Physics-based modeling of contaminant leaching in road construction

Abstract

Coal combustion products (CCPs) offer a sustainable solution for road construction but pose environmental risks due to trace element leaching. Predicting solute concentrations accurately is critical to mitigating these risks as it guides contamination assessment and effective remediation. However, the heterogeneity of soils and materials in pavement layers, along with environmental factors, hinders reliable predictive models. To address this, this study utilizes a novel method to predict seepage velocity as a field, a critical parameter for modeling contaminant transport, integrated into the advection–dispersion–reaction governing equation. Unlike traditional assumptions of constant velocity parameters, our approach provides accurate prediction of solute concentrations and valuable insights into when pollutants may reach groundwater. Numerical simulations demonstrate superior performance in estimating seepage velocity and pollutant concentrations. The findings underscore the potential of this methodology to enhance environmental risk assessment in pavement engineering and support the safe, sustainable use of CCPs in infrastructure development.