摘要
利用大气细颗粒物快速捕集分析系统和微量天平方法实时、在线分析了北京夏末秋初PM2.5中水溶性无机盐和PM25质量浓度的变化，并结合气象资料和部分前体物SO2、NOx监测数据进行了相关分析．结果表明，北京夏末秋初空气质量良好时，PM2.5日平均浓度为61．0±30．6μg·m^-3，其中水溶性无机盐占PM25的40％-56％，（亚）硝酸盐、硫酸盐、铵盐是水溶性无机盐中的主要成分，占所测水溶性组分的80％以上．SO2向硫酸盐的转化率高于NOx向（亚）硝酸盐的转化率．亚硝酸盐浓度受气象要素和大气化学过程影响，白天亚硝酸盐有向硝酸盐转化的趋势．
The concentration of water-soluble chemical in PM2.5 and the mass concentration of PM2.5 during 19 August to 15 September in Beijing was analyzed by using the system of rapid collection of fine particles and RP1400a, and at the same time, the meteorological data and SO2 , NOx data were also analyzed. The results showed that the average concentration of PM2.5 was （61.0 ± 30.6）μg·m^-3 in the good air quality period , and the proportion of water-soluble chemical in PM2.5 was 40% - 56%. Nitrite, nitrate, sulfate and ammonium were the dominant water-soluble chemical, constituting more than 80% of water-soluble chemical, and they appeared daily variation obviously. The ratio of SO2 to SO4^2- was higher than that of NOx to NO2^- and NO3^-. The concentration of nitrite had relation with meteorological element and atmospheric chemistry reactions, and nitrite transformed into nitrate in daytime.
出处
《环境科学学报》
CAS
CSCD
北大核心
2007年第3期459-465,共7页
Acta Scientiae Circumstantiae
基金
国家自然科学基金项目(No.40525016)
国家重点基础研究发展计划(973)项目(No.2007CB407300)~~
