Xu Dandan, Zhang Xiaona, Hong Xiuping, Qian YaHui, Liang Handong
State Key Laboratory of Coal Resources and Safe Mining, Beijing, 100083, China.
College of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing, 100083, China.
Environ Sci Pollut Res Int. 2023 Apr;30(20):58674-58683. doi: 10.1007/s11356-023-25990-x. Epub 2023 Mar 30.
Coal gangue is a by-product of coal, the output of which is as high as 30% of raw coal, whereas only 30% of it is recycled. The leftover remains in the environment from gangue backfilling areas and overlap with residential, agricultural, and industrial areas. Coal gangue accumulated in the environment is easily weathered and oxidized and becomes a source of various pollutants. In this paper, 30 coal gangue samples (fresh and weathered coal gangues) were collected from three mine areas in Huaibei, Anhui province, China. Gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) was used to qualitatively and quantitatively analyze thirty polycyclic aromatic compounds (PACs), including 16 polycyclic aromatic hydrocarbons (16PAHs), preferentially controlled by the United States Environmental Protection Agency (US EPA), and the corresponding alkylated polycyclic aromatic hydrocarbons (a-PAHs). The results showed that PACs existed objectively in coal gangue, and the content of a-PAHs was higher than that of 16PAHs (average values for 16PAHs ranged from 77.8 to 581 ng/g; average values for a-PAHs ranged from 97.4 to 3179 ng/g). Moreover, coal types not only affected the content and type of PACs but also affected the distribution pattern of a-PAHs at different substitution sites. With the increase of gangue weathering degree, the composition of a-PAHs kept changing; the low ring a-PAHs were more easily diffused to the environment, and the high ring a-PAHs remained enriched in the weathered coal gangue. The correlation analysis showed that the correlation between fluoranthene (FLU) and alkylated fluoranthene (a-FLU) was as high as 94%, and the calculated ratios were not more than 1.5. The basic conclusion is that not only 16PAHs and a-PAHs objectively existed in the coal gangue, but also the characteristic compound belonging to the pollution source of coal gangue oxidation have been discovered. The results of the study provide a new perspective for the analysis of existing pollution sources.
煤矸石是煤炭开采的副产品，其产量高达原煤的30%，而仅有30%得到回收利用。剩余的煤矸石堆积在矸石回填区，与居民区、农业区和工业区重叠。堆积在环境中的煤矸石易风化和氧化，成为各种污染物的来源。本文从中国安徽省淮北市的三个矿区采集了30个煤矸石样品（新鲜煤矸石和风化煤矸石）。采用气相色谱-三重四极杆质谱联用仪（GC-MS/MS）对30种多环芳烃化合物（PACs）进行定性和定量分析，其中包括美国环境保护局（US EPA）优先控制的16种多环芳烃（16PAHs）及其相应的烷基化多环芳烃（a-PAHs）。结果表明，PACs在煤矸石中客观存在，且a-PAHs的含量高于16PAHs（16PAHs的平均值范围为77.8至581 ng/g；a-PAHs的平均值范围为97.4至3179 ng/g）。此外，煤种不仅影响PACs的含量和种类，还影响a-PAHs在不同取代位点的分布模式。随着煤矸石风化程度的增加，a-PAHs的组成不断变化；低环a-PAHs更容易扩散到环境中，高环a-PAHs则在风化煤矸石中保持富集。相关性分析表明，荧蒽（FLU）与烷基化荧蒽（a-FLU）的相关性高达94%，计算比值不超过1.5。基本结论是，煤矸石中不仅客观存在16PAHs和a-PAHs，还发现了属于煤矸石氧化污染源的特征化合物。该研究结果为分析现有污染源提供了新的视角
