Characteristics of ozone and ozone precursors(VOCs and NOx) around a petroleum refinery in Beijing, China
Characteristics of ozone and ozone precursors(VOCs and NOx) around a petroleum refinery in Beijing, China作者机构:Department of Environmental Science and Engineering Beijing University of Technology State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Tsinghua University
出 版 物:《Journal of Environmental Sciences》 (环境科学学报(英文版))
年 卷 期:2014年第26卷第2期
页 面:332-342页
核心收录:
学科分类:07[理学] 070602[理学-大气物理学与大气环境] 0706[理学-大气科学]
基 金:supported by the National Natural Science Foundation of China (No. 51108006) Ph.D. Programs Foundation of the Ministry of Education of China (No. 20111103120008) the State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex
主 题:ozone volatile organic compounds (VOCs) photochemical degradations petroleum refinery
摘 要:A field measurement campaign for ozone and ozone precursors (VOCs and NOx) was conducted in summer 2011 around a petroleum refinery in the Beijing rural region. Three observation sites were arranged, one at southwest of the refinery as the background, and two at northeast of the refinery as the downwind receptors. Monitoring data revealed the presence of serious surface 03 pollution with the characteristics of high average daily mean and maximum concentrations (64.0 and 145.4 ppbV in no-rain days, respectively) and multi-peak diurnal variation. For NOx, the average hourly concentrations of NO2 and NO were in the range of 20.546.1 and 1.8-6.4 ppbV, respectively. For VOC measurement, a total of 51 compounds were detected. Normally, TVOCs at the background site was only dozens of ppbC, while TVOCs at the downwind sites reached several hundreds of ppbC. By subtracting the VOC concentrations at background, chemical profiles of VOC emission from the refinery were obtained, mainly including alkanes (60.0% ± 4.3%), alkenes (21.1% ± 5.5%) and aromatics (18.9% ±3.9%). Moreover, some differences in chemical profiles for the same measurement hours were observed between the downwind sites; the volume ratios of alkanes with low reactivity and those of alkenes with high reactivity respectively showed an increasing trend and a decreasing trend. Finally, based on temporal and spatial variations of VOC mixing ratios, their photochemical degradations and dispersion degradations were estimated to be 0.15-0.27 and 0.42-0.62, respectively, by the photochemical age calculation method, indicating stronger photochemical reactions around the refinery.