北京城区降雨径流污染特征分析

发布时间：2018-05-30 04:28

本文选题：降雨径流污染 + 初始冲刷效应　；参考：《河南大学》2016年硕士论文

【摘要】：水环境是城市生态环境的重要组成部分,水环境污染一般分为点源和非点源污染。由于点源污染具有排污明显、污染强度大等特点,相关研究开展早,治理投入大。在点源污染得到控制之后,非点源污染逐渐显现出来,降雨径流作为污染物迁移转化的主要驱动力,是城市非点源污染研究的热点和重点。城市化是中国社会、经济发展的必然趋势。暴雨发生时,冲刷聚集大量污染物的下垫面产生径流,对城市生态环境造成污染。屋面是城市3种主要下垫面(路面、屋面、草地)之一。为了进一步了解我国城市降雨径流污染的普遍特征,本文基于室外定位观测和室内实验监测,对比不同功能区的混合沉降以及不同模拟屋面的降雨径流污染过程。(1)以北京城区不同典型功能区的天然降雨样品进行污染物分析,分析显示北京城区天然降雨超标严重,属于劣V类水;TN是城市混合沉降的主要污染物,氮素主要以硝态氮的沉降为主,而城市边缘森林生态系统氮沉降主要以铵态氮为主。根据水质优劣排序规则,蟒山教学植物园生态中心,表明混合沉降在空间上有明显的差异,与受人类活动影响程度正相关。(2)对居民区不同材质模拟屋面(油毡、水泥、砖瓦、石瓦、铁)产生的降雨径流污染进行特征研究表明屋面的材料不同对降雨径流水质有影响显著,由于油毡材料粗糙以及一般采用“层叠法”铺设,油毡屋面降雨径流水质最差,并且TSS变化趋势相比其余屋面有一定的滞后性;屋面平均降雨径流污染与同一研究区域前人的研究结果进行对比,说明北京市大气污染的控制与治理初见成效,对减少降雨径流污染物含量有促进作用;(3)对北京油毡屋面进行间隔时间为5min的降雨径流过程监测,将常规检测指标与硝酸盐氮氧稳定同位素手段相结合,对北京降雨污染的历时变化特征、初始冲刷现象、污染物来源等进行进一步解析。由于不同粒径的颗粒物受降雨冲刷运移的能力不同,TSS呈锯齿状分布。(4)常规检测指标中降雨径流过程中硝酸盐氮的质量浓度变化没有明显的规律,但对硝酸盐氮氧稳定同位素进行实验分析,δ~(15)N-NO_3~-和δ~(18)O-NO_3~-在降雨径流开始初期变化显著,而通过长时间的降雨冲刷之后,δ~(15)N-NO_3~-和δ~(18)O-NO_3~-的值均稳定在一个较小的波动范围内,并且δ~(15)N-NO_3~-及δ~(18)O-NO_3~-的变化均符合多元线性回归方程,证明硝酸盐氮氧稳定同位素对硝酸盐污染有更明显的表征;将硝酸盐氮氧稳定同位素手段运用于降雨径流过程硝酸盐污染物的检测,得出油毡屋面降雨径流中硝酸盐氮同位素值的范围是0.425~24.94‰,氧同位素的范围值是-3.468‰~13.401‰,均处于化肥、降雨中的NH4+、土壤有机氮和粪便及生活污水的特征值范围内。对硝酸盐来源解析可知:在暴雨事件的前期以降雨冲刷屋面上的沉积物为硝酸盐的主要来源,在中期转变为土壤有机氮,而在暴雨径流的后期,硝酸盐来源以化肥、降雨中的NH4+为主。
[Abstract]:Water environment is an important part of urban ecological environment. Water environmental pollution is usually divided into point source and non point source pollution. Since point source pollution has the characteristics of obvious pollutant discharge and high pollution intensity, the related research is carried out early and has great management input. After the control of point source pollution, the non-point source pollution gradually appears, rainfall runoff is used as pollutant. The main driving force of migration and transformation is the focus and focus of the research on urban non-point source pollution. Urbanization is the inevitable trend of the Chinese society and economic development. When the rainstorm occurs, it scours the underlying surface of a large number of pollutants to produce runoff and pollute the urban ecological environment. The roof is one of the 3 main underlying surfaces (pavement, roofing, grassland) of the city. In order to further understand the common characteristics of urban rainfall runoff pollution in China, based on outdoor location observation and indoor experimental monitoring, this paper contrasts the mixed settlement of different functional areas and the rainfall runoff pollution process of different simulated roofs. (1) the analysis of pollutants in different typical functional areas of Beijing city is analyzed and analyzed. The natural rainfall in the urban area of Beijing is serious and belongs to the inferior V water; TN is the main pollutant in the urban mixed settlement, nitrogen is mainly the settlement of nitrate nitrogen, while the nitrogen settlement of the urban fringe forest ecosystem is mainly ammonium nitrogen. According to the rules of the quality of the water quality, the ecological center of the boa botanic garden botanical garden shows that the mixed settlement is in space. There are obvious differences in the influence degree of human activities. (2) the characteristics of rainfall runoff pollution caused by different material simulated roofs (linoleum, cement, brick, tile, iron) in residential areas show that the material of roofing has significant influence on the quality of rainfall runoff, because of the rough linoleum material and the general use of "stacking method" "Laying, the water quality of the linoleum roof is the worst, and the change trend of TSS has a certain lag compared with the rest of the roof. The average rainfall runoff pollution of the roof is compared with the previous research results in the same research area, which shows that the control and control of air pollution in Beijing is the first effect, and can promote the reduction of the pollutant content of the rainfall runoff. (3) monitoring the rainfall runoff process of the Beijing linoleum roof with the interval of 5min, the conventional detection indexes are combined with the nitrate oxygen stable isotope method. The characteristics of the diachronic change of the rainfall pollution in Beijing, the initial scour and the source of the pollutants are further analyzed. The particles of different particle sizes are washed by rainfall and scour. The transport capacity is different, TSS is zigzag. (4) there is no obvious change in the mass concentration of nitrate nitrogen in the process of rainfall runoff, but the experimental analysis of nitrate nitrogen and nitrogen isotopes shows that delta ~ (15) N-NO_3~- and delta ~ (18) O-NO_3~- change significantly at the beginning of the beginning of rainfall runoff, and through a long period of rainfall. After the scouring, the values of delta ~ (15) N-NO_3~- and delta ~ (18) O-NO_3~- are stable in a small fluctuation range, and the changes of delta ~ (15) N-NO_3~- and delta ~ (18) O-NO_3~- are all consistent with multiple linear regression equations. It is proved that nitrate nitrogen oxygen stable isotopes have a more obvious characterization of nitrate pollution; the application of nitrate nitrogen and oxygen stable isotopes is used. The range of nitrate nitrogen isotope value in the rainfall runoff of linoleum is 0.425~24.94 per thousand, and the range value of oxygen isotope is -3.468 per 1000 ~13.401 per 1000, and it is in the range of chemical fertilizer, NH4+, soil organic nitrogen and feces and raw sewage. It is known that the sediment on the roof of the roof in the early stage of the rainstorm event is the main source of nitrate, and changes into soil organic nitrogen in the middle period. In the later period of the storm runoff, the source of nitrate is chemical fertilizer, and the NH4+ in the rainfall is the main.
【学位授予单位】：河南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X52

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