哈尔滨市供暖期PM_2.5组分特征及来源解析

During the heating period (2014.01-03) in Harbin, indoor and outdoor PM_2.5 samples were collected simultaneously in urban, suburban, and rural. After analyzing the carbonaceous components, water-soluble ions, and inorganic elements of the samples, PM_2.5 in-situ acidity was calculated using a particulate thermodynamic model. Sources of indoor-outdoor PM_2.5 were characterized by marker-based Positive Matrix Factorization (PMF) model. The acidity results show that the in-situ acidity of PM_2.5 for indoor is greater than outdoor at all sites. Horizontally, the in-situ acidity of PM_2.5 in the outdoor followed a descending sequence of urban, rural, and suburban and in the indoor followed a descending sequence of urban, suburban, and rural. PMF analysis shows that the third pollution source of outdoor PM_2.5 was secondary source at all three sites. Traffic had a greater impact on urban and suburban (16%~20%), but traffic was the weakest factor at rural (4%~5%). Biomass burning is the first source of indoor-outdoor PM_2.5 at rural; coal combustion, industry were dominant sources of both indoor and outdoor PM_2.5 at the urban site; and industry was the first source of outdoor PM_2.5 at suburban site, associated with emissions of nearby petrochemical and metals industry. Therefore, in order to improve the air quality of Harbin during the heating period, we should strengthen the biomass combustion and rural bulk coal management, pay attention to the improvement of urban traffic conditions, and promote the upgrading of coal-fired boilers and industrial ultra-low emission technology, which could achieve the aim of regional collaborative governance.