【摘要】 为了解常州春季大气气溶胶中水溶性有机碳（WSOC）和有机氮（WSON）的特点和来源,在常州市城郊于2017年春季的3月1日⁵月30日采集了84个细颗粒物(PM_2.5)样品.分析了其中的水溶性组分包括水溶性有机碳、水溶性总氮（WSTN）、水溶性离子以及碳质组分（有机碳/元素碳,OC/EC）的浓度,探讨了WSOC和WSON的浓度水平及其来源.结果表明,采样期间,PM_2.5、WSOC和WSON日平均浓度分别为101.97、7.63和1.50μg·m^-3.其中,WSON占WSTN的12.9%,水溶性无机氮主要以NH+4、NO-3两种形式存在,两者占WSTN的86.15%.WSOC与WSON弱相关（r=0.58）,说明WSOC和WSON来源并不完全一致.WSOC与SOC、K+、二次离子（SO2-4、NH+4和NO-3）相关,说明WSOC主要来自生物质燃烧和二次转化;WSON与二次离子相关性强,说明主要来自二次转化.风速是影响WSOC和WSON浓度水平的主要因素,WSON与大气压正相关且与温度负相关.主成分分析结果表明,PM_2.5主要来自二次形成、扬尘和燃煤、生物质燃烧、海洋等4个来源.后向轨迹分析表明,长距离传输方向气团中PM_2.5和WSOC、WSON总浓度高于短距离传输,但不同传输路径中WSON/WSTN占比无明显差异.更多还原

【Abstract】 To understand the characteristics and sources of water-soluble organic carbon（WSOC） and organic nitrogen（WSON） in atmospheric aerosols during spring in Changzhou,84 fine particle(PM_2.5) samples were collected from March 1 to May 30,2017,in Changzhou.The water-soluble components,including water-soluble organic carbon,water-soluble total nitrogen（WSTN）,watersoluble ions,and carbonaceous components（OC and EC）,were analyzed.The levels of WSOC and WSON and their source characteristics were discussed.The results show that the average concentrations of PM_2.5,WSOC,and WSON are 101.97,7.63,and1.50 μg·m^-3,respectively,during the sampling period.The WSON accounts for 12.9% of the WSTN and the water-soluble inorganic nitrogen mainly exists in two forms,that is,NH+4 and NO-3,accounting for 86.15% of the WSTN.The WSOC is weakly correlated with WSON（r=0.58）,indicating that WSOC and WSON do not have the same sources.The WSOC is related to SOC,K+,and secondary ions（SO2-4,NH+4,and NO-3）,indicating that it is mainly derived from biomass burning and secondary conversion;WSON is strongly correlated to secondary ions,indicating that it is mainly derived from secondary conversion.The wind speed is the main factor affecting the WSOC and WSON concentration levels.Furthermore,the WSON is positively correlated with the air pressure and negatively correlated with the temperature.The results of the principal component analysis show that PM_2.5 mainly originates from four sources:secondary formation,dust,coal combustion,biomass burning,and the ocean.The backward trajectory analysis indicates that the total concentrations of PM_2.5,WSOC,and WSON in air masses from long-distance transformation are higher than that from shortdistance transmission,whereas there is no significant difference in the WSON/WSTN ratio from different transmission paths.更多还原