沈阳经济区典型城市街道灰尘的污染特征

发布时间：2018-08-27 06:20

【摘要】：随着城市经济的快速发展与城市规模的不断扩大,城市环境的污染问题也越来越受到人们的关注。城市街道灰尘是一种典型的城市环境污染物,其在城市环境污染中一直起着传播媒介的作用,并与城市大气污染、水体污染以及土壤污染有着密切的关联。城市街道灰尘是一种附着或沉积于城市道路或街道表面上的固体颗粒物,其既可以在风力和车流的扰动下扬起,以悬浮颗粒的形式存在于大气中或沉降在城市土壤里,也可以在雨水的冲刷作用下进入江河、湖泊等或渗入地下,易对城市环境造成二次污染。沈阳经济区是我国新型工业化综合配套改革试验区,区内城市具有典型的老工业基地特征,街道灰尘的污染特征与该区域城市居民的身体健康密切相关。本文针对辽宁省沈阳经济区仅在沈阳市开展过街道灰尘初步研究的实际情况,选取沈阳经济区的沈阳、抚顺、铁岭三个典型城市,分析城市市区街道灰尘的基本理化性质、重金属的含量、空间分布特征以及污染程度,同时还对街道灰尘中氨氮、硝氮和溶解性有机碳的含量和空间分布进行了探究,旨在为城市环境污染防治、环境质量评价、城市规划以及保障城市人群健康提供科学依据。本文得出的主要结论如下:(1)沈阳、抚顺、铁岭三个城市的街道灰尘均呈碱性,p H均值分别为8.39、7.87、7.80。(2)沈阳、抚顺、铁岭三个城市的街道灰尘均为中粒径占比最大,均超过50%,表明这三个城市的街道灰尘颗粒多半都以跳跃移动为主要的迁移方式(3)沈阳、铁岭、抚顺三个城市的街道灰尘中Cu的含量均值分别为88.2 mg/kg、64.1 mg/kg、48.9 mg/kg,Cd的含量均值分别为1.9 mg/kg、2.1 mg/kg、1.4 mg/kg,Pb的含量均值分别为70.1 mg/kg、101.1 mg/kg、82.6 mg/kg,Zn的含量均值分别为231.1 mg/kg、167.9 mg/kg、150.8 mg/kg,Mn的含量均值分别为1225.0 mg/kg、1000.6 mg/kg、659.6 mg/kg,均明显高于土壤背景值。沈阳市街道灰尘中的Cu、Zn、Mn的平均含量均高于抚顺和铁岭两市,Pb的含量为抚顺市最高,其次是铁岭、沈阳最低。沈阳、抚顺、铁岭三城市街道灰尘中Cd含量相差不大,按含量由高到低的顺序依次为抚顺沈阳铁岭。(4)沈阳、抚顺、铁岭三个城市街道灰尘中Cu、Pb、Zn、Mn的潜在生态危害程度均为轻微污染,而三个城市街道灰尘中Cd的生态危害程度则都达到了极强污染,三个城市街道灰尘中重金属Cu、Cd、Pb、Zn、Mn的总生态危害程度,由于Cd的存在污染级别也很高,其中沈阳和抚顺均为极强污染,铁岭为强度污染。与此同时,沈阳、抚顺、铁岭三个城市街道灰尘重金属地质累积风险指数的结果显示,沈阳市街道灰尘中Cu、Pb、Zn的地质累积风险程度为中度污染,Mn为无污染到中度污染,而Cd则为强度污染到极度污染;抚顺市街道灰尘中Cu、Mn的地质累积风险程度均为无污染到中度污染,Zn、Pb为中度污染,Cd为强度污染到极度污染;铁岭市街道灰尘中Cu、Zn的地质累积风险程度均为无污染到中度污染、Pb为中度污染、Mn为无污染到中度污染,而Cd为强度污染。(5)沈阳、抚顺、铁岭三个城市街道灰尘中的Cu、Cd、Pb、Zn易在火车站、汽车客运站、商业街和工矿企业附近出现较高值,说明这些重金属受到道路交通、人群活动和工矿企业的重要影响。而Mn的高值点主要出现在郊区和工矿企业较多的地域,说明Mn的含量主要受到工矿企业和城市土壤的影响。(6)沈阳、抚顺、铁岭三个城市的街道灰尘中NH3-N的含量均值分别为35.04 mg/kg、8.45 mg/kg、26.86 mg/kg,NO3-N的含量均值分别为58.62 mg/kg、8.89 mg/kg、25.00 mg/kg,可见,三个城市街道灰尘中NH3-N、NO3-N的含量均为沈阳市最高,其次是铁岭市,抚顺市为最低。沈阳、抚顺、铁岭街道灰尘中的NH3-N的高值点均出现在公园附近或郊区路段,说明其主要来源可能是城市土壤,而NO3-N则在公园附近路段或者火车站、商业街等机动车流量大、人群活动频繁的路段都会出现高值,说明其会受到城市土壤、机动车尾气以及人群活动的共同影响。(7)沈阳、抚顺、铁岭三个城市的街道灰尘中DOC的含量均值分别为542.55 mg/kg、223.04 mg/kg、392.06 mg/kg,按含量由高到低的顺序依次为沈阳铁岭抚顺。与NO3-N情况类似,沈阳、抚顺、铁岭街道灰尘中的DOC多在公园附近路段或者火车站、商业街等机动车流量较大路段出现高值,可能也是受城市土壤、机动车尾气以及人群活动的共同影响所致。
[Abstract]:With the rapid development of urban economy and the continuous expansion of urban scale, people are paying more and more attention to the problem of urban environmental pollution. Urban street dust is a typical urban environmental pollutant, which has been playing a role as a media in urban environmental pollution, and has been associated with urban air pollution, water pollution and soil pollution. Urban street dust is a kind of solid particulate matter attached or deposited on the surface of urban roads or streets. It can be raised under the disturbance of wind and traffic flow, exists in the atmosphere in the form of suspended particles or settled in urban soil, and can also enter rivers, lakes, etc. or seep under the action of rain erosion. Shenyang Economic Zone is a pilot area of comprehensive reform of new industrialization in China. The cities in this area have typical characteristics of old industrial bases. The pollution characteristics of street dust are closely related to the health of urban residents in this area. The basic physical and chemical properties, heavy metal content, spatial distribution characteristics and pollution degree of street dust in Shenyang, Fushun and Tieling are analyzed. The contents and spatial distribution of ammonia nitrogen, nitrate nitrogen and dissolved organic carbon in street dust are also analyzed. The main conclusions are as follows: (1) The street dust in Shenyang, Fushun and Tieling is alkaline, and the mean values of P H are 8.39, 7.87 and 7.80 respectively. (2) Shenyang, Fushun and Tieling are three cities. The average content of Cu in the street dust of Shenyang, Tieling and Fushun was 88.2 mg/kg, 64.1 mg/kg, 48.9 mg/kg, and the average content of Cd was 1.9 mg/kg, 2.1 mg/kg, respectively. The average contents of g, 1.4 mg/kg, Pb, Zn and Mn were 70.1 mg/kg, 101.1 mg/kg, 82.6 mg/kg, 231.1 mg/kg, 167.9 mg/kg, 150.8 mg/kg, 1225.0 mg/kg, 1000.6 mg/kg, 659.6 mg/kg, respectively. The average contents of Cu, Zn and Mn in the street dust in Shenyang were higher than those in Fushun and Fushun respectively. In Tieling and Fushun, the content of Pb was the highest, followed by Tieling and Shenyang. The content of Cd in the street dust of Shenyang, Fushun and Tieling had little difference, and the order of content from high to low was Tieling in Fushun. (4) The potential ecological hazards of Cu, Pb, Zn and Mn in the street dust of Shenyang, Fushun and Tieling were all slight pollution. The total ecological harm degree of heavy metals Cu, Cd, Pb, Zn, Mn in the dust of three urban streets is also very high because of the existence of Cd. Shenyang and Fushun are both extremely strong pollution, Tieling is intensity pollution. The results of geological cumulative risk index of heavy metals in urban street dust show that the geological cumulative risk of Cu, Pb, Zn in Shenyang street dust is moderate pollution, Mn is non-pollution to moderate pollution, and Cd is intensity pollution to extreme pollution. Pollution, Zn, Pb are moderate pollution, Cd is intensity pollution to extreme pollution; the geological cumulative risk degree of Cu, Zn in Tieling city street dust is non-pollution to moderate pollution, Pb is moderate pollution, Mn is non-pollution to moderate pollution, and Cd is intensity pollution. (5) Cu, Cd, Pb, Zn in Shenyang, Fushun, Tieling city street dust are easy to be in Railway station, steam. Higher values of Mn were found in bus and passenger stations, commercial streets and near industrial and mining enterprises, indicating that these heavy metals were affected by road traffic, crowd activities and industrial and mining enterprises. The average contents of NH3-N in the street dust of three cities in Ling were 35.04 mg/kg, 8.45 mg/kg, 26.86 mg/kg, 58.62 mg/kg, 8.89 mg/kg and 25.00 mg/kg, respectively. It can be seen that the contents of NH3-N and NO3-N in the street dust of three cities were the highest in Shenyang, followed by Tieling and Fushun, respectively. Shenyang, Fushun and Tieling Streets were the lowest. The high value of NH3-N in the road dust appears in the vicinity of the park or suburban road section, indicating that the main source of NH3-N may be urban soil, while NO3-N is in the vicinity of the park road or railway station, commercial street and other motor vehicles flow, frequent crowd activity of the road section will appear high value, indicating that it will be subject to urban soil, motor vehicle emissions and crowd. (7) The average DOC content in the street dust of Shenyang, Fushun and Tieling was 542.55 mg/kg, 223.04 mg/kg and 392.06 mg/kg, respectively. The order of DOC content from high to low was Fushun in Tieling, Shenyang. Similar to the situation of NO3-N, the DOC content in the street dust of Shenyang, Fushun and Tieling was mostly in the road or train section near the park. The high value of motor vehicle flow at stations, commercial streets and other sections may also be due to the combined effects of urban soil, motor vehicle exhaust and crowd activities.
【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X513

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