A simulation study of surface water purifying through a polystyrene foam filter

The study has improved the mathematical model of water purification in view of the physicochemical properties of surface water, the type of filter loading, and the filtration characteristics of filtering structures. The advanced mathematical model takes into account the inverse influence of the process characteristics on the filtration parameters, changes in the diameters of the loaded grains throughout the height, the direction of filtering, and the turbidity of water at the inlet. The authors performed a comparative analysis of the work of filters with homogeneous and non-uniform loading for water filtration in different directions and carried out statistical processing of the results of the study with the establishment of the adequacy and the possibility of its use for a mathematical description of water treatment processes. Physicochemical properties of surface water entering filtration structures are taken into account in the model in the form of kinetic coefficients. The kinetic coefficients, which characterize the intensity of contaminants’ separation from and adhesion to the loaded grains, were obtained using the dimension theory method and were deduced for floating densities. It has been determined that the optimum loading height is 1.0 m for the ascending and descending filtration directions, where the output water quality is of the normative values. The improved mathematical model can help select the optimal design (the loading height and area, the granulometric composition, etc.) and the technological parameters (velocity and direction of filtration, degree of vaporization of incoming water) of polystyrene foam filters; it allows producing simulation of filters’ work in different conditions. A simulation of the work of polystyrene foam filters with different parameters of operation was carried out, which made it possible to specify optimal structural and technological parameters of the polystyrene foam filters for purifying water of the Horyn River (Rivne Oblast, Ukraine), the composition of which is typical for most plain rivers in Ukraine