ultrasound

The paper analyzes the perspectives for natural sorbents to be used in environmental technologies. The object of the study is the clay rock from the left side of the upper Pivdennyi Bug river (in the vicinity of the Khmelnytskyi city). The rock was enriched in montmorillonite by centrifugation of a clay suspension to obtain the fraction with a size of less than 5∙10-6 m. The researchers defined the mineral composition of the enriched clay based on the findings of the X-ray diffraction and complex thermal analyses.

Snails are often found in Indonesia, especially at Kediri, but the snail shell has no commercial value. This research report describes the characterization and antioxidant activity of chitosan from snail shell waste (chitosan-SSW) by ultrasonic technique and analyzes the potential of chitosan as an inhibitor of receptors of free radicals using an in silico molecular docking method.

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.

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.

The regularities of the change of the concentration of microorganisms and water-soluble organic compounds in the polluted water in the conditions of cavitation treatment and the influence of the amount of biological water pollution on the value of the chemical oxygen consumption are investigated.

Sonogalvanic replacement and galvanic replacement synthesis of silver nanoparticles (AgNPs) by magnesium scrap in sodium polyacrylate solutions were studied. It was found that during these processes in NaPA solutions silver is practically not deposited on the magnesium surface. Sodium polyacrylate provides stabilization of AgNPs with the formation of yellow solutions with maximum absorption of ~415 nm.

The grafted copolymerization of 2-hydroxyethyl methacrylate to polyvinylpyrrolidone in the presence of mineral fillers (hydroxyapatite, montmorillonite and wollastonite) under ultrasound has been investigated. The effect of ultrasound, nature and amount of mineral filler on the polymerization rate and composition of copolymers has been determined. Ultrasound substantially intensifies the polymerization process and actively affects the formation of the copolymer composition. Under its action, a porous structure of composites is formed, even without adding special foaming agents.

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.

The article analyzes the topicality of the primary standard creation of the ultrasonic pressure unit in water for the frequency  range of 0.5–10.0 MHz  in Ukraine.  Its creation  is predetermined by  the necessity of  the exploited ultrasound medical equipment metrological maintenance as well as for the assessment of compliance with the requirements of the technical regulations for medical products to be exploited.