<p>This article is devoted to the problem of the propagation of harmful pollutants in the atmosphere from point sources taking into account photochemical transformations. A complete list of typical atmospheric pollutants of the industrial city was determined. The fifteen most common types of harmful substances such as NO<sub>2</sub> (nitrogen dioxide), H<sub>2</sub>SO<sub>4</sub> (sulfuric acid) to examine the transformation of impurities were selected. A scheme for the conversion of pollutants by chemical reactions was created. The transfer process and the transformation of substances were described by a system of differential equations. The resulting differential equations are constructed on the basis of stoichiometric formulas and the constant of reaction rate in accordance with the law of mass conservation. To account for the influence of anthropogenic heat sources and heterogeneity of the underlying surface on the propagation of harmful substances taking into photochemical reactions, a model of atmospheric boundary layer and the transport equation and transformation of pollutants by the example of the city of Ust-Kamenogorsk was considered. The schemes of stable and convergent difference for the equations of the atmospheric boundary layer and transport and transformation of admixture of harmful substances were designed. A software package for numerical simulation of air pollution taking into account photochemical transformations and corresponding visualization of scenarios was developed. The software package allows simulating the spread of pollutants under different weather conditions. The results of the daily monitoring of distribution and dynamics of the formation of chemical substances were obtained. The results of numerical simulation of the propagation and transformation of harmful impurities on mesometeorological background processes taking into account the terrain and water surfaces were presented. The analysis of the propagation of the substance concentration taking into the transformation of harmful substances of components was carried out. The results show that the description of photochemical reactions in the mathematical model proposed in this paper allows identifying areas which are heavily contaminated with salts such as MgSO<sub>4</sub>, CaSO<sub>4</sub> and acids of H<sub>2</sub>SO<sub>4</sub> with a reasonable accuracy due to the sequantial chemical reactions taking place in the atmosphere.</p>
Statistics of recent years shows an annual increase in the volume of technogenic waste (in particular "tailings") of mining and metallurgical enterprises of Kazakhstan by about 1.5 billion tons, which at the current time is already about 4.7 billion that entails certain environmental and economic consequences. This article proposes the potential use of the tailings of the enterprises as a fine aggregate to partially replace the consumption of cement in the concrete mixture for the manufacture of paving slabs. Carbonate tailings of Kazzinc LLP enterprise were used. To determine the optimum composition of concrete mix with the use of tailings were made control and 4 experimental compositions with the replacement of part of the cement waste in the amount of 5, 10, 15, 20% respectively. Samples of concrete mixtures were tested for compressive strength, flexural tensile strength, abrasion, frost resistance, and resistance to wetting and drying. According to the test results, it was found that as the concentration of tailings increases, the physical-mechanical and operational indicators of the concrete mixture and concrete for the manufacture of paving slabs improve.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.