State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
University of Chinese Academy of Science, Beijing, 100049, China.
Environ Sci Pollut Res Int. 2020 Mar;27(7):7096-7104. doi: 10.1007/s11356-019-07398-8. Epub 2019 Dec 27.
Water samples and sediments from Liangzi Lake were taken and used to study the vertical distribution characteristics of nitrogen (N) and phosphorus (P) in both the overlying and pore water. Fluxes of ammonia (NH-N) and phosphate (PO-P) were calculated using a one-dimensional transport-reaction model based on Fick's First Law. The results showed that the mean NH-N and NO-N concentrations in the overlying water of Liangzi Lake were 2.59 and 0.46 mg L, respectively. The mean PO-P concentrations were lower than the detection limit. Both N and P displayed peaks at the sediment-water interface. For example, the mean concentration of ammonia in pore water in the surficial layer (0-5 cm) was 4.29 ± 2.74 mg·L, which was twice than that of the overlying water. Two PO-P vertical profile regimes were identified; one had a gradually increasing trend, while the other first increased and then decreased. The mean orthophosphate concentration in the pore water of the surface layer (0-5 cm) was 0.01 ± 0.01 mg·L. The spatial distribution of ammonia flux values was highly heterogeneous. Using these data, the annual load contribution of autochthonous ammonia was calculated to be 481 t a. Studying N and P pollution and fluxes in the lakes of urban drinking water sources facilitates the provision of protection measures.
采集梁子湖的水样和沉积物，研究上覆水和孔隙水中氮（N）和磷（P）的垂直分布特征。基于菲克第一定律的一维输运反应模型计算氨（NH-N）和磷酸盐（PO-P）的通量。结果表明，梁子湖上覆水中平均 NH-N 和 NO-N 浓度分别为 2.59 和 0.46 mg/L。平均 PO-P 浓度低于检测限。N 和 P 均在沉积物-水界面处出现峰值。例如，表层（0-5 cm）孔隙水中氨的平均浓度为 4.29±2.74 mg·L，是上覆水的两倍。确定了两种 PO-P 垂直分布模式；一种呈逐渐增加的趋势，另一种先增加后减少。表层（0-5 cm）孔隙水中正磷酸盐的平均浓度为 0.01±0.01 mg·L。氨通量值的空间分布高度不均匀。利用这些数据，计算出自生氨的年负荷贡献为 481 t a。研究城市饮用水源湖中 N 和 P 的污染和通量有助于提供保护措施。
