene aqueous solution is greater than the adsorption of benzene aqueous solution. |
