cavitation

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. Relative series of effective destruction of microbial cells was established: Ar/US > О2/US >Не/US > СО2/US.

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. The most efficient microorganism destruction has been obtained using Ar/US compared to Не/US, СО2/US and О2/US and is accounted for by those gas properties able to affect sonochemical activity.

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.

INVESTIGATION OF CAVITATIONAL EXPANSION OF SODIUM HYPOCHLORITE UNDER ISOTHERMAL CONDITIONS

Liquid waste and wastewater, that contain hypochlorites, are formed during the production of chlorine and caustic soda; electrolytic production of magnesium and chlorine; in the production of pulp and paper products etc. Such wastewaters belongs to sub-standard, therefore they are not reused in corresponding technological processes. In accordance with the current normative documents, hypochlorite wastewaters must be disposed of at the local treatment facilities of the enterprises where they are produced.

CAVITATION WASTEWATER TREATMENT OF OIL-FAT FACTORY FROM ORGANIC CONTAMINATION IN THE PRESENCE OF THE GASES OF DIFFERENT NATURE

Oil-fat industry produces and recycles vegetable fats and related products. Sewage of this industry contain a large number of pollutants different nature. But, the main contaminating components of this sewage are organic compounds, mainly fatty character. Existing methods of water purification are not capable of providing sufficient degree of wastewater treatment, which would comply established sanitary norms. It’s creates a big problem, because it’s cause pollution of surface waters with organic compounds. Solving this problem is possible when switching to closed water systems.