This paper looked back on the current situation about simulation using PHREEQC of heavy metal transport in soil and the current situation of coupling with other value simulation software. On such a base, the feasibility, advantages and problems of heavy metal reactive solute transport in soil using PHREEQC were discussed.

Ion beam etching can achieve nanometer size easily, processing in nanometer size, then put forward higher requirements on the workpiece surface. Ion beam etching is based on the Sigmund sputtering principle to remove the material, and the defects such as vacancies and interstitials in substrate material atomic lattice will be produced in this process. When these defects are enough, they lead to material damage. This paper is based on this effect to explore the effect of the processing parameters like Ar ion incident energy and incident angle of plasma beam on the implantation depth and the lattice change, through the SRIM software simulation which Ar ions used to the silica etching, moreover, forecast and put forward the suitable parameters for ion beam etching of nanocrystals on the workpiece, to produce the smaller nanowires damage.

Through the soil column experiments, the migration behavior of heavy metal copper ions in saturated sandy loam is analyzed, and it is found that the inflow solution with high concentration is conducive to the migration of copper ions. In the meantime, the software package of CXTFIT is utilized to conduct fitting for the outflow dynamics of copper ions with deterministic equilibrium model and non-equilibrium two-zone model, and predict the changing process of copper ion concentration at the different depths of soil column over the time. The results show that in the indoor saturated homogeneous conditions, the simulation accuracy of fitting parameters that applied deterministic equilibrium model is higher than that used the non-equilibrium two-zone model. Moreover, the influence of fixed water on the copper ion migration can be ignored.

The characteristics of nitrate nitrogen leaching in soil under different irrigation levels were studied by soil column simulation experiment with numerical simulation done using LEACHM model taking nitrate nitrogen leaching under different irrigation levels as the research background. In sandy soils, an irrigation amount of 300 mm would cause nitrate nitrogen to leach downward 75~150 cm, with a leaching amount of 10~30.7 kg/ha; and an irrigation amount of 700 mm would make nitrate nitrogen leach downward about 3.5 m, with a leaching amount of 98 kg/ha. Research data showed that the amount of nitrate nitrogen leaching was positively correlated with the irrigation intensity level, irrigation level directly determined the amount of nitrate nitrogen leaching, and influenced its leaching depth.