Cadmium Transport Simulation under Different Soil Conditions Using the Physical Non-Equilibrium Model

In this study three dominant soil textures of Hamedan province (Sandy-Loam, Clay-Loam and Loam) in two conditions, with and without maize cultivation, were contaminated with the wastewater containing cadmium. Cd concentration in drainage water was analyzed by completely randomized factorial design in the repeated measures, with three replications of each treatment. Also the Two-Region Non-equilibrium models (TRM) in CXTFIT software were used to simulate the transport of Cadmium in non-cultivated soils and to estimate the residual cadmium concentration at the end of experiments. The results showed that the Sandy-Loam and Loamy soil textures both under cultivation conditions had the minimum and maximum effects on Cd contaminated water filtration, respectively. The CXTFIT software showed that the best fitting for breakthrough curve derived from simulated and observed data was for the loam soil with a correlation coefficient value of r =0.84. Also the simulation results showed that under the conditions of this experiment, residual cadmium concentrations in the soil at the end of the growing season were low in the sandy-loam soil and high in the Clay-Loam and Loam soils.