全国多环芳烃年排放量估算

根据排放因子和相关排放活动的统计资料,估算了USEPA优先污染物清单中16种PAHs的全国年排放量。结果表明,1999年16种PAHs排放总量约为9799t,其中7种致癌性PAHs排放总量约2000t。主要排放源为家庭燃煤和炼焦,两者分别占总排放量的66.6%和30.6%。在75%置信区间上,估算结果的不确定性大致为正负一个数量级。PAHs排放谱中荧蒽、蒽、芘以及高环化合物比例显著高于北美大湖地区。

Estimation of Annual Emission of Polycyclic Aromatic Hydrocarbons (PAHs) in China

Quantification of PAHs emission was significant due to improving government policy on energy and environment and conducting fate simulation and risk assessment of PAHs in large scale. Based on emission factors and corresponding statistics of emission activities from various literatures, annual PAH emissions in China in 1999, including 16 PAH species in the inventory of prior pollutants suggested by USEPA, were estimated. Different activities involved fossil fuel consumption as the dominant PAH emission source in China were classified as following: (1) industrial (including public power/heating plants) coal combustion, (2) non-industrial (mostly residential) coal combustion, (3) coking coal, (4) oil burning for transportation, (5) non-transportation oil burning, and (6) natural gas combustion. For each group, the total amount consumed in national scale was provided by official statistical archive, while the emission factors were derived from medians of numerous available literature data, mainly originated from Europe and North American. By multiplying each consumption data with the corresponding emission factor, the estimated annual emissions of 16 PAH components in China were obtained. In addition, the uncertainties of emission results, caused by use of averaged emission factor, were also analyzed based on the variations of the concerned emission factors. The results indicated that in 1999, the total emission of 16 PAH species in China was around 9799 tons, the related contributions of the 6 aforementioned sources were in the sequence as 1.0%, 65.6%, 30.6%, 0.9%, 1.8% and 0.1%. At the confidence interval of 75%, there were around one order of magnitude uncertainties for the 5 major emission sources, excluding natural gas for its trivial influence. In the total PAHs emission, the percentage of high molecular weight PAH species, including the 7 carcinogenic PAHs, was significantly higher in China than that in Great Lakes of North America, showing dominant coal combustion and coking production in China and relatively higher ecological risk.