苏州市臭氧污染特征及影响因素分析OA

In recent years,ozone pollution in Suzhou has occurred frequently,and emerged as a key bottleneck restricting continuous improvement of air quality.Based on ambient air monitoring data,this study analyzes characteristics of ozone pollution in Suzhou,and influencing factors,focusing on atmospheric Volatile Organic Compounds(VOCs)and meteorological conditions.Furthermore,sources of VOCs are explored by using Positive Matrix Factorization(PMF)model and on-site investigations of exhaust emissions from industrial enterprises in National Economic and Technological Development Zone.The major results are as follows.The ozone concentration in Suzhou has shown a fluctuating upward trend,with an average annual growth rate of 2.6 μg·m-3·a-1.The proportion of ozone-exceeding days has continued to rise,from 34.9%in 2016 to 72.9%in 2023.Seasonal variation of ozone concentration presents a bimodal distribution,with the first peak in June and the second in August.Among the VOCs in Suzhou,acetaldehyde,ethylene,toluene,m-p-xylene and propylene exhibit relatively high ozone formation potential.PMF model analysis reveals that industrial processes,motor vehicle exhaust,fossil fuel combustion,oil&gas volatile and solvent usage are the primary emission sources of VOCs.Combined with on-site exhaust emission investigations of most industrial enterprises,the electronic equipment manufacturing,general equipment manufacturing,and rubber&plastic products industries contribute significantly to VOCs emissions,accounting for 71.2%of the total.Regarding meteorological factors,the relative ozone-exceeding rate in Suzhou is positively correlated with daily maximum temperature,while negatively correlated with relative humidity and wind speed.When the wind direction is southeast,south-southeast,or south,the ozone-exceeding rate ranges from 22.3%to 31.9%,which is higher than that under other wind directions.Targeted and sustained in-depth reduction of atmospheric VOCs is of great practical significance for the prevention of ozone pollution and the continuous improvement of air quality.