云浮市2018-2020年颗粒物和臭氧污染特征及污染案例研究

Pollution Characteristics and a Pollution Case of Particulate Matter and O_(3) in Yunfu City from 2018 to 2020

为探究云浮市颗粒物和臭氧(O_(3))污染特征,利用多元统计分析方法分析了云浮市2018—2020年6项环境空气污染物浓度、气象因子等监测数据,并对2020年12月25—29日冬季PM_(2.5)和O_(3)污染过程进行了研究.结果表明:①PM_(2.5)、PM10、NO_(2)、CO月均浓度呈夏季低、冬季高的变化特征;O_(3)-8 h第90百分位数呈夏秋季高、冬春季低的变化特征.②PM10、PM_(2.5)和CO小时浓度日变化呈波浪型变化特征,PM_(2.5)、CO小时浓度最大值均出现在09:00,PM10小时浓度最大值出现在02:00.O_(3)、SO_(2)小时浓度日变化呈单峰型变化特征,O_(3)、SO_(2)小时浓度最大值分别出现在16:00、10:00.NO_(2)小时浓度日变化呈单谷型变化特征,最小值出现在14:00.③PM_(2.5)-10、SO_(2)、NO_(2)、O_(3)小时浓度与PM_(2.5)小时浓度均呈正相关,说明PM_(2.5)-10、SO_(2)、NO_(2)、O_(3)与PM_(2.5)具有一定程度的同源性.O_(3)小时浓度与NO_(2)、CO小时浓度呈负相关,且O_(3)小时浓度与NO_(2)小时浓度相关性更强.夏秋季NO_(2)、CO、O_(3)、PM_(2.5)小时浓度与气温的相关性比冬春季的更强.SO_(2)、PM10、PM_(2.5)、O_(3)小时浓度均与湿度呈负相关,其中O_(3)小时浓度与湿度的相关性最强,相关系数为−0.586.④2020年12月25—29日云浮市城区PM_(2.5)污染受到静稳天气影响,O_(3)污染与28日午后太阳高温辐射以及来自珠三角地区O_(3)污染气团的输入影响有关.利用ART-2a对该时段采集的颗粒物进行成分分析,得到K、EC、OC、ECOC、HM、LEV、Na、SiO_(3)这8种单颗粒物.整个时段EC、OC、ECOC谱图中都存在明显的硫酸盐峰和硝酸盐峰.PM_(2.5)小时浓度与硫酸盐离子、硝酸盐离子、硅酸盐离子、铵离子、氯离子的数量均呈显著正相关,二次反应和老化过程对PM_(2.5)污染有显著影响.研究显示,云浮市PM_(2.5)和O_(3)复合污染防控需要关注本地污染物变化特征和排放源影响,也需关注外来污染气团特别是来自珠三角地区污染气团输入的影响.

In order to explore the pollution characteristics of particulate matter and O_(3) in Yunfu City,the concentrations of six ambient air pollutants and meteorological factors in Yunfu City from 2018 to 2020 were analyzed using multivariate statistical analysis methods,and the pollution process of PM_(2.5) and O_(3) in winter from December 25th to 29th,2020 was studied.The results showed that:(1)The monthly average concentrations of PM_(2.5),PM10,NO_(2),CO showed the characteristics of low in summer and high in winter.The 90%pentitle of maximum daily 8-hour average ozone showed the characteristics of high in summer and autumn,and low in spring and winter.(2)The hourly concentrations of PM10,PM_(2.5),CO exhibited wave-shaped changes.The hourly concentrations of PM_(2.5) and CO all reached their maximum at 09:00,and the maximum hourly concentration of PM10 appeared at 02:00.The hourly concentrations of O_(3) and SO_(2) showed a single-peak type changes.The maximum hourly concentration of O_(3),SO_(2) appeared at 16:00 and 10:00,respectively.The hourly concentration of NO_(2) showed a single-valley type change,in which the minimum appeared at 14:00.(3)The concentrations of PM_(2.5)-10,SO_(2),NO_(2) and O_(3) are all positively correlated with the concentration of PM_(2.5).PM_(2.5)-10,SO_(2),NO_(2) and O_(3) had certain homology with the concentration of PM_(2.5).The concentration of O_(3) was negatively correlated with the concentrations of NO_(2),CO,and the concentration of O_(3) was more closely related to the concentration of NO_(2).The temperature was positively correlated with the concentration of O_(3),and negatively correlated with the concentrations of SO_(2),NO_(2),CO,PM10,PM_(2.5),and the temperature had a stronger correlation with the concentrations of NO_(2),CO,PM10,PM_(2.5),O_(3) in summer and autumn.Air pressure was positively correlated with the concentrations of NO_(2),CO,PM10,PM_(2.5),and the correlation is stronger in summer and autumn.Humidity was negatively correlated with the concentrations of SO_(2),PM10,PM_(2.5),and O_(3),and had the strongest correlation with the concentration of O_(3).(4)From December 25th to 29th,2020,the PM_(2.5) pollution in the urban area of Yunfu City was affected by static and stable weather,the O_(3) pollution was related to the high-temperature solar radiation in the afternoon on the 28th and the external input from the O_(3) polluted air mass in the Pearl River Delta.Using ART-2a to analyze the composition of the particles collected during the period,eight single particles of K,EC,OC,ECOC,HM,LEV,Na,and SiO_(3) were obtained.There were obvious sulfate and nitrate peaks in the EC,OC,and ECOC spectra throughout the entire period.The hourly concentration of PM_(2.5) was significantly positively correlated with the numbers of sulfate ion,nitrate ion,silicate ion,ammonium ion,and chloride ion,which indicated that the secondary reaction and aging process had a significant impact on the PM_(2.5) pollution.The coordinated prevention and control of PM_(2.5) and O_(3) pollution in Yunfu City needs to focus on the characteristics of local pollutants and the impact of emission sources,as well as the impact of external polluted air masses,especially the impact of polluted air mass from the Pearl River Delta region.