Studying Of Nitrogen Transport And Transformation Law In Unsaturated Zone And Model Foundation

This thesis is mainly about the transportation and transition regulation of nitrogen in unsaturated zone. Based on the different character, nitrogen falls into four parts: ammonia, nitrite, nitrate and organic nitrogen which behave differently in unsaturated zone. The regulation consists of four parts: adsorption, nitration, denitrification, mineralization. We adopt the quantitative analysis method to study the behavior in the process of the transport, and then set up a model.The experiment consists of there parts: adsorption experiment, degradation experiment, eluviate experiment.We mainly study the adsorption kinetics regulation of nitrogen in adsorption experiment. In order to present a accurately quantitative description ,we should have a research on single nitrogen and multi-nitrogen and find the difference between the both, and calculate relative kinetics parameters.The degradation experiment is composed of three parts: nitration, denitrification, mineralization. Through these experiment, we can find character of nitrogen degradation and calculate appropriate degradation kinetics parameters. Nitration and mineralization is in aerobic condition , and denitrification is in anaerobic condition.With the aim of stimulating nitrogen transport in unsaturated zone , we carry out the Eluviate experiment and study the different behavior of nitrogen in different depth.Based on the convection-dispersion equation applied by solute transportin groundwater , we set up a one-dimension model and adopt NEWTON iterative method to change non-linear equations into linear ones. Due to the unsaturated flow, we introduce the relative permeability and diffusivity of porous medium with respect to the unsaturated aqueous phase.