杭州西湖龙泓涧流域非点源污染源解析及控制措施研究
发布时间：2018-08-23 08:02
【摘要】：随着点源污染的控制,非点源污染逐步成为水环境的首要污染源,引起了严重的生态环境问题,已成为地表和地下水的最大威胁。因此,开展流域非点源污染研究,对流域水资源管理与保护有重要的理论和实践意义。本论文以杭州西湖龙泓涧流域为研究对象,通过对龙泓涧水质及降雨径流的监测分析,利用15N和180稳定同位素技术,结合遥感、GIS技术,系统分析龙泓涧水体污染特征、污染物来源及迁移转化过程,评估龙泓涧生态修复效果,提出湿地设计优化建议及龙泓涧非点源污染控制措施,为改善龙泓涧及西湖水质提供科学依据。论文对龙泓涧15个水质监测点进行了为期两年的逐月监测,对龙泓涧11个底泥监测点进行了为期一年的季度监测,共监测分析21个指标。结合arcGIS技术,对龙泓涧水环境的时空分布及水质状况进行了综合分析。水质分析结果显示,龙泓涧水体已经富营养化,总体水质呈现"低碳、低磷、高氮、富氧、偏碱"的特点。氮是龙泓涧水体的主要污染物,远远超过地表V类水标准,以N03--N为主要成分。空间分析结果显示,TN浓度在上游森林和茶园区域较高,TP浓度在茶园附近较高,NH4+-N和BOD5浓度在居民区附近较高,CODMn浓度在下游湿地系统较高,水体经下游湿地系统后,N、P浓度显著降低。水质时间分析结果显示,丰水期水体较枯水期污染严重。论文运用描述性分析、相关性分析、主成分分析、聚类分析等统计分析方法,对龙泓涧水质及底质进行了分析。相关性分析显示TDS、SAL与TN、NOCV-N、NO2--N、TP呈显著正相关关系。HCA分析按照近似原则将15个监测点分为三组:主流上游、支流上游、下游湿地系统。PCA分析可知,龙泓涧水体污染的主要因子是营养盐。对水体污染的初步源解析表明,龙泓涧水体污染主要来源区域是森林和茶园,可能与肥料、土壤和地下水有关。底质分析结果显示,底泥污染状况较轻,不会对上覆水造成污染。枯败植物的沉积分解可能是底泥污染的主要来源。论文对龙泓涧流域四种主要土地利用类型的降雨及径流进行了六次监测分析。分析结果显示,TSS、CODcr、TN、N03--N、TP是降雨径流的主要污染物,高于龙泓涧溪流水体浓度,说明地表径流是龙泓涧水体N、P及有机污染物的重要来源。在四种土地利用类型中,茶园的TN和NO3--N浓度最高,森林的TN和NO3--N浓度次之,说明茶园和森林是龙泓涧溪流水体N的主要来源区域。径流中的P主要以颗粒态形式存在,茶园施肥可能是径流中P的主要来源。径流CODCr也主要以颗粒态形式存在,受雨强及前干期等因素的影响。居民区和道路径流污染对溪流水体的总体影响小。雨水中污染物浓度很低,说明湿沉降对龙泓涧水体污染的贡献小,溪流水体的污染物主要来自于地面。鉴别多土地利用类型流域非点源氮污染的来源是一个长期复杂的研究。本论文将降雨径流、溪流水质监测与15N-NO3-和180-NO3-双同位素测定相结合,鉴别非点源N的污染源及主要迁移转化过程。研究结果表明,水体N浓度的变化主要受季节及土地利用类型的影响。NO3--N浓度在春夏较高,秋冬较低。δ15N-NO3-和ε18O-NO3-值在夏季及下游出现富集。龙泓涧水体N的来源分析表明,铵肥、土壤、凋落物及地下水是龙泓涧水体N污染的主要来源,大气沉降、硝基肥料、农家肥对水体污染的影响较小。N的迁移转化研究表明,龙泓涧流域的NO3--N主要由陆域NH4+-N硝化而来,被降雨径流的冲刷携带进入溪流水体。溪流水体中的N转化过程主要以植物吸收作用为主,反硝化作用在溪流水体中很少或几乎不发生。论文评价了龙泓涧主、支流下游两个湿地系统(九个湿地)对TN、NO3--N、TP和DP的去除效果,提出了湿地优化设计建议及龙泓涧流域非点源污染控制措施。研究结果表明,两个湿地系统对营养盐的去除效果显著。TN的去除率高达45%,NO3--N去除率高达57%,TP去除率高达78%,DP去除率高达86%。营养盐的去除率受气候变化影响显著,气温高时去除率较高。植物吸收是湿地系统营养盐去除的主要机制。对两个湿地系统比较分析表明,多个湿地串联作用比单个湿地的营养盐去除效果好,串联作用的湿地越多,营养盐的去除效率越高。对九个湿地的研究结果表明,湿地设计参数,如容量、面积、流程、周长,对营养盐的去除效果有重要影响。对龙泓涧非点源污染的控制建议采取源头控制、传输控制、水文改善等方式。
[Abstract]:With the control of point source pollution, non-point source pollution has gradually become the primary pollution source of water environment, causing serious ecological environment problems, and has become the biggest threat to the surface and groundwater. Based on the monitoring and analysis of water quality and rainfall runoff in Longjian watershed, 15N and 180 stable isotope techniques, remote sensing and GIS techniques were used to systematically analyze the pollution characteristics of Longjian watershed, the sources of pollutants, the migration and transformation process of pollutants, the ecological restoration effect of Longjian watershed was evaluated, and the suggestions for wetland design optimization and non-Longjian watershed were put forward. Point source pollution control measures provide scientific basis for improving water quality of Longhuan and West Lake. Fifteen water quality monitoring points in Longhuan were monitored monthly for two years, and 11 sediment monitoring points in Longhuan were monitored quarterly for one year. A total of 21 indexes were monitored and analyzed. The results of water quality analysis show that Longhuanjian water body has been eutrophication, and the overall water quality is characterized by "low carbon, low phosphorus, high nitrogen, rich oxygen, partial alkali". Nitrogen is the main pollutant in Longhuanjian water body, far exceeding the surface V water standard, with N03--N as the main component. The concentration of N, P in the upstream forest and tea garden was higher, TP in the vicinity of tea garden was higher, NH4 + - N and BOD5 in the vicinity of residential area were higher, CODMn in the downstream wetland system was higher, and the concentration of N, P in the water body decreased significantly after passing through the downstream wetland system. Correlation analysis, principal component analysis, cluster analysis and other statistical analysis methods were used to analyze the water quality and sediment of Longhongjian. Correlation analysis showed that TDS, SAL and TN, NOCV-N, NO2-N, TP were significantly positively correlated. HCA analysis divided 15 monitoring points into three groups according to the approximate principle: mainstream upstream, tributary upstream, downstream wetland system. The primary source analysis of water pollution showed that the main source areas of pollution were forests and tea gardens, possibly related to fertilizer, soil and groundwater. The results show that TSS, CODcr, TN, N03--N and TP are the main pollutants in rainfall runoff, which are higher than those in Longhuan stream, indicating that surface runoff is N, P and organic in Longhuan river. Among the four types of land use, TN and NO3--N concentrations in tea garden were the highest, followed by that in forest, indicating that tea garden and forest were the main sources of N in Longjian stream. The pollution of residential area and road runoff has little influence on the whole stream water body. The concentration of pollutants in rainwater is very low, indicating that the contribution of wet deposition to the pollution of Longhongjian water body is small, and the pollutants in the stream water body mainly come from the ground. The source of point source nitrogen pollution is a long-term and complex study. In this paper, rainfall runoff and stream water quality monitoring are combined with 15N-NO3-and 180-NO3-isotope measurements to identify the sources of non-point source nitrogen pollution and the main migration and transformation processes. The concentration of ammonium fertilizer, soil, litter and groundwater are the main sources of N pollution in Longjian waters. Atmospheric sedimentation, nitro fertilizer and farm manure have little effect on water pollution. The nitrification of NH4 + - N in the Longhuanjian watershed was carried into the stream water by the erosion of rainfall runoff. The main process of N transformation in the stream water was plant absorption, and denitrification rarely or rarely occurred in the stream water. Removal of TN, NO3-N, TP and DP from wetland was studied. The optimal design of wetland and control measures of non-point source pollution in Longhongjian watershed were proposed. The results showed that the removal efficiency of nutrients by the two wetland systems was remarkable. The removal rates of TN, NO3-N, TP and DP were as high as 45%, 57%, 78% and 86% respectively. Plant uptake is the main mechanism of nutrient removal in the wetland system. Comparing the two wetland systems, the results show that the nutrient removal efficiency of multiple wetlands in series is better than that of single wetland. The more wetlands in series, the higher the nutrient removal efficiency. The results show that the design parameters of wetland, such as capacity, area, flow and perimeter, have important effects on the removal of nutrients.
【学位授予单位】：华东师范大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X52
[Abstract]:With the control of point source pollution, non-point source pollution has gradually become the primary pollution source of water environment, causing serious ecological environment problems, and has become the biggest threat to the surface and groundwater. Based on the monitoring and analysis of water quality and rainfall runoff in Longjian watershed, 15N and 180 stable isotope techniques, remote sensing and GIS techniques were used to systematically analyze the pollution characteristics of Longjian watershed, the sources of pollutants, the migration and transformation process of pollutants, the ecological restoration effect of Longjian watershed was evaluated, and the suggestions for wetland design optimization and non-Longjian watershed were put forward. Point source pollution control measures provide scientific basis for improving water quality of Longhuan and West Lake. Fifteen water quality monitoring points in Longhuan were monitored monthly for two years, and 11 sediment monitoring points in Longhuan were monitored quarterly for one year. A total of 21 indexes were monitored and analyzed. The results of water quality analysis show that Longhuanjian water body has been eutrophication, and the overall water quality is characterized by "low carbon, low phosphorus, high nitrogen, rich oxygen, partial alkali". Nitrogen is the main pollutant in Longhuanjian water body, far exceeding the surface V water standard, with N03--N as the main component. The concentration of N, P in the upstream forest and tea garden was higher, TP in the vicinity of tea garden was higher, NH4 + - N and BOD5 in the vicinity of residential area were higher, CODMn in the downstream wetland system was higher, and the concentration of N, P in the water body decreased significantly after passing through the downstream wetland system. Correlation analysis, principal component analysis, cluster analysis and other statistical analysis methods were used to analyze the water quality and sediment of Longhongjian. Correlation analysis showed that TDS, SAL and TN, NOCV-N, NO2-N, TP were significantly positively correlated. HCA analysis divided 15 monitoring points into three groups according to the approximate principle: mainstream upstream, tributary upstream, downstream wetland system. The primary source analysis of water pollution showed that the main source areas of pollution were forests and tea gardens, possibly related to fertilizer, soil and groundwater. The results show that TSS, CODcr, TN, N03--N and TP are the main pollutants in rainfall runoff, which are higher than those in Longhuan stream, indicating that surface runoff is N, P and organic in Longhuan river. Among the four types of land use, TN and NO3--N concentrations in tea garden were the highest, followed by that in forest, indicating that tea garden and forest were the main sources of N in Longjian stream. The pollution of residential area and road runoff has little influence on the whole stream water body. The concentration of pollutants in rainwater is very low, indicating that the contribution of wet deposition to the pollution of Longhongjian water body is small, and the pollutants in the stream water body mainly come from the ground. The source of point source nitrogen pollution is a long-term and complex study. In this paper, rainfall runoff and stream water quality monitoring are combined with 15N-NO3-and 180-NO3-isotope measurements to identify the sources of non-point source nitrogen pollution and the main migration and transformation processes. The concentration of ammonium fertilizer, soil, litter and groundwater are the main sources of N pollution in Longjian waters. Atmospheric sedimentation, nitro fertilizer and farm manure have little effect on water pollution. The nitrification of NH4 + - N in the Longhuanjian watershed was carried into the stream water by the erosion of rainfall runoff. The main process of N transformation in the stream water was plant absorption, and denitrification rarely or rarely occurred in the stream water. Removal of TN, NO3-N, TP and DP from wetland was studied. The optimal design of wetland and control measures of non-point source pollution in Longhongjian watershed were proposed. The results showed that the removal efficiency of nutrients by the two wetland systems was remarkable. The removal rates of TN, NO3-N, TP and DP were as high as 45%, 57%, 78% and 86% respectively. Plant uptake is the main mechanism of nutrient removal in the wetland system. Comparing the two wetland systems, the results show that the nutrient removal efficiency of multiple wetlands in series is better than that of single wetland. The more wetlands in series, the higher the nutrient removal efficiency. The results show that the design parameters of wetland, such as capacity, area, flow and perimeter, have important effects on the removal of nutrients.
【学位授予单位】：华东师范大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X52
【参考文献】
相关期刊论文 前10条
1 陈世博;汪亚峰;高扬;贾s，
本文编号：2198414
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