Ji Xuanyu, Tiraferri Alberto, Zhang Xiaofei, Liu Peng, Gan Zhiwei, Crittenden John C, Ma Jun, Liu Baicang
State Key Laboratory of Hydraulics and Mountain River Engineering, College of Architecture and Environment, Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu, Sichuan 610207, PR China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Section 2, Lingang Ave., Cuiping District, Yibin, Sichuan 644000, PR China.
Department of Environment, Land and Infrastructure Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy.
J Hazard Mater. 2023 Apr 5;447:130823. doi: 10.1016/j.jhazmat.2023.130823. Epub 2023 Jan 18.
Knowledge on the composition and characteristics of dissolved organic matter (DOM) in complex shale gas wastewater (SGW) is critical to evaluate environmental risks and to determine effective management strategies. Herein, five SGW samples from four key shale gas blocks in the Sichuan Basin, China, were comprehensively characterized. Specifically, FT-ICR MS was employed to provide insights into the sources, composition, and characteristics of SGW DOM. Organic matter was characterized by low average molecular weight, high saturation degree, and low aromaticity. Notably, the absence of correlations between molecular-level parameters and spectral indexes might be attributed to the high complexity and variability of SGW. The unique distribution depicted in van Krevelen diagrams suggested various sources of DOM in SGW, such as microbially derived organics in shales and biochemical transformations. Moreover, linear alkyl benzene sulfonates, as well as associated biodegraded metabolites and coproducts, were identified in SGW, implying the distinct anthropogenic imprints and abundant microbial activities. Furthermore, high DOC removal rates (31.42-79.23 %) were achieved by biological treatment, fully supporting the inherently labile nature of SGW and the feasibility of biodegradation for SGW management. Therefore, we conclude that DOM in SGW is a complex but mostly labile mixture reflecting both autochthonous and anthropogenic sources.
了解复杂页岩气废水（SGW）中溶解有机物（DOM）的组成和特性对于评估环境风险和确定有效的管理策略至关重要。在此，对来自中国四川盆地四个关键页岩气区块的五个SGW样本进行了全面表征。具体而言，采用傅里叶变换离子回旋共振质谱（FT-ICR MS）来深入了解SGW DOM的来源、组成和特性。有机物的特点是平均分子量低、饱和度高且芳香性低。值得注意的是，分子水平参数与光谱指数之间缺乏相关性可能归因于SGW的高度复杂性和变异性。范克雷维伦图中描绘的独特分布表明SGW中DOM有多种来源，如页岩中微生物衍生的有机物和生物化学转化。此外，在SGW中鉴定出线性烷基苯磺酸盐以及相关的生物降解代谢物和副产物，这意味着明显的人为印记和丰富的微生物活动。此外，通过生物处理实现了较高的溶解有机碳去除率（31.42 - 79.23%），充分支持了SGW固有的易降解性质以及生物降解用于SGW管理的可行性。因此，我们得出结论，SGW中的DOM是一种复杂但大多易降解的混合物，反映了自生和人为来源。
