填埋初期水溶性有机物结构受电子转移的影响

发布时间：2018-02-04 05:37

本文关键词： DOM 三维荧光光谱平行因子分析电子转移　出处：《中国环境科学》2017年01期 　论文类型：期刊论文

【摘要】：采集填埋初期的生活垃圾并提取DOM,以希瓦氏菌MR-1和柠檬酸铁(FeCit)分别作为电子供体和电子受体,利用三维荧光光谱(EEM)结合平行因子分析(PARAFAC)对电子转移前后DOM结构变化进行解析,以期揭示DOM电子转移对其结构的影响.PARAFAC模型揭示DOM由4个荧光组分组成,组分1(类色氨酸)和组分3(类酪氨酸)为类蛋白物质且其是DOM荧光的主要贡献成分,组分2(类富里酸)和组分4(类胡敏酸)为类腐殖质物质.类蛋白物质的荧光增强效应源于结构上含氮的杂环结构被破坏,疏水性增强.类腐殖质物质得到电子后其结构上的部分羰基变为醇基,荧光强度增加,且其荧光增加幅度在填埋过程中呈降低的趋势.类蛋白物质具有供电子能力,但其失去电子后结构改变荧光完全被猝灭.类腐殖质物质同样是DOM具有供电子能力的功能性组分且其荧光猝灭幅度受控于其结构上羧基和酚基等供电子基团的含量.类蛋白物质失去电子后不能重新被微生物还原返回原态,类腐殖质物质部分基团具有循环氧化还原能力,DOM的电子穿梭能力源于类腐殖质物质且随填埋的进行不断增强.
[Abstract]:Collecting and extracting Dom from MSW at the early stage of landfill, using MR-1 and Fecitrate as electron donor and electron acceptor, respectively. The structural changes of DOM before and after electron transfer were analyzed by means of three-dimensional fluorescence spectroscopy (EEM) and parallel factor analysis (PARAFAC). In order to reveal the effect of electron transfer of DOM on its structure. The PARAFAC model revealed that DOM was composed of four fluorescent components. Components 1 (tryptophan) and 3 (tyrosine) are protein-like substances and they are the main contributing components of DOM fluorescence. Components 2 (fulvic acid) and 4 (Hu Min acid) are humus-like substances. The fluorescence enhancement of protein-like substances is due to the destruction of heterocyclic structures containing nitrogen. The hydrophobicity of the humus-like substance was enhanced. Some carbonyl groups in the structure of the humus-like substance were changed into alcohols, and the fluorescence intensity increased. And its fluorescence increased in the landfill process showed a decreasing trend. Protein-like substances have the ability to supply electronic. However, the fluorescence was completely quenched after the loss of electron. The humus-like substance is also a functional component of DOM with the ability to supply electrons, and its fluorescence quenching amplitude is controlled by the carboxyl and phenolic groups in its structure. The protein-like substance can not be reduced back to its original state by microorganism after the loss of electrons. Some groups of humus-like substances have the ability to cycle redox and the electron shuttle ability of Dom originates from humus-like substances and increases with the landfill.
【作者单位】：中国环境科学研究院环境基准与风险评估国家重点实验室;中国环境科学研究院国家环境保护地下水污染模拟与控制重点实验室;兰州交通大学环境与市政工程学院;
【基金】：国家自然科学基金青年基金(51408573,51325804)
【分类号】：X799.3
【正文快照】： 水溶性有机物(Dissolved Organic Matter,DOM)是多相的、不均匀的有机混合物,具有不同的结构和分子量,既包括小分子的有机酸和氨基酸等,又包括大分子的腐殖质和蛋白质物质等[1-5].DOM在自然环境中不仅能够作为微生物的营养源促进有机物的降解和营养物在生态系统的循环[2,6-7],

【参考文献】