大气气溶胶离子溶出特性的研究

Dissolve character of ion of aerosol

大气气溶胶酸碱特性呈现出明显的季节变化 ,冬季 SO2 - 4、NH+ 4要明显高于夏季 ,大致是夏季的 2～ 3倍 ,其他离子变化不大 .SO2 - 4为 IP中的主要阴离子 ,占总阴离子的 70 %以上 ,NH+ 4为 IP中的主要阳离子 ,约占总量的4 0 %～ 5 0 % .各离子质量分数之间有很好的相关关系 ,特别是硫酸根与铵根 ,说明这两个离子的来源比较类似 .可吸入尘与大颗粒气溶胶在去离子水水浸之后溶液的 p H值存在着很好的相关性 ,相关系数达到 0 .99以上 ;同时 IP粒子与 >10μm气溶胶在用去离子水及不同的酸性溶液浸取之后 ,所得浸出液的 p H值也成很好的相关关系 .气溶胶中主要的碱性离子 Ca2 + 和 Mg2 + 随着浸取液 p H值的变小 ,溶解度会有相应的增加 ,特别是 Ca2 + ,用 p H 4 .0 0的酸溶液浸取比用去离子水浸取的溶出率可增加 2 0 %左右 。

The acid- base characteristics of atmospheric Inhalable Particle shown the seasonal change clear- ly. Concentrations of ions SO2 -4、NH+ 4 in winteris about2～ 3times,than in summer,the concentrations of the other ions are little change.SO2 -4is the main positive ion,which accounts for more than70 % of total positive ions concentration,and NH+ 4 is the main negative ion,which accounts for 40 %～ 5 0 % of negative ions concentration.The different ions have good correlation,especially the relationship of SO2 -4with NH+ 4 ,which accounts for the same source. The p H of marinate solution by deionize water of IP and >1 0 μm particles also have good correlation,the correlation coefficientis more than 0 .99. in the same time,the p H of marinate solution by deionized water or by the difference acid solution also have good correlation. The concentration ofalkalescence ions Ca2 + and Mg2 + especially the concentration Ca2 + ,will increase as the p H of marinate solution diminish.The dissolve of Ca2 + will increase about2 0 % if the aerosol was marinat- ed by acid solution( p H=4.0 0 ) compared with by deionize water,which shown that aerosol have good neutralization when the acid rain formed.