A Modeling Analysis Approach for Heavy Metal Transport in Soil by Surface Runoff

Abstract

The discharge of heavy metals from industrial activity has been found to have detrimental effects on humans and the environment. In this paper, a com­plete modeling approach is developed to simulate the transport process of heavy metals in soil due to rainfall runoff. In this approach, the PCSWMM model is ap­plied to simulate the formation of runoff by precipitation, the Hairsine-Rose soil erosion model is used to calculate the dissolution of heavy metals from the soil surface into runoff, and the STANMOD model is employed to simulate the solute transport process in the soil. These models take into account parameters includ­ing the rainfall rate and the characteristics of the soil and contaminants, the data for which were obtained from the case study and related experiments. The mod­eling approach offers a distribution profile of the concentration of Pb in the soil and the relative concentrations at different locations and soil depths. Meanwhile, a three-dimensional analytic solution based on the ADE equation is applied to val­idate the accuracy of the modeling approach. Both results present similar values to those found in the literature data. This study also makes use of the Monte Carlo probabilistic analysis in which soil porosity is chosen as the uncertain variant. The results present the probability function of the Pb concentration range, which can be used for environmental risk assessment.