| 秸秆烟尘和灰烬中元素碳的稳定同位素组成 |
| 摘要点击 3248 全文点击 1674 投稿时间：2013-09-04 修订日期：2013-10-17 |
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| 中文关键词 秸秆 烟尘 灰烬 元素碳 同位素 |
| 英文关键词 crop straw smoke ash elemental carbon isotope |
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| 中文摘要 |
| 选取稻草、麦草和玉米秸秆各6个品种，进行室内模拟焚烧试验，用同位素质谱计测定了灰烬和烟尘中元素碳（EC）的同位素比值. 结果表明，稻草明火和闷烧烟尘中 EC的δ13C平均值分别是-28.3‰、-28.7‰，比稻草总碳分别轻2.7‰、3.0‰. 麦草明火和闷烧烟尘中EC的δ13C平均值分别为-28.5‰、-28.0‰，比麦草总碳分别轻0.1‰、重0.4‰. 玉米秸秆 明火和闷烧烟尘中EC的δ13C平均值分别为-17.2‰、-13.6‰，比秸秆总碳分别轻3.4‰、重0.2‰. 在稻草明火和闷烧灰烬中，EC的δ13C平均值分别是-27.5‰、-27.3‰，比稻草总碳分别轻1.8‰、1.6‰. 在麦草的明火和闷烧灰烬中，EC的δ13C平均值分别为-27.4‰和-26.0‰，比麦草总碳分别重0.9‰和2.4‰. 在玉米秸秆的明火和闷烧灰烬中，EC的δ13C平均值分别为-15.0‰和-14.8‰，比玉米秆总碳分别轻1.2‰和1.0‰. 3类秸秆，尤其是稻草和玉米秸秆，其烟尘和灰烬中的 EC均发生了明显的同位素分馏. 其同位素组成对于识别和估算大气气溶胶中此类秸秆燃烧来源的 EC有参考意义. |
| 英文摘要 |
| Six genotypes of straws for rice, maize and wheat, respectively, were combusted under flaming and smoldering conditions, and the isotope compositions for elemental carbon (EC) in the straw smoke and ash were investigated with an isotopic mass spectrometer. The results showed that the mean δ13C values for EC in the flaming and smoldering smoke of rice straw were -28.3‰ and -28.7‰, with depletions of 2.7‰ and 3.0‰ relative to that of total carbon (TC) in the straw, respectively. The mean δ13C values for EC in the flaming and smoldering smoke of wheat straw were -28.5‰ and -28.0‰, with a depletion of 0.1‰ and enrichment of 0.4‰ comparing to TC in the straw, respectively. The average values in two types of maize straw smoke were -17.2‰ and -13.6‰,with a depletion of 3.4‰ and an enrichment of 0.2‰ relative to TC in the straw, respectively. The mean δ13C ratios for EC in the flaming and smoldering ash of rice straw were -27.5‰ and -27.3‰, with depletions of 1.8‰ and 1.6‰ comparing with TC in the straw, respectively. In the flaming and smoldering ash of wheat straw, the mean ratios were -27.4‰ and -26.0‰, with enrichments of 0.9‰ and 2.4‰ relative to TC in the straw, respectively. In the two types of ash for maize straw, the average δ13C values for EC were -15.0‰ and -14.8‰,which were 1.2‰ and 1.0‰ lighter than those of the straw TC. In general, evident isotope fractionations occur between EC in both smoke and ash and TC in the corresponding straws, especially for rice and maize straws. The isotopic ratios may be useful in identifying and estimating the contribution of EC from straw combustion to ambient aerosol. |
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