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论文类型：期刊论文

发表时间：2017-03-01

发表刊物：ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES

收录刊物：SCIE、PubMed

卷号：53

期号：1

页面范围：36-53

ISSN号：1025-6016

关键字：Groundwater; hydrogen-2; isotope hydrology; multiple isotopes approach; nitrogen-15; nitrogen transformation process; oxygen-18; phosphorus; underground cut-off wall; Wang River

摘要：Underground cut-off walls in coastal regions are mainly used to prevent saltwater intrusion, but their impact on nutrient dynamics in groundwater is not clear. In this study, a combined analysis of multiple isotopes (delta N-15-NO3-, delta O-18-NO3-, delta H-2 and delta O-18-H2O) and nitrogen and phosphorus concentrations is used in order to assess the impact of the underground cut-off walls on the nutrient dynamics in groundwater in the lower Wang River watershed, China. Compared with the nitrogen and phosphorus concentrations in groundwater downstream of the underground cut-off walls, high NO3- and total dissolved nitrogen concentrations and similar concentration levels of NH4+, NO2-, PO43- and total dissolved phosphorus are found in groundwater upstream of the underground cut-off walls. The isotopic data indicated the probable occurrence of denitrification and nitrification processes in groundwater upstream, whereas the fingerprint of these processes was not shown in groundwater downstream. The management of fertilizer application is critical to control nitrogen concentrations in groundwater restricted by the underground cut-off walls.