Zhou Xi, Li Zhongqin, Zhang Tinjun, Wang Fanglin, Wang Feiteng, Tao Yan, Zhang Xin, Wang Fanglong, Huang Ju
Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China; State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Tianshan Glaciological Station, Chinese Academy of Sciences, Lanzhou 730000, China.
State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Tianshan Glaciological Station, Chinese Academy of Sciences, Lanzhou 730000, China; College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730000, China.
Sci Total Environ. 2019 Jun 25;671:883-896. doi: 10.1016/j.scitotenv.2019.03.283. Epub 2019 Mar 22.
To scientifically understand the emissions and chemistry of volatile organic compounds (VOCs) in a typical petrochemical industrialized and dust-rich region of Northwest China, VOCs were measured at a receptor site in the Lanzhou Valley using a high-resolution online proton transfer reaction-mass spectrometer (PTR-MS). The ranking of VOC mixing ratios was methanol (32.72 ± 8.94 ppb) > acetaldehyde (5.05 ± 2.4 ppb) > acetic acid (3.42 ± 1.71 ppb). Lanzhou has higher oxygenated VOCs (OVOCs) mixing ratios (methanol and acetaldehyde) and lower aromatics levels (benzene, toluene and C8-aromatics) compared with other cities. The positive matrix factorization (PMF) model showed eight sources of VOCs as follows: (1) mixed industrial process-1 (13.5%), (2) secondary formation (13.2%), (3) mixed industrial process-2 (11.8%), (4) residential biofuel use and waste disposal (13.80%), (5) solvent usage (10.1%), (6) vehicular exhaust (11.8%), (7) biogenic (13.8%) and (8) biomass burning (12.0%). Both the PSCF and the CWT results of mixed industrial process-1 were mainly from the northeast of Lanzhou and the biomass burning was from the southeast; the other four sources (without secondary formation and biogenic) were mainly from the west and northwest of Lanzhou, which were associated with the dust area of the Gobi Desert. A trajectory sector analysis revealed that the local emissions contributed 64.9-71.1% to the VOCs. OVOCs accounted for 43% of the ozone production potential (OFP), and residential biofuel use and waste disposal (25.1%), mixed industrial process-2 (15.3%) and solvent usage (13.4%) appeared to be the dominant sources contributors to O production. The rank of main secondary organic aerosols (SOA) precursors under low-NOx conditions is xylene > toluene > benzene > naphthalene > styrene > C10-aromatics > isoprene, while under high-NOx conditions, it is toluene > naphthalene > xylene > C10-aromatics > styrene > benzene > isoprene. Solvent usage and vehicular exhaust appeared to be the dominant contributors to SOA formation.
为科学了解中国西北典型石化工业化且多尘地区挥发性有机化合物（VOCs）的排放和化学特征，利用高分辨率在线质子转移反应质谱仪（PTR-MS）在兰州河谷的一个受体站点对VOCs进行了测量。VOC混合比的排序为甲醇（32.72±8.94 ppb）＞乙醛（5.05±2.4 ppb）＞乙酸（3.42±1.71 ppb）。与其他城市相比，兰州具有较高的含氧挥发性有机化合物（OVOCs）混合比（甲醇和乙醛）以及较低的芳烃水平（苯、甲苯和C8芳烃）。正定矩阵因子分解（PMF）模型显示VOCs有八个来源，如下：（1）混合工业过程-1（13.5%），（2）二次生成（13.2%），（3）混合工业过程-2（11.8%），（4）居民生物燃料使用和废物处理（13.80%），（5）溶剂使用（10.1%），（6）汽车尾气（11.8%），（7）生物源（13.8%）和（8）生物质燃烧（12.0%）。混合工业过程-1的潜在源贡献函数（PSCF）和浓度权重轨迹（CWT）结果主要来自兰州东北部，生物质燃烧来自东南部；其他四个来源（不包括二次生成和生物源）主要来自兰州西部和西北部，这与戈壁沙漠的沙尘区域有关。轨迹扇形分析表明，本地排放对VOCs的贡献率为64.9 - 71.1%。OVOCs占臭氧生成潜势（OFP）的43%，居民生物燃料使用和废物处理（25.1%）、混合工业过程-2（15.3%）和溶剂使用（13.4%）似乎是O生成的主要来源贡献者。低NOx条件下主要二次有机气溶胶（SOA）前体的排序为二甲苯＞甲苯＞苯＞萘＞苯乙烯＞C10芳烃＞异戊二烯，而在高NOx条件下，排序为甲苯＞萘＞二甲苯＞C10芳烃＞苯乙烯＞苯＞异戊二烯。溶剂使用和汽车尾气似乎是SOA形成的主要贡献者。
