Study Of Sorbing Oil And Recycling Of Exfoliated Graphite Mounted With TiO₂

The purpose of this dissertation is to develop a kind of absorbent having high sorption and recycling capacity,offering an efficient approach to remove floating oil on seawater.Exfoliated graphite mounted with TiO₂ (EG/TiO₂) and Exfoliated graphite mounted with TiO₂ doped by NiO (EG/TiO₂/NiO) were prepared by mixing catalyst materials with exfoliated graphite(EG) as supporter.These compounds could work as the absorbent of oil and also as the catalyst for the decomposition of absorbed oil,which was likely to be a new focus of study on environmental material.Exfoliated graphite was prepared by using chemical method,and the affecting factors on expandable volume of exfoliated graphite were studied. Results showed that expanded graphite having an exfoliation volume of 250 ml/g could be produced under the optimum conditions with the weight ratio of natural flake graphite:sulfuric acid being 1:3, the volume ratio of sulfuric acid:hydrogen peroxide being 1:0.1, reaction time of 90 min, reaction temperature of 50℃,exfoliation temperature of 1000℃,and exfoliation time of 20 s.Based on this, EG/TiO₂ and EG/ TiO₂/NiO were prepared.In addition,the microstructure and phase of these absorbents were studied by using SEM and XRD,respectively.The maximum sorption capacities and the time needed for maximum sorption of exfoliated graphite for gear oil,crude oil, hydraulic pressure oil and gasoline was determined.The effect of the temperature and viscosity of oil, the expandable volume of exfoliated graphite, the PH value of water on maximum sorption capacity of exfoliated graphite was studied.Moreover,the relationship between the maximum sorption capacity of exfoliated graphite mounted with TiO₂ of crude oil and the content of TiO₂ in it was investigated. The affecting factors on decomposition degree of crude oil sorbed intoabsorbents were investigated by using FT-IR.The affecting factors on recycling rate of absorbents were studied.Results showed that exfoliated graphite mounted with TiO₂ doped by NiO had the highest recycling rate among used absorbents.