南京北郊VOCs對(duì)臭氧和二次有機(jī)氣溶膠潛在貢獻(xiàn)的研究

摘　　要：2013年3月1日～2014年2月28日采用GC5000在線氣相色譜儀對(duì)南京北郊大氣環(huán)境中的揮發(fā)性有機(jī)物（VOCs）進(jìn)行了為期一年的連續(xù)監(jiān)測,分析了VOCs的組成特征及季節(jié)、日變化規(guī)律,并結(jié)合PMF受體模型,采用最大增量反應(yīng)活性（MIR）系數(shù)及氣溶膠生成系數(shù)（FAC）分析了VOCs及其各來源的O3和SOA生成潛勢.結(jié)果顯示,南京北郊大氣環(huán)境中TVOCs小時(shí)平均體積分?jǐn)?shù)為45.63×10-9,TVOCs及各組分濃度呈現(xiàn)秋冬季高、夏季低的季節(jié)變化特征和雙峰結(jié)構(gòu)的日變化規(guī)律.SOA總生成量約為2.07μg/m3,芳香烴對(duì)其貢獻(xiàn)率最大,占95.93%,其中的苯系物是生成SOA的優(yōu)勢物種;烯烴對(duì)OFP的貢獻(xiàn)最大,接近65%;烷烴雖為VOCs的優(yōu)勢組分,卻并非OFP和SOA的主要貢獻(xiàn)者.不同季節(jié)VOCs的受體模型解析結(jié)果顯示,工業(yè)排放和汽車尾氣是南京北郊最主要的VOCs來源.富含苯系物的VOCs來源對(duì)SOA的貢獻(xiàn)最大,對(duì)OFP貢獻(xiàn)最大的則為富含乙、丙烯及異戊二烯的VOCs來源;春、秋、冬三季汽車尾氣及工業(yè)排放（包括石化工業(yè)）二源對(duì)大氣中的VOCs濃度、SOA的貢獻(xiàn)及OFP的貢獻(xiàn)影響最為顯著,而夏季溶劑使用及植物源對(duì)SOA及OFP的貢獻(xiàn)不容忽視。A continuous observation campaign was carried out with the GC5000 volatile organics online monitoring system from March 1, 2013 to February 28, 2014 in the northern suburb of Nanjing, characteristics of their composition, seasonal variation and diurnal variation were analyzed, PMF, the maximum incremental reactivity coefficient（MIR）and the fractional aerosol coefficients（FAC）were used to estimate the potential formation of secondary organic aerosols（SOA） and O3 from VOCs and their sources. The results showed that the hourly average mixing ratio of the TVOCs was 45.63×10-9. There was an obvious seasonal cycle of VOCs, with the maximum in winter and autumn and minimum in summer. Diurnal variation of VOCs mixing ratios showed a very clear bimodal structure. The SOA concentration values obtained by the VOCs were 2.07μg/m3, as the largest contributor, aromatic hydrocarbons accounted for 95.93% and BTEX are the dominant species. Alkenes contributed the largest parts of the ozone formation potential（OFP）, closing to 65%. Although alkanes were the most abundant components of VOCs, it is not the main contributor of OFP and SOA. The results from different seasons of receptor model showed that vehicle emissions and industrial emissions were main sources of VOCs in the northern suburb of Nanjing. The sources which contain rich BTEX contributed the largest parts of SOA. Moreover, the sources which contain rich ethylene, propylene and isoprene are the largest contributor of OFP. Vehicle emissions and industrial emissions（including the petrochemical industry） were the main contributor to the concentrations of VOCs, SOA and OFP in spring, autumn and winter. As the influential sources to SOA and OFP, solvent source and plant source should not be overlooked in summer.關(guān)鍵詞：揮發(fā)性有機(jī)物 SOA OFP 來源 貢獻(xiàn)volatile organic compounds ; SOA ; OFP ; sources ; contribution ;全文下載