State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China.
State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China.
J Environ Sci (China). 2020 Nov;97:96-101. doi: 10.1016/j.jes.2020.05.010. Epub 2020 Jun 7.
Emission from burning coals is one of the major sources of the airborne particles in China. We carried out a study on the rare earth elements (REEs) in the inhalable particulate matter (PM) emitted from burning coals and soil-coal honeycomb briquettes with different volatile contents and ash yields in a combustion-dilution system. Gravimetric analysis indicates that the equivalent mass concentration of the PM emitted from burning the coals is higher than that emitted from burning the briquettes. The ICP-MS analysis indicates that the contents of total REEs in the coal-burning PM are lower than those in the briquette-burning PM. In addition, the contents of the light rare earth elements (LREEs) are higher than those of the heavy rare earth elements (HREEs) in the PM emitted from burning the coals and briquettes, demonstrating that the REEs in both the coal-burning and briquette-burning PM are dominated by LREEs. The higher contents of total REEs and LREEs in the coal-burning PM are associated with the higher ash yields and lower volatile contents in the raw coals. A comparative analysis indicates that the La/Sm ratios in the PM emitted from burning the coals and briquettes, being lower than 2, are lower than those in the particles from gasoline-powered vehicle emission.
燃煤排放是中国空气中颗粒物的主要来源之一。我们在燃烧稀释系统中，对不同挥发分和灰分产率的燃煤和土壤-蜂窝煤型煤燃烧排放的可吸入颗粒物（PM）中的稀土元素（REEs）进行了研究。重量分析表明，燃烧煤产生的 PM 的等效质量浓度高于燃烧型煤产生的 PM。ICP-MS 分析表明，燃煤 PM 中总 REE 含量低于型煤燃烧 PM。此外，燃煤和型煤燃烧 PM 中轻稀土元素（LREEs）的含量高于重稀土元素（HREEs），表明燃煤和型煤燃烧 PM 中的 REEs 均以 LREEs 为主。燃煤 PM 中总 REEs 和 LREEs 含量较高，与原煤灰分产率较高、挥发分含量较低有关。对比分析表明，燃煤和型煤燃烧 PM 中 La/Sm 比值低于 2，低于汽油车排放颗粒中的比值。
