Analysis and study of the migration pattern of microplastic particles in saturated porous media pavement

This work aims to establish an analytical and comparative model of pavement stormwater runoff and determine how to solve water pollution in saturated porous media pavements. Heavy metal element particles in the stormwater runoff due to the rainfall will cause inevitable environmental pollution. First, the pavement runoff and materials of saturated porous media are analyzed. Besides, particle migration laws and separation effects of different materials are compared. Based on this, microplastics are selected as the primary material for pavement filling. Then, the adsorption effect of microplastics and the parameters of rainwater infiltration rate and infiltration ratio are analyzed to propose a multi-level ecological integrated treatment system for pavement runoff. Specifically, the environmental resource pollution and saturated porous media materials are analyzed. In addition, the adsorption effect of microplastic particles is analyzed to establish a model to study the selection process of the optimal adsorption material. The main contribution of the research is to analyze the migration process of metal particles in the soil in combination with the internal particle migration rules of plastic granular materials. The research results demonstrate that the rain runoff coefficient gradually increases with the expansion of the permeable area of the pavement. The rain runoff coefficient reaches the maximum value under the pavement of 120 square meters. In addition, a comparative analysis of three street pavements is conducted on the residential street pavement (RSP), commercial street pavement (CSP), and active street pavement (ASP). When comparing the two sets of data, the overall average permeability of the RSP is better than CSP and ASP. The research materials are compared under isothermal conditions. The particle adsorption effect of the same material at 50 °C is significantly better than that at 30 °C. Therefore, it is feasible to resolve the pavement runoff water pollution through technical schemes.