垃圾填埋初期水溶性有机物电子转移能力特征研究

Characteristic Study of Dissolved Organic Matter for Electron Transfer Capacity During Initial Landfill Stage

为了阐明填埋垃圾初期水溶性有机物(DOM)电子转移能力的演变规律及影响因素,采集不同深度填埋垃圾并提取DOM,以希瓦氏菌MR-1和柠檬酸铁(Fe Cit)分别作为电子供体和电子受体,测定DOM的电子供给能力(EDC)、电子接受能力(EAC)和电子穿梭能力(ESC),采用光谱分析技术对电子转移能力的3种影响因素进行解析。结果表明,DOM中类腐殖质物质和类蛋白物质既能够作为电子供体传递出自身携带的电子,又可以作为电子受体接受微生物供给的电子。随着垃圾填埋的进行,DOM的电子供给能力和电子接受能力均先升高后降低,而电子穿梭能力持续增强。类蛋白物质是填埋初期DOM的主要成分,其含量决定DOM的电子供给能力和电子接受能力的演变。随着填埋时间的延长,类蛋白物质的降解是DOM的电子接受能力和电子供给能力降低的主要原因。DOM反复氧化还原过程中光谱特征和参数变化规律显示DOM的电子穿梭能力主要源于DOM中类腐殖质物质。在填埋垃圾降解和腐殖化过程中,DOM中类腐殖质物质不断合成,致使其电子穿梭能力不断增强。

To investigate the evolution law and influenced factors of dissolved organic matter for electron transfer capacity during initial landfill stage,dissolved organic matter（ DOM） was extracted from landfill wastes at different depth. Shewanella oneidensis MR-1 and citrate iron（ Fe Cit） were respectively used as electron donor and electron acceptor to measure electron donating capacity,electron accepting capacity and electron shuttling capacity. Afterwards,the influenced factors of electron transfer capacity were studied by analyzing spectral information. The results showed that protein-like components and humic-like components were able to transfer electrons,and they also accepted electrons from microorganisms. Electron donating capacity and electron accepting capacity increased firstly and then decreased. However,the electron shuttling capacity increased persistently during the landfill process. Protein-like components were the main components of dissolved organic matter during the initial landfill stage,and it was mainly responsible for the electron donoring capacity and electron accepting capacity of DOM. Electron shuttling capacity resulted from humic-like components during the cyclic redox process. Electron shuttling capacity persistently increased during the landfill process based on humic-like components generated during the stage.