109

3,222 千元

科技發展-環境科學及技術之研究

2020/01/09

2020/12/31

周崇光

監資處

張志偉

中央研究院

環境監測及檢測

同位素、細懸浮微粒、空氣污染辨識

Isotope, PM2.5, Air Pollution Forensics

李崇德；榮建誠

黃譯樘

02-27875983#

yitang@rcec.sinica.edu.tw

本計畫透過建立高屏地區大氣和主要污染源排放之PM2.5的傳統化學組成和碳與鉛同位素特徵，探討高屏地區的大氣PM2.5污染來源。2020年春季 (3月) 和夏季 (8月) 分別採集橋頭站、左營站、鳳山站、小港站、林園站、大寮站、屏東站和潮州站等8站的大氣PM2.5樣本，也陸續採集高雄境內的燃煤火力發電廠、煉油廠、焚化爐、化工廠和造紙廠排放的PM2.5樣本，並完成水溶性陰陽離子、有機碳、元素碳、地殼元素、重金屬和碳 (δ13C和14C) 與鉛同位素 (206Pb、207Pb和208Pb) 的分析，最後整合2019年和2020年的研究資料，探討造成高屏地區高PM2.5污染的成因與來源。 5種固定污染源排放的PM2.5都以可凝結性微粒 (Condensable particulate matter，CPM) 為主，煙道排放的CPM則以無機成分為主。在化學組成部分 (均來自過濾性微粒，Filterable particulate matter，FPM)，可發現1.) 燃煤電廠排放的PM2.5有較高的金屬元素和硫酸鹽，Mg、Ni、Cu、Zn、Mo、Cd、Sn、Sb、Tl、Pb、Cr、As、Y、Se、Ge和Ga等元素的EF超過10，平均206Pb/207Pb比值為1.2430 (1.1759-1.3056)，平均208Pb/207Pb比值為2.4507 (2.4373~2.4796)；2.) 焚化爐排放的PM2.5有較高的金屬元素、硫酸鹽、鈣離子和氯離子，而金屬元素以Na、K、Ca、Ba、Co、Ni和Zn等元素佔優勢，平均206Pb/207Pb比值為1.1479 (1.1439-1.1522)，平均208Pb/207Pb比值為2.4281 (2.4217~2.4365)；3.) 煉油廠排放的PM2.5有較高的硫酸鹽比例 (18%)，特徵元素包括Na、Ni、Zn、Mo、Cd、Sn、Sb和Se等，平均206Pb/207Pb比值為1.2663 (1.2200-1.3070)，平均208Pb/207Pb比值為2.4206 (2.4113-2.4259)；4.) 化工廠排放的PM2.5有較高的硫酸鹽比例 (31%)，特徵元素包括Co、Ni、Cu、Zn、Mo、Cd、Sn、Tl、Pb、Cr、As和Se等，平均206Pb/207Pb比值為1.1715 (1.1594-1.1847)，平均208Pb/207Pb比值為2.4241 (2.4198-2.4282)；5.) 造紙廠排放的PM2.5有較高的硫酸鹽 (7%) 和鈣離子 (3%) 濃度，特徵元素包括Ni、Zn、Cd、Sn、Sb和Se等，平均206Pb/207Pb平均比值為1.2067 (1.1713-1.2342)，平均208Pb/207Pb比值為2.4336 (2.4308-2.4359)。 8個測站的日平均PM2.5濃度為20.1 ± 11.3 μg/m3，其值低於國家日平均標準值 (35 μg/m3)。在傳統化學組成部分，8個測站的PM2.5之主要化學組成均為硫酸鹽、硝酸鹽、銨鹽和有機碳，其濃度各佔PM2.5質量濃度的19%、24%、14%和24%；此外，高雄6個測站的現代碳和化石碳濃度分別佔PM2.5質量濃度的14%和16%，位於屏東的2個測站則以現代碳略佔優勢 (化石碳：15%；現代碳：16%)。當以PM2.5濃度標準值將樣本劃分為PM2.5事件日和非事件日時，分析資料顯示相較於非事件日，事件日期間的硫酸鹽、硝酸鹽和銨鹽濃度加總對PM2.5總濃度的增量貢獻比例最大，顯示光化反應之前驅物的管制有助於降低高屏地區PM2.5濃度；化石碳和現代碳對PM2.5總濃度的增量貢獻比例亦明顯，說明管制化石燃料的燃燒或生質燃燒活動有助於降低高屏地區的PM2.5濃度。 大氣PM2.5中的δ13C和鉛同位素分析結果顯示，春季和夏季的大氣平均δ13C分別為-25.7‰ (-34.0至-21.0‰) 和-28.3‰ (-38.2至-20.3‰)；在鉛同位素比值部分，春季和夏季的平均206Pb/207Pb比值分別為1.1493 (1.1021-1.1581) 和1.1525 (1.0897-1.2081)，平均208Pb/207Pb比值分別為2.4251 (2.3768-2.4393) 和2.4247 (2.3677-2.4570)。每一個測站在量測期間，碳或鉛同位素比值變異較過去的研究大，暗示每個測站在每一天的碳或鉛污染源不穩定，但夏季和春季的δ13C或鉛同位素比值卻無明顯的季節差異，顯示高屏地區的碳和鉛污染源無明顯的季節變化。 本計畫綜合傳統化學組成和同位素量測結果發現，生質燃燒、燃料油燃燒和硝酸鹽二次氣膠是造成高屏地區碳濃度偏高的原因，其中左營站、鳳山站、小港站和林園站受化石燃料的影響較大，屏東站和潮州站則有較高的現代碳貢獻源，大寮站和橋頭站的碳污染源有季節變化，但確切污染源仍需要更多的量測資料來探討。鉛污染源分析結果顯示交通排放、重油燃燒、港口作業活動和焚化爐是重要的鉛污染源。

同位素、細懸浮微粒、空氣污染辨識

109年度細懸浮微粒碳與鉛同位素分析技術之發展與應用研究計畫.pdf

32MB

2021/1/31 上午 12:00:00

The objective of this study is to investigate the potential pollution sources of PM2.5 in Kaohsiung and Pingtung with the isotopic fingerprints. During the period from the spring (March) of 2020 to the summer (August) of 2020, ambient PM2.5 samples were collected from 8 sampling stations (Ciaotou, Zuoying, Fengshan, Siaogang, Daliao, Linyuan, Pingtung, and Chaozhou) in Kaohsiung and Pingtung, respectively. In addition, we also collected PM2.5 samples from 5 specific sources: a coal-fired power plant, an incinerator, an oil refinery plant, a plastic factory, and a paper-making factory in 2020. All the PM2.5 samples were characterized with the measurements of water-soluble ions, organic carbon, elemental carbon, crustal elements, heavy metals, and isotopic compositions of carbon (δ13C and 14C) and lead (206Pb, 207Pb, and 208Pb). The results revealed that condensable particulate matter (CPM) was predominant particles in the PM2.5 emitted from stationary pollution sources. Moreover, the level of inorganic CPM was higher than that organic CPM in all stationary pollution sources. The chemical compositions from five pollution sources were: (1) coal power-fired plant: sulfate was important specie, predominant elementals included Mg, Ni, Cu, Zn, Mo, Cd, Sn, Sb, Tl, Pb, Cr, As, Y, Se, Ge, and Ga, average 206Pb/207Pb and 208Pb/207Pb were 1.2430 (1.1759-1.3056) and2.4507 (2.4373~2.4796), respectively; (2) incinerator: sulfate, Ca+2, and Cl- were important species, predominant elementals included Na, K, Ca, Ba, Co, Ni, and Zn, average 206Pb/207Pb and 208Pb/207Pb were 1.1479 (1.1439-1.1522) and 2.4281 (2.4217~2.4365), respectively; (3) oil-refinery plant: EC, sulfate, and Ca+2 were important species (69%), predominant elementals included Na, Ni, Zn, Mo, Cd, Sn, Sb, and Se, average 206Pb/207Pb and 208Pb/207Pb were 1.2663 (1.2200-1.3070) and 2.4206 (2.4113-2.4259), respectively; (4) plastic factory: sulfate was important species (31%), predominant elementals included Co, Ni, Cu, Zn, Mo, Cd, Sn, Tl, Pb, Cr, As, and Se, average 206Pb/207Pb and 208Pb/207Pb were 1.1715 (1.1594-1.1847) and 2.4241 (2.4198-2.4282), respectively; (5) paper-making factory: sulfate and Ca+2 were important species (10%), predominant elementals included Ni, Zn Cd, Sn, Sb, and Se, average 206Pb/207Pb and 208Pb/207Pb were 1.2067 (1.1713-1.2342) and 2.4336 (2.4308-2.4359), respectively. The average level of ambient PM2.5 from all sampling sites was 20.1 ± 11.3 μg/m3, which lower than national standard (35 μg/m3). The major constituents of the ambient PM2.5 in the study area included sulfate, nitrate, ammonium, and organic carbon, which accounted for 19%, 24%, 14%, and 24% of the PM2.5 mass, respectively. The contributions of fossil (16%) and modern (14%) carbon were similar in the six sampling sites in Kaohsiung. Modern carbon was a predominant carbonaceou aerosol in Pingtung and Chaozhou sampling sites (modern carbon: 15%; fossil carbon: 14%). It was found from the chemical analysis that the concentrations of inorganic secondary aerosols (sulfate, nitrate, and ammonium) and fossil/modern carbonaceous aerosols were elevated during high PM2.5 episodes. These results implied that photochemical reactions and burning activities of fossil/modern carbon were important factors influencing the PM2.5 in the study areas. The averages of δ13C for ambient PM2.5 are -25.7‰ (-34.0 to -21.0‰) and -28.3‰ (-38.2 to -20.3‰) in the spring and summer, respectively. The average 206Pb/207Pb ratios were 1.1493 (1.1021-1.1581) and 1.1525 (1.0897-1.2081) in the spring and summer, respectively, and 208Pb/207Pb ratios were 2.4251 (2.3768-2.4393) and 2.4247 (2.3677-2.4570), respectively. The variation of δ13C and Pb isotopic compositions were larger, which means the pollution sources were unstable in Kaohsiung and Pingtung for carbon and Pb. In comparison, the values of isotopic compositions were similar to the data in central Taiwan, which reflects the pollution sources and influencing factors were different according to different locations in Taiwan. In this study, we combined with the traditional chemical and isotopic compositions of ambient and pollution sources to investigate the pollution sources for PM2.5 in Kaohsiung and Pingtung. Our results indicated that biomass burning, oil-combustion, and nitrate (secondary aerosol) were major pollution sources for carbon. In the Zuoying, Fengshan, Linyuan, and Siaogang stations, fossil carbon burning was an important contrubtor; in the Pingtung and Chaozhou stations, modern carbon burning plays an important role. In the Ciaotou and Daliao stations, we need more information to investigate completely the potential sources for the both sties due to unstable of carbon pollution sources on different seasons. Based on the PMF model and Pb isotopic compositions, traffic emission, oil-combustion, Kaohsiung port activities, and incinerator were major pollution sources for Pb in the Kaohsiung and Pingtung.

Isotope, PM2.5, Air Pollution Forensics