秦皇岛市夏季大气污染物的降雨清除效率及影响因素

Precipitation removal efficiency of atmospheric pollutants and influencing factors in summer Qinhuangdao

降雨是大气污染物最主要的湿沉降过程。通过对秦皇岛市夏季降雨前后及降雨过程大气污染物浓度变化进行分析,定量计算降雨对污染物的清除率,探讨不同气象要素对清除率的影响。结果表明,降雨对颗粒物的清除率高于气态污染物,PM10清除率最高,其次是PM2.5,SO2清除率较低,与夏季秦皇岛市SO2本底浓度较低有关;NOX浓度变化和O3呈负相关;降雨量与污染物的清除率呈正相关,但连续降雨清除率呈下降趋势,甚至不降反升;SO2清除率与最大降雨强度相关性最强;O3清除率与气压相关性最强;PM2.5清除率与风速相关性最强;其他气象要素对大气污染物清除效率影响很小或没有影响。

Rainfall is the main wet precipitation process of atmospheric pollutants.The influence of different meteorological elements on atmospheric pollutants clearance rate were discussed through analyzing atmospheric pollutant concentration before,during and after summer rainfall and quantitatively calculation of the pollutant clearance rate in Qinhuangdao city.The results showed that the removal rate of particulate pollutants by rainfall was higher than that of gaseous pollutants,with the highest removal rate of PM10,followed by PM2.5,the lower SO2 clearance rate is related to the lower SO2 background concentration in Qinhuangdao in summer;The change of NOX concentration was negatively correlated with O3;There was a positive correlation between precipitation and pollutant clearance rate,but the clearance rate of continuous rainfall showed a downward trend or even increased instead of decreasing;The SO2 clearance rate has the strongest correlation with the maximum rainfall intensity;O3 clearance rate has the strongest correlation with air pressure;PM2.5 clearance rate has the strongest correlation with wind speed;Other meteorological elements have little or no effect on the removal efficiency of atmospheric pollutants.