Migration of Infiltrated NH_4 and NO_3 in a Soil and Groundwater System Simulated by a Soil Tank  

作　　者：WANG Chao WANG Pei-Fang 

机构地区：[1]State Key Laboratory of Hydrology- Water Resources and Hydraulic Engineering, Key Laboratory of Integrated Regulationand Resource Department on Shallow Lakes, Ministry of Education, Environmental Science and Engineering College,Hohai University, Nanjing 210098 （China）.

出　　处：《Pedosphere》2008年第5期628-637,共10页土壤圈（英文版）

基　　金：the National Key Basic Research Program (973 Program) of China (No.2002CB412303);the National Natural Science Foundation of China (No.50709009);the Key Project of Chinese Ministry of Education (No.106088).

摘　　要：The infiltration of water contaminants into soil and groundwater systems can greatly affect the quality of groundwater. A laboratory-designed large soil tank with periodic and continuous infiltration models, respectively, was used to simulate the migration of the contaminants NH4 and NO3 in a soil and groundwater system, including unsaturated and saturated zones. The unsaturated soil zone had a significant effect on removing NH4 and NO3 infiltrated from the surface water. The patterns of breakthrough curves of NH4 and NO3 in the unsaturated zone were related to the infiltration time. A short infiltration time resulted in a single sharp peak in the breakthrough curve, while a long infiltration time led to a plateau curve. When NH4 and NO3 migrated from the unsaturated zone to the saturated zone, an interracial retardation was formed, resulting in an increased contaminant concentration on the interface. Under the influence of horizontal groundwater movement, the infiltrated contaminants formed a contamination-prone area downstream. As the contaminants migrated downstream, their concentrations were significantly reduced. Under the same infiltration concentration, the concentration of NO3 was greater than that of NH4 at every corresponding cross-section in the soil and groundwater tank, suggesting that the removal efficiency of NH4 was greater than that of NO3 in the soil and groundwater system.The infiltration of water contaminants into soil and groundwater systems can greatly affect the quality of groundwater. A laboratory-designed large soil tank with periodic and continuous infiltration models,respectively,was used to simulate the migration of the contaminants NH4 and NO3 in a soil and groundwater system,including unsaturated and saturated zones. The unsaturated soil zone had a significant effect on removing NH4 and NO3 infiltrated from the surface water. The patterns of breakthrough curves of NH4 and NO3 in the unsaturated zone were related to the infiltration time. A short infiltration time resulted in a single sharp peak in the breakthrough curve,while a long infiltration time led to a plateau curve. When NH4 and NO3 migrated from the unsaturated zone to the saturated zone,an interfacial retardation was formed,resulting in an increased contaminant concentration on the interface. Under the infiuence of horizontal groundwater movement,the infiltrated contaminants formed a contamination-prone area downstream. As the contaminants migrated downstream,their concentrations were significantly reduced. Under the same infiltration concentration,the concentration of NO3 was greater than that of NH4 at every corresponding cross-section in the soil and groundwater tank,suggesting that the removal effciency of NH4 was greater than that of NO3 in the soil and groundwater system.

关 键 词：breakthrough curve MIGRATION NH4 NO3 soil tank experiment 

分 类 号：S15[农业科学—土壤学]