中文摘要：

结合十几年来国内外相关研究进展,分析梳理了我国环境空气PM2.5中SO2-4、NO-3和NH＋4的浓度及百分含量的时空变化特征,发现PM2.5中不同二次组分的浓度及含量均呈现不同的地区性差异,其中SO2-4污染在西北地区较严重,其次是在气候湿润的华南和西南地区;NO-3的污染在西北地区较严重,在西南地区污染较轻;NH＋4污染在华东地区较严重,而在西南地区污染较轻.不同组分均呈现出不同的季节变化特征,SO2-4在夏季较高,春季较低;NO-3在夏季较低,秋冬季较高;NH＋4在春季较低,冬季较高.此外,近年来我国PM2.5中NO-3呈明显的上升趋势,而SO2-4在不同地区呈现出不同的变化特征.硫酸盐和硝酸盐组分的这些时空变化特征均与污染前体物的排放情况以及适宜产生二次反应的环境状况有密切关系.其中SO2-4的生成与环境条件有较大关系,而NO-3的生成与前体物的排放关系较大.根据我国经济发展与主要排放源的变化趋势,预测未来我国PM2.5中SO2-4含量有下降的可能,而NO-3含量会不断升高.

英文摘要：

Spatial and temporal characteristics of sulfate and nitrate components in PM2.5 in China were studied according to the published data.The results showed that there were obvious spatial distributions diversities for SO2-4,NO-3 and NH＋4 components,i.e.,highest SO2-pollution occurred in southern and southwest China,and lowest in eastern region;highest NO-3 pollution occurred in northern and eastern China,and lowest in southwest region;and highest NH＋4 pollution also occurred in eastern regions.Distinct seasonal characteristics for each ionic composition can also be seen that concentrations as well as contents of SO2-4 were highest in summer and lowest in spring,while that of NO-3 were highest in winter and autumn and lowest in summer,and NH＋4 were highest in winter and lowest in spring.Besides,NO-3 in PM2.5 showed obvious increasing trend in the past years while SO2-4 not.All the above spatial and temporal characteristics can be attributed to the differences of precursor gases emissions such as SO2 and NOx and environmental conditions in favor of secondary reactions in different regions in China.Hence,we can deduce that in the future sulfate contents in PM2.5 maybe decrease while nitrate will likely increase.