cavitation

Оxidative destruction of benzene in the conditions of unstationary cavitation excitation

The threshold value of the energy required for the decomposition of benzene after the cessation of cavitation has been established. The regularities of the oxidative destruction of benzene in the cyclic mode "cavitation-exposure" were established. The possibility of destruction of benzene in case of initiation of the process by introducing a certain amount of its cavitationally activated part into the water-benzene medium is shown. The role of oxygen in the cavitation decomposition of benzene was experimentally confirmed.

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.

AN INFLUENCE OF CAVITATION PHENOMENA ON THE DESTRUCTION PROCESSES OF ORGANIC AND BIOLOGICAL POLLUTIONS IN THE WATER

The regularities of cavitation treatment of food and chemical industries wastewater from organic and biological contaminants in the presence of gases of different nature were studied. The optimal temperature range 313K - 318 K for cavitation wastewater treatment was established. It is shown that the process of cavitation destruction of organic compounds can be described by a first - order kinetic equation.

Correlation between Diameter of Microorganisms and Efficiency of Microorganisms Destruction under Gas/Cavitation Conditions

The values of еffective rate constants of microorganisms destruction (kd) were compared, depending on the diameter of cells and gas nature bubbling under cavitation conditions. The efficiency of cell destruction under Ar/US is larger by 2–2.5 times compared to He/US, O2/US and CO2/US. Yeast cells were destroyed faster than bacteria (kd (yeast cells) >> kd (bacteria cells)) that is explained by the cells size. The cell stability under cavitational conditions is reversely proportional to the cell diameter.

Gas Nature Effect on the Destruction of Various Microorganisms Under Cavitation Action

The disinfection of water from Diplococcus, S.lutea, B.cereus, and Ps.fluorescens bacteria types and the yeast Sacch.cerevisiae via the joint action of gas/US has been investigated. The investigated microorganisms were identified in natural water and wastewater in dominant amounts. The relative ranges of effective cell destruction by combined gas/US action have been established.

Improving the Method for Producing Adsorbents from Agro-Industrial Wastes

A multi-stage method for producing an absorbent with increased absorption capacity based on agro-industrial wastes has been proposed. The method includes treatment of raw materials with sulfuric acid, mechanochemical modification, electrostatic separation, and cavitation stage. The expediency of the proposed adsorbent usage in the process of purification of contaminated water from fats, phenols, petroleum products, and heavy metal ions has been proved. The complex application of adsorbents (absorption of gaseous pollutants and wastewater purification) has been tested.

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.

Synthesis of Methanol from Methane in Cavitation Field

Methanol synthesis was achieved by a free-radical mechanism of the compounding reaction of methane and hydroxyl radical. Experiments were performed by feeding methane and hydrogen-peroxide into a cavitation field. The major reaction products were methanol and water molecules. The calculated degree of methane conversion equals to ~10 %.

Flotation as a stage of cavitation-flotation technology for the treatment of aqueous heterogeneous media from dispersive solids and organic compounds

Integration of physical and physical-chemical processes is a principle that is inextricably linked with the development of modern technologies. Trends in the integration of technological processes are also characteristic for branches of water treatment and preparation. The combination of processes makes it possible to significantly increase the degree of sewage treatment, reduce the duration and energy intensity of the purification process, the costs to maintain optimal reagent, temperature, hydrodynamic regimes, etc.