沈阳大气环境中典型污染物分布规律及来源解析

发布时间：2018-09-19 10:01

【摘要】：颗粒物和挥发性有机物是造成大气空气质量下降的主要污染物,而且对人类身体健康产生危害。本研究对沈阳市不同功能区大气环境中典型大气污染物VOCs(芳香类、烯烃类等)、不同粒径颗粒物(PM1、PM2.5、PM4、PM10)进行了监测,并对不同气象条件下污染物分布规律及组成进行分析和讨论;同时分析了颗粒物中水溶性离子和重金属的分布状况,并进行来源解析。本研究旨在了解沈阳市大气污染现状,以便为改善沈阳市的大气污染现状提供科学借鉴。通过本文研究,得出如下结论:(1)沈阳市VOCs含量变化范围为61μL/m3~320μL/m3,工业与交通密集区监测点总VOCs浓度最高,居民区VOCs含量最低。沈阳市大气环境中的B/T别为1.15,说明VOCs的排放受生物质燃烧影响高于受机动车尾气的影响。VOCs日变化受交通源和气相因子影响大,早晚出行高峰出现浓度峰值,风力增大,光照增强会导致挥发性有机物浓度因扩散迁移和光化学反应而降低。(2)沈阳市颗粒物浓度处于较高水平,PM2.5和PM10年均浓度分别为96.7μg/m3和128.3μg/m3。不同季节对比分析,四种粒径的颗粒物浓度呈春季最高,夏季最低的规律。机动车尾气导致细颗粒物浓度较高,生物质、燃煤及道路扬尘导致粗颗粒物浓度较高。颗粒物浓度与温度呈正相关,与湿度呈负相关,与风速相关性不明显。(3)利用离子色谱法和原子吸收法分别对颗粒物中的水溶性离子和重金属组分进行研究,得出如下结论:PM10中SO42-、NO3-、Cl-、F-4种离子的含量均高于PM2.5,PM2.5和PM10中各离子浓度的关系为SO42-NO3-Cl-F-,离子总含量比例为7.63%、13.95%,PM2.5和PM10的NO3-/SO42-的质量比分别为0.36、0.45,均小于1,说明沈阳市大气环境中水溶性组分主要来自固定排放源。颗粒物中Zn和Pb波动幅度较大,Cu和Cd含量稳定。不同粒径的颗粒物中重金属浓度规律保持一致,即ZnPbCuCd,4种重金属占PM2.5和PM10的质量百分比为0.69%、1.23%。
[Abstract]:Particulate matter and volatile organic compounds (VOCs) are the main pollutants that cause the decrease of atmospheric air quality, and they are harmful to human health. In this study, VOCs (aromatic, olefin, etc.) and particle size (PM1,PM2.5,PM4,PM10) of typical atmospheric pollutants in different functional areas of Shenyang were monitored, and the distribution and composition of pollutants under different meteorological conditions were analyzed and discussed. At the same time, the distribution of water soluble ions and heavy metals in particulate matter was analyzed, and the source was analyzed. The purpose of this study is to understand the present situation of air pollution in Shenyang, and to provide scientific reference for improving the present situation of air pollution in Shenyang. The main conclusions are as follows: (1) the range of VOCs content in Shenyang is 61 渭 L/m3~320 渭 L / m ~ (3). The concentration of total VOCs is the highest in the industrial and traffic dense area and the lowest in residential area. The B / T ratio in the atmospheric environment of Shenyang is 1.15, which indicates that the daily variation of VOCs emissions is more affected by biomass combustion than by vehicle exhaust. The diurnal variation of VOCs is greatly affected by traffic source and gas phase factor, and the peak of concentration appears in the morning and evening travel peak, and the wind increases. (2) the average annual concentrations of PM2.5 and PM10 in Shenyang were 96.7 渭 g/m3 and 128.3 渭 g / m3, respectively. Compared with different seasons, the concentration of the four kinds of particles was the highest in spring and the lowest in summer. Vehicle exhaust resulted in higher concentration of fine particulate matter, biomass, coal combustion and road dust caused higher concentration of coarse particulate matter. The concentration of particulate matter was positively correlated with temperature, negatively correlated with humidity, and not significantly correlated with wind speed. (3) Water soluble ions and heavy metal components in particulate matter were studied by ion chromatography and atomic absorption spectrometry, respectively. It is concluded that the content of SO42-,NO3-,Cl-,F-4 species is higher than that of PM2.5,PM2.5 and PM10. The relationship between the content of SO42-NO3-Cl-F-, and the concentration of PM10 is that the ratio of total content of SO42-NO3-Cl-F-, to that of NO3-/SO42- of PM2.5 and PM10 is 0.36 0. 45 and less than 1, respectively, indicating that the water solubility in the atmosphere of Shenyang City is less than 1. The components are mainly from fixed emission sources. The contents of Cu and Cd were stable in Zn and Pb. The concentrations of heavy metals in different particle sizes were consistent, that is, the percentage of heavy metals of ZnPbCuCd,4 species to PM2.5 and PM10 was 0.69% and 1.23%, respectively.
【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】：X51

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