【作者】 李凯；

【导师】 张承中；

【作者基本信息】 西安建筑科技大学 ， 环境科学， 2009， 硕士

【摘要】 本文以西安建筑科技大学2007年11月-2008年10月以及2008-2009年采暖期PM_2.5的日均监测值为基础数据,对西安市南郊的PM_2.5各种分布特征及气象因子的影响作了相关分析,并对PM_2.5中的Pb、Ni、Cd三种重金属进行了分析,探讨了其来源、对人体健康的影响以及污染防治对策。PM_2.5和PM₁₀的月平均浓度分布呈现的趋势大致相似,PM_2.5在PM₁₀中所占的比例较大且稳定,平均值为72%,各个季节PM_2.5和PM₁₀的平均浓度大致为:冬季＞秋季＞春季＞夏季;PM_2.5在采暖期的日浓度分布状况呈现出一定的规律,大致出现两个高峰期,分别为12点至15点,21点至24点;西安市南郊非采暖期和采暖期PM_2.5的平均浓度分别为63.43μg/m³和108.95μg/m³,分别是美国PM_2.5空气质量标准的4.23倍和7.26倍;PM_2.5的粒径集中在0.375μm-2.423μm之间。PM_2.5的质量浓度同各种气象条件关系密切:PM_2.5与总云量和湿度呈正相关性,而与气压、气温、日照时数、辐射量、风速和能见度都呈现负相关性。其中,辐射量和相对湿度对PM_2.5的质量浓度影响很大,而PM_2.5的质量浓度高低对能见度有着很大的影响,使其大大降低。采样期间各种重金属的平均浓度有较大差异,其中Pb的平均浓度为0.266μg/m³,Ni的平均浓度为0.013μg/m³,Cd的平均浓度为0.006μg/m³,Pb的浓度明显要高于Ni和Cd;通过富集因子法对重金属的来源进行分析,得出Pb和Cd主要来自人为贡献,而Ni主要来自于自然源;分析了重金属对人体健康的危害并指出了相关的污染防治对策。更多还原

【Abstract】 Spatial distribution of PM_2.5 in southern suburbs of Xi’an and influence of meteorological factor were studied base on the monitoring values of daily average of Xi’an University of Architecture and Technology during November 2007 to October 2008 and heating period from 2008 to 2009 in this study,furthermore,three heavy metals Pb、Ni and Cd of PM_2.5 were analyzed,and investigated its source、influence on human health and countermeasure of pollution prevention.It is approximately similar of distributed tendency of monthly mean concentration of PM_2.5 and PM₁₀,a large proportion of PM_2.5 were engaged in PM₁₀ and it was steady, the average value was 72%,average values of each season of PM_2.5 and PM₁₀ approximately were:winter＞autumn＞spring＞summer;the daily concentration distribution of PM_2.5 in heating period demonstrated definite discipline,there approximately were two fastigium,during 12 to 15 pm and 21 to 24 pm;average concentration of PM_2.5 in time of unheating period and heating period in southern suburbs of Xi’an were 63.43μg/m³ and 108.95μg/m³,it was 4.23 and 7.26 times to stateside PM_2.5 air quality standards;The grain diameter of PM_2.5 focused on range 0.375μm-2.423μm.There was a consanguineous relationship between mass concentration of PM_2.5 and various kinds of meteorologic condition:the relationship between PM_2.5 and total amount of cloud and humidity level was a positive correlation,the relationships between PM_2.5 and atmospheric pressure、air temperature、hours of sunshine、quantity of radiation、wind speed and visibility were negative correlation.Among these factors, quantity of radiation and relative humidity level consumingly influence on mass concentration of PM_2.5,mass concentration of PM_2.5 influence on visibility and make it lower.A large discrepancy of various kinds of heavy metal concentration presented in time of sampling,the average concentration of Pb was 0.266μg/m³,the concentration of Ni was 0.013μg/m³,and Cd was 0.006μg/m³,the average concentration of Pb was obviously higher than the average concentration of Ni and Cd;we analyzed the source of heavy metal with the method of enrichment factor,the result manifested Pb and Cd were mainly sourced in contribution from people,Ni was mainly rooted in natural source;and investigated the influence of heavy metal on people health and proposed the interrelated countermeasure of pollution prevention.更多还原