Influence of Air Pollutant Reduction Measures on Aerosol Water-soluble Ions and Carbonaceous Components During the 14th National Games in Xi'an City of Shaanxi,China
In order to study the influence of air pollutant reduction measures on aerosol water-soluble ions,and organic carbon(OC)and element carbon(EC)during the 14th National Games in Xi'an city of Shaanxi,China,real-time observation instruments were used to motor the hourly concentration of the atmospheric pollutants(PM2.5,PM10,SO2,NO2,O3 and CO),meteorological elements,and chemical composition(OC,EC and water-soluble ions)of PM2.5 from August 6 to October 1,2021.The results show that the air pollutant reduction measures have different effects on the diurnal variations of concentrations of O3 and PM2.5,mainly caused by the influence of temperature on photochemical processes and differences in diffusion conditions.The peak concentration of O3 on sunny days during the implementation of air pollutant reduction measures is higher,last longer,and the concentration changes more rapidly.The peak concentration of PM2.5 is higher in the daytime of the sunny days before the implementation of air pollutant reduction measures,while the peak concentration is higher at night of sunny days during the implementation of air pollutant reduction measures.The air pollutant reduction measures have different effects on the chemical components in PM2.5,especially the composition of OC.On sunny days during the implementation of air pollutant reduction measures,the concentrations of NO3-,SO42-,NH4+,Cl-,Ca2+,Na+and NO2-decrease by 17.9％—71.8％,and the concentrations of K+,Mg2+and EC increase by 1.9％—13.6％,the concentration of OC on sunny days only decreases by 1.0％,but the primary organic carbon(POC)increases by 13.6％,and the secondary organic carbon(SOC)decreases by 4.7％.The NO3-/SO42-ratio on sunny days during the implementation of air pollutant reduction measures(0.53)is much lower than that on sunny days before the implementation of air pollutant reduction measures(1.66),indicating that the contribution of traffic source emission is significantly reduced during the implementation of air pollutant reduction measures.Rainfall has a weak scavenging effect on NO3-and NH4+,and increases their concentrations,but it has a strong scavenging effect on K+,Mg2+,Ca2+and Na+.NO3-,SO42-and NH4+are the essential components of water-soluble ions,accounting for 90.8％of the water-soluble ions(sunny days before the implementation of air pollutant reduction measures)to 95.8％(rainy days during the implementation of air pollutant reduction measures).The diurnal variations of water-soluble ions and carbonaceous aerosols differ at different stages.The diurnal variations of NO3-,SO42-and NH4+present unimodal distributions on sunny days and multimodal distributions on rainy days.
water-soluble ionorganic carbonelemental carbondiurnal variationPM2.5O3the 14th National GamesXi'an
万方数据
维普
