Establishment of High-Resolution Emissions Inventory in Wuhai and Its Application in Exploring the Causes of Ozone Pollution

Abstract

Wuhai is a typical coking industrial base including three industrial parks within its jurisdiction. The emission amount of air pollutants is considerable here, and O3 pollution has become serious in recent years. Clarifying the air pollutant emission characteristics and exploring the formation mechanism of O3 are the basis for objectively understanding the O3 pollution and formulating scientific prevention and control measures. This study established the high-resolution emission inventory of Wuhai in 2018 (HEI-WH18) based on the "coefficient method," evaluated the applicability and accuracy of HEI-WH18 using the WRF-Chem model, and explored the causes of O3 pollution in summer using WRF-Chem diagnosis module output. The HEI-WH18 showed that the total emissions amount of SO2, NOx, CO, PM10, PM2.5, VOCs, NH3, BC, and OC were 65943, 40934, 172867, 159771, 47469, 69191, 1407, 1491, and 1648 t·a-1, respectively. HEI-WH18 could capture the variation and magnitude of O3 and its precursors better than the MEIC, which was suitable for the O3 simulation and source analysis in summer. From the perspective of spatial distribution, Haibowan was a high-value area of O3 during the daytime, and the three industrial parks were low-value areas of O3 and high-value areas of NO2 during the daytime and nighttime. The spatial distribution characteristics of CO were consistent with the spontaneous combustion of coal and coal gangue sources. According to the diagnostic analysis of two O3 pollution processes, the O3 increase in the upper boundary layer was mainly related to the advection transport and chemical process, and it was caused by vertical mixing and the advection transport process in the lower boundary layer. The contribution of the chemical process in the lower boundary layer was complicated, and its positive contribution played a role in maintaining a high O3 concentration, whereas its negative contribution combined with advection transport resulted in the final dissipation of O3 pollution.