沈阳地区PM_(2.5)和O_(3)复合污染特征及协同增长研究

利用2019年沈阳地区11个环境空气质量监测点位和3个VOCs监测点位污染物浓度观测数据,研究了PM_(2.5)等常规污染物和VOCs的时空变化特征;统计分析了2015—2020年沈阳地区PM_(2.5)与O_(3)协同趋长增势。结果表明:沈阳地区各类污染物基本呈单周期峰谷分布,其中NO,NO_(2),CO,NO_(X)(NO+NO_(2)),TVOCs(VOCs总浓度)等一次污染物以及PM_(2.5)在冷季(秋、冬季)较高、暖季(春、夏季)较低,二次污染物O_(3)和O_(X)(O_(3)+NO_(2))则反之。O_(3)和O_(X)浓度夜间低,上午逐渐升高,下午达到峰值;一次污染物浓度下午低,傍晚逐渐升高,早晨到达峰值。O_(3)浓度在下风向郊区高、闹市区低。PM_(2.5),NO,NO_(2),CO和VOCs浓度基本在闹市区和工业区高、下风向郊区低。对不同类别的VOCs而言,烷烃浓度最高,其次是炔烃、烯烃、芳香烃。2015—2020年沈阳地区PM_(2.5)和O_(3)的协同增长现象在夏季表现得最明显,且呈现波动增强趋势。夏季的协同增长与O_(3)浓度在年际变化趋势上具有较好的一致性,都在2017年达到峰值后略有下降,此后再逐渐回升。

Research on the characteristics and interaction of PM_(2.5)and O_(3)composite pollution in Shenyang region using the 2019 pollutant concentration observation data from 11 environmental air quality monitoring sites and 3 VOCs(Volatile Organic Compound)Monitoring Sites in Shenyang Region,the spatiotemporal variation characteristics of conventional pollutants such as PM_(2.5)and VOCs were studied.Statistical analysis was conducted on the long-term synergistic growth trend of PM_(2.5)and O_(3)in Shenyang region from 2015 to 2020.The results showed that all types of pollutants in the Shenyang area show a single cycle peak valley distribution,among which primary pollutants such as NO,NO_(2),CO,NO_(X)(NO+NO_(2)),TVOCs(total concentration of VOCs),and PM_(2.5)are higher in the cold season(autumn and winter)and lower in the warm season(spring and summer),while secondary pollutants O_(3)and O_(X)(O_(3)+NO_(2))are the opposite.The concentrations of O_(3)and O_(X)are low at night,gradually increasing in the morning and reaching their peak in the afternoon.The concentration of pollutants decreases in the afternoon,gradually increases in the evening,and reaches its peak in the morning.The concentration of O_(3)is higher in the downwind direction towards the suburbs and lower in the bustling areas.The concentrations of PM_(2.5),NO,NO_(2),CO,and VOCs are generally high in bustling areas and industrial areas,and low in the downwind direction towards the suburbs.For different categories of VOCs,alkanes have the highest concentration,followed by alkynes,olefins,and aromatics.The synergistic growth phenomenon of PM_(2.5)and O_(3)in Shenyang region from 2015 to 2020 was most evident in summer,and showed an increasing trend of fluctuations.The synergistic growth in summer and the interannual variation trend of O_(3)concentration have good consistency,both reaching their peak in 2017 and slightly decreasing before gradually recovering thereafter.