Exploration Of Ozone Pollution Origin And Control Strategies In A Typical City Area,Guangzhou

In recent years,the level of tropospheric ozone（O₃）in China has been rising year by year,and O₃pollution incidents occur frequently.As one of the developed urban agglomerations in China,Pearl River Delta area of O₃pollution is more serious,which has caused widespread concern.Huangpu District in Guangzhou,one of the emerging urban areas in the east of Guangzhou,where the rapid development of population,transportation and industry bring a series of O₃pollution problems.The complex industrial system and dense traffic arteries also make it difficult to control the emission sources of O₃precursors.In order to analyze the situation and causes of O₃pollution in Huangpu District,and to put forward effective O₃control suggestions,the No.86 Middle School site was selected in Huangpu District,Guangzhou,for one-year online monitoring of air quality parameters and volatile organic compounds（VOCs）.After a series of analyses and discussions,the following conclusions are drawn:During the monitoring period,weather conditions with sunny,high temperature and low humidity are prone to O₃pollution.The O₃pollution was mainly concentrated in summer and autumn in Huangpu District,and the seasonal variation characteristics were weakening.The diurnal variation characteristics of O₃and its precursor including NO_x（NO_x=NO+NO₂）and VOCs showed a significant negative correlation.VOCs seasonal characteristics showed high in winter and low in spring.The highest proportion of VOCs were alkanes,but aromatics contributed the most to O₃formation.Among the species,xylene,toluene and ethylene were the key species for local O₃formation.In terms of meteorological impact,O₃pollution was easily affected by tropical cyclones and southerly winds in spring;tropical cyclones in summer and autumn;anticyclones and southerly winds in winter.In terms of the impact of precursor emissions,aromatics as the domain in O₃local formation.The key species of O₃formation were similar,namely xylene,toluene and ethylene.For spring and winter,reduce O₃with a VOCs/NO_xratio of 2:1 to 3:1 were recommended.In spring,propose to control the paint solvent and vehicle exhaust of AVOCs sources;in winter,propose to control the paint solvent,vehicle exhaust and LPG use in AVOCs sources.For the summer and autumn,the O₃control suggestion is to reduce the VOCs/NO_xratio of 3:1,and propose to control the paint solvent of AVOCs sources.