成都市冬季一次重污染过程污染特征分析

ANALYSIS ON POLLTUIN CHARACTERISTICS OF HEAVY POLLUTION IN WINTER IN CHENGDU

为了解成都市重污染过程中的污染特征,利用在线监测数据,对2014年12月26日至2015年1月7日成都市重污染过程中主干道的颗粒物浓度、气象要素、气态污染物浓度以及细颗粒物中的水溶性无机离子进行了分析。结果表明:污染期间,PM10、PM2.5、PM1的浓度均值分别为268,188,110μg/m3,PM2.5/PM10、PM1/PM2.5浓度比值为0.70、0.59,首要污染物以细颗粒为主;气象要素呈现风速小（0.2m/s）、湿度高（83%）、能见度低的特征,颗粒物与能见度呈显著负相关（0.720.78）,在80%≤RH<90%湿度段时各粒径段颗粒物与能见度相关性最好,各粒径中PM2.5与能见度之间的相关性最好;水溶性二次无机离子的气态前体物NO2、SO2、NH3平均浓度分别为93.6,20,29.5μg/m3,NO2超标,NO2、SO2与颗粒物呈正相关,且与PM1和PM10相关性好于PM2.5,NH3与颗粒物的相关性较低;PM2.5中的二次离子NO-3、SO2-4、NH+4占PM2.5的50.9%,阴阳离子基本达到了电荷平衡（C/A值为1.04）,（[NO-3]+2[SO2-4]）/[NH+4]比值为0.92,说明NH+4过量;SOR和NOR分别为0.64和0.23,表明硫氧化率大于氮氧化率,NO-3/SO2-4比值为1.40,表明移动源成为颗粒物的主要来源。

In order to study the pollution characteristics of heavy pollution in Chengdu, the particle concentration,meteorological factors,gaseous pollutants and the water soluble inorganic ions in fine particles were analyzed in the main road of heavy pollution during December 26,2014 to January 7,2015 in Chengdu. The results showed that during the period of pollution the mass concentration of PM10,PM_(2.5) and PM1 were 268,188,110 g/m3,respectively. the concentration ratio of PM_(2.5) /PM10,PM1/PM_(2.5) were 0. 70 and 0. 59,respectively. Fine particles was the primary pollutant;. The characteristics of meteorological factors were low wind speed( 0. 2 m/s),high humidity( 83%) and low visibility,. There was a significant negative correlation between particulate matter and visibility(-0. 72 ^-0. 78),among which the correlation coefficient of each level particulate matter and visibility was the highest when relative humidity was 80% < RH < 90%,the best correlation is between PM_(2.5) and visibility among all the particle sizes. The average concentration of NO2,SO2,NH3 were 93. 6,20,29. 5 g/m3,respectively. The concentration of NO2 exceed the national standard. NO2,SO2 were positively correction with particles,and the corrections of PM1 and PM10ware better than PM_(2.5) ,the correlation between NH3 and PM was not significant; the total mass concentration of secondary ions( NO-3,SO2-4,NH+4) accounted for 50. 9% in PM_(2.5) . The anion and cation basically reach the charge balance( C/A = 1. 04),the ratio of [NH+4]/( [NO-3]+ 2[SO2-4]) was 0. 92,which showed NH+4was excess. SOR and NOR were 0. 64 and 0. 23,which illustrated that sulfur conversion rate was greater than nitrogen,. The mobile source become the main source because the ratio of NO-3/SO2-4was 1. 40.