北京市可吸入颗粒物(PM_(10))中单颗粒的矿物组成特征

Mineral compositions of individual particulates in PM_(10) over Beijing

使用SEM/EDX对北京不同月份采集的可吸入颗粒物 (PM10 )中的 14 5 4个矿物颗粒进行了识别和统计。结果显示 ,矿物颗粒的种类十分复杂 ,可以鉴定出的矿物有 38种 ,其中以粘土矿物的含量最高 ,年平均值为 30 .1% ;粘土矿物中以伊利石 /蒙皂石混层为主 ,占粘土矿物总数的 35 % ;石英、方解石、复合颗粒、碳颗粒的年均值分别为13.5 %、10 .9%、11.95 %、10 .31% ;年平均含量小于 10 %的矿物有石膏、长石、白云石等 ;首次检测出萤石、磷灰石、岩盐、重晶石、氯化锌等矿物。研究还发现 ,硫化现象可以发生在不同矿物颗粒表面 ,且这种现象主要发生在夏季 。

individual mineral particulates in PM 10 samples, collected over different months in Beijing, were analyzed by SEM/EDX. The results show that mineral particulates in PM 10 over Beijing are complex and heterogeneous. Some 38 mineral species in PM 10 were identified, in which clay minerals occupy the dominant position, accounting for 30.1%. The illite/smectite mixed layers seem to be the most common species in clay minerals. Quartz, calcite, composite particles and carbonaceous particles make up 13.5 %, 10.9%, 11.95% and 10.31% respectively. Gypsum, feldspar and dolomite are below 10% on average. Fluorite, apatite, halite, barite and zinc chlorides were recognized firstly in Beijing PM 10 . Sulfuration occurs on the surface of most mineral particles, especially in summer, suggesting a relatively extensive atmospheric reaction over Beijing in summer.