硝态氮在河床垂向渗滤系统中环境行为的模拟实验

采用自行设计的室内土柱实验装置模拟硝态氮在河床中的垂向渗滤过程,以阶梯状加大浓度的硝酸钾溶液为淋滤液,研究了硝态氮在河床垂向渗滤系统中的环境行为,借以了解河床渗滤系统对硝态氮污染的净化机理。实验表明,硝态氮在河床渗滤过程中分别参与了异化还原作用及反硝化作用。在以上两种作用的影响下,河床渗滤系统对硝态氮的去除率高达100%。但是,异化还原作用却导致了地下水中氨氮浓度的上升,这是值得注意的不利因素。

Simulating Experiment of NO- 3 -N in Vertical System of Riverbank Filtration

The soil column was used to model the vertical infiltration of NO-3-N in the riverbank. In the experi-ment, the KNO3solution is added to the soil column to study the environmental behaviors of NO-3-N in the verti-cal system of riverbank filtration and the purification mechanism of nitrogen pollution. The results indicate thatNO-3-N takes part in the dissimilation-deoxidization and de-nitrification during the process of River bank filtra-tion. Under the influence of above processes, the NO-3-N is wiped off though the riverbank filtration, the remov-al efficiency reaches almost 100 percent. But dissimilation-deoxidization can lead that the rising of concentration ofNH+4-N, which is the disadvantage of this process.