采用DRI Model 2001A热/光碳分析仪测定了2011年南京地区大气PM1.1中OC、EC的含量,并具体探讨了其来源.结果表明,南师OC、EC年均浓度分别为10.10μg·m-3、2.52μg·m-3,南化分别为11.22μg·m-3、3.12μg·m-3,南化污...采用DRI Model 2001A热/光碳分析仪测定了2011年南京地区大气PM1.1中OC、EC的含量,并具体探讨了其来源.结果表明,南师OC、EC年均浓度分别为10.10μg·m-3、2.52μg·m-3,南化分别为11.22μg·m-3、3.12μg·m-3,南化污染相对严重.夏季两地OC、EC含量较低,而冬春季较高,这与冬春季燃煤量增加,并且受内陆西风及逆温的影响,污染物集中在南京市上空不易扩散有关.两地PM1.1中SOC/TOC均在夏季较高,冬季最低.秋季SOC和O3有较好的相关性,表明秋季光化学反应是SOC的重要生成途径.展开更多
为了解华南背景区域鼎湖山站碳质气溶胶的浓度水平与来源,采用DRI Model 2001A热/光碳分析仪测定了鼎湖山站大气颗粒物分级样品中的有机碳(OC)与元素碳(EC)浓度水平,并分析了碳质组分的浓度特征和粒径分布.结果表明,在PM1.1、PM2.1和PM...为了解华南背景区域鼎湖山站碳质气溶胶的浓度水平与来源,采用DRI Model 2001A热/光碳分析仪测定了鼎湖山站大气颗粒物分级样品中的有机碳(OC)与元素碳(EC)浓度水平,并分析了碳质组分的浓度特征和粒径分布.结果表明,在PM1.1、PM2.1和PM9.0中,鼎湖山OC的平均质量浓度分别为(5.6±2.0)、(7.3±2.4)和(12.8±4.0)μg·m^-3,EC的平均质量浓度分别为(2.3±1.4)、(2.7±1.6)和(3.4±1.7)μg·m^-3.PM1.1和PM2.1中OC分别占PM9.0中OC的43.8%和57.0%,EC占67.6%和79.4%.OC和EC主要富集在细粒子中.PM1.1和PM2.1中OC和EC在秋季最高,OC在冬季最低,EC在夏季最低.PM9.0中OC夏季最高.鼎湖山中碳质气溶胶以OC2、EC1、OC3和OC4为主,夏季OC3>EC1,生物排放源增强,冬季EC1质量浓度最高,局地的机动车排放源更强.OC和EC在4个季节都呈现双峰型分布,细粒径段峰值位于0.43~0.65μm,粗粒径段峰值出现在3.3~5.8μm.PM1.1和PM2.1中OC以一次排放为主,二次有机碳(SOC)在春季最高[(3.0±1.4)μg·m^-3],冬季最低[(1.3±1.4)μg·m^-3],春季二次转化更强.鼎湖山大气细粒径段OC主要来自燃煤和机动车排放,粗粒径段主要来自生物源排放,EC主要受到燃煤、机动车排放和扬尘的影响.展开更多
Long-time large-area haze weather appeared in Wuhan on June 11, 2012. It was monitored that PM2.5 hourly concentration obviously rose, and peak value reached 658 μg/m3. OC and PM2.5 presented high correlation, and co...Long-time large-area haze weather appeared in Wuhan on June 11, 2012. It was monitored that PM2.5 hourly concentration obviously rose, and peak value reached 658 μg/m3. OC and PM2.5 presented high correlation, and correlation coefficient was 0.96. OC daily average concentration occupied 10% -20% in PM2.5, and difference was big between haze and normal weather. EC occupied 5%, and difference was very small between haze and normal weather. By analyzing change trend of OC/EC, it was found that OC/EC presented increasing trend in late May and was even higher than that during 11 -15 June. It was clear that biomass combustion taking straw as the representation has started in late May. But two strong precipitation on May 29 and June 6 inhibited haze weather, and specific meteorological condition caused haze on June 11. Proportion of SOC to OC reached 14% -70%, illustrating that daily difference of secondary photochemical reaction was very big in Wuhan. OC/EC values were respectively 2.7, 3.5 and 4.2 in May, June and haze period. SOC daily means were respectively （5.33 ±4.77） and （32.5 ±23.4） μg/m^3 in May and haze period. Major pollution source of haze weather was biomass combustion, and haze occurrence had very big relationship with special meteorological condition.展开更多
Carbonaceous components contribute significant fraction of fine particulate matter (PM2.5). Study of organic carbon (OC) and elemental carbon (EC) in PM2.5 may lead to better understanding of secondary organic carbon ...Carbonaceous components contribute significant fraction of fine particulate matter (PM2.5). Study of organic carbon (OC) and elemental carbon (EC) in PM2.5 may lead to better understanding of secondary organic carbon (SOC) formation. This year-long (December 2008 to December 2009) field study was conducted in an animal agriculture intensive area in North Carolina of United States. Samples of PM2.5 were collected from five stations located in an egg production facility and its vicinities. Concentrations of OC/EC and thermograms were obtained using a thermal-optical carbon analyzer. Average levels of OC in the egg production house and at ambient stations were 42.7 μg/m3 and 3.26 - 3.47 μg/m3, respectively. Average levels of EC in the house and at ambient stations were 1.14 μg/m3 and 0.36 - 0.42 μg/m3, respectively. The OC to total carbon (TC) ratios at ambient stations exceeded 0.67, indicating a significant fraction of SOC presented in PM2.5. Principal factor analysis results suggested that possible major source of in-house PM2.5 was from poultry feed and possible major sources of ambient PM2.5 was from contributions of secondary inorganic and organic PM. Using the OC/EC primary ratio analysis method, ambient stations SOC fractions ranged from 68% to 87%. These findings suggested that SOC could appreciably contribute to total PM2.5 mass concentrations in this agriculture intensive area.展开更多
文摘采用DRI Model 2001A热/光碳分析仪测定了2011年南京地区大气PM1.1中OC、EC的含量,并具体探讨了其来源.结果表明,南师OC、EC年均浓度分别为10.10μg·m-3、2.52μg·m-3,南化分别为11.22μg·m-3、3.12μg·m-3,南化污染相对严重.夏季两地OC、EC含量较低,而冬春季较高,这与冬春季燃煤量增加,并且受内陆西风及逆温的影响,污染物集中在南京市上空不易扩散有关.两地PM1.1中SOC/TOC均在夏季较高,冬季最低.秋季SOC和O3有较好的相关性,表明秋季光化学反应是SOC的重要生成途径.
文摘为了解华南背景区域鼎湖山站碳质气溶胶的浓度水平与来源,采用DRI Model 2001A热/光碳分析仪测定了鼎湖山站大气颗粒物分级样品中的有机碳(OC)与元素碳(EC)浓度水平,并分析了碳质组分的浓度特征和粒径分布.结果表明,在PM1.1、PM2.1和PM9.0中,鼎湖山OC的平均质量浓度分别为(5.6±2.0)、(7.3±2.4)和(12.8±4.0)μg·m^-3,EC的平均质量浓度分别为(2.3±1.4)、(2.7±1.6)和(3.4±1.7)μg·m^-3.PM1.1和PM2.1中OC分别占PM9.0中OC的43.8%和57.0%,EC占67.6%和79.4%.OC和EC主要富集在细粒子中.PM1.1和PM2.1中OC和EC在秋季最高,OC在冬季最低,EC在夏季最低.PM9.0中OC夏季最高.鼎湖山中碳质气溶胶以OC2、EC1、OC3和OC4为主,夏季OC3>EC1,生物排放源增强,冬季EC1质量浓度最高,局地的机动车排放源更强.OC和EC在4个季节都呈现双峰型分布,细粒径段峰值位于0.43~0.65μm,粗粒径段峰值出现在3.3~5.8μm.PM1.1和PM2.1中OC以一次排放为主,二次有机碳(SOC)在春季最高[(3.0±1.4)μg·m^-3],冬季最低[(1.3±1.4)μg·m^-3],春季二次转化更强.鼎湖山大气细粒径段OC主要来自燃煤和机动车排放,粗粒径段主要来自生物源排放,EC主要受到燃煤、机动车排放和扬尘的影响.
文摘Long-time large-area haze weather appeared in Wuhan on June 11, 2012. It was monitored that PM2.5 hourly concentration obviously rose, and peak value reached 658 μg/m3. OC and PM2.5 presented high correlation, and correlation coefficient was 0.96. OC daily average concentration occupied 10% -20% in PM2.5, and difference was big between haze and normal weather. EC occupied 5%, and difference was very small between haze and normal weather. By analyzing change trend of OC/EC, it was found that OC/EC presented increasing trend in late May and was even higher than that during 11 -15 June. It was clear that biomass combustion taking straw as the representation has started in late May. But two strong precipitation on May 29 and June 6 inhibited haze weather, and specific meteorological condition caused haze on June 11. Proportion of SOC to OC reached 14% -70%, illustrating that daily difference of secondary photochemical reaction was very big in Wuhan. OC/EC values were respectively 2.7, 3.5 and 4.2 in May, June and haze period. SOC daily means were respectively （5.33 ±4.77） and （32.5 ±23.4） μg/m^3 in May and haze period. Major pollution source of haze weather was biomass combustion, and haze occurrence had very big relationship with special meteorological condition.
文摘Carbonaceous components contribute significant fraction of fine particulate matter (PM2.5). Study of organic carbon (OC) and elemental carbon (EC) in PM2.5 may lead to better understanding of secondary organic carbon (SOC) formation. This year-long (December 2008 to December 2009) field study was conducted in an animal agriculture intensive area in North Carolina of United States. Samples of PM2.5 were collected from five stations located in an egg production facility and its vicinities. Concentrations of OC/EC and thermograms were obtained using a thermal-optical carbon analyzer. Average levels of OC in the egg production house and at ambient stations were 42.7 μg/m3 and 3.26 - 3.47 μg/m3, respectively. Average levels of EC in the house and at ambient stations were 1.14 μg/m3 and 0.36 - 0.42 μg/m3, respectively. The OC to total carbon (TC) ratios at ambient stations exceeded 0.67, indicating a significant fraction of SOC presented in PM2.5. Principal factor analysis results suggested that possible major source of in-house PM2.5 was from poultry feed and possible major sources of ambient PM2.5 was from contributions of secondary inorganic and organic PM. Using the OC/EC primary ratio analysis method, ambient stations SOC fractions ranged from 68% to 87%. These findings suggested that SOC could appreciably contribute to total PM2.5 mass concentrations in this agriculture intensive area.
