反应性溶质在不同质地饱和土柱中运移的数值模拟

Numerical simulation of reactive solute transport in saturated column of different soils

盐渍土壤中的物理化学作用对溶质运移具有重要影响。吸附和离子交换作用是土壤中常见的反应。利用室内土柱出流实验对这两种作用下的单组分和多组分溶质运移进行了探讨,用CXTFIT软件模拟了只考虑对流-弥散的常规溶质运移;用水文地球化学模拟软件PHREEQC进行了耦合吸附和离子交换反应的模拟。结果表明,土壤质地对单组分溶质的运移具有重要影响,而在多组分溶质运移中,组分之间的相互作用对溶质运移具有更为重要的影响,并且耦合物理化学作用的模拟精度更高。

Physical chemistry reaction in saline soils has some important effect on saline solute transport, and ion exchanges are the common chemical reactions observed in soil. Indoor leaching experiment were conducted to explore effects of the two reaction solute on single component/multi-component saline solute transport. The traditional convection-dispersion equation （CDE） regardless of chemical reactions was simulated by CXTFIT, and the reaction solutes coupled with adsorption, and ion exchange were simulated by PHREEQC, a hydrologic geochemical software. Results show that soil texture has important effect on single component saline solute transport, the effects between components are important in saline solute transport, and the effect coupled physical and chemical reaction is more precise in simulation.