本文關(guān)鍵詞： 高分辨率飛行時(shí)間氣溶膠質(zhì)譜儀 亞微米氣溶膠 化學(xué)組成 后向軌跡 有機(jī)物來(lái)源解析　出處：《西南大學(xué)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：北京作為中國(guó)的政治、經(jīng)濟(jì)和文化中心,近年來(lái)遭遇了嚴(yán)重的細(xì)顆粒物污染。隨著北京及其周邊地區(qū)經(jīng)濟(jì)的迅速發(fā)展,工業(yè)化和城市化進(jìn)程的不斷推進(jìn),能源消耗和機(jī)動(dòng)車保有量也出現(xiàn)了持續(xù)的增長(zhǎng),導(dǎo)致空氣質(zhì)量不斷惡化,大氣細(xì)顆粒處于高濃度水平,重霾污染頻繁發(fā)生。亞微米顆粒物是細(xì)顆粒物的重要組成部分,具有比表面積大、大氣壽命長(zhǎng)和光散射效率高等特征,對(duì)大氣水平能見(jiàn)度具有重要影響。因此,系統(tǒng)研究亞微米氣溶膠的特征及其有機(jī)氣溶膠的來(lái)源,有助于深入了解亞微米顆粒物在大氣中的環(huán)境效應(yīng)。本研究站點(diǎn)位于北京中國(guó)科學(xué)院大氣物理研究所325 m氣象觀測(cè)塔院內(nèi)(東經(jīng)116.37o,北緯39.97o)進(jìn)行,利用高分辨率飛行時(shí)間氣溶膠質(zhì)譜儀(HR-ToF-AMS)、顆粒物快速捕集系統(tǒng)(RCFP-IC)和黑碳儀(BC)(MAAP-5012)等觀測(cè)儀器于2015年8月~2016年8月對(duì)北京城區(qū)亞微米氣溶膠進(jìn)行了高時(shí)間分辨率的觀測(cè)研究。通過(guò)對(duì)觀測(cè)資料整理和分析研究,歸納了北京城區(qū)不同季節(jié)亞微米氣溶膠濃度變化、化學(xué)成分組成、日變化和酸度變化特征;利用HYSPLIT4.9后向軌跡模式分析了氣團(tuán)傳輸對(duì)北京城區(qū)亞微米氣溶膠的影響;評(píng)估了2015年抗戰(zhàn)紀(jì)念活動(dòng)閱兵期間污染減排措施對(duì)亞微米氣溶膠的影響;研究了春節(jié)除夕夜煙花爆竹燃放對(duì)細(xì)顆粒物濃度及其水溶性離子組分的影響。通過(guò)對(duì)HR-ToF-AMS高分辨率質(zhì)譜數(shù)據(jù)分析得到不同季節(jié)有機(jī)氣溶膠(Organic aerosol,OA)中的元素比例和多環(huán)芳烴;利用PMF模型對(duì)HR-ToF-AMS高分辨率的OA質(zhì)譜數(shù)據(jù)和硝酸鹽質(zhì)譜數(shù)據(jù)進(jìn)行耦合解析,識(shí)別出了各個(gè)季節(jié)有機(jī)氣溶膠的主要來(lái)源及貢獻(xiàn)以及分離出有機(jī)硝酸鹽和無(wú)機(jī)硝酸鹽。主要研究結(jié)果如下:(1)北京城區(qū)亞微米氣溶膠的春、夏、秋和冬季的平均濃度分別為44.1±49.5、31.8±21.1、46.4±58.0和61.7±71.6μg?m-3,可知冬季空氣質(zhì)量最差,夏季最好,春季和秋季污染較冬季輕。春、夏、秋和冬季有機(jī)物對(duì)pm1的貢獻(xiàn)始終為最高,分別為40%、41%、50%和52%。無(wú)機(jī)組分中,夏季硫酸鹽、硝酸鹽和銨鹽對(duì)pm1貢獻(xiàn)分別為20%、17%和13%;春季和秋季硝酸鹽對(duì)pm1的貢獻(xiàn)比例稍微高于硫酸鹽;而夏季和冬季,硫酸鹽對(duì)pm1的貢獻(xiàn)比例高于硝酸鹽。由于北京及其周邊地區(qū)冬季燃煤,硫酸鹽對(duì)pm1的貢獻(xiàn)達(dá)到了18%;夏季光化學(xué)反應(yīng)強(qiáng)烈,氣態(tài)前體物向顆粒物的轉(zhuǎn)化加快,再加之相對(duì)濕度大,更有利于液相反應(yīng),因此夏季硫酸鹽對(duì)pm1的貢獻(xiàn)比例達(dá)到了20%。秋季硫酸鹽和硝酸鹽對(duì)pm1的貢獻(xiàn)達(dá)到了15%和16%;四季銨鹽貢獻(xiàn)比例范圍為7%~13%,bc貢獻(xiàn)比例范圍分別為8%~11%;氯鹽對(duì)pm1的貢獻(xiàn)比例較高的季節(jié)出現(xiàn)在春季和冬季,這與北京地區(qū)春季的沙塵和冬季的燃煤有關(guān)。(2)隨著季節(jié)變化,pm1中各組分的日變化出現(xiàn)一定的差異。pm1中有機(jī)物在中午(11:00-12:00)和晚上(19:00-22:00)用餐時(shí)段出現(xiàn)兩個(gè)明顯峰值,但晚間峰值明顯高于中午。春、夏、秋和冬季有機(jī)物午間和晚間峰值分別為16.7和22.5、12.7和14.1、20.1和30.5、25.6和37.5μg?m-3;由于北京城區(qū)夜間允許重型和輕型柴油車通過(guò),bc日變化呈現(xiàn)出夜間濃度高于白天;春、夏、秋硝酸鹽在上午(8:00-9:00)出現(xiàn)峰值,而冬季則是在上午10:00后呈現(xiàn)緩慢增加。春、夏、秋、冬季硫酸鹽在午后15:00出現(xiàn)峰值。(3)污染天,oa對(duì)pm1的貢獻(xiàn)比例降低,而二次無(wú)機(jī)氣溶膠(secondaryinorganicaerosol,sia)(硫酸鹽+硝酸鹽+銨鹽)貢獻(xiàn)比例增加,尤其在重污染過(guò)程增長(zhǎng)最快。不同季節(jié)的氧化性有機(jī)氣溶膠(ooa,包括lv-ooa和sv-ooa,其中l(wèi)v-ooa為低揮發(fā)的氧化性有機(jī)氣溶膠,sv-ooa為半揮發(fā)的氧化性有機(jī)氣溶膠)是oa的主要貢獻(xiàn)組分。不同污染程度下,生物質(zhì)燃燒氣溶膠(bboa)和燃煤有機(jī)氣溶膠(ccoa)貢獻(xiàn)比例較穩(wěn)定,而不同季節(jié)不同污染程度的烹飪有機(jī)氣溶膠(coa)和碳?xì)溆袡C(jī)氣溶膠(hoa)變化差異很大。(4)ams和rcfp-ic兩組系統(tǒng)同期對(duì)亞微米氣溶膠中氯鹽、硝酸鹽、硫酸鹽和銨鹽監(jiān)測(cè)對(duì)比表明,二者對(duì)觀測(cè)的上述組分在不同季節(jié)都呈現(xiàn)一致的變化趨勢(shì)。春季ams觀測(cè)的氯鹽,硝酸鹽和硫酸鹽濃度都低于rcfp-ic。夏、冬季ams觀測(cè)的硝酸鹽,硫酸鹽濃度高于rcfp-ic;春、夏、秋、冬季ams觀測(cè)的銨鹽濃度都低于rcfp-ic。(5)通過(guò)ams的測(cè)定的nh4+(measured)與nh4+(predicted)的比值分析發(fā)現(xiàn)春、夏、秋、冬季大氣中的亞微米氣溶膠呈現(xiàn)不同程度的酸性,春夏秋季的斜率分別為0.88、0.95和0.76,說(shuō)明氣溶膠呈現(xiàn)出弱酸性;而在冬季,斜率值最低,為0.69,氣溶膠呈較強(qiáng)的酸性。(6)通過(guò)后向軌跡聚類分析表明,不同季節(jié)遠(yuǎn)距離傳輸對(duì)北京地區(qū)大氣污染有著不同的影響,春、冬季氣團(tuán)軌跡來(lái)向多樣化,氣團(tuán)軌跡傳輸方向多于夏、秋季節(jié),而在秋、冬季節(jié),氣團(tuán)來(lái)向基本整體以西北和西南方向?yàn)橹鳌?lái)自南部氣團(tuán)攜帶有高濃度亞微米氣溶膠濃度,其組成主要以二次無(wú)機(jī)和有機(jī)組分為主,而北部氣團(tuán)中亞微米氣溶膠濃度最低,其二次無(wú)機(jī)組分的貢獻(xiàn)明顯低于南部氣團(tuán)。(7)典型個(gè)例事件分析結(jié)果表明,抗戰(zhàn)紀(jì)念活動(dòng)閱兵期間(2015年8月20日~2015年9月3日),北京城區(qū)pm2.5和pm1平均濃度為13.5和12μg?m-3,有機(jī)物對(duì)pm1貢獻(xiàn)超過(guò)60%,與減排前期(2015年8月12日~2015年8月19日)相比,pm2.5和pm1分別下降了74.7%和72.2%。減排后期(2015年9月4日~2015年9月10日),隨著污染減排措施的取消,顆粒物濃度出現(xiàn)反彈,pm2.5和pm1的平均濃度達(dá)到了27和31μg?m-3,硫酸鹽和硝酸鹽比例明顯提高。(8)春節(jié)除夕夜煙花爆竹燃放(2月7日20:00-2月8日8:00)導(dǎo)致pm10、pm2.5和pm1的平均濃度達(dá)到589、414和318μg?m-3,pm2.5/pm10的比例為0.70,表明細(xì)顆粒物是主要貢獻(xiàn)。pm2.5和pm1的twsi質(zhì)量濃度分別為277和146μg?m-3,相應(yīng)的貢獻(xiàn)比例分別為46%和66.8%。pm2.5中k+、cl-和so42-的平均濃度為101、51和101μg?m-3,對(duì)總水溶性離子(twsi)的貢獻(xiàn)分別為36%、18%和38%;pm1中k+、cl-和so42-的平均濃度為39、34和55μg?m-3,對(duì)twsi的貢獻(xiàn)分別為25%、22%和38%。(9)利用pmf模型對(duì)不同季節(jié)北京亞微米氣溶膠中有機(jī)物和硝酸鹽的高分辨率質(zhì)譜(highresolutionmassspectra,hrms)數(shù)據(jù)耦合進(jìn)行深入解析發(fā)現(xiàn),春、夏、秋和冬季都有相同的5種組分,分別是:低揮發(fā)的氧化性有機(jī)氣溶膠(lv-ooa)、半揮發(fā)的氧化性有機(jī)氣溶膠(sv-ooa)、烹飪?cè)磁欧诺呐腼冇袡C(jī)氣溶膠(coa)、交通源排放的碳?xì)溆袡C(jī)氣溶膠(hoa)和無(wú)機(jī)硝酸鹽氣溶膠(nia)。在秋季和冬季,由于受到生物質(zhì)燃燒和燃煤取暖的影響,oa被解析出了生物質(zhì)燃燒氣溶膠(bboa)和燃煤有機(jī)氣溶膠(ccoa)。在春季,lv-ooa、sv-ooa、coa和hoa四種組分對(duì)oa的貢獻(xiàn)分別為29%、34%、17和20%;在夏季,四種組分對(duì)oa的貢獻(xiàn)分別為47%、12%、22%和19%;在秋季,四種組分對(duì)oa的貢獻(xiàn)分別為43%、12%、18%和11%;在冬季,四種組分對(duì)oa的貢獻(xiàn)分別為16%、22%、13%和25%。由于秋季生物質(zhì)燃燒和冬季燃煤的影響,bboa和ccoa對(duì)oa的貢獻(xiàn)分別為16%和24%。(10)通過(guò)對(duì)hr-tof-ams的hrms數(shù)據(jù)分析得到不同季節(jié)亞微米有機(jī)氣溶膠中多環(huán)芳烴(polycyclicaromatichydrocarbons,pahs)濃度,結(jié)果表明,夏季pahs濃度最低(0.01±0.004μg?m-3),冬季最高(0.22±0.24μg?m-3),春季和秋季節(jié)分別為0.03±0.03和0.04±0.01μg?m-3。冬季的pahs日變化濃度高于其它三個(gè)季節(jié)且夜間濃度高于白天。(11)通過(guò)nox+(no+和no2+)離子碎片在nia和oa組分質(zhì)譜中的占比,結(jié)合相應(yīng)的計(jì)算公式可以直接計(jì)算不同季節(jié)的有機(jī)硝酸鹽和無(wú)機(jī)硝酸鹽,結(jié)果表明,有機(jī)硝酸鹽季節(jié)變化為:冬季(2.5±2.3μg?m-3)秋季(0.8±1.2μg?m-3)夏季(0.7±0.2μg?m-3)春季(0.6±0.5μg?m-3);無(wú)機(jī)硝酸鹽的季節(jié)變化為:冬季(7.6±8.2μg?m-3)秋季(6.8±11.0μg?m-3)夏季(6.1±5.8μg?m-3)春季(4.1±5.7μg?m-3)。有機(jī)硝酸鹽日變化呈現(xiàn)夏季白天濃度高于夜間,春、秋和冬季濃度都呈現(xiàn)夜間濃度高于白天;無(wú)機(jī)硝酸鹽日變化各季節(jié)變化各不相同。
[Abstract]:Beijing China as political, economic and cultural center, in recent years, suffered a fine particle pollution serious. With the rapid development of economy in Beijing and its surrounding areas, industrialization and city development, energy consumption and the amount of vehicle also has sustained growth, resulting in deteriorating air quality, atmospheric fine particles are the high level of concentration, heavy haze pollution occurred frequently. Submicron particle is an important part of fine particles, with a large surface area, long atmospheric lifetimes and light scattering characteristics of high efficiency, atmospheric horizontal visibility has important influence. Therefore, the source characteristics of submicron aerosols and organic aerosol. Helps to deepen the environmental effects of solution of submicron particles in the atmosphere. The study site is located in Beijing China Atmospheric Physics Research Institute 325 m meteorological observation in Tayuan (East By 116.37o, 39.97o, North) using high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), fast particle trapping system (RCFP-IC) and carbon black (BC) instrument (MAAP-5012) and other instruments in August 2015 ~2016 year in August in Beijing city of submicron aerosols were observed with high time resolution. Based on study on data collection and analysis, summarizes the seasonal changes of submicron aerosol concentration in Beijing City, chemical composition, diurnal variation and acidity change characteristics; using HYSPLIT4.9 back trajectory model of gas transmission group in Beijing city of submicron aerosols; evaluated the impact of the 2015 war memorial activities during the parade of Asian pollution reduction measures micron aerosol; on the spring Festival Eve fireworks effect of soluble ion component of water and concentration of fine particles on the HR-ToF-AMS score. High-resolution mass spectrometry data analysis in different seasons organic aerosol (Organic aerosol, OA) in the proportion of elements and PAHs; coupling analysis of the HR-ToF-AMS OA high resolution mass spectrometry data and nitrate MS data using the PMF model, to identify the main sources and the contribution of each season and isolate the organic aerosol nitrate and organic inorganic nitrate. The main results are as follows: (1) Beijing city of submicron aerosols in spring, summer, autumn and winter, the average concentration was 44.1 + 49.5,31.8 + 21.1,46.4 + 58 and 61.7 + 71.6 G? M-3, can know the worst winter air quality, the best in summer, spring and autumn than in winter and light pollution. Spring, summer, autumn and winter with organic matter on PM1 always is the highest, respectively 40%, 41%, 50% and 52%. units in summer, sulfate, nitrate and ammonium on the contribution of PM1 were 20%, 17% and 13%; the spring and autumn nitrate Contribution ratio of acid salt of PM1 is slightly higher than that of sulfate; and summer and winter, the contribution proportion of PM1 was higher than that of sulfate nitrate. As winter coal in Beijing and its surrounding areas, the contribution of sulfate on PM1 reached 18%; summer photochemical reaction, before transforming the objects to gaseous particles accelerated, coupled with the relative humidity larger, more conducive to the liquid phase reaction, so the contribution ratio of summer sulfate on PM1 reached 20%. in autumn with sulfate and nitrate of PM1 reached 15% and 16%; quaternary ammonium contribution ratio in the range of 7%~13%, BC proportion range were 8%~11%; chloride PM1 contribution of the higher proportion of the season in spring and in winter, and the Beijing area in spring and winter. The coal dust (2) with seasonal variation, diurnal variation of each component of some differences in organic matter in.Pm1 PM1 (11: 00-12:00) at noon and night (19:00-22:00) the dining hours there are two obvious peak, but the evening peak was significantly higher than at noon. Spring, summer, autumn and winter organic midday and evening peak were 16.7 and 22.5,12.7 and 14.1,20.1 and 30.5,25.6 and 37.5 G? M-3; because of Beijing city at night to allow heavy and light diesel engine by BC, showed the day changes the night was higher than in spring, summer, autumn day; nitrate (8:00-9:00) in the morning peak, while in winter it is 10:00 in the morning after a slow increase. Spring, summer, autumn, winter peak appeared at 15:00 in the afternoon. The sulfate (3) pollution days, proportion of the contribution of OA to PM1 decreased, while the two inorganic aerosol (secondaryinorganicaerosol, SIA) (nitrate + ammonium sulfate +) proportion increased, especially in the growth of heavy pollution in different seasons. The oxidation of organic aerosol (OOA, including lv-ooa and sv-ooa, where lv-ooa is the oxidation of the low volatile Machine aerosol, sv-ooa oxidation of semi volatile organic aerosol) is the main component of OA. With different degree of pollution, biomass burning aerosols (bboa) and coal organic aerosol (CCOA) contribution ratio is relatively stable, and different seasons and different pollution degree of cooking organic aerosol (COA) and hydrocarbon organic aerosol (HOA) the change is very different. (4) AMS and rcfp-ic two system over the same period of chloride, submicron aerosol nitrate and ammonium sulfate, shows that the monitoring results, the two group of the observation points in different seasons are presented the same trend in spring. AMS observation of chloride, nitrate and sulfate concentrations are lower than rcfp-ic. summer, AMS observation of nitrate sulfate concentration was higher than that of rcfp-ic; in winter, spring, summer, autumn and winter, ammonium AMS observations are less than rcfp-ic. (5) through the determination of AMS nh4+ (measured) and nh4+ (predicted) ratio analysis Find the spring, summer, autumn and winter in the atmosphere of the submicron aerosol showed different degrees of acidity, the slope of spring and autumn were 0.88,0.95 and 0.76, showing that the aerosol weak acid; while in winter, the slope was the lowest, 0.69, aerosol more acidic. (6) through back trajectory cluster analysis showed in different seasons, long-distance transmission has a different effect on the air pollution in Beijing area, spring, winter air mass trajectories to diversification, air mass trajectory propagation direction more than summer and autumn, and in autumn, winter, air to the basic overall to the northwest and southwest. From the southern air with high concentration of sub micron aerosol concentration, it is composed of two inorganic and organic components, while the north air mass the submicron aerosol concentration is lowest, the inorganic component contribution was significantly lower than that of the southern air. (7) the typical case analysis of events The results show that during the commemoration of the war Parade (August 20, 2015 ~2015 September 3rd), Beijing City PM2.5 and PM1 average concentration of 13.5 and 12 g? M-3, organic matter more than 60% contribution to PM1 reduction, and early (August 12, 2015 ~2015 August 19th), PM2.5 and PM1 were decreased by 74.7% and 72.2%. emission reduction period (September 4, 2015 ~2015 in September 10th), with the abolition of pollution reduction measures, particle concentration rebound, the average concentration of PM2.5 and PM1 reached 27 and 31 G? M-3, sulfate and nitrate increased significantly. (8) the Spring Festival New Year's Eve Fireworks (February 7th 20:00-2 month 8 days at 8:00) lead to PM10, the average concentration of PM2.5 and PM1 reached 589414 and 318 G? M-3, pm2.5/pm10 ratio was 0.70, showed that the mass concentration of TWSI fine particulate matter is the main contribution of.Pm2.5 and PM1 were 277 and 146 G? M-3, the corresponding contribution rates were 46% and 66.8%.pm2.5 In k+, the average concentration of cl- and so42- 101,51 and 101 G? M-3, the total water soluble ions (TWSI) contributions were 36%, 18% and 38%; PM1 k+, the average concentration of cl- and so42- 39,34 and 55 G? M-3, the contribution to TWSI was 25%, 22% and 38%. (9) PMF model using high resolution mass spectrometry of organic matter and nitrate in different seasons in Beijing submicron aerosols (highresolutionmassspectra, HRMS) data coupling in-depth analysis found that the spring, summer, autumn and winter are the same 5 components, namely: low volatile organic gas oxidation sol (lv-ooa), the oxidation of semi volatile organic aerosol (sv-ooa), cooking cooking organic aerosol source emission (COA), hydrocarbon organic aerosol traffic source emission (HOA) and inorganic nitrate aerosol (NIA). In the autumn and winter, due to biomass burning and burning coal-fired heating effect, OA the analysis of biomass fuel 鐑ф皵婧惰兌(bboa)鍜岀噧鐓ゆ湁鏈烘皵婧惰兌(ccoa).鍦ㄦ槬瀛，

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