• 关键词：污水补给  氮  扩散通量  沉积物-水界面

• 基金项目：国家水体污染控制与治理科技重大专项(No.2012ZX07203-003,2012ZX07203-006)

• 张淑珍
• 1. 辽宁大学环境学院, 沈阳 110036;2. 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085

• 赵钰
• 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085

• 单保庆
• 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085

• 张洪
• 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085

• 段圣辉
• 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085

• 郎超
• 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085

• 摘要：为了揭示非常规水源补给河流沉积物-水界面氮交换过程及其特点,为非常规水源补给河流富营养化机制提供基础数据.选择典型非常规水源补给河流(滏阳河)为研究对象,分析河流沉积物中氮素空间分布及上覆水-孔隙水氮营养盐垂直分布特征,并估算滏阳河不同区段沉积物-水界面无机氮扩散通量.结果表明,滏阳河整体表层沉积物总氮含量范围在770~10590 mg·kg^-1之间,其中有机态氮为氮素的主要存在形式,占总氮比例达84.9%~99.3%.NH₃-N为无机氮的主要形态,含量范围为3.23~1135.00 mg·kg^-1.溶氧量作为影响沉积物-水界面无机氮分布的主要因素.邯郸段硝氮浓度在孔隙水中随深度逐渐升高,孔隙水平均硝态氮浓度达3.54 mg·L^-1,为上覆水8倍之多.邢台、衡水、沧州段硝氮浓度随深度而逐渐降低;滏阳河下游衡水段和沧州段进入沉积物-水界面后氨氮浓度呈下降趋势.滏阳河上游邯郸段与邢台段沉积物-水界面NH₃-N由沉积物向上覆水扩散,扩散通量为48.9~1471.0μmol·m^-2·d^-1.下游河段部分点位NH₃-N表现为上覆水向沉积物中扩散,扩散通量在-932~-456μmol·m^-2·d^-1之间.非常规水源补给河流在氮营养盐外源得到控制后,仍存在内源释放风险,将会加大河流治理与修复的难度.

• Abstract：Wastewater is the major water source for rivers in northern China because of low precipitation. In order to investigate the nitrogen behavior in sediment-water interface, surface sediments and sediment cores from FuYang River with wastewater recharge were collected to study the spatial distribution characteristics and vertical distribution patterns of nitrogen from the overlying water to porewater. the fluxes of inorganic nitrogen from different areas of Fuyang River were calculated using a one-dimensional transport-reaction model based on the Fick's First Law. The results show that the total nitrogen contents in surface sediments of Fuyang River ranged from 770 to 10590 mg·kg^-1, wherein the organic nitrogen was the major form of nitrogenous substances, accounting for 84.9%~99.3% of TN. NH₃-N, ranging of 3.23~1135.00 mg·kg^-1, was the main form of inorganic nitrogen. NO₃^--N contents of sediment in Handan Reach of Fuyang river tended to increase downwards, while other reaches showed decreasing trends. The mean NO₃^--N concentrations in porewater was 3.54 mg·L^-1, 8-fold higher compared with that in the overlying water of Handan Reach. NH₃-N contents in Hengshui Reach and Cangzhou Reach decreased with depth. Ammonia in the upper reaches of Fuyang River were released from sediments to overlying water with the diffusion fluxes 48.9 μmol·m^-2·d^-1 to 1471.00 μmol·m^-2·d^-1. Due to the input of high ammonia nitrogen wastewater, NH₃-N in the downriver released from overlying water to sediments. High nitrogen wastewater increase the nitrogen content of sediment, result in high nitrogen diffusion flux. The release of endogenous nitrogen from sediments significantly affects water quality and accelerates eutrophication, which makes the river more difficult to remediate.

• Key words：waste water recharge  nitrogen  diffusion flux  sediment-water interface

• 
  摘要点击次数： 1663 全文下载次数： 2252