【摘要】 采用热/光法测定了2011年夏季和冬季佛山市城区和对照点大气细粒子碳质组分浓度水平,并讨论了城区与对照点碳质组分的污染水平和时空差异;通过分析OC与EC的相关性,研究了各站点大气中碳质组分的主要来源;最后采用ρ(OC)/ρ(EC)最小比值法估算了各站点SOC的污染水平。结果表明:佛山市大气细粒子碳质组分中有机碳(OC)和元素碳(EC)质量浓度分别为9.93μg·m-3和6.47μg·m-3。从季节上看,佛山市碳质组分季节分布明显,冬季污染程度明显高于夏季,各个区域夏季和冬季OC质量浓度分别为5.33～10.60μg·m-3和10.60～15.94μg·m-3,相应的EC质量浓度分别为3.58～6.94μg·m-3和6.03～10.12μg·m-3;夏季和冬季ρ(OC)/ρ(EC)比值分别为1.15～1.84和1.32～2.34。从空间上看,佛山市各区域OC、EC、ρ(OC)/ρ(EC)和ρ(SOC)/ρ(OC)的变化范围较大,城区与对照点二次有机碳(SOC)占OC比例分别为19%～56%和21%～76%,反映了佛山市碳质组分空间分布存在着显著差异。总体上,佛山市各采样点夏季明显受局地污染影响,冬季明显受区域污染影响。OC与EC的相关性系数r2在0.4～0.7之间,说明佛山市大气颗粒物中OC和EC有相似来源。从大气细粒子浓度来看,对照点更合镇污染程度相对较轻,明显低于其他几个城区采样点,但从大气细粒子碳质组分浓度来看,更合镇碳质组分污染水平较高,特别是冬季EC浓度明显高于城区,表明一次燃烧源对更合镇细粒子污染有重要贡献。研究结果对于对后续评估佛山市大气污染整治效果具有一定参考价值,同时可为产业结构类似佛山的其他重工业城市大气污染控制提供基础数据。更多还原

【Abstract】 Thermal/Optical method was used to get the polluted levels of atmospheric carbonaceous species in urban and background sites of Foshan, the spatial and temporal distribution of carbonyls were investigated as well. Correlation analysis was conducted to find possible sources of carbonaceous species and minimum ρ(OC)/ρ(EC) ratio was utilized to estimate the SOC value of each region. Results showed that the concentration of organic carbon(OC) and elemental carbon(EC) was 9.93 μg·m-3 and 6.47 μg·m-3 in PM2.5, respectively. The concentrations of OC were in the range of 5.33～10.60 and 10.60～15.94 μg·m-3 in summer and winter, respectively and the concentrations of EC were 3.58～6.94 μg·m-3 and 6.03～10.12 μg·m-3 in summer and winter, respectively. ρ(OC)/ρ(EC) were in the range of 1.15～1.84 and 1.32～2.34, and ρ(SOC)/ρ(OC) were in the range of 19%～56% and 21%～76%, in summer and winter, respectively. Apparent seasonal difference and very distinct spatial distribution of carbonaceous compounds were observed in Foshan. Carbonaceous components were significantly higher in winter than those in summer, and ρ(SOC)/ρ(OC) was higher in winter, as well. The seasonal difference of OC and EC values and wide spatial distribution of ρ(OC)/ρ(EC) and ρ(SOC)/ρ(OC) in summer but minor changes in winter suggested that carbonaceous components were more affected by local pollution in summer and regional pollution in winter. The correlation coefficients between OC and EC were 0.4～0.7(r2), indicating that there were similar sources of OC and EC in Foshan. Low concentrations of PM2.5 were found at Genghe, a rural sampling site, comparing to other urban sites. However, the levels of carbonaceous species, especially EC were relatively high in winter, indicating that primary sources had significant contribution to carbonaceous species in Genghe. These research results are of great significance to evaluate the effect of air pollution control policies in Foshan and have significant reference value for other typical heavy industrial cities.更多还原