春季敏感时期三峡水库典型支流沉积物-水界面氮释放特性  

Characteristics of Nitrogen Release at the Sediment-Water Interface in the Typical Tributaries of the Three Gorges Reservoir During the Sensitive Period in Spring

作　　者：李欣[1] 宋林旭[1] 纪道斌[1] 刘德富[2] 苏青青[1] 吕林鹏 王雄[1] 黄亚男[1] 吴庆[1] 

机构地区：[1]三峡大学水利与环境学院,宜昌443002 [2]湖北工业大学,河湖生态修复与藻类利用湖北省重点实验室,武汉430068

出　　处：《环境科学》2018年第3期1113-1121,共9页Environmental Science

基　　金：国家自然科学基金重大项目(91647207);国家自然科学基金项目(51779128);国家自然科学基金青年科学基金项目(51509086); 国际科技合作与交流专项(2014DFE70070); 国家水体污染控制与治理科技重大专项(2014ZX07104-005-02)

摘　　要：为研究春季敏感时期三峡水库典型支流沉积物-水界面氮释放特性,于2016年4月采集香溪河库湾上覆水和沉积物样品,分析香溪河库湾沉积物-水系统不同氮形态营养盐浓度的分布特征,计算沉积物-水界面不同氮形态的扩散通量并与环境因子进行相关性分析.结果表明,香溪河库湾上覆水和沉积物间隙水中ρ(TN)的变化范围分别为1.10~6.90 mg·L-1和6.19~32.57 mg·L-1;上覆水和沉积物间隙水中氮质量浓度在沿程和垂向上有一定的变化规律:各采样点上覆水中氮质量浓度在沿程和垂向上没有明显的变化趋势,上游区域的沉积物间隙水中氮质量浓度明显大于下游区域,沉积物间隙水ρ(NH_4^+-N)明显大于上覆水,沉积物间隙水ρ(NO-3-N)略小于上覆水;香溪河沉积物总体上表现为NH_4^+-N的"源",NO-3-N的"汇";NH_4^+-N的扩散通量范围为2.70~4.72 mg·(m2·d)-1;NO-3-N的释放通量范围为-1.61^-0.62 mg·(m2·d)-1;香溪河库湾沉积物氮主要以铵态氮的形态存在:沉积物中ρ(NH_4^+-N)范围为69.97~1 185.97 mg·kg-1,ρ(NO-3-N)范围为2.78~38.17mg·kg-1,沉积物ρ(NH_4^+-N)与沉积物间隙水ρ(NH_4^+-N)在表层0~8 cm的变化趋势一致.Overlying water and sediment interstitial water samples were acquired to study the nitrogen release between sediments and water interfaces in Xiangxi Bay in April 2016 during the Sensitive Period in spring. The spatial distribution of different forms of nitrogen in the sediment was analyzed,the diffusion fluxes of different forms of nitrogen in the sediments and water systems were also measured,and a correlation analysis with environmental factors was conducted. The results show that overlying water and sediment interstitial water ρ（TN） ranges from 1. 10 to 6. 90 mg·L^-1 and 6. 19 to 32. 57 mg·L^-1 respectively; indicating the nitrogen concentrations in the overlying and interstitial water of sediments have a certain variation along the process and vertically. The interstitial water nitrogen concentrations in the upstream area are higher than those in the downstream area. The interstitial water ρ（NH4^＋-N） in the sediment is significantly larger than that in the overlying water,but the interstitial water ρ（NO3^--N） in the sediment is slightly smaller than that in the overlying water. Xiangxi Bay sediment acts as a source of NH4^＋-N; however,for NO3^--N it is a sink. The diffusive fluxes of NH4^＋-N range from 2. 70 to 4. 72 mg·（m^2·d）-1; and the diffusive fluxes of NO3^--N range from-1. 61 to-0. 62 mg·（m^2·d）-1.Nitrogen is mainly present in the form of ammonium nitrogen in the sediment of Xiangxi Bay. The ρ（NH4^＋-N） in the sediment ranges from 69. 97-1 185. 97 mg·kg-1,ρ（NO3^--N） ranges from 2. 78-38. 17 mg·kg-1,and the ρ（NH4^＋-N） in sediments in the surface at 0-8 cm changes with the same trend.

关 键 词：三峡水库 香溪河 氮 沉积物-水界面 扩散通量 

分 类 号：X524[环境科学与工程—环境工程]