| 摘要: |
| 湖泊沉积物参与水体元素循环重要环节，是目前水体富营养化的治理难点之一。为揭示城市内湖沉积物氮磷和有机质污染特征及来源，并为水环境综合治理的环境效应评估提供新视角，采集并测定了黄冈市遗爱湖25个点位沉积物柱状样中的TN、TP和OM含量，监测湖泊9个点位与排口溢流污水水质，解析湖泊水质与沉积物N、P和OM空间分布特征，采用综合污染指数法定量评估沉积物氮磷和有机质污染风险，利用聚类分析和化学计量特征相结合的手段对湖泊沉积物N、P和OM的来源进行定性识别和定量解析。结果表明:水平分布上，沉积物TN、TP和OM含量范围分别在940~3677 mg·kg-1、323~1667 mg·kg-1和1.03%~7.44%，空间分布差异大，且氮磷和有机质高值区集中在湖泊沿岸及排口附近。垂向上总体表现为表层>中、底层，表层沉积物中TN、TP和OM的含量范围分别在920~4450 mg·kg-1、208~1970 mg·kg-1、2.05~7.48%之间，表层TP含量较中国东湖浅水湖泊平均值处于较高水平，与国内沉积物污染严重的湖泊水平相近。综合污染指数法显示表层沉积物TP污染严重，52%的湖区总磷处于中度及重度污染状态，TN污染和综合污染程度较低。聚类分析-化学计量特征结果表明，表层沉积物C/N值为10.67，C/P值在20.16～190.97之间，OM来源受内源释放(55%)、溢流排放和面源污染(45%)的共同影响，TP主要来自面源污染、其次是溢流污水，TN的来源与OM相似。 |
| 关键词: 城市内湖 沉积物 营养物质 聚类分析 化学计量特征 综合污染指数法 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Identification and traceability analysis of the distribution characteristics of nitrogen, phosphorus and organic matter in lake sediments in typical cities |
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Yangzixuan,CHEN Xiang,Liyiping,Wangyv,Zhuxiaoling,Baohangtong,Panhongzhe,Zhangshuangshuang,Yanchunmin
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College of Environment, Hohai University, Nanjing 210098, China
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| Abstract: |
| In order to reveal the characteristics of nutrient pollution and its pollution sources in lake sediments in the city, and to provide a new perspective for the assessment of the environmental effect of comprehensive water environment management, the contents of TN, TP and OM in sediment columnar samples at 25 points in Yiai Lake in Huanggang City were collected and measured, the water quality of overflow sewage from 9 points and outlets of the lake was monitored, the spatial distribution characteristics of lake water quality and sediment nutrients were analyzed, and the sediment pollution risk was assessed by comprehensive pollution index method, and cluster analysis, carbon-nitrogen ratio (C/N) and carbon-phosphorus ratio (C/P) were used A combination of methods to analyze the sources of nutrients in lake sediments. The results showed that: 1) There were spatial differences in the distribution of TN, TP and OM in sediments. The horizontal distribution of TN, TP and OM contents ranged from 940~3677, 323~1667 mg·kg-1 and 1.03%~7.44%, and the overall vertical expression was surface >The contents of TN, TP and OM in the middle and bottom layers and surface sediments ranged from 920~4450 mg·kg-1, 208~1970 mg·kg-1 and 2.05~7.48%, respectively. 2) The TP content of surface sediments was higher than that of the lakes in the middle and lower reaches of the Yangtze River, and the results of the comprehensive pollution index method showed that the TP pollution of surface sediments was serious, and the total phosphorus in 52% of the lake area was in a moderate and severe pollution state, and the degree of TN pollution and comprehensive pollution was low. 3) The nutrient distribution of surface sediments was affected by overflow discharge, non-point source pollution and endogenous release, and the C/N value of surface sediment was 10.67, and the C/P value was between 20.16~190.97. TP mainly comes from non-point source pollution, followed by overflow sewage. The source of TN is similar to that of OM, which is derived from about 45% of endogenous release and 55% of non-point source and overflow pollution. |
| Key words: Yiai Lake Eutrophication Sediment Nutrients Overflow Pollution evaluation |
