Petroleum products and water sorption by expanded graphite enhanced with magnetic iron phases

The liquid hydrocarbon sorption behavior of expanded graphite (EG) enhanced with iron phases (α-Fe, α-Fe₂O₃, Fe₃O₄, and FeOOH) was studied. Iron phases were shown not to affect the porous structure of EG or its sorption capacity. The utilization of the three EG samples with the high magnetic saturation (10.5, 30, and 35 emu/g) as magnetic sorbents for the petroleum products spill response was considered. The requirements in values of the magnetic saturation of EG to be attracted by a magnet were estimated. Also, the water sorption of EG was studied, which competes with liquid hydrocarbons for pore spaces. The method of the dynamic contact angle measurement in water is suggested as a useful characterization of EG surface chemistry for this application.