芜湖市臭氧污染特征与影响因素分析

Pollution characteristics and influence factors of ozone in Wuhu City

为了解芜湖市O_(3)污染变化特征及与主要影响因子相关性,本文对芜湖市环境监测站点和基本气象站点的监测数据进行统计分析。结果表明,芜湖市O_(3)污染程度呈现西南向东北逐步加重的趋势,科创中心、济民医院和四水厂站点月度变化呈现双峰分布的特征,峰值出现在4月和6月,而监测站则是显著单峰型,峰值出现在6月。各站点O_(3)日变化均呈现显著的“单峰单谷”型,在15:00前后达到峰值。在NO_(2)/NO比值区间为10—20时,夜间更易出现高浓度O_(3),而昼间O_(3)浓度高值更易出现在比值低于10时。PM2.5和O_(3)间的相关性更趋向于非线性关系。温度和相对湿度对O_(3)的影响分别呈现正相关和负相关,O_(3)峰值易出现在温度为25—35℃、相对湿度为60%—80%的气象条件下。在东-东南风向下,O_(3)的超标天最多。

Using the air pollutant monitoring data and meteorological data,the pollution characteristics and influence factors of ozone pollution were researched in Wuhu city.The results showed that:(1)The trend of the ozone pollution was aggravated gradually from southwest to northeast.Bimodal distribution of ozone monthly change existed at Kechuangzhongxin,Jiminyiyuan statsion and the highest value is in April and June.However,the Jiancezhan urban station showed a single peak distribution with the highest value at June.(2)For ozone diurnal variation,there are a single peak and a single valley in all the stations and the highest value of ozone concentration appeared in around 15:00.(3)The high ozone concertation was more likely to happen at night when the ratio of NO_(2)/NO was 10—20,while that was more likely to appear at daytime when the ratio was lower than 10.There was a nonlinear relationship between ozone and PM2.5.(4)The ozone concentration had a positive correlation with temperature and a negative correlation with relative humidity.The peak value of ozone concentration normally happened under the favorable meteorological conditions of 25—35℃for temperature and 60%—80%for relative humidity.Most of over standard days of ozone were appeared under east-southeast wind.