Evaluation of the effectiveness of the parameters of reagent-free electrolysis wastewater treatment from nitrogen-containing compounds

The relevance of wastewater treatment from nitrogen-containing compounds, including using stationary and non-stationary electrolysis processes, is analyzed. A design has been developed, a reagentless electrochemical water treatment module has been manufactured and tested in the conditions of real production of hydrobionts. The results of the study of the influence of the power supply modes of the electrolysis unit on the reduction of ammonium nitrogen, ammonia, nitrites and nitrates from the recycled solution of the industrial aquaculture plant are presented. The results of the study showed that when using stationary and non-stationary electrolysis modes, the conversion processes of nitrogen-containing compounds are generally performed according to the classical algorithm: increasing the concentration of compounds along the chain "ammonium nitrogen → nitrites → nitrates", and the use of non-stationary electrolysis to remove nitrogen-containing compounds from the solution for growing hydrobionts is more effective. The analysis of the results demonstrated the effectiveness of the proposed approach and the possibility of scaling the results to municipal and industrial facilities. The advantages of the proposed method are: non-reactivity, mobility, the possibility of automating the process.Проанализирована актуальность очистки сточных вод от азотсодержащих соединений, в том числе с использованием процессов стационарного и нестационарного электролиза. Разработана конструкция, изготовлен и испытан в условиях реального производства гидробионтов безреагентный электрохимический модуль водообработки. Приведены результаты исследования влияния режимов электропитания электролизного блока на редукцию азота аммонийного, аммиака, нитритов и нитратов из обо-ротного раствора установки индустриальной аквакультуры. Результаты исследования показали, что при использовании стационарного и нестационарного режима электролиза процессы преобразования азотсодержащих соединений в целом выполняются согласно классическому алгоритму: повышение концентрации соединений по цепочке «азот аммонийный → нитриты → нитраты», а применение нестационарного электролиза для удаления азотсодержащих соединений из раствора для выращивания гидробионтов более эффективно. Анализ полученных результатов продемонстрировал эффективность предлагаемого подхода и возможность масштабирования результатов на коммунально-промышленные объекты. Преимуществами предлагаемого метода являются: безреагентность, мобильность, возможность автоматизации процесса

Laser Mass Spectrometry Analysis of the Formation of Phosphazene-Containing Epoxy Oligomers

The main features of two methods for the synthesis of phosphazene-containing epoxy oligomers— namely, the methods based on oxidation of double bonds in organooxyphosphazenes and on the reaction of chlorocyclophosphazenes with diphenols and the subsequent interaction of the resulting hydroxy-aryloxy phosphazenes with epichlorohydrin—were examined. Using the example of hexa- and octa-eugenol derivatives of the corresponding cyclophosphazenes, optimal conditions were established for the oxidation of allyl groups of these compounds with peroxy acids and hexa- and octa-epoxide cyclophosphazenes were characterized. It was noted that the epoxidation of eugenol derivatives of a mixture of cyclophosphazenes with three to eight phosphazo groups is accompanied by side reactions leading to the formation of P–OH bonds and the partial opening of oxirane cycles. Bisphenol A phosphazene-containing oligoepoxides were synthesized both via the stage involving the formation of hydroxy-aryloxy cyclophosphazenes and their subsequent epoxidation with epichlorohydrin and via the direct interaction of chlorocyclophosphazenes with an excess of bisphenol A (BPA) in the presence of solid alkali. In the latter case, the resulting oligomers are mixtures of the conventional epoxide and phosphazene-containing epoxy oligomers. The content of the latter can be adjusted up to 50%. The synthesized oligomers contain 1–5% phosphorus. They can be cured by conventional hardeners to form flameproof or noncombustible compositions. © 2018, Pleiades Publishing, Ltd

Synthesis of oligomeric epoxycyclotriphosphazenes and their properties as reactive flame-retardants for epoxy resins

Hydroxyaryloxycyclophosphazenes containing 2–4 OH groups have been synthesized by the substitution of chlorine atoms of hexachlorocyclotriphosphazene via the reaction with sodium phenolates of halogenophenols followed by the interaction with sodium monophenolate of diphenylolpropane. Oligoepoxyphosphazenes (OEPs) with molecular masses up to 2000 and the contents of epoxy groups, phosphorus, and halogens atoms about 5–8, 5–8, and 5–11%, respectively, have been obtained via the interaction of the aforementioned phosphazenes with epichlorohydrin. The curing of the OEPs with amines or acid anhydrides gives rise to the formation of self-extinguishing composites. The incorporation of the OEPs (5–75 wt %) into commercial epoxy resins followed by their curing, results in the formation of composites with excellent nonflammability or capability of self-quenching, and good dielectric, heat resistant and mechanical properties. It has been established that mixtures of common epoxides with different amounts of the OEPs can be synthesized by a “single-reactor” method. © 2017 Taylor & Francis Group, LLC

Synthesis of oligomeric epoxycyclotriphosphazenes and their properties as reactive flame-retardants for epoxy resins

Hydroxyaryloxycyclophosphazenes containing 2–4 OH groups have been synthesized by the substitution of chlorine atoms of hexachlorocyclotriphosphazene via the reaction with sodium phenolates of halogenophenols followed by the interaction with sodium monophenolate of diphenylolpropane. Oligoepoxyphosphazenes (OEPs) with molecular masses up to 2000 and the contents of epoxy groups, phosphorus, and halogens atoms about 5–8, 5–8, and 5–11%, respectively, have been obtained via the interaction of the aforementioned phosphazenes with epichlorohydrin. The curing of the OEPs with amines or acid anhydrides gives rise to the formation of self-extinguishing composites. The incorporation of the OEPs (5–75 wt %) into commercial epoxy resins followed by their curing, results in the formation of composites with excellent nonflammability or capability of self-quenching, and good dielectric, heat resistant and mechanical properties. It has been established that mixtures of common epoxides with different amounts of the OEPs can be synthesized by a “single-reactor” method. © 2017 Taylor & Francis Group, LLC

Laser Mass Spectrometry Analysis of the Formation of Phosphazene-Containing Epoxy Oligomers

The main features of two methods for the synthesis of phosphazene-containing epoxy oligomers— namely, the methods based on oxidation of double bonds in organooxyphosphazenes and on the reaction of chlorocyclophosphazenes with diphenols and the subsequent interaction of the resulting hydroxy-aryloxy phosphazenes with epichlorohydrin—were examined. Using the example of hexa- and octa-eugenol derivatives of the corresponding cyclophosphazenes, optimal conditions were established for the oxidation of allyl groups of these compounds with peroxy acids and hexa- and octa-epoxide cyclophosphazenes were characterized. It was noted that the epoxidation of eugenol derivatives of a mixture of cyclophosphazenes with three to eight phosphazo groups is accompanied by side reactions leading to the formation of P–OH bonds and the partial opening of oxirane cycles. Bisphenol A phosphazene-containing oligoepoxides were synthesized both via the stage involving the formation of hydroxy-aryloxy cyclophosphazenes and their subsequent epoxidation with epichlorohydrin and via the direct interaction of chlorocyclophosphazenes with an excess of bisphenol A (BPA) in the presence of solid alkali. In the latter case, the resulting oligomers are mixtures of the conventional epoxide and phosphazene-containing epoxy oligomers. The content of the latter can be adjusted up to 50%. The synthesized oligomers contain 1–5% phosphorus. They can be cured by conventional hardeners to form flameproof or noncombustible compositions. © 2018, Pleiades Publishing, Ltd

Perspectives for vertebrology teaching development in higher medical schools

The article deals with the issues on improving the efficiency of vertebrology teaching in specialist training at pre-and postgraduate stages. Modern epidemiologic trends for spine traumas and diseases form the increasing interest to the problems of care and prevention of the considered pathology and define the necessity of single-skilled specialists training. Developing vertebrology into a separate discipline that is studied at medical universities at both pre- and postgraduate stages is one of the topic issues for higher medical schools where the search of effective ways of its realization is stressed

THE INFLUENCE OF BINDING MATERIAL ON POROUS STRUCTURE OF SHAPED HOPCALITE

The authors have investigated the equilibrated adsorption of water vapors on GFG hopcalite, which was obtained using the extrusion shaping method, with bentonite clay as the binding compound. In the frames of the BET model, the values of the monolayer capacity and the size of medium area occupied by the water molecule in the filled monolayer have been determined. The distribution of pores according to their sizes has been evaluated. It has been established that the modification of the bentonitic clay allows directed construction of the hopcalite porous structure,i.e. the formation of the mesoporous structure with a narrow distribution of the pores capacities by sizes, which was achieved varying the sizes of binding compound particles

Oligomeric Hydroxyaryloxycyclotriphosphazenes with Decreased Functionality Based on Resorcinol

Abstract: Oligomeric hydroxyaryloxycyclotriphosphazenes P3N3Cln(OC6H5)x(OC6H4OH)y are obtained by the polycondensation of phenoxychlorocyclotriphosphazenes with the general formula P3N3Cl(6 −x)(OC6H5)x (x = 3.1, 4.5) with an excess of resorcinol under homogeneous (pyridine) and heterogeneous (K2CO3) acceptance of HCl in a yield of 60–85%. Full substitution of the chlorine atoms in the specified oligomers (n = 0) under homogenous acceptance of HCl by pyridine is reached only at a molar ratio of phenoxychlorocyclophosphazene : resorcinol = 1 : 12; the formed oligomers contain up to 3% Cl at a ratio of 1 : 6. The structure of the compounds present in the composition of oligohydroxyaryloxycyclotriphosphazenes and their relative concentration are determined by 31P NMR spectroscopy and MALDI-TOF mass spectrometry. © 2020, Pleiades Publishing, Ltd