基于特征物种的挥发性有机物排放源强受体反演技术研究

A featured-species-based receptor inversion technology for estimating emission source intensities of volatile organic compounds

本研究通过污染源测试获取了典型专用型树脂生产企业各生产环节的挥发性有机物(VOCs)排放化学成分谱特征;基于下风向受体点采样分析,结合AERMOD模型和企业排放成分谱,充分利用目标企业各化学物种排放强度之间的关联性,建立了一套基于特征物种的VOCs排放源强受体反演技术;最后将反演结果与企业实测结果进行了对比.结果表明:芳香烃是该树脂生产企业的主要排放物种,其次为烷烃和含氧VOCs;模型反演过程中,烷烃和芳香烃因其在排放源成分谱中贡献占比较高以及无组织排放潜在贡献较高,拟合效果优于其他VOCs类别;对于本研究的目标企业,采用实测法可能造成企业臭氧生成潜势的低估.本研究对点源、面源相结合的复杂VOCs污染源的源强估算方法进行了探索,开发了基于特征物种的源强反演技术,有效识别修正由于企业特殊生产状况所造成的排放强度偏差,避免了进厂实测困难、次数受限等所导致的源强测量结果的不确定性,反映了目标企业在一段时间内的平均排放源强,并将无组织排放考虑在内,反演结果较为准确,一定程度解决了传统排放因子法和实测法在无组织排放估算方面存在的忽视、低估的问题.

Emission profiles of volatile organic compounds(VOCs)for each process of a typical special resin plant were obtained through field tests.Based on sample collection and analysis at downwind receptors,combined with the AERMOD model and source profiles,making full use of the relationship between different chemical species,a featured-species-based receptor inversion technology for estimating VOCs emission intensities was established.Comparison between field tests and model results was conducted.Results show that:aromatics are the main species from the manufacturer,followed by alkanes and oxygenated VOCs.The model fitting results of alkanes and aromatics are better than those of other VOCs due to their high contribution to the source profiles and high percentages of fugitive emission.The ozone formation potential for the target enterprise could be underestimated based on field tests.This study explored a VOCs emission estimation method for complex sources,and effectively identified and corrected the bias caused by abnormal conditions.Uncertainty caused by the difficulty and limited times of entering the factory was reduced.In addition,this method can reflect the average emission intensity of both organized and fugitive emissions of the target plant in a period of time with higher accuracy,which to a certain extent solved the problem of neglection and underestimation of fugitive emissions by the traditional emission factor method and the field test method.