Photocatalytic activity of the iron-containing natural composites in the reaction of oxidative destruction of oxalic acid and phenol

This paper presents the results of a study of the photocatalytic activity of iron-containing composites based on natural peat and zeolite under external influences: Ultraviolet irradiation (UVI) and UVI + H2O2. It is shown that the optimal method for the photocatalytic destruction of pollutants (oxalic acid and phenol) with composites is to introduce hydrogen peroxide in the system. The composites studied are sources of iron ions in the Ruff-Fenton system; they provide the generation of •OH radicals, which have a high reactivity in the oxidative degradation reactions of organic substances and can be recommended for reuse to purify water drain

Control of structurization processes in wood-cement systems at fixed pH

The paper presents a study of structurization processes in the wood-cement systemmixed with the buffer solutions and the improvement of service properties of products produced therefrom. Infrared spectroscopy, X-ray phase analysis, and pH measurements show that structurization processes in wood-cement systems depend on the acidity of aqueous solution, the behavior of hydration, neutralization, and polycondensation reactions with the formation of polymer products including those with cement grout components and functional groups of wood. It is shown that phosphate buffer solutions used for mixing wood-cement compositions improve their strength properties and reduce water absorption. The optimum acidity of the buffered medium for service properties of the wood-cement systemis pH = 4.8

Creation of functional solid-state composites based on black peat

The paper presents investigations of composite materials based on black peats of Barabinskoe and Taganskoe deposits of the Tomsk region and carboxymethyl cellulose, both modified with iron (Ш) and copper (II) chloride solutions. In order to improve hydrophobic properties of compositions, optimum salt concentrations are detected. Water sorption and desorption isotherms are obtained for modified specimens. It is suggested to employ synthesized solid-state compositions as insulators in the capacity of both humidity controller and indoor-contaminant absorber

Hydrophobic composition based on mixed-molecular weight polyethylene

The paper presents investigations of compositions based on low and high molecular weight polyethylene so as to synthesize a hydrophobic composition for moisture protection of timber. X-ray phase analysis and measurements of the tear-off force of hydrophobic coating needed to apply to the timber surface and the limiting wetting angle are carried out to detect the hydrophobic, adhesive, electrophysical, and physicochemical properties of compositions. Kinetic dependencies are given for moisture absorption of timber specimens. It is shown that the preliminary formation of the texture by the surface patterning or its treatment with low-temperature plasma with the following protective coating results in the improvement of hydrophobic properties of the suggested compositions. These compositions can be used in the capacity of water repellents to protect building materials from moisture including restoration works

Water-repellent coatings for surface and 3D wood processing

The paper presents the results of research in organic chemical compositions for hydrophobic protection of wood with the use of surface and three-dimensional coating techniques of impregnation and chemical compositions. Water absorption indicators, angles of contact on the surface of treated samples are detected herein. Kinetic equation of the moisture diffusion transition in capillary-porous structure of wood is suggested

Structural-energy states of water and aqueous solutions under external influence

The surface state of alkaline-earth metals and magnesium oxides obtained by means of commercial and laboratory ways has been studied in this paper. A complex of methods has been used for identification, determination of a phase composition and morphology of the samples. The high basic character of surface centres has been shown with the help of pH-metry and adsorption of indicators methods. Acid-basic parameters (pHt, pHiis, etc.) can be used for the estimation of a general acid-basic state of metal oxides samples surface and for the supposition about different nature and strength of acid-basic centres as well as for the initial control in the process of acid basic properties of solid oxides surface properties evaluation

Study of absorption of organic pollutants by modified natural materials

The paper presents the study of the absorption mechanism of organic pollutants such as formaldehyde and oxalic acid by natural zeolite and peat materials modified by iron (III) ions using the limited volume method.The relevance of this paper is a search for the use of inexpensive and available natural sorbents for waste water purification from ecologically hazardous water-soluble organic pollutants. The impact produced by the solution concentration and temperature and the size of natural composite particles on the sorption rate of organic substances is described in this paper. The effective factors for diffusion and energy of the process activation are calculated. It is found that the mixed-diffusion kinetics is the determinant stage of the process. In case of peat and zeolite composites, the internal diffusion prevails in the mixed-diffusion kinetics

Atomic emission spectrometer "Grand" for studying the features of accumulation and distribution of chemical elements in objects of animal origin

In this paper, the possibilities of using the arc atomic emission spectrometer “Grand” with multichannel emission spectrum analyzers (MAES) in terms of elemental analysis of objects of animal origin are expanded. Metrologically certified methods that have passed preliminary metrological examination were used for research. Of particular interest is the construction of periodic dependences of changes in certain parameters of the objects under study with an increase in the ordinal number of the element determining their structure and organization, as well as the construction on this foundation of predictions about the properties and behavior of living objects when interacting with each other. The features of the distribution of chemical elements as the charge of the atomic nucleus increases are reflected in the internal structure of the periodic system. In this regard, it is established in this work that the dependences of the accumulation and distribution of chemical elements in the studied living organisms with increasing ordinal number of the element in the periodic table of D. I. Mendeleev are also periodic