摘要
白洋淀沼泽化趋势不断加重,本文分析了沉积物氨氮释放风险与水质效应,评估沉积物中氨氮交换通量对上覆水体水质产生的重要影响.结果表明:白洋淀淀区表层水氨氮(NH_4^+-N)平均浓度在0.0~0.49 mg·L^(-1)之间,硝氮(NO_3^--N)平均浓度维持在0.09~0.20 mg·L^(-1),总氮(TN)浓度范围为1.40~4.52 mg·L^(-1),淀区水质在V类水平和劣V类水平.沉积物NH_4^+-N的平均含量在61.1~160.6 mg·kg^(-1),NO_3^--N含量整体平均值较低,范围在4.3~9.0 mg·kg^(-1),TN含量平均值在1555~4400 mg·kg^(-1)之间.整个白洋淀淀区表层沉积物孔隙水中NH_4^+-N浓度明显高于上覆水浓度,NH_4^+-N存在从沉积物向上覆水释放的风险.淀区沉积物-水界面潜在NH_4^+-N扩散通量范围为-9.3~38.3 mg·m^(-2)·d^(-1),NH_4^+-N潜在内源释放风险非常高.烧车淀区、南刘庄区、圈头区的潜在NH_4^+-N平均释放通量达到10.0 mg·m^(-2)·d^(-1)以上.为了避免白洋淀沼泽化过程加快,水质氮污染需要采取相应措施进行有效控制,而控制沉积物NH_4^+-N的内源释放是其中的关键环节.
The swamping trend of Baiyangdian Lake is increasing. This paper investigated the risk of ammonia nitrogen release from sediments and its water quality effect,and assessed the impact posed by exchange flux of ammonia nitrogen in sediments to the overlying water. The results showed that the mean NH4＋-N concentration in surface water was from 0. 03 to 0. 49 mg·L（-1）,mean NO3--N concentration was from 0. 09 to 0. 20 mg·L（-1） and mean TN concentration was from 1.40 to 4.52 mg·L（-1）. Water quality in Baiyangdian Lake were belonged to grade V and below grade V. NH4＋-N in surface sediments of Baiyangdian Lake ranged from 61.0 to 160.6 mg·kg（-1）,the average value of NO3--N content was relative low,which was from 4.3 to 9.0 mg·kg（-1）. TN concentrations ranged from 1555 to 4400 mg·kg（-1）. For all sampling sites,NH4＋-N concentrations were higher in the pore water than that in the overlying water. The releasing of NH4＋-N from sediments to overlying water clearly revealed the releasing risk of internal nutrient in Baiyangdian Lake. The NH4＋-N influxes across the sediment-water interface varied from-9. 3 to 38. 3 mg·m（-2）·d（-1）. In Shaochedian Area,Nanliuzhuang Area and Quantou Area,the NH4＋-N fluxes across the sediment-water interface reached up to 10. 0 mg·m（-2）·d（-1）. Appropriate measures should be taken to effectively control the nitrogen pollution in the water of Baiyangdian Lake,among which,the controlling of endogenous release of NH4＋-N in sediments is the key step.
作者
朱曜曜
金鑫
孟鑫
张超
唐文忠
单保庆
赵钰
ZHU Yaoyao;JIN Xin;MENG Xin;ZHANG Chao;TANG Wenzhong;SHAN Baoqing;ZHAO Yu(State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eeo-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085;University of Chinese Academy of Science, Beijing 100049)
出处
《环境科学学报》
CAS
CSCD
北大核心
2018年第6期2435-2444,共10页
Acta Scientiae Circumstantiae
基金
国家自然科学基金青年科学基金项目(No.41701546)
环境模拟与污染控制国家重点联合实验室专项经费(No.17L02ESPC)~~
关键词
氨氮
沉积物
通量
营养盐
白洋淀
ammonia nitrogen
sediment
flux
nutrients
Baiyangdian Lake
