Experimental study of non-reactive anion transport in the soil-stone mixture

To make known the process and the mechanism of the chemical transport in the soil-stone mixture,we measured the process of the water and solute transport,based on the displacement experiments using Cl^- during the saturated and steady flow in the soil containing rock fragments,and stuied the effect of different content and constitutes of rock fragments on the breakthrough curves of the solute. The parameters(D,R)of classic CDE were fitted to the measured BTCs using CXTFIT211 at the given pore velocities. The results show that:D values varied from 0.258 cm²·h^-1 to 22.31 cm²·h^-1,and R values from 0.6 to 1.54.The relations between the soil-stone ratios and the averaged pore velocities,the dispersion coefficients and the dispersivitis all fit the power functions repeatedly. After correlate analyses,the effect of size and constitutes of rock frag-ments on the parameters is expressed in the content of rock fragment. When the content of rock fragments smaller than 5mm increases,the pore velocity and the D have decreasing trend;while the rock fragments bigger than 10mm in diameter are favorable to the solute transport. The result of transport of the non-reactive anion in this paper may provide important data and be useful for better understanding of the solute transport in the heterogeneous porous media.