Zaporozhets J. Method for assessing environmental safety of soil contamination caused by an industrial plant.

This dissertation work is dedicated to a major problem on reduction of human impact on soil caused by an industrial plant by modeling and forecasting the emission of pollutants with moisture flow in the soil during infiltration process under the impact of industrial plants. General infiltration process is considered a system of separate physical and physicochemical processes in the soil. In this research, certain components of infiltration process were studied and the mathematical models for their description were reasonably selected. The recommended models comprise peculiar properties of the soil indirectly, i.e. via mechanisms of fluid transport in the soil, therefore they do not allow full assessment of human impact on condition and quality of soil and groundwater in practice. For this reason, to consider properties of the soil in the mathematical model of the infiltration process, a new model that will take into account properties of the porous media was designed. One of the challenges to evaluate industrial impact on soil and groundwater condition is the impact assessment of soil type and corresponding to this type mechanism of fluid transport in the soil upon general results of infiltration processes. To take into accout the soil media when evaluating an impact of an industrial plant on soil condition, the soil classification has been considered in terms of infiltration processes that occur in soils. Significant coefficients of impact of separate processes, which represent geofiltration in the soil media, were defined for different types of soil. To assess the impact of an industrial plant on soil, a technique for identifying values of purification efficiency, based on simulation experiment, was proposed. An algorithm to conduct a simulation experiment on a set of models taking into account defined coefficients was designed; it was implemented 10,000 times. According to the simulation experiment results, we defined values that provide assessment of soil condition: interval estimation of purification degree; soil depth that provides a maximum possible purification degree and probabilities of full purification from a contaminant while passing through soil for all soil types provided in the Ukrainian system of soil classification. To assess the impact level of an industrial plant on soil condition, it was proposed to consider a risk of pollutant penetration to groundwater through soil, and a scale for assessment of such a risk was developed based on Harrington’s desirability scale. The risk of contamination penetration to soils was evaluated for all reviewed soil types from the classification in cases when initial pollutant concentration exceeds back-ground concentration by three, five and ten times. The provided technique was implemented to analyze impact of emissions caused by iron and steel industries and thermal power stations on soil condition. Use of this technique allows us to obtain parameter values of soil purification efficiency depending on the initial pollutant concentration with regard to a soil type to evaluate risk of pollutant penetration to groundwater through soil.