民用燃煤排放颗粒物中金属元素组成及单颗粒分析  

Emission characteristics of metals in particles emitted from residential coal burning and individual particle analysis

作　　者：武振晓 胡塔峰[2] 薛凡利 任秀龙 李淑娇 牛红亚[1] WU Zhenxiao;HU Tafeng;XUE Fanli;REN Xiulong;LI Shujiao;NIU Hongya(Key Laboratory of Resource Survey and Research of Hebei Province,Hebei University of Engineering,Handan 056038,Hebei,China;Key Lab Aerosol Chemistry&Physics,Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710061,Shaanxi China)

机构地区：[1]河北工程大学河北省资源勘测研究重点实验室,河北邯郸056038 [2]中国科学院地球环境研究所气溶胶化学与物理重点实验室,陕西西安710061

出　　处：《地球化学》2022年第1期46-57,共12页Geochimica

基　　金：国家自然科学基金(41807305、41805118);河北省杰出青年科学基金(D2018402149);河北省自然科学基金面上项目(D2021402004);河北省高校百名优秀创新人才支持计划(SLRC2019021);河北省人力资源和社会保障厅“三三三人才”工程(A201803004、A201901051);河北省重点研发计划项目(19273705D)联合资助。

摘　　要：借助稀释通道采样系统,采集了5种民用煤(3种块煤、1种蜂窝煤和1种煤球)燃烧排放的PM_(2.5)和单颗粒样品。利用ICP-MS分析了PM_(2.5)中16种金属元素(Mg、Al和K 3种轻金属;V、Cr、Mn、Fe、Co、Ni、Cu、As、Rb、Sr、Cd、Ba和Bi共13种重金属)的含量,并运用TEM和SEM-EDX研究了燃煤排放粒子的单颗粒特征。结果显示,蜂窝煤和煤球燃烧排放的颗粒物中金属元素质量分数分别为29.7%和33.0%,高于块煤燃烧排放颗粒物中金属元素的质量分数8.9%~23.7%;Al是民用煤燃烧排放主要的轻金属元素,占3种轻金属总量的45.0%~57.8%;Fe、Ba和As是主要的重金属元素,其质量浓度总和占13种重金属总量的69.5%~78.4%。单颗粒分析结果表明,块煤燃烧生成大量的烟尘集合体、球形粒子和不规则颗粒物,蜂窝煤和煤球燃烧排放颗粒物以球形粒子为主。蜂窝煤燃烧不同阶段(前期、中期和后期)排放颗粒物的粒径均值分别为0.26μm、0.17μm和0.28μm,煤球燃烧排放颗粒物的粒径均值分别为0.11μm、0.47μm和0.06μm。与蜂窝煤和煤球相比,块煤小火燃烧阶段排放颗粒物的粒径均值较高,其3个燃烧阶段的粒径均值分别为0.38μm、0.45μm和0.36μm。块煤燃烧排放颗粒物的针状比值更高,球形度值更低,其燃烧排放90%以上的颗粒物针状比数值介于1.0~2.0,而蜂窝煤和煤球燃烧排放95%的颗粒物针状比值主要介于1.0~1.5;块煤燃烧不同阶段排放颗粒物的球形度均值分别为0.60、0.65和0.75,蜂窝煤3个阶段排放颗粒物的球形度值均在0.90附近,煤球的球形度值在0.80附近。单颗粒能谱结果显示,组成烟尘集合体的主要元素为C、O和Si;而其它形貌的粒子除C和O元素外,部分颗粒物中Al的峰值也较为明显,与全样分析Al元素含量较高的结果具有一致性。A dilution sampling system was used to collect PM_(2.5) samples and individual particles emitted from the combustion of five typical residential coals(three raw coals,one honeycomb coal,and one coal ball).The concentrations of 16 metals(3 light metals as Mg,Al,and K;and 13 heavy metals including V,Cr,Mn,Fe,Co,Ni,Cu,As,Rb,Sr,Cd,Ba,and Bi)in PM_(2.5) were measured by an inductively coupled plasma mass spectrometry(ICP-MS).Individual particles were observed by transmission electron microscopy(TEM)and scanning electron microscopy with energy-dispersive X-ray spectrometry(SEM-EDX).Results showed that the concentration of metals in PM2.5 emitted from honeycomb coal(29.7%)and coal ball(33.0%)burning were higher than those from raw coal(8.9%-23.7%)burning.Al dominated among the three light metals,accounting for 45.0% to 57.8%.Fe,Ba,and As were the dominant heavy metals,accounting for 69.5%to 78.4% of the 13 heavy metals.Single particle analysis showed that the typical particle morphologies of raw coal combustion were soot aggregates,spherical particles,and particles with irregular shapes.Spherical particles dominated the particles from honeycomb coal and coal ball combustion.The mean particle sizes of honeycomb coal combustion were 0.26,0.17,and 0.28μm in different combustion stages(the early stage,the mid stage,and the later stage),and the average particle sizes of coal ball combustion were 0.11,0.47,and 0.06μm,respectively.Compared with honeycomb coal and coal ball,the average particle size of raw coal in smaller fire combustion was higher,and the average particle sizes of the three combustion stages were 0.38,0.45,and 0.36μm.The results showed that the aspect ratio of particles emitted from raw coal combustion was higher,and the circularity factor was lower than those of the particles emitted from honeycomb coal and coal ball.The aspect ratio of 90% of the particles emitted from raw coal combustion was mainly between 1.0 and 2.0,and 95% of the particles emitted from honeycomb coal and coal ball mainly had an aspect

关 键 词：民用煤 颗粒物 金属 单颗粒 

分 类 号：X513[环境科学与工程—环境工程]