Everyone knows that forest air is very good for health, and one of the most important reasons for this is the presence of phytoncides in it, which kill or suppress pathogens and have a healing effect. Also, phytoncides are one of the factors of the natural immunity of plants (plants sterilize themselves with the products of their vital activity). Their large number is allocated by plants. One of them is the common bird cherry. Cherry-a representative of the genus of plums of the Rosaceae family. The view includes low trees and shrubs. Cheremukha-forest orderly. Its flowers and leaves are rich in phytoncides, thanks to which they exude an alluring aroma. However, when they break down, they release prussic acid, which is dangerous for all living things. This gave them the opportunity to attract and destroy pests. Phytoncides are volatile biologically active substances formed by plants that kill or inhibit the growth and development of bacteria, microscopic fungi, and protozoa. In addition to all of the above, bird cherry has exceptional properties. The strong, somewhat intoxicating scent of flowers and leaves cleanses the air of germs. Antimicrobial properties of phytoncides have led to a large number of studies on their use in medicine, veterinary medicine, plant protection, storage of fruit and vegetable products, in the food industry and other areas of practice. Almost all parts of the plant have bactericidal, fungicidal and insecticidal properties. In folk medicine, bird cherry has long been used as an astringent, fixing, anti-inflammatory and anti-scurvy agent. Bird cherry produces the most powerful phytoncides containing prussic acid. Protozoa die under the influence of bird cherry phytoncides in 5 minutes. On the basis of numerous studies, the time of death of protozoa after noncontact exposure to phytoncidal plants has been established. Especially a lot of phytoncides are released by young leaves in spring and summer, in autumn phytoncides are released much less. The presence of tannins and essential oil in the fruit has an anti-inflammatory effect, which is used to treat inflammatory processes in the gastrointestinal tract and dysentery. The infusion of cherry fruits has a destructive effect on microorganisms. Preparations of the fruits of the common cherry have an antiseptic effect. They are used in dental practice in the treatment of inflammatory processes of the oral mucosa, paradontosis, toothache and hypovitaminosis.

The article is devoted to the study of selenium (VI) reduction processes in sulfuric acid solutions when titanium electrodes are polarized by alternating current of industrial frequency (50 Hz). It was found that selenate ion reduction occurs on the surface of titanium electrodes in the cathode half-cycle of alternating current (practically at the cathode) by reaction: ${\mathrm{SeO}}_4^{2-}$+ 6e + 8H⁺ → Se + 4H₂O. In addition, the recovery is carried out by titanium (III) ions: 6Ti³+ ${\mathrm{SeO}}_4^{2-}$+ 8H⁺ → Se + 6Ti⁴⁺ + 4H₂O. It has been established that titanium (III) ions are products of dissolution of titanium during polarization by alternating current, so they can be formed by reaction: 2Ti + 6H⁺ → 2Ti³⁺ + 3H₂. Reduction in selenate ions during polarization by alternating current can also occur due to the cementation reaction with titanium: 3Ti + 2${\mathrm{SeO}}_4^{2-}$ + 16H⁺ → 2Se + 8H₂O + 3Ti⁴⁺. It was shown for the first time that the selenate ion is reduced to form a dispersed selenium powder with a high current efficiency. Depending on the conditions, both amorphous and crystalline selenium modifications are produced.