摘要
城市空气质量问题已经引起广泛关注。通过对中英2个大城市北京与伦敦2004年8月～2005年12月空气中气态污染物O3、NOx、SO2和CO浓度变化的分析与对比发现：参照世界卫生组织空气质量准则、欧盟空气质量标准、美国国家空气质量标准或国家空气质量二级标准，北京O3、NOx、SO2和CO浓度的超标天数或时数明显高于伦敦。观测期内，北京O3、NOx、SO2和CO浓度明显高于伦敦，平均值分别是17．9±22．1×10^-9、72．4±76．1×10^-9、19．5±21．8×10、2004．6±1509．8×10^-9。与10．8±9．9×10^-9、54．6±38．9×10、1．8±2．2×10^-9、372．3±235．0×10^-9。两城市O3统计日变化形式均表现为白天高，夜晚低，峰值出现在午后14：00左右，日较差分别为31．5±30．9×10^-9与11．1±7．7×10^-9；NO、NO2、SO2和CO呈双峰态日变化，峰值出现在交通的早高峰与晚高峰附近。北京O，最高值出现在夏季，而伦敦出现在春季；但两城市NOx、SO2和CO最高值均出现在冬季。北京与伦敦的NOx与NO呈显著线性相关，且斜率与截距十分相似，分别是1．25和1．28与28．1和23．2；同时两城市CO／NOx比率明显高于SO2／NOx分别为14．0、4．5与0．13、0．03。由此可以判断：对于两城市空气污染问题，交通源的贡献要远大于点源；但点源也对两城市李气质量造成影响。此外，连续逆温的天气是造成重污染事件的原因。
Urban air-quality problem has received increasing attention. To evaluate air quality in Beijing and London, the measurement data of the gaseous air pollutants were analyzed comparatively including 03 , NOx , SO2 and CO from August 2004 to December 2005. The results showed that the accumulative number of days or hours in Beijing was more than that in London above WHO-AQG, air quality EU threshold values, NAAQS or CEPBII. And the average concentrations of these gaseous air pollutants in Beijing were higher than those in London. They were 17.9±22.1×10^-9、72.4±76.1×10^-9、19.5±21.8×10、2004.6±1509.8×10^-9 in Beijing ,and10.8±9.9×10^-9、54.6±38.9×10、1.8±2.2×10^-9、372.3±235.0×10^-9 in London. The diurnal variation patterns of NO ,O3 ,SO2 and CO in Beijing were similar with those in London. The diurnal variation patterns of 03 showed the high concentrations during daytime, the low concentrations during night and early morning and the peak values at 14：00. The daily ranges were 31.5±30.9 ×10^-9 and 11.1 ±7.7 ×10^-9 in Beijing and London. There are two peak values in each of diurnal variations patterns of NOx, SO2 and CO. The first peak value appeared in the early morning rush hours; and the second one appeared around late evening. The highest concentrations of ozone existed in summer in Beijing, while those existed in spring in London. There are peak concentrations of NOx , SO2 , CO in winter in both Beijing and London. Strong positive correlations exis- ted between NOx and NO in both cities. And the slopes and interprets of NO-NO lines were similar. They were 1.25 and 28. 1 for Beijing, 1.28 and 23.2 for London. The ratios of CO/NQ were higher than those of SO2/NOx in Beijing and London. They were 14.0, 4.5 and 0. 13, 0.03, respectively. The ratios of CO/NOx suggested that mobile sources were the major contributor to gaseous air pollutants in both cities. But the point sources had yet influences on air quality of two mega-cities. In addition, continuous temperature inversion leaded to severe air pollution in Beijing sometimes.
出处
《环境工程学报》
CAS
CSCD
北大核心
2008年第9期1199-1206,共8页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(40525016)
国家"973"重点基础研究发展规划项目(2007CB407303)
国家"863"高技术研究发展计划项目(2006AA06A301)
