Том 87, № 13 (2017)

A new sorption method for the production of highly purified hydrolytic enzyme α-amylase from Bacillus subtilis with the use of FAF microfine anion exchanger was developed. The α-amylase enzyme obtained is suitable for the preparation of enzymatic drugs.

The results of physicochemical modeling of oxidation of sulfide minerals in the Central Concentrating Mill tailing dump (Komsomolsky tin-ore district) with account taken of the cementation zone in the temperature range from–25 to +45°C are given. The Eh-pH parameters for the formation of micropore solutions in technogenic systems have been determined at different host rock–sulfide ratios (95: 5, 90: 10, 80: 20, 60: 40, 40: 60, 20: 80, 10: 90, 5: 95). Crystallization of hypergene minerals from the micropore solutions have been considered, their qualitaitve and quantitative ion compositions have been determined, and their effect on the hydrosphere has been assessed.

Polysubstituted derivatives of sterically hindered phenol were found to reduce accumulation of hydroperoxides in the lipid extract from fish feed after 8-week incubation. Feeding of juvenile Russian sturgeon with fish food containing these compounds showed no negative effect on hydrobionts. Both in vivo and in vitro experiments revealed inhibition of hepatic lipid oxidation in juvenile Russian sturgeon in the presence of new bis-pyrrolidine derivatives of 2,6-di-tert-butylphenol. A reliable positive correlation was observed between the concentration of hydroperoxides in the lipid extract from fish feed and accumulation level of secondary enzymatic oxidation products of hepatic lipids in hydrobionts.

Initiation of energetic compounds by optical radiation is considered. In comparison to the traditional initiation ways, optical initiation is safe and environmentally benign.

A procedure has been developed for the assessment of transboundary river water quality. The procedure is based on the calculation of the chemical index and classification of water quality. The quality of river waters is assessed by measuring a set of chemical parameters in water samples, followed by data representation in the form of the chemical index CJ which characterizes generalized water quality. A classification system has been proposed for the estimation of contamination of transboundary water bodies on the basis of a “broken bar” model. Using the developed procedure, year-to-year, within-year, and seasonal dynamics of water quality in watercourses of the transboundary Narva River basin have been determined.

Chemisorption of phosphate anions by crystalline iron oxides is confined to those sites of the sorbent surface where substitution of silicate (in hydrohematite) or hydroxo and aqua (in hydrogoethite) ligands by phosphate ions is possible. In these sites, new crystalline spherical entities were detected, which were able to pass into the liquid phase. The new formations were identified as ammonium salts of сomplex iron-phosphoric acids. Binding of ammonium cations from solution indicates that the primary phosphate chemisorption products are complex iron phosphate anions capable of being transferred to solution and destructuring iron oxides.

General principles of the theory of polyfunctional role of biota in self-purification of water in aquatic ecosystems have been formulated. The theory includes the following elements: (1) energy sources for self-purification of aquatic ecosystems; (2) main functional units of the self-purification system; (3) main selfpurification processes; (4) contributions of major taxa to self-purification of aquatic ecosystems; (5) reliability of the system and mechanisms ensuring it; (6) self-regulation of biota; (7) response of the system to external stimuli (impacts); (8) analogy between an ecosystem and a bioreactor; (9) conclusions for nature conservation practice. The theory covers both freshwater and marine ecosystems.

Sorption of lead and cadmium cations from solutions of their salts on amorphous cellulose, potato starch, apple pectin, and chicory root inulin was studied. Sample preparation was performed in conditions (pH and stirring time and intensity) similar to those in the stomach and intestines of a typical person. The sorption properties of the studied polysaccharides with respect to both the individual heavy metals and their mixtures is variable. The sorption properties series are cellulose ≈ pectin < starch< inulin for Pb²⁺ and cellulose < pectin < starch ≈ inulin for Cd²⁺.

The results of long-term studies on the contents and seasonal dynamics of neutral carbohydrate metal complexes in the surface water bodies of different types (lakes, rivers, reservoirs) are summarized. It is established that the weight fraction of the mentioned complexes characteristically varies significantly depending on the type of the water body and the component composition of dissolved organic substances. In water bodies with a highly colored water, the relative contents of dissolved metals in neutral complexes are low due to their preferential binding to anionic complexes with humic substances. In small eutrophic water bodies with a relatively low content of humic substances, the carbohydrate concentrations are the highest and, accordingly, the weight fractions of metals in their neutral complexes is also very noticeable. The molecular weight distributions of neutral metal complexes are discussed. The neutral complexes with the molecular weight ≤5.0 kDa form a significant part of metals associated with carbohydrates. The seasonal dynamics of these metal complexes are discussed.

On the way to solving the problem of developing an ecofriendly technology for preparing hydrophobic protective coatings to replace the existing technology involving casting from polymer solutions in toxic organic solvents, amphiphilic organosilicon oligomers, promising emulsifiers for preparing aqueous emulsions of organosilicon polymers, were synthesized. The synthesized oligomers were used to obtain stable aqueous emulsions of a film-forming silicone block copolymer. The resulting emulsions can be used to form hydrophobic protective coatings on the surface of construction materials. It was shown that the contact angle of wetting depends on the specific features of the preparation of the emulsion and reaches a maximum of 134°.

The possibility of enantioselective bioreduction of acetophenone into (R)- and (S)-1-phenylethanol used in the synthesis of antifeedant, antidiabetic, antidepressant, antirabic, antiparasitic, antimicrobial, and antifungal agents is investigated. The influence of various exogenous reducing agents (isopropanol, ethanol, and glucose) on the yields of the target products and the enantioselectivity of the bioreduction of acetophenone is studied.

The data of hydrochemical and hydrobiological monitoring of the Estonian water area of Lake Peipsi (Peipus, Chudskoe) during 1985–2016 are presented. The trophic state of the water area has been determined according to different methods. According to the method developed at the Hydrochemical Institute, the trophic state of the Estonian waters of Lake Peipsi during the analyzed period is characterized as “mesotrophic,” whereas other methods (OECD, Ministry for the Environment of New Zealand, the Carlson index, the criteria by O.A. Alekin and I.S. Trifonova) it is “eutrophic.” According to the probabilistic estimate accounting for the total phosphorus concentration, the trophic state of the Estonian water area of Lake Peipsi is characterized as “mesotrophic-eutrophic.”