Optimal emission control plan aiming to basically eliminate PM2.5 heavy pollution in North and Northwest China in 2018

Abstract

The fundamental eradication of heavy air pollution is the core objective during China's "14th Five-Year Plan" period. The purpose of this study was to basically eliminate fine particulate matter (PM2.5) heavy pollution in North and Northwest China during all PM2.5 heavy pollution process throughout 2018 through optimal emission control model based on linear programming technique. The results showed that the sensitivity coefficient of PM2.5 concentration to precursor emissions in North China increased with emissions disturbances, ranging from 0.23 to 0.93 with −80% disturbances. Compared to non-optimal control (NOC) scenario in North China, the optimal control (OC) scenario implemented in various precursors in various regions not only resulted in less precursors mitigation (with emission reduction of 4.1%, 5.9%, 16.6%, 3.5%, and 4.5% for primary PM2.5, SO2, NOx, NH3, and VOCs, respectively), but also led to greater air quality improvements (with the number of PM2.5 heavy pollution days (HPDs) reduced by 37 days, achieving the goal of basically eliminate PM2.5 heavy pollution in North China). If the polluting industries in North China were transferred to Northwest China and the synergistic control (SC scenario) measures were applied, both regions could achieve basically elimination of PM2.5 heavy pollution during the whole simulation periods. However, without implementing optimal control measures in Northwest China (FU scenario), the air quality in that region was poised to deteriorate. Specifically, the number of HPDs in Northwest China changed from 95 days under business as usual (BAU) scenario to 376 days under FU scenario and 29 days under SC scenario, and no new cities with PM2.5 heavy pollution emerged under SC scenario compared to BAU scenario. This study could provide scientific support for the battle against heavy pollution weather in China by redistributing the domestic industrial layout, rather than solely reducing local emissions.