Sources and photodecomposition of formaldehyde and acetaldehyde in Rome ambient air
Sources and photodecomposition of formaldehyde and acetaldehyde in Rome ambient air
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DOI：
10.1016/s1352-2310(02)00192-9
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发表时间：
2002-07-01
影响因子：
5
通讯作者：
Cecinato, A
中科院分区：
文献类型：
--
作者：
Possanzini, M;Di Palo, V;Cecinato, A
1994年至1997年，在晴朗和风平静的日子里，在罗马市中心的甲醛和乙醛的大气水平以及它们的日变化和季节变化进行了调查。甲醛的小时浓度在夏季为8至28 ppbV，冬季为7至17 ppbv;乙醛浓度相应地在3-18和2-7 ppbv区间内变化。通过比较环境空气和汽车尾气中甲醛和乙醛与甲苯的比例，建立了一个简单的关系，估算了光化学产生的两种醛的吸收率。在夏季，光化学生产被发现对大气水平有80-90%的影响。在冬季，当交通直接排放占主导地位时，它下降到35%以下。光化学夏季源对乙醛的吸收效率高于甲醛，尤其是在清晨。还评估了甲醛作为罗马羟自由基主要来源的重要性。(C)2002年由Elsevier Science Ltd.出版
Atmospheric levels of formaldehyde and acetaldehyde as well as their diurnal and seasonal variations were investigated from 1994 to 1997 in downtown Rome during sunny and wind calm days. Hourly concentrations of formaldehyde ranged from 8 to 28 ppbV in summer and 7 to 17 ppbv in winter; acetaldehyde concentrations varied correspondingly within the 3-18 and 2-7 ppbv intervals. Percentages of both aldehydes photochemically produced were estimated through a simple relationship based upon the comparison of individual ratios of formaldehyde and acetaldehyde to toluene in ambient air and automobile emission. Photochemical production was found to weigh upon atmospheric levels for 80-90% in summer days. It dropped below 35% in the winter period, when direct emission from traffic largely predominated. Photochemical summer source was more efficient for acetaldehyde than for formaldehyde, especially in the early morning. The importance of formaldehyde as the major source of hydroxyl radicals in Rome was also assessed. (C) 2002 Published by Elsevier Science Ltd.