Surface properties of metal hydroxide microparticles in the ambient air

The adsorption and photoadsorption properties of Mg(OH)2 and Ca(OH)2 microparticles in the ambient air were investigated. The compositional analysis of an adsorption layer of microparticles was carried out. The kinetics of photodesorption of molecules from microcrystal surfaces and the interaction of HCFC-22 (CHF2Cl) in the dark and under light were studied. Quantum yields and their spectral dependencies were determined for CO2 photodesorption, O2 and CO photoadsorption. The effect of weakly bound CO displacement from the surface of microparticles was revealed during dark adsorption of HCFC-22. It is supposed that adsorbed CO is formed as a result of atmospheric CO2 reduction after the break of Mg—OH bonds. In case of calcium hydroxide, CO is generated during the interaction of calcium hydroxide with carbon dioxide in the presence of water

Surface layer composition of titania produced by various methods: the change of layer state under illumination

The comparative analysis of experimental data over titanium dioxide powders prepared by various ways under ambient air is carried out. The results over TiO2 prepared by high-temperature heating of anatase, produced by burning of titanium micro particles and grinding of rutile crystal are used for that comparison. Water and carbon dioxide were the main products released from the surface of the titania powders. It was found that under UV irradiation absorbed by titania, in absent oxygen, water effectively reacts with lattice oxygen of titanium dioxide

Peculiarities of acid-base properties of peat formed in various agroclimatic zones of the Altai mountainous region

The results of the study of acid-base indicators of peat in the Altai mountainous region are presented. The natural factors that in the aggregate determine the peculiarities of the physicochemical properties of mountain peat of different agro-climatic zones of the Altai Mountains have been revealed. The variation in the acid values, total absorbed bases, adsorption capacity and the degree of saturation of raised-bog, transitional, fen peat, the number of exchangeable ions Са2+ and Mg2+ has been estimated. The interrelation among these indicators has been presented. For the first time, regression equations of the relationship between exchangeable acidity рНKCl and the degree of peat base saturation V, between total absorbed bases S and the degree of peat base saturation V have been obtained using nonlinear regression analysis. The adequacy and stability of the developed models have been verified. The calculated mean errors of approximation of regression models characterise the high accuracy of the forecast and are indicative of a good selection of models for the initial data

Surface properties of metal hydroxide microparticles in the ambient air

The adsorption and photoadsorption properties of Mg(OH)2 and Ca(OH)2 microparticles in the ambient air were investigated. The compositional analysis of an adsorption layer of microparticles was carried out. The kinetics of photodesorption of molecules from microcrystal surfaces and the interaction of HCFC-22 (CHF2Cl) in the dark and under light were studied. Quantum yields and their spectral dependencies were determined for CO2 photodesorption, O2 and CO photoadsorption. The effect of weakly bound CO displacement from the surface of microparticles was revealed during dark adsorption of HCFC-22. It is supposed that adsorbed CO is formed as a result of atmospheric CO2 reduction after the break of Mg—OH bonds. In case of calcium hydroxide, CO is generated during the interaction of calcium hydroxide with carbon dioxide in the presence of water

Surface layer composition of titania produced by various methods: the change of layer state under illumination

The comparative analysis of experimental data over titanium dioxide powders prepared by various ways under ambient air is carried out. The results over TiO2 prepared by high-temperature heating of anatase, produced by burning of titanium micro particles and grinding of rutile crystal are used for that comparison. Water and carbon dioxide were the main products released from the surface of the titania powders. It was found that under UV irradiation absorbed by titania, in absent oxygen, water effectively reacts with lattice oxygen of titanium dioxide

Acid-base and photoinduced processes on magnesium-containing minerals and their influence on the troposphere cleaning

Acid-base, adsorption and photosorption properties of microparticles surface of magnesium-containing compounds produced by dispersion of natural minerals after exposure to the air were studied. It was revealed that the reduction in predominant basicity of minerals surface in a range of periclase (MgO), brucite (Mg (OH)2) and magnesite (MgCO3) can be considered as a result of the presence of iron, silicon and magnesium oxide compounds. Quantum-chemical calculations made during the investigation, the decrease of pressure in the process of long-term contact of Freon 22 with the surface of MgO, irreversible character of adsorption and the absence of fluorine and chlorine-containing products in a gaseous phase give evidence of CFC destructive adsorption on the surface of magnesium oxide. The interaction of chlorine and fluorine derivatives of methane with the surface of aerosol particles from minerals in the darkness and under the influence of sunlight tropospheric radiation was studied. The evaluation of such interactions influence on the process of the Earth troposphere purification from carbon dioxide and dichlorofluoromethane during their adsorption and photosorption on the surface of precipitated aerosol was made.</jats:p

Physicochemical and photosorption properties of oxygen-containing calcium compounds – components of troposferic aerosol

The Importance of this Paper is Determined by the Research of Conditions of Photosorption Processes Occurance on the Surface of Aerosol Particles Resulting in the Removal of Toxic Substances from the Atmosphere. Acid-Base Properties of Oxygen-Containing Calcium Compounds being Components of Troposphere Aerosol Particles were Studied by Methods of Ph-Metry and Hammet’s Indicators. the Basic Properties of the Investigated Compounds Surfaces are Predominant Ones: рНiis of Calcium Oxide and Hydroxide has a Value of 9.3 – 9.5, and that for Carbonate and Calcite Equals to 12.3-12.4. Indicator Method Distinguishes Three Areas of Spectrum Corresponding to Lewis Base, and Brensted Neutral and Basic Centers. the Intencity of Peaks is much Higher for Ca(OH)2 and CaO. the Interaction Process of Halogen-Containing Organic Compounds (Freons: 134a, 22 and 12) with Calcium Carbonate Surface under Illumination in Conditions close to Tropospheric Conditions was Studied. it is Shown that the Interaction is the Destructive Photosorption of Freons (134a or 22). the Spectral Dependence of Effective Quantum Yield of Destructive Photosorption is Determined. as a Result of the Interaction Calcium Fluoride and Calcium Chloride are Formed at the Surface.</jats:p