某化工区典型高污染过程VOCs污染特征及来源解析

使用在线色谱观测了冬季某化工区典型雾霾污染时段VOCs污染特征,同时应用PMF模型对化工区VOCs来源进行分析.结果表明,观测期间VOCs主要组分是甲苯、二甲苯、C3~C4烷烃和氯仿等,有机硫组分是化工区异味的主要来源之一.2个高污染时段内主要污染因子为异丁烷、正丁烷、丙烷和丙烯腈这4种组分.VOCs和NOx具有夜间高而白天低的日变化特征,体现了其主要受化工区排放源的影响.O_3的日变化特征反映出明显的光化学反应过程,表明由于化工区VOCs排放影响,虽时处冬季,区域仍受到较明显的光化学污染影响.PMF解析得到6个因子,分别表征合成材料、涉硫工艺与废水处理、工业有机溶剂使用和石化工艺,排放贡献率分别是48.0%、24.0%、14.7%和13.3%.化工企业的废水处理单元为区域异味的重要来源之一.

Characteristics and Source Apportionment of VOCs of High Pollution Process at Chemical Industrial Area in Winter of China

Online GC was adopted to monitor VOCs of high pollution process near a chemical industrial area in winter. PMF model was used to identify the major sources of VOCs and evaluate their contributions. The result showed that the main components during the period of observation were toluene, xylene, C3-C4 hydrocarbon and chloroform, etc. Organic sulfur compounds were the major odor pollutants at the chemical industrial area. The compounds including isobutane, n-butane, propane and acrylonitrile were enriched during two pollution periods. VOCs and NO_x had the diurnal features of high concentration in the evening versus lower concentration during daytime, indicating the main influence from chemical industrial sources. While O₃ had the diurnal features reflecting the photochemical reaction at chemical industrial area in winter. The PMF result showed that 48.0% of the total VOCs concentrations were attributed to synthetic materials industry, 24.0% to industrial organic sulfur process and wastewater treatment (including three sources), 14.7% to industrial organic solvent usage, and 13.3% to petrochemical process. So the wastewater treatment unit was a major source of odor pollution at chemical industrial area.