摘要
入海河流的氮污染问题已引起全球关注。大沽河是胶州湾最大的入海河流,河口附近海域无机氮和活性磷酸盐浓度多年不达标,已成为陆源污染物控制入海的关键区域。为此,本研究分别于2018年8月、10月和2019年1月在大沽河流域开展河流水样及可能污染源的样品采集工作,运用非参数检验、聚类分析和Pearson相关分析等方法对大沽河河流溶解态无机氮(Dissolved inorganic nitrogen,DIN)浓度的时空差异、影响因素进行分析,并对其主要来源进行探讨。结果表明,DIN浓度在研究期间表现出显著的季节差异(P<0.05),枯水期最高,丰水期最低,主要是受到降水、气温、溶解氧(DO)等因素的影响。DIN浓度的空间差异也比较明显,其中,上游水体NO3--N浓度较高,主要是受农业化肥施用和农村生活污水等非点源污染的影响;支流水体NH4+-N含量相对较高,主要受畜禽养殖废水等非点源和工业废水、污水处理厂出水等点源污染的共同影响;中下游干流处DIN浓度较低,主要是受闸坝的拦截和滞留效应的影响。
Rivers discharge large amounts of nitrogen into the oceans, which has caused increasing concern worldwide. The Dagu River is the largest river in the Jiaodong Peninsula, and the estuary has higher inorganic nitrogen and reactive phosphate concentrations than the environmental standard for long period. As such, the estuary is a critical zone to control the land-based sources of pollutants into the ocean.River water and possible pollutant sources were collected three times considering seasonal differences in 2018 and 2019 to determine the dissolved inorganic nitrogen(DIN)concentration. The spatiotemporal variation, controlling factors, and possible sources of DIN were analyzed using non-parametric test, cluster analysis, and Pearson correlation analysis. The DIN concentration exhibited a significant seasonal difference(P<0.05), which was high in the dry season and low in the wet season. The seasonal variations in DIN were mainly affected by precipitation, temperature, and dissolved oxygen(DO). Spatially, the upstream NO-3-N concentration was higher because of the potential non-point source emissions from fertilizer application and rural domestic wastewater discharge. The NH+4-N concentration was higher in the tributaries than in the main stream, which was attributed to the possible discharge of domestic sewage, industrial wastewater, and livestock wastewater. The DIN concentration was low in the middle and lower reaches owing to the interception and retention by cascade dams.
作者
夏云
张波涛
姜德娟
XIA Yun;ZHANG Bo-tao;JIANG De-juan(College of Chemical Science and Engineering,Qingdao University,Qingdao 266071,China;Key Laboratory of Coastal Environmental Processes and Ecological Remediation,Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Yantai 264003,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2020年第1期182-190,共9页
Journal of Agro-Environment Science
基金
国家自然科学基金项目(41671473)~~
关键词
无机氮
时空特征
影响因素
污染来源
大沽河
dissolved inorganic nitrogen
spatiotemporal characteristics
influencing factors
pollution sources
Dagu River
