| 不同生物质燃烧排放多环芳烃及糖醇类化合物的模拟研究 |
| 摘要点击 2285 全文点击 1015 投稿时间：2015-04-02 修订日期：2015-05-22 |
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| 中文关键词 PM2.5 生物质燃烧 多环芳烃 糖醇类化合物 光解 |
| 英文关键词 PM2.5 biomass burning PAHs sugar alcohols photolysis |
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| 中文摘要 |
| 选择水稻、小麦、玉米及棉花秸秆与马尾松枝,采集模拟燃烧时排放的PM2.5,分析PM2.5中多环芳烃(PAHs)和糖醇类化合物的含量,获得PM2.5及负载的两类化合物的排放因子;采用500 W汞灯直接照射收集了PM2.5的尘膜,获得了中、高环PAHs及左旋葡聚糖的光解动力学. 结果表明, PM2.5的排放因子介于(2.26±0.60)g·kg-1(马尾松枝)~(14.33±5.26)g·kg-1(玉米秸秆)之间;19种PAHs的排放因子介于(0.82±0.21)mg·kg-1(马尾松枝)~(11.14±5.69)mg·kg-1(棉花秸秆)之间,且以4环类PAHs所占比例最高,介于51%~71%之间(其中马尾松枝燃烧时惹烯的排放因子最大);9种糖醇类化合物的排放因子范围为(52.34±50.16)mg·kg-1(水稻秸秆)~(238.81±33.62)mg·kg-1(小麦秸秆),且都以左旋葡聚糖占绝对优势(72%~96%). 光照模拟显示,目标化合物的光照损失都遵循拟一级动力学,其中≥4环的PAHs的光解速率常数随着尘膜中PAHs的负载量增大而减小,来源特征比值Flua/(Flua+Py)和Ip/(Ip+BgP)相对稳定,而左旋葡聚糖的光解速率常数为0.0045 min-1,与苯并[a]蒽的光解速率常数(0.0041~0.0050 min-1)接近. |
| 英文摘要 |
| To measure the emission factors of PM2.5 and its associated PAHs and sugar alcohols, Chinese red pine stick and four crop straw including rice, wheat, corn and cotton were burned in a chamber.In addition, the kinetics of certain compounds were obtained through the irradiation of the glass filters with PM2.5 loading by 500 W mercury lamp.The emission factors of PM2.5 were ranged from (2.26±0.60) g·kg-1 (Chinese red pine stick) to (14.33±5.26) g·kg-1 (corn straw).Although the emission factors of the total 19 PAHs differed from (0.82±0.21) mg·kg-1 (Chinese red pine stick) to (11.14±5.69) mg·kg-1 (cotton straw), 4 ring PAHs showed predominance over other PAHs accounting for 51%-71% except Chinese red pine in which retene was the predominant compound.The emission factors of 9 sugar alcohols were ranged from (52.34±50.16) mg·kg-1 (rice straw) to (238.81±33.62) mg·kg-1 (wheat straw) with levoglucosan accounting for 72%-96% of the total sugar alcohols.Both the selected PAHs and levoglucosan associated with PM2.5 followed the first order kinetics.The photolysis kinetic coefficient of PAHs (ring number≥4) was decreased with the increase of PAHs loading in filters.Two PAHs source characteristic ratios such as Flua/(Flua+Py) and IP/(IP+BgP) were relative stable during the irradiation.The photolysis kinetic coefficient of levoglucosan (0.0045 min-1) was comparable to benzo[a]anthracene (0.0041-0.0050 min-1). |
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