| 北京及周边地区大气羰基化合物的时空分布特征初探 |
| 摘要点击 3377 全文点击 1432 投稿时间：2011-05-06 修订日期：2011-08-12 |
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| 中文关键词 北京及周边地区 羰基化合物 时空变化 机动车尾气 燃煤 |
| 英文关键词 Beijing and surrounding areas carbonyl compounds spatial and temporal variations vehicular exhaust coal burning |
| 作者 | 单位 | E-mail | | 王琴 | 北京大学环境科学与工程学院, 环境模拟与污染控制国家重点联合实验室, 北京 100871
北京市环境保护监测中心, 北京 100048 | | | 邵敏 | 北京大学环境科学与工程学院, 环境模拟与污染控制国家重点联合实验室, 北京 100871 | mshao@pku.edu.cn | | 魏强 | 北京市环境保护监测中心, 北京 100048 | | | 陈文泰 | 北京大学环境科学与工程学院, 环境模拟与污染控制国家重点联合实验室, 北京 100871 | | | 陆思华 | 北京大学环境科学与工程学院, 环境模拟与污染控制国家重点联合实验室, 北京 100871 | | | 赵越 | 北京市环境保护监测中心, 北京 100048 | |
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| 中文摘要 |
| 利用2, 4-二硝基苯肼(DNPH)/HPLC方法,于2010年6月24日、7月22日、8月24日、9月14日(夏季)和2011年1月13日(冬季),在北京及周边地区38个采样点组织5次同步观测,测定了大气中23种羰基化合物的浓度水平.观测结果表明,北京市各类站点夏季和冬季的总羰基化合物体积分数分别为(16.38±6.03)×10-9, (8.50±5.27)×10-9; 周边城市夏季和冬季的体积分数分别为(13.19±5.71)×10-9, (13.05±2.44)×10-9.区域大气中最主要的羰基化合物是甲醛、乙醛和丙酮,三者约占总羰基化合物浓度的78%～91%.夏季羰基化合物的浓度水平明显高于冬季,并且上午09:00～12:00时段的浓度高于下午13:00～16:00时段的浓度.在空间分布上,北京市夏季羰基化合物的高值区主要集中在交通密集的主城区,而冬季受西北风影响呈现由西北向东南递增的趋势.夏季,机动车尾气对大气羰基化合物有显著的一次和二次贡献,同时在不利的气象条件影响下,造成城市地区羰基化合物的污染现象.冬季,大气羰基化合物以一次排放为主,燃煤和机动车可能是主要的污染源. |
| 英文摘要 |
| Concentrations of 23 carbonyl compounds were measured by DNPH/HPLC method at 38 sites within Beijing and its surrounding areas on June 24, July 22, August 22, September 14 in 2010 and January 13, 2011.The average mixing ratios of total carbonyl compounds in Beijing were (16.38±6.03) ×10-9 and (8.50±5.27) ×10-9 in summer and winter; and the average mixing ratios in surrounding cites were (13.19±5.71) ×10-9 and (13.05±2.44) ×10-9 in summer and winter, respectively. The most abundant carbonyl compound was formaldehyde, followed by acetaldehyde and acetone, the sum of these 3 species accounted for 78% to 91% of the total mixing ratio of carbonyl compounds. The average mixing ratio in summer was significant higher than that in winter, and higher in morning (09:00-12:00) hours than in afternoon (13:00-16:00). The spatial distributions for carbonyl compounds showed that:in summer, high mixing ratios were typically found in city center; while in winter, a building-up trend was found from northwest to southeast, driving by the prevailing northwest wind. In summer, vehicular exhaust had important contributions to ambient carbonyls, and combined with the adverse weather conditions and the strong photochemical production, resulted in carbonyls pollutions; in winter, directly emissions were the main sources of carbonyls, such as vehicular exhaust and coal burning. |
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