淮北童亭矿区煤矸石中烷基多环芳烃污染特征

Pollution characteristics of alkyl polycyclic aromatic hydrocarbons in coal gangue in Tongting mining area,Huaibei

煤矸石作为煤的副产品是目前我国排放量最大的工矿业固体废弃物之一。以往针对矿区有机污染物的研究多集中于土壤、水和气溶胶,且对煤矸石污染的研究多集中在重金属,缺乏对煤矸石中烷基多环芳烃(aPAHs)的研究。以童亭矿区14个煤矸石样品为研究对象,采用气相色谱串联三重四级杆质谱(GC-MS)测定了样品中aPAHs和被美国环保署(EPA)确定为优先控制的16PAHs的浓度。研究表明,煤矸石样品中aPAHs含量为910~39335μg/kg,平均13529μg/kg,是16PAHs的5.45倍;2环和3环aPAHs占比最多,分别为45%和44%,其中烷基萘和烷基菲含量最高,二者总量占aPAHs总量的87%;同时,C0-C4 PAHs、C0-C4 NAP与C0-C4 PHE均呈“钟型”分布,属于典型的成岩源特征。风化煤矸石中aPAHs含量均值(17058μg/kg)高于新鲜煤矸石(9999μg/kg),这可能是由于风化煤矸石自解聚作用及其破碎化,提高了PAHs的萃取效果。在中国东部类似研究区生产中的煤田众多,是否普遍存在煤矸石衍生的多环芳烃污染问题,值得今后关注和调查研究。

Coal gangue,as a by-product of coal,is currently one of the largest industrial and mining solid wastes in China.The previous research on organic pollutants in mining areas mostly concentrated on soil,water and aerosols,and the research on coal gangue pollution mostly focused on heavy metals,lacking the research on alkyl polycyclic aromatic hydrocarbons(aPAHs)in coal gangue.This paper takes 14 coal gangue samples from Tongting mining area as the research object,the concentrations of aPAHs and 16PAHs determined by the U.S.Environmental Protection Agency(EPA)as the priority control in the samples were determined by gas chromatography tandem triple quadrupole mass spectrometry(GC-MS).The main conclusions are as follows:the average content of aPAHs in coal gangue samples is 13529μg/kg(910~39335μg/kg),which is 5.45 times that of 16PAHs;2-ring and 3-ring aPAHs account for the largest proportion,45%and 44%,respectively.The content of alkyl naphthalene and alkyl phenanthrene is the highest,and the total amount of the two accounts for 87%of the total aPAHs;at the same time,C0-C4 PAHs,C0-C4 NAP and C0-C4 PHE are distributed in a"bell shape",belonging to typical diagenetic source characteristics.Average content of aPAHs in weathered coal gangue(17058μg/kg)is higher than that of fresh coal gangue(9999μg/kg),which may be due to the self depolymerization and fragmentation of weathered coal gangue,which improves the extraction effect of PAHs.In eastern China,there are many coal fields in production similar to this study area.Whether there is a widespread problem of polycyclic aromatic hydrocarbons derived from coal gangue is worthy of attention and investigation in the future.