Determination of the Rate Constant of Microorganisms Destruction after Ultrasound Water Treatment and Different Gases Action

The change of microorganisms number (rod-like spore-containing Bacillus cereus bacteria type) for the range of 102 ÷ 106 CFU in 1 cm3 from the duration of simultaneous action of ultrasound (US) cavitation and the nature of different gas (carbon dioxide, oxygen, argon) is presented. The graphical dependences of the effective rate constant values of microorganisms destruction (kd) on its initial number per unit volume of water at different modes of its treatment are shown.

Synergistic Effect of Ultrasound Cavitation and Gas in the Water Disinfection

The paper considers water purification processes from Bacillus bacteria type under the conditions of gases bubbling only (argon, helium, oxygen, and carbon dioxide), cavitation and combined action of gas and cavitation. The synergistic effect was found under conditions of simultaneous action of gas and cavitation (kd(gas/US ) >kd(gas) + kd(US) almost double) and it was shown that kd(gas/US) >kd(gas) by almost an order of magnitude.


The absorption of air oxygen by water in the horizontal absorber with bucket-shaped dispersants (HABD) and the vertical apparatus with a continuous bubbling layer (VABL) was studied. It is shown that these processes occur according to the law of First-Order Reactions. It was found that the constant absorption rate is 46.5 times higher in HABD than in VABL at a gas content of 0.05 and a bubble diameter of 0.002 m. It is recommended to use the VABL device for water deironing at pH <6, and for pH greater than 6.0 - HABD.

Partial case of thermochemical analysis of cavitation sonolysis of water

The mechanism of water sonolysis with the formation of both intermediates (free radicals) and basic products (hydrogen and oxygen), which are important for thermal power engineering and water purification technologies, based on the use of advanced oxidation processes, wasresearched. The efficiency of hydroxyl radical generation in the environment of inert gases and oxygen was analyzed.

Corrosion-Electrochemical Behaviour of Low-Alloy Steel in Alkaline Media

The authors demonstrated that low-alloy chrome-molybdenum-vanadium 12Cr1MoV steel has more positive open circuit potential and lower hydrogen evolution overvoltage in concentrated alkaline solution, compared to ordinary-quality St3 steel. After 1100 A∙h∙m-2 charge passing, 12Cr1MoV anodic dissolution rate becomes lower than St3 dissolution rate. It does not increase with current density increase.

Oxidation of unsaturated aldehydes by different oxidants

The new data about oxidation of unsaturated aldehydes of a general structure R–CH = C(R)–CHO by molecular oxygen (in liquid and gaseous phase), peracids and hydrogen peroxide were obtained. The composition of reaction products for a series of aldehydes with different structures was determined. The dependencies of the selectivity of reaction from an aldehyde structure and oxidant type have been evaluated. It has been assumed that a stage of aldehyde interaction with peracid determines the formation of reaction products.

Catalytic Oxidation of Ethylene Glycol by Dioxygen in Alkaline Medium. The New Example of One-stage Oxidative Cleavage of C–C Bond

Reaction of low temperature oxidations of ethylene glycol (EG) by molecular oxygen in the presence of salts of bivalent copper and alkali both in water and in waterless solutions was investigated. It was found that at low (close to room) temperatures and in waterless solutions the basic product of EG oxidation is formic acid. Rise in the temperature from 290–315 K to 350–360 K or reaction flow in water-containing solutions leads to sharp change of reaction direction. EG in these conditions is oxidized with primary formation of glycolic acids salts.