厦门市冬春季灰霾期间大气PM10中多环芳烃的污染特征及来源分析

采集了厦门市冬春季(2008-12-04～2009-03-20)湖里工业区和大嶝岛旅游区大气PM10样品,用GC-MS定量了PM10负载的19种多环芳烃(PAHs),并结合采样期间气象资料对灰霾期和非灰霾期多环芳烃的差异特征进行对比分析.结果表明,冬春季采样期内,厦门市大气PM10中PAHs的浓度变化范围为12.93～79.27 ng.m-3,平均42.28 ng.m-3,比2004年冬季增长近3倍.灰霾期间PM10中PAHs总的质量浓度明显高于非灰霾期,并且灰霾期间低分子量组分菲、荧蒽和芘的质量分数显著下降,高分子量组分苯并b]荧蒽、苯并k]荧、苯并a]芘、苝、茚并1,2,3-cd]芘、苯并ghi]苝和晕苯的质量分数相对升高.采用特征化合物比值、主成分分析与多元线性回归对来源与贡献率进行了分析和估算.灰霾期间识别出3类污染源:机动车尾气排放+天然气燃烧、煤燃烧和焦炉排放,其贡献率分别为62.7%、28.1%和9.2%;非灰霾期间同样识别出这3类污染源,其贡献率分别为48.6%、36.9%和14.5%.表明厦门市冬春季灰霾期间PM10中PAHs受本地源排放影响相对较多,非灰霾期间受北方燃煤长距离传输影响更显著.

Characteristics and Sources of PM10-bound PAHs During Haze Period in Winter-Spring of Xiamen

PM₁₀ samples were collected at Huli (industrial zone) and Dadeng Island in Xiamen from December 2008 to March 2009. Nineteen polycyclic aromatic hydrocarbons (PAHs) during haze and non-haze periods were determined by GC/MS. Combined with the meteorological data, the differences of chemical composition and source of PAHs were compared. During sampling periods, the concentrations of PM₁₀-bound PAHs ranged from 12.93 to 79.27 ng·m^-3 with the average of 42.28 ng·m^-3, which were almost three times higher than those in the winter of 2004. PAHs concentrations were much higher during the haze periods than those in the non-haze periods. Meanwhile, during the haze periods the percentages of lower molecular weight PAHs such as Phe, Fluo and Pyr decreased significantly, on the contrary, individual components of BbF, BkF, BaP, Per, Icdp, BghiP and COR were more abundant. The main sources of PAHs were estimated by the Principal Component Analysis method and the contributions of various pollution sources to PAHs were calculated by the Multiple Linear Regression method. Results showed that the main pollutant sources of PM₁₀-bound PAHs in winter-spring of Xiamen during the haze period were vehicle emission plus natural gas, coal combustion and coke oven, their contribution rates were 62.7%, 28.1% and 9.2%, respectively. During non-haze periods, the main pollutant sources identified were the same and the contribution rates were 48.6%, 36.9% and 14.5%, respectively. In winter-spring of Xiamen, PM₁₀-bound PAHs were more influenced by local emission sources during the haze periods; coal combustion emissions in north China had a big contribution to PAHs during the non-haze periods.