污水灌溉系统中氮素转化运移的数值模拟分析

本文研究了不同类型氮素在二维饱和-非饱和土壤中运动及转化的数学模型,概化和简化了氮素集合体的划分,给出了氮素转化和运移的对流、弥散、硝化、反硝化、挥发、作物吸收、深层渗漏、固持和矿化等转化运移方式和控制方程。通过野外两个灌溉季节的污水灌溉试验,利用第一灌溉季节的试验数据进行参数求解,利用第二个灌溉季节的数据对该数值模型的实际应用进行检验。数值模拟的内容包括地下水位,排水中铵态氮、硝态氮的浓度变化三个部分,研究结果表明,模型正确可靠,预测结果可信,可用于实际污水灌溉的模拟分析。

Numerical modeling of nitrogen transport and transformation in sewage irrigation and treatment system

The numerical model for simulating the transport and transformation of nitrogen in 2-D saturated-unsaturated soil is studied. A general and complete model of water flow is established and the nitrogen pools of organic and inorganic form are generalized and discussed. The nitrogen transport and transformation include convection, dispersion, nitrification, dentitrification, volatilization, uptake by plants, deep leakage, mineralization and immobilization. The observation data obtained from field test in first sewage irrigation season are used to calibrate t he parameters of the model and the data of second season are used to check the reliability of the model. It is concluded that the model is reliable and can be used to forecast the nitrogen distribution and transformation in field.