A comprehensive emission inventory of air pollutants from municipal solid waste incineration in China's megacity, Beijing based on the field measurements.

The rising of municipal solid waste incineration (MSWI), constituting 5 % of NOx emissions in Beijing, poses a significant challenge to improving air quality. This study establishes a comprehensive historical inventory of air pollutants (APs) emitted from MSWI plants between 2004 and 2023. The inventory was developed using both the continuous emissions monitoring systems (CEMS)-based method and the EF (emission factors) -based method, incorporating detailed plant-level activity data and localized EF derived from field measurements. These include data from CEMS and manual monitoring. Analysis of CEMS data reveals high compliance rates with emission limits for MSW in Beijing, with 99.9 %, 99.5 %, 99.8 %, 98.7 %, and 99.5 % of units meeting standards for PM, SO2, NOx, CO and HCl, respectively. This suggests effective implementation of emission standards in Beijing, although further strengthening of policies, particularly for CO emissions, is warranted. Overall, total AP emissions have increased annually largely attributed to measures implemented for DeSOx, DeNOx, and DePM since 1998. Most MSWI facilities are located in suburban areas rather than urban cores. Emissions of SO2, HCl, CO, Hg, Cd + Ti, other metals, dioxins, VOCs, and NH3 exhibit a spatially homogeneous distribution at the district level, while PM and NOx emissions demonstrate heterogeneity. Scenario analysis underscores the importance of continuous improvement and upgrading of advanced air pollution control devices. This study contributes a methodological framework for estimating emissions, reducing uncertainties, and informing policy-making to mitigate APs emissions in megacities. It serves as a valuable reference for similar cities grappling with air quality challenges.

[Mass size distributions and existing forms of sulfate and nitrate and atmospheric environment in Beijing].

In order to understand the formations and the concentrations of the secondary sulfate and nitrate of PM10 in Beijing. From May 2008 to April 2009, MOUDI has been used to collect the PM10 samples in Beijing atmospheric environment and the ion chromatography has been used to analyze the inorganic water-soluble components of the PM10 samples. The results showed that the mass size distributions of soluble sulfate and nitrate of PM10 in Beijing were single-mode distribution and the peak rang was from 0.32 microm to 0.56 microm, and the primary formation ways was the chemical reaction in the gas phase. The results of partial correlation analysis indicated that the primary formations of sulfate and nitrate of PM10 in Beijing was (NH4)2SO4, NH4NO3, NaNO3, KNO3 and Ca(NO3)2. The mass concentration of secondary (NH4)2SO4 and NH4NO3 were (17.0 +/- 8.2) microg/m3 and (8.8 +/- 3.3) microg/m3 respectively, which accounted for (14.7 +/- 3.6)% and (7.6 +/- 2.2)% of PM10 respectively. The sum of them accounted for (22.3 +/- 4.3)% of PM10.