Ensuring Environmental Safety of Solid Municipal Waste Landfills Based on Calculations of Volumetric Fire Parameters Using a Heat and Mass Transfer Model

Abstract

The purpose is to ensure the environmental safety of municipal solid waste landfi lls by adapting heat and mass transfer equations for mathematical modeling of the parameters of dangerous volumetric fi res, whose rapid development causes high levels of air pollution and increases environmental risks. Materials and Methods. A multicomponent heat and mass transfer model was used to mathematically describe the combustion processes in waste layers and the subsequent development of combustion in the surface air layer. This model takes into account the thermal transformation of matter, the humidity and temperature of the environment, and the horizontal and vertical air transport velocities. A refi ned formula by R. Rothermel was used to account for the contribution of vertical thermal diff use convection. The mathematical problem was solved using the Monin-Obukhov hypothesis in a cylindrical coordinate system. Results and Discussion. The physical processes that facilitate and accompany ignition in the waste layer are described, as well as the parameters characterizing combustion centers in the surface waste layer and the vertical development of the fi re process during thermal turbulent convection within the fi re source. The initial and boundary conditions of volumetric fi res are established based on the principles of heat and mass transfer. Conclusions. To prevent the development of large-scale fi res in the waste layer, it is envisaged to develop a series of measures aimed at layer-by-layer storage of waste with mandatory compaction to prevent the formation of cavities with a concentration of biogas, the introduction of a system of vertical gas removal wells with its subsequent disposal, which will ensure increased environmental and fi re safety of landfills, taking into account the parameters obtained in the work and the relationships between them.