||Pool air quality commonly observed in Kaohsiung is mainly attributed to industrial pollution. Particularty, fine particles (PM2.5) concentrations are significantly higher than the EPA standard (35 μg/m3). The present study was consequently conducted to collect atmospheric fine particles at the boundary and the surrounding sensitive sites of a steelwork plant, respectively. Twenty-four hour PM2.5 sampling was undertaken for three consecutive days in each season from January to November of 2014. Aerosol samplers including PQ200 PM2.5 sampler and MOUDI were applied to collect fine particles for their physical and chemical characteristics including mass concentration, particle size distribution, water-soluble ions, metallic elements, and carbonaceous contents. This study further used principal component analysis (PCA) and chemical mass balance (CMB) receptor model to resolve the source apportionment of ambient fine particles.|
This study revealed that the concentrations of PM2.5 sampled at the plant boundary were generally higher than those at the surrounding sensitive sites. PM2.5 concentrations were generally higher in winter due to poor atmospheric dispersion condition, while the concentrations of PM2.5 in summer were always lower at the plant boundary and the surrounding sensitive sites. Furthermore, the PM2.5 concentration contour showed a high correlation with wind direction in the Xiaogang region. Chemical analysis results showed that the most abundant water-soluble ionic species of PM2.5 were secondary inorganic aerosols which were formed by atmospheric chemical reactions of primary pollutants emitted from industrial and mobile sources. Fe and Ca were the major metallic elements of PM2.5 mainly emitted from the steel plants. Organic carbons were generally higher than elemental carbons emitted from mobile sources and incomplete combustion, and the primary elemental carbons were generally higher when PM2.5 was affected by the manufacturing processes at the plant boundary.
In addition, this study used the source profiles of PM2.5 emitted from eight manufacturing processes in a steel plant to resolve the source apportionment of PM2.5 by using a chemical mass balance (CMB) receptor model. Results obtained from CMB showed that the major sources of PM2.5 were steel plants, petrochemical industries, secondary inorganic aerosols, and mobile sources in the Xiaogang region, plant boundary was mainly affected by the blast furnace and the steelmaking processes. The contribution of steel plant in plant boundary were 38.49, 38.11, 37.34, and 40.14%, and those at the surrounding sensitive sites were 35.13, 30.31, 27.03, and 35.39% in winter, spring, summer and fall, respectively. The results showed that PM2.5 at boundary sites were mainly affected by steel plant, however, the impacts of steel plants towards the surrounding sensitive sites showed higher PM2.5 concentration in winter and lower in summer due to poor atmospheric dispersion condition.