Development of an air pollutant emission inventory for Tianjin

The amounts of several air pollutants emitted in each district and county of Tianjin in 2003 were calculated by investigating the statistical data of Tianjin industry, agriculture and residential life and analyzing every air pollutant emission factors in the literature. An emission inventory of NOx, SO2, NMVOC, CO, NH3, PM10 and PM2.5 for Tianjin is developed. According to this inventory, the total amount of pollutants emitted in the year of 2003 are NOx: 1.77×105 ton, SO2: 2.59×105 ton, NMVOC: 2.24×105 ton, CO: 1.33×106 ton, NH3: 7.40×104 ton, PM10: 2.52×105 ton, and PM2.5: 1.10×105 ton. For source attribution, coal combustion, automobile exhaust and crop burning are the most important emission sources in Tianjin. The contribution of coal combustion to the totals is 46% for NOx, 84% for SO2, 1% for NMVOC, 58% for CO, 18% for PM10, and 24% for PM2.5. Power stations, cement production, steel production, coking plants and oil refineries are also important industrial pollution sources. Specifically, power stations contribute 13% of the total SO2, while iron and steel production contributes 24% of the total SO2 and 30% of the total CO. The urban area contributes more to NOx, SO2, NMVOC and CO, as well as to PM10 and PM2.5, than the other areas in Tianjin. The Tanggu district has very large emission sources of NOx, SO2, NMVOC and CO, and the Jixian, Wuqing and Baodi districts have large emission sources of NH3, PM10 and PM2.5.