煤矿区地下水中天然有机质的量化表征及迁移转化机理

Traditional water chemistry methods were difficult to determinate water-bursting source, while new research showed that components and characteristics of natural organic matter (NOM) were obviously different among each aquifer. Quantitative characterization and the rule of migration and transformation of natural organic matter in groundwater of coal mine area were researched, and the research contents were as follows: (1) Three-dimensional excitation emission matrix fluorescence spectroscopy was used to discriminate fluorescence fingerprint characteristics of NOM in each aquifer. The right separation condition was chosen, and HPLC/MS was used to quantitative measure NOM. (2) Surface plants were taken and decomposed in recharge area, and NOMs of different decomposition stages were gotten. The elements, components and structures of NOM were measured to make clear the rules of molecular constitution, aromatic degree and function group of NOM in different conditions. (3) Based on aquifer lithology and hydrogeological condition in typical coal mine area, the influence on the migration and transformation by the electron trapping capacity in aquifer was researched through the experimental simulation. All above researches could help to make clear the distribution characteristics and change regulation of NOM in groundwater of coal mine area, and that gave a basis for water-bursting source determination.

煤矿突水过程中传统水化学方法往往难以确定突水水源，而对地下水中天然有机质（Natural Organic Matter, NOM）的初步研究发现，不同含水层中NOM组成和特征存在较大差异。本研究以此为基础，对煤矿区地下水中NOM进行量化表征和迁移转化机理研究，主要研究内容包括：（1）利用三维荧光光谱分析技术，鉴别不同含水层中NOM的指纹差异，选择合适的分离条件，利用HPLC/MS进行NOM的量化表征分析；（2）采集补给区地表植被并腐解处理，获得不同腐解阶段的NOM溶液，测试和表征NOM的元素构成、组分构成及结构特征等，弄清不同条件下NOM分子构成、芳香度和官能团组成等方面的变化规律；（3）根据典型煤矿区含水层岩性和水文地质特征，通过实验模拟考察含水层中电子捕获能力变化对NOM迁移转化的影响。研究结果将有助于确定煤矿区地下水中天然有机质分布特征和变化规律，为突水水源识别提供依据。

为了解决传统水化学方法在煤矿突水水源判别中存在的不足，本项目利用三维荧光指纹技术对地下水中天然有机质的具体类型进行鉴别和量化表征；通过研究地表环境中的天然有机质进入地下含水层（特别是煤层开采围岩破坏能够波及的含水层）后，随地下水迁移过程中的演化机理，并结合矿区不同含水层水样采集分析，掌握各含水层水文地球化学特征，结果表明：.地下水中天然有机质的鉴别和量化表征：利用三维荧光光谱指纹技术，结合NOM浓度指标（TOC、UV254、COD），鉴别了我国典型矿区不同含水层中DOM的指纹差异，考察了地下水中酪氨酸、色氨酸、疏水性有机酸、海洋性腐殖酸等在三维荧光谱图中的指纹响应。.地质水文地质、水文地球化学特征：以华北石炭二叠纪煤田岩溶-裂隙水和西北侏罗纪煤田裂隙水为重点研究对象，分析研究区地层岩性、矿物组分和沉积规律，考察所研究区域的地下水流场和补径排条件，并对其地下水中NOM、NO3-、Mn、Fe、SO42-等水质指标进行检测，弄清了研究区地质水文地质和水文地球化学特征。.地下水中NOM迁移转化机理：根据典型含水层岩性和水文地质特征，构建室内的地下水运移模拟系统，通过实验考察含水层中NOM浓度和三维荧光光谱指纹特征变化随入渗浓度、流速、温度的变化规律，确定NOM的指纹敏感区域，弄清典型含水层中NOM 的迁移转化机理。结合典型矿区水文地质条件，开展现场有机水文地球化学特征研究，掌握了研究区综合水文地球化学特征。