Hygroscopic properties of potassium chloride and its internal mixtures with organic compounds relevant to biomass burning aerosol particles.
Hygroscopic properties of potassium chloride and its internal mixtures with organic compounds relevant to biomass burning aerosol particles.
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氯化钾及其内部混合物与生物质燃烧气溶胶颗粒相关有机化合物的吸湿特性
DOI：
10.1038/srep43572
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发表时间：
2017-02-27
影响因子：
4.6
通讯作者：
Ge M
中科院分区：
文献类型：
--
作者：
Jing B;Peng C;Wang Y;Liu Q;Tong S;Zhang Y;Ge M
虽然气溶胶的水分吸收对气候产生了相当大的影响，但气溶胶成分和物种之间的潜在相互作用对大气颗粒物吸湿性的影响尚未得到充分的表征。利用吸湿性串联微分迁移率分析仪（HTDMA）研究了生物质燃烧气溶胶中氯化钾及其与草酸、左旋葡聚糖和腐殖酸等水溶性有机物（WSOC）的内部混合物的吸水行为。KCl/有机混合物的潮解点，观察到发生在较低的RH值和在一个较宽的RH范围内，最终消失在高有机质量分数。这导致在中等相对湿度下对吸水量的预测严重不足。对于草酸含量为75%（重量）的KCl气溶胶，观察到模型预测值与测量值之间的含水量存在较大差异，这可能是由于KCl和草酸之间的相互作用形成吸湿性较低的草酸钾而未考虑模型方法。我们的研究结果还表明，强烈的影响左旋葡聚糖的多元混合颗粒的吸湿行为。这些发现对于进一步理解WSOC和无机盐之间的相互作用对大气颗粒物吸湿行为和环境效应的作用具有重要意义。
While water uptake of aerosols exerts considerable impacts on climate, the effects of aerosol composition and potential interactions between species on hygroscopicity of atmospheric particles have not been fully characterized. The water uptake behaviors of potassium chloride and its internal mixtures with water soluble organic compounds (WSOCs) related to biomass burning aerosols including oxalic acid, levoglucosan and humic acid at different mass ratios were investigated using a hygroscopicity tandem differential mobility analyzer (HTDMA). Deliquescence points of KCl/organic mixtures were observed to occur at lower RH values and over a broader RH range eventually disappearing at high organic mass fractions. This leads to substantial under-prediction of water uptake at intermediate RH. Large discrepancies for water content between model predictions and measurements were observed for KCl aerosols with 75 wt% oxalic acid content, which is likely due to the formation of less hygroscopic potassium oxalate from interactions between KCl and oxalic acid without taken into account in the model methods. Our results also indicate strong influence of levoglucosan on hygroscopic behaviors of multicomponent mixed particles. These findings are important in further understanding the role of interactions between WSOCs and inorganic salt on hygroscopic behaviors and environmental effects of atmospheric particles.