DEVELOPMENT OF MATHEMATICAL MODEL OF INFILTRATION OF IRON SULFATE ACID SOLUTION

The chemical industry is the leader, which is characterized by significant volumes of production and multiplicity of waste. The accumulation of a large amount of waste negatively affects the environment. The most obvious example is the state of the soils, where there are enterprises producing pigmentary titanium dioxide. The purpose of the work is to study the processes of penetration and accumulation of acidic solutions from chemical industry wastes into the soil and development of mathematical model of infiltration of iron sulfate acid solution. The study of the infiltration of solutions of sulfuric acid was carried out on the example of gray soil, since this type dominates in the area of the inkstone dump. Soil infiltration is estimated by the coefficient of filtration, which is determined by Darcy's law. The diffusion density was determined experimentally – 1.6310-10 kg/m2 , and the diffusion coefficient was calculated – 1.5110-8 m2 /s. On the basis of experimental research, an effective mathematical model for the propagation of acid solutions of iron sulfate in soil was developmented. By numerical modeling of the developed model, the acidity distribution in the 3D projection is obtained. At the initial stage, there is no water movement in dry soil. However, in the presence of slight convection, an increase in the acidity of the soil occurs. Soil oxidation occurs faster and its leveling is observed at different depths. Comparison of the results of numerical simulation and statistical data obtained experimentally shows the relationship between the hydrolytic acidity of the soil environment and the depth of impregnation of acid solutions of ferrous sulfate. It is established that between the values obtained by the experimental method and the results of the solution of the mathematical model, there is a close correlation connection. The correlation coefficient was 0.89. Keywords: iron sulfate; sulfuric acid; water permeability; acidification; diffusion