E. E. Sirotkina

Oxidation of hydrocarbons in a barrier discharge reactor

The oxidation of n-hexane, cyclohexane, cumene (isopropylbenzene), and cyclohexene in a barrier discharge reactor under conditions ensuring effective product transport out of the discharge zone was studied. It was shown that hydrocarbon oxidation reactions can be carried out in barrier discharge plasma reactors with a fairly high selectivity. The oxidation of n-hexane, cyclohexane, and cumene primarily yields the hydroxy and carbonyl compounds alcohols, aldehydes and ketones. The major product of cyclohexene oxidation is epoxycyclohexane (~62 wt %).

Peat-based sorbents for the purification of contaminated environments: A review

The review surveys the most interesting published data on the development of sorbents based on peat and the applicability of these sorbents to the removal of petroleum, petroleum products, metals, surfactants, etc., from contaminated environments. Peat is an inexpensive, accessible, and effective sorbent for a wide range of biosphere pollutants. It can be used either individually or as a constituent of combined sorbents and complex composite materials.

Preparation and study of properties of sulfonic acid ion exchangers based on polypropylene fibrous material

The possibility of raising the static exchange capacity of strongly acidic ion-exchange materials produced by grafting of styrene onto polypropylene fibers, with the subsequent sulfonation of the products synthesized, was analyzed. The chemical and osmotic stabilities of the sulfonic cation exchangers obtained and their frost resistance in freeze-thaw cycles were studied.

Transformations of n-Hexane and Cyclohexane by Barrier Discharge Processing in Inert Gases

The conversion of n-hexane and cyclohexane by barrier discharge treatment in He, Ar, Kr, or Xe was studied. The action of a barrier discharge on n-hexane vapor primarily results in the formation of branched-chain hydrocarbons (93.48 wt %). Bicyclohexyl is the main reaction product of cyclohexane; alkyl and alkenyl substituted cyclohexanes (48.12 wt %) are also formed. Using n-hexane as an example, it was demonstrated that the energy consumption increased from 1.30 to 2.17 keV per hydrocarbon molecule converted in the following order of inert gases: He, Ar, Kr, and Xe.

The influence of thermal treatment on the properties of sorbents prepared from water conditioning precipitates

Sorbent samples based on the thermally activated precipitate formed in iron removal from under-ground water (water conditioning wastes) were studied by low-temperature nitrogen adsorption and thermal and X-ray analysis. The precipitate was found to be a material with a developed porous structure (the specific surface area of the initial sample was 229.9 m2/g). Calcining at 300°C decreased the specific surface area of the samples by 1.6–1.7 times and increased the volume of sorbing pores by 1.6 times. The precipitate material largely contained iron phases. An increase in the temperature of calcining contributed to deeper crystallization of the main phase, α-Fe2O3.

Simulation of the Kinetics of Cyclohexane Oxidation in a Barrier Discharge Reactor

The kinetics of cyclohexane oxidation in a barrier discharge reactor was simulated for a single voltage pulse. A significant difference between the yields of O3 obtained experimentally (not detected) and theoretically (15.5 wt %) suggests that O3 was absent from the reaction mixture because of a fast reaction between O(3P) and an excited cyclohexane molecule. This hypothesis was indirectly supported by experimental data on the oxidation of a mixture of n-hexane and cyclohexene (50 : 50 wt %). The integrated rate constant of the reaction of O(3P) with n-hexane was 1.4 × 10–12 cm3/s, which is an order of magnitude higher than the published value 1.2 × 10–13 cm3/s.

Aluminosilicate microspheres in fly ashes from thermal power plants and their use for the removal of petroleum and phenol from water

Conditions for the thermal activation of hollow aluminosilicate microspheres separated from ash residues from the Novosibirsk TPP were chosen. The sorption properties of parent and activated microspheres toward petroleum and phenol were studied.

Utilization of water treatment sludge in processes of oil recovery from aqueous media

The potential use of iron removal sludge of freshwater treatment facilities for the recovery of oil from aqueous media was established. A high adsorption capacity for oil of this material was shown using the deep-well water iron removal sludge from the Tomsk Akademgorodok water intake site. The oil-absorbing capacity of as-recived sludge was studied, conditions for its thermal treatment were chosen, and the ability of the thermally activated sludge to recover oil from aqueous media was examined.

Electrochemical oxidation of tritane dyes

The oxidation of tritane dyes at a stationary glassy carbon electrode in methylene chloride is studied using voltammetry. It is shown that electron-donor-type dialkylamino-groups in the dye molecules favor the decreasing of the oxidation half-wave potentials; by contrast, the strong electron-acceptor-type nitroso-group contributes to their increasing. The Cl− anion and complex anion In Cl4−, which are constituents of triphenylmethane dyes, are not oxidized in these conditions.

Oxidation of Cyclohexene in the Presence of Alkanes in a Barrier Discharge Plasma

The oxidation of cyclohexene mixtures with hexane, octane, decane, and cyclohexane was studied in a dielectric-barrier discharge reactor. It was shown that a decrease in the partial pressure of cyclohexene in the mixture resulted in a significant increase in the yield of cyclohexene oxide to ∼75%, with the composition of oxidation products being the same as in the oxidation of individual compounds. A plausible mechanism of the reaction is proposed.