摘要
挥发性有机物(VOCs)是臭氧和二次有机气溶胶的重要前体物.为研究中国东北背景地区大气中VOCs浓度和变化特征,应用苏码罐采样技术、三步冷冻浓缩和GC/MS联用技术测定了长白山大气本底站中的VOCs组成、浓度及季节变化,并利用PCA(principal component analysis)受体模型初步解析了白山大气中VOCs来源.结果表明,长白山地区TVOCs年平均浓度(体积分数)为10.7×10^(-9)±6.2×10^(-9),其中卤代烃所占比例最高,占VOCs总浓度的37%,其次是烷烃33%、芳香烃15%、烯烃15%.长白山地区TVOCs呈现明显的季节变化,变化特征为春季﹥秋季﹥夏季﹥冬季,春季大气中的TVOCs浓度显著(P﹤0.05)高于其他季节.利用主成分分析VOCs物种,提取出5个因子,分别归纳为交通源、液化石油气(LPG)、生物源、燃烧源和区域工业输送.结合HYSPLIT-4.0后向轨迹模型,分析周边区域传输对VOCs物种浓度的影响,发现来自西南向气团传输是长白山VOCs物种浓度增加的主要原因.
Volatile organic compounds( VOCs) play very important roles in the formation of ozone and secondary organic aerosols. The concentrations,compositions,and seasonal variation of VOCs were measured in 2012 at Changbai Mountain Forest Ecosystem Research Station,a remote station in Northeast China. Weekly samples were collected in the Changbai Mountain area and analyzed via gas chromatography-mass spectrometry. The results showed that the annual mean concentration of total VOCs( TVOCs) was 10. 7 × 10-9±6. 2 × 10-9. Halohydrocarbon was the most abundant component,accounting for 37% of the total VOCs,followed by alkanes and aromatics,accounting for 33% and 15% respectively,and alkenes accounted for 15%. The seasonal variation of TVOCs in this area was obvious,and the order was spring ﹥ autumn ﹥ summer ﹥ winter. TVOCs concentration in spring was very significantly higher than those in any other season( P〈0. 05). The principal component analysis( PCA) was used to identify the sources of the VOCs.Five sources were resolved by the PCA,including traffic sources,LPG,biogenic sources,combustion sources,industrial sources and regional transportation. The HYSPLIT-4. 0 model was used to analyze the effect of pollutant transport,and the results indicated that the transport of pollutants from southwest had a significant effect on the increase of VOCs concentration.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2016年第9期3308-3314,共7页
Environmental Science
基金
中国科学院战略性先导科技专项(XDA05100100
XDB05020000)