[Emissions Inventory of Smoldering Chinese Kangs and Their Contribution to PM_2.5 Pollution in Lanzhou City]

Considering regional differences in economic development, the activity level of smoldering Chinese kangs was confirmed by surveys in typical areas in Lanzhou City. An emissions inventory of smoldering Chinese kangs in Lanzhou City in 2016 was established using the emissions factor approach. The emissions amounts of SO₂, NO_x, NH₃, CO, volatile organic compounds (VOCs), PM₁₀, PM_2.5, organic carbon (OC) and elemental carbon (EC) were 340.8, 201.8, 106.0, 36628.2, 4997.2, 6070.3, 5645.1, 1089.3, and 1233.1 t·a^-1, respectively. Emissions amounts were allocated by spatial and temporal characteristics. The emissions were concentrated from November to mid-April of the following year. Spatially, there were significant differences in emissions at different economic levels. The high value areas of emissions were mainly concentrated in the southern part of Yuzhong, central Yongdeng, and south of Qilihe. The weather research and forecasting with chemistry (WRF-Chem) model was used to determine the average contribution of smoldering Chinese kangs to PM_2.5 concentration in Lanzhou City during the heating season. The simulation results were improved after applying the emissions inventory. The average PM_2.5 concentration at Lanyuan Hotel (in the city) and Yuzhong Station (in the countryside) increased 32 μg·m^-3 and 34 μg·m^-3 in the simulation, respectively, and the corresponding rates of pollution contribution were 37.6% and 49.2%. Thus, researching and enacting scientific control measures for smoldering Chinese kang pollutants is significant to improving regional air quality.