摘要
利用在线高分辨率仪器对2013年和2014年北京市PM_(2.5)中OC、EC浓度进行了连续观测。结果表明,2013年OC和EC的平均浓度分别为(16.9±12.4)μg/m^3和(2.1±2.1)μg/m^3;2014年OC和EC的平均浓度分别为(16.7±14.6)μg/m^3和(2.7±2.5)μg/m^3。OC和EC均呈现夜间高、白天低的日变化规律。OC浓度呈双峰型分布,在14:00和20:00出现2个峰值。EC浓度呈现单峰型分布,在0:00左右出现峰值,在14:00出现谷值。受燃煤排放和较高的二次有机碳(SOC)转化的影响,冬季OC和EC的浓度最高。利用OC/EC最小比值法计算得出,2013年和2014年SOC占OC的平均比例分别为65.0%和60.1%。OC与OX表现出显著的正相关性,表明较强的大气氧化性能促进SOC的生成,从而造成OC浓度升高。
An online high time-resolution observation instrument was applied to monitor the concentrations of OC and EC in Beijing in 2013 and 2014. The results showed that annual concentration of OC and EC was（16.9 ±12.4） μg/m^3and（2.1±2.1）μg/m^3 in 2013, respectively, while annual concentration of OC and EC was（16.7±14.6） μg/m^3and（2.7±2.5） μg/m^3 in 2014,respectively. In general, concentrations of OC and EC were higher in the night and lower in the daytime. Diurnal variation of OC showed a bimodal curve, with the peaks appearing at 14：00 and 20：00. Diurnal variation of EC showed a single-peak curve, with the peak and the trough appearing at around 0：00 and 14：00, respectively. Concentrations of OC and EC were the highest in winter due to the coal consumption and high concentration of SOC. The average proportion of SOC to OC was65.0% and 60.1% in 2013 and 2014, respectively, calculated through the minimum ratio of OC/EC. OC and OX showed significant positive correlations, which indicated that strong atmospheric oxidation could promote the formation of SOC and lead to the increase of OC concentration.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2016年第5期157-161,共5页
Environmental Science & Technology
基金
环保公益性行业科研专项(201409005)
国家科技支撑计划课题(2014BAC23B03)
北京市优秀人才培养资助
