猪粪堆肥过程中腐殖酸电子转移机制及光谱演化特征  

ELECTRON TRANSFER MECHANISM AND SPECTRAL EVOLUTION CHARACTERISTICS OF HUMIC ACID DURING PIG MANURE COMPOSTING

作　　者：李柯蒙 李洁月 游少鸿[1] 孙晓杰[1] 李宁杰[1] 黄宏伟 肖河 LI Kemeng;LI Jieyue;YOU Shaohong;SUN Xiaojie;LI Ningjie;HUANG Hongwei;XIAO He(College of Environment Science and Engineering,Guilin University of Technology,Guilin 541004,China;Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology,Guilin 541004,China)

机构地区：[1]桂林理工大学环境科学与工程学院,广西桂林541004 [2]广西环境污染控制理论与技术重点实验室,广西桂林541004

出　　处：《环境工程》2022年第12期79-88,共10页Environmental Engineering

基　　金：广西青年科学基金项目(2020GXNSFBA159040);广西创新研究团队项目(2018GXNSFGA281001)。

摘　　要：胡敏酸(humic acid, HA)、富里酸(fulvic acid, FA)是堆肥过程中产生的有机组分,因其含有醌基、酚基等活性官能团而具有氧化还原能力,可以作为电子穿梭体介导污染物的生物还原。通过电化学方法测定了猪粪堆肥不同时期HA和FA的电子转移能力(ETC),并联合紫外-可见光谱(UV-Vis)、傅里叶红外光谱(FTIR)和三维荧光光谱(3D-EEM),探究了猪粪堆肥过程中HA和FA的化学结构变化以及对ETC的影响。结果表明:HA的ETC由堆肥初期10.06μmol e^(-)/g C增长至末期40.07μmol e^(-)/g C,FA的ETC由堆肥初期的15.36μmol e^(-)/g C增长至末期的69.73μmol e^(-)/g C,二者均随时间变化呈波动上升趋势,且EDC在电子转移中占主要地位。光谱分析表明,堆肥中的木质素类物质经堆肥化后会转变为聚合度高的腐殖质类物质,相比于堆肥初期,腐熟期时有机质的腐殖化程度和芳香化程度增大,相对分子质量也增高。类蛋白物质(组分C4)在堆肥过程中逐渐减少,易被微生物作为碳源利用从而转化为类腐殖质物质(组分C2),且C2是堆肥中较为稳定的组分。相关性分析表明:类蛋白质物质减少、腐殖化程度增加会使HA和FA的ETC增强,FA的电子转移能力更容易受到腐殖化程度的影响。Humic acid(HA) and Fulvic acid(FA) are organic components produced during the composting process, which have redox ability to act as electron shuttles to mediate the bioreduction of pollutants, due to the presence of active functional groups such as quinone and phenol groups. In this study, the electron transfer capacity(ETC) of HA and FA in different periods of pig manure composting was determined by electrochemical method, and the chemical structure changes of HA and FA and their effects on ETC were investigated by combining UV-Vis, FTIR and 3D-EEM. The results showed that from beginning to the end, the ETC of HA increased from 10.06 μmol e^(-)/g C to 40.07 μmol e^(-)/g C, and the ETC of FA increased from 15.36 μmol e^(-)/g C to 69.73 μmol e^(-)/g C, both of which showed a fluctuating increasing trend with time, and EDC was dominant in the electron transfer process. Spectral analysis showed that lignin-like substances in the compost would be transformed into humus with a high degree of polymerization after composting. Compared with the initial stage of composting, the degree of humification and aromatization of organic matter at the maturity stage increased, and the molecular weight also raised. Protein-like substances(component C4) gradually decreased in the composting process, which was easy to be used as carbon sources by microorganisms to convert into humic-like substances(component C2), and component C2 was relatively stable in composting. Correlation analysis showed that a decrease in protein-like substances and an increase in humification enhanced the ETC of HA and FA, and the electron transfer capacity of FA was more susceptible to the degree of humification.

关 键 词：猪粪堆肥 腐殖酸 电子转移机制 光谱演化特征 

分 类 号：X713[环境科学与工程—环境工程] S141.4[农业科学—肥料学]