【作者】 何晓锋；

【导师】 钱家忠；

【作者基本信息】 合肥工业大学 ， 环境工程， 2007， 硕士

【摘要】 地下水中硝酸盐的污染自从20世纪60年代以来日趋严重。由于其性质稳定、溶解度高，因此随地下水运移，成为当前世界上许多地区地下水污染最普遍的环境因子，并且污染程度不断增加。硝酸盐污染去除技术研究已经引起世界上许多学者的高度关注，是当今水文地质学的一个重要研究方向，所以控制硝酸盐迁移转化的过程和终产物、及预测其浓度非常重要。本文得到国家自然科学基金的资助，基于国内外相关地下水中硝酸盐污染迁移转化的研究成果及趋势，设计制作了实验室物理模型并进行模拟实验；深入研究了地下水水力梯度和含水层厚度的变化对硝酸盐迁移转化的影响、分别完成了水力梯度和含水层厚度不变的情况下每层和每组的硝酸盐迁移转化的实验、揭示其迁移转化规律，建立了硝酸盐迁移转化预测模型，得出主要结论如下：(1)在其他条件不变时，随着水力梯度的增加，各个采样点的pH值降低，电导率、COD、氨氮及硝酸盐氮浓度增大，亚硝酸盐浓度的变化趋势不明显；(2)在其他条件不变时，随着含水层厚度的减小，各个采样点的pH值降低，COD、电导率、氨氮及硝酸盐氮浓度增加，亚硝酸盐氮浓度的变化趋势不明显；(3)得到了地下水饱和带硝酸盐空间分布特征：径向上硝酸盐氮浓度总体上随距离增大而减小；垂向上硝酸盐氮浓度总体上随埋深增大降低；(4)地下水饱和带硝酸盐迁移转化受多种因素影响，统计结果表明：径向上随着硝酸盐氮浓度的降低，pH值增大，电导率、COD、氨氮浓度降低，亚硝酸盐氮浓度增加；垂向上随着硝酸盐氮浓度的降低，pH值增大，电导率、COD、氨氮浓度降低，亚硝酸盐氮浓度增加；(5)确定地下水流态为层流，建立了地下水饱和带硝酸盐迁移转化一维对流—弥散方程，并预报了硝酸盐迁移转化趋势，其预报曲线具有较高的精度。更多还原

【Abstract】 Nitrate pollution in groundwater is more and more serious since 1960s. Because of its quality stabilization and big solubility, it has already become the furthest universal environmental pollute of groundwater pollution in many areas today, and its contaminated degree is uninterruptedly increased. Nitrate pollution reducing technology research has already brought many scholastic high attention. Nitrate contamination of groundwater is an important research aspect in hydrogeology of nowadays. So it is very much the important that control the process of nitrate transportation and reduction, final substance and forecast its concentration.This study is supported by Natural Science Foundation of China. Based on the study about nitrate contamination in groundwater at home and abroad. A set of experiment physical equipment simulating nitrate transportation and reduction in groundwater is designed. We deeply research the change of that hydraulic gradient and aquiferous thickness how to affect nitrate transportation and reduction. And nitrate transportation and reduction experiment of every layer and group at the changeless of hydraulic gradient and aquiferous thickness is completed. It is exposed the rules of nitrate transportation and reduction and established its forecasted model. The conclusions are drawn as followings: （1） Under the same condition, with the accretion of hydraulic gradient, pH value of each sampling point falls, conductance ratio, COD, NH₄⁺-N, NO₃^--N concentration of every sampling point augments; （2） Under the same condition of hydraulic gradient, pH value of each layer increases, the concentration of conductance ratio, COD, NH₄⁺-N, NO₂^--N, NO₃^--N decreases. Nitrite and pH value of every group increase, conductance ratio, COD, NH₄⁺-N, NO₃^--N decreases; （3） spacial distributing character of nitrate in groundwater saturated zone is obtained: whole variation of nitrate in radial decrease along with increase of distance; whole variation of nitrate in length decrease along with increase of depth of groundwater; （4） nitrate transportation and reduction in saturated zone is influenced by a lot of factors, the result of statistics: pH value and NO₂^--N increase, conductance ratio, COD and NH₄⁺-N decrease along with decrease of nitrate in radial; pH value and NO₂^--N increase, conductance ratio, COD and NH₄⁺-N decrease along with increase of nitrate in length; （5） ensure flow condition of groundwater is laminar flow, one-dimension convection-dispersion equation of transportation and reduction of nitrate in groundwater saturated zone is established, and forecasts the trend of nitrate transportation and reduction, its forecasted curve has finer precision.更多还原