Determination of Nutrient Fluzes Across the Sediment-water Interface in a Nitrate-rich Reservoir
(0) This study was to quantify the interfacial flux of nutrients and to explore the potential effects of nitrate on phosphate release from sediments in a nitrate-rich reservoir. Typical sediment samples were collected from the Tianzhuang Reservoir. Porewater profiles of nutrients (Nitrate, ammonium, and soluble reactive phosphorus) and diffusive fluxes of these nutrients across the sediment-water interface were determined. The interfacial flux of NH4 +-N, NO3 --N, and PO4 3--P were 141.39～175.83 mg/(m2·d), -43.68～-42.50 mg/(m2·d), and 0.14 mg/(m2·d), respectively. The results show that the sediment is an important source for NH4 +-N, and a sink for NO3 --N. The high nitrate rate into sediments indicates that denitrification is actively occurring in the anoxic surficial sediments. In addition, the increase of phosphate concentration coincides with the decrease of nitrate concentration in the porewaters of sediments ranging from the interface down to about 7.5 cm. These evidence suggest that nitrate in overlying water may retard the phosphate release from the redox-sensitive sediments. This retard effect has to be considered when countering nitrogen pollution by decreasing external loadings of nitrate.
sediment-water interface nitrate denitrification phosphate release retard effect
Zengwen Gao Xilai Zheng Wei Li Hui Song
Key Lab of Marine Environmental Science and Ecology Ocean University of China Qingdao, China Yiyuan Water Resource Administrative Office Zibo, China
国际会议
上海
英文
2969-2972
2008-05-16（万方平台首次上网日期，不代表论文的发表时间）