珠海市秋季大气挥发性有机物变化趋势和大气化学反应活性
摘要
為探究珠海市大氣揮發性有機物（VOCs）的來源和影響,制定有效的臭氧控制政策,本研究利用在線氣相色譜-質譜儀/火焰離子檢測器（Online-GC-MS/FID）于2016年9—10月對珠海市大氣中96種VOCs進行了測量,并分析了珠海市大氣VOCs的組成特征、日變化趨勢、來源及其對臭氧生成的貢獻.研究結果表明:珠海市大氣VOCs中烷烴的體積混合比最高,其次為芳香烴;烷烴、芳香烴日變化趨勢明顯,具有雙峰特征;珠海市大氣中丙烷、異戊二烯和芳香烴分別來自于液化石油氣（LPG）、天然源和工業排放.通過反向軌跡分析發現,來自珠三角內陸地區的氣團傳輸對珠海VOCs污染具有重要貢獻,其對臭氧生成潛勢（OFP）的影響主要來自芳香烴.VOCs活性分析表明,芳香烴和烷烴是珠海市OFP的最主要貢獻者,其中甲苯、間/對二甲苯和乙烯是對OFP貢獻最大的物種,因此控制人為源VOCs排放是未來珠海市臭氧污染控制的重點. To investigate the sources and influences of ambient volatile organic compounds (VOCs) in Zhuhai, as well as to establish effective ozone control measures, 96 kinds of VOCs were measured by using online Gas Chromatography Mass Spectrometer/Flame Ionization Detector (GC-MS/FID) at a regional site of Zhuhai from September to October 2016. The VOCs mixing ratios, diurnal variations, sources, and ozone formation potential were analyzed. Alkanes were the most abundant compounds, followed by aromatics. Alkanes and aromatics showed obvious bi-modal diurnal variation. The correlation analysis indicates that propane was mainly from liquid petrol gas (LPG) usage. Isoprene was from biogenic sources. The aromatics were mainly from industrial emissions. Back trajectory analysis showed that the VOCs concentrations were high when the air mass was from inland Pearl River Delta (PRD) region. The ozone formation potential (OFP) from different VOCs was calculated. Aromatics and alkanes contributed large OFP in Zhuhai. Toluene, m/p-xylene and ethene were the top 3 species that contributed to ozone formation. As a result, reducing anthropogenic VOCs emission will be an important measure to control the ozone pollution in Zhuhai.