ИСТИНА

Nowadays, amount of oil spills is increased causing significant harm to the ecosystem and leads to negative economic and social consequences. Therefore containment of oil spills is an actual problem. Existing methods of containment, such as mechanical collection, controlled burning, dispersion are restricted for use, depending on environmental and weather conditions. One of the perspective areas that can be used under the restriction of other methods is technology based on the use of sorbents. Exfoliated graphite is a promising sorbent of medium and heavy hydrocarbons. Limiting factor to widespread use of this technology is the need for the emplacement of a large amount of the sorbent to the place of pollution and collection of sorbent after sorption. Iron oxides modification of exfoliated graphite leads to the appearance of magnetic properties, which significantly simplifies its use as a sorbent, because all above mentioned procedures can be carried out with use of a magnet [3]. That’s why the aim of our research work was to obtain exfoliated graphite modified with iron compounds and to study its sorption and magnetic properties. For the preparation of modified exfoliated graphite we have synthesized the samples of expandable graphite doped with iron oxides by three ways: hydrolysis of graphite nitrate of the second stage with iron (III) nitrate solution and iron (III) hydroxide sol, impregnation of expandable graphite with iron (III) nitrate solution and iron (III) hydroxide sol, electrochemical polarization of graphite in iron (III) nitrate electrolyte. After preparation, expandable graphite was subjected to the thermal shock at 250-900 0C with formation of expanded graphite. Porous structure of samples of exfoliated graphite was determined by dynamic drying method using benzene. Sorption isotherm and pore size distribution in samples are depended on preparation methods. Sorption capacity of the samples toward to medium and heavy hydrocarbons was measured by standard technique ASTMF 726-99. The sorption capacity reaches a value of 120 g of hydrocarbon per 1 g of exfoliated graphite. Phase composition and morphology of the samples were investigated by X-ray diffraction analysis, SEM and EDX analysis, Mossbauer spectroscopy. It was determined that particles of α-Fe2O3 and γ-Fe2O3 are distributed over surface of exfoliated graphite, the size of particles depending on the conditions of synthesis. The magnetic measurements were carried out using Faraday balance at a room temperature. To increase the magnetic saturation of the sorbent exfoliated graphite was further reduced in hydrogen at 350 0C. It was shown that exfoliated graphite modified with iron oxides is a promising sorbent toward to medium and heavy hydrocarbons