不同腐殖酸氧化还原产羟基自由基潜力及其对微塑料降解的影响  

Hydroxyl radical production potential of various humic acids through oxidative reduction and their impacts on microplastic degradation

作　　者：刘钰洁 陈祖森 崔骏凯 陈泽伟 吴杰峰 曾秋婷 陈志[1] LIU Yujie;CHEN Zusen;CUI Junkai;CHEN Zewei;WU Jiefeng;ZENG Qiuting;CHEN Zhi(College of Resources and Environment,Fujian Agriculture and Forestry University,Fuzhou,Fujian 350002,China)

机构地区：[1]福建农林大学资源与环境学院,福建福州350002

出　　处：《福建农林大学学报(自然科学版)》2025年第3期365-374,共10页Journal of Fujian Agriculture and Forestry University:Natural Science Edition

基　　金：福建农林大学科技创新专项(CXZX2020068A)。

摘　　要：【目的】研究不同来源的腐殖酸(humic acid,HA)在氧化还原过程中产生羟基自由基(·OH)的能力,并评估其对聚苯乙烯微塑料(polystyrene microplastics,PS-MPs)氧化降解的效果,以深入理解微生物介导的HA氧化还原循环中·OH的持续生成机制及其对污染物转化的作用。【方法】以兼性厌氧菌Bacillus thermotoleran SgZ-8(具有HA还原能力)作为模式菌株,利用牛粪堆肥HA(dung compost humic acid,dc-HA)、鸡粪堆肥HA(chicken manure compost humic acid,cc-HA)、污泥堆肥HA(sludge compost humic acid,sc-HA)建立氧化还原循环体系。采用傅里叶变换红外光谱、三维荧光光谱、X射线光电能谱等技术分析HA的结构、官能团及其产·OH能力,并测定不同HA对PS-MPs的降解效果。【结果】dc-HA、cc-HA、sc-HA在化学结构、官能团和产·OH能力方面存在显著差异。其中,dc-HA的醌基和酚基等含氧官能团更多,电子转移能力更强,产·OH能力最强。皮尔逊相关性分析表明,总酚含量、电子供给能力以及H_(2)O_(2)含量与·OH生成呈显著正相关。PS-MPs的表征结果表明,dc-HA、cc-HA、sc-HA的氧碳比(O/C)均有提升。其中,dc-HA的羰基指数由0.001升高至0.077,表明其含氧基团数量增多,产生更多的·OH,进而导致更高的PS-MPs降解率。【结论】不同来源的HA之间的差异主要取决于含氧基团的不同,含氧基团的数量与产自由基能力和污染物降解能力呈正相关。【Objective】This study focused on the ability of humic acid(HA)from different sources to generate hydroxyl radicals(·OH)during redox process and their effectiveness in the oxidative degradation of polystyrene microplastics(PS-MPs),to provide a theoretical basis for a deeper understanding of the continuous production of·OH in microbial-mediated HA redox processes and its role in pollutant transformation.【Method】Bacillus thermotoleran SgZ-8 was selected as a model strain to establish HA redox cycle system using cow dung compost humic acid(dc-HA),chicken manure compost humic acid(cc-HA),and sludge compost humic acid(sc-HA).Fourier transform infrared spectroscopy(FTIR),3-dimensional fluorescence spectroscopy,X-ray photoelectron spectroscopy(XPS),and other techniques were employed to analyze the structure,functional groups,·OH generation capacity of HA,and the impact of different HA on the degradation of PS-MPs.【Result】dc-HA,cc-HA and sc-HA differed in structure,functional groups and·OH production capacity,among which dc-HA contained more oxygen-containing functional groups,such as quinone and phenol groups,thus exhibiting stronger electron transfer ability and the highest·OH production capacity.Referring to Pearson's correlation coefficient analysis,the·OH production capacity of HA was positively correlated with its total phenolic content,electron donating capacity and H_(2)O_(2)content.Characterization analysis of PS-MPs revealed an overall increase in the O/C ratio of all the 3 types of HA.Specifically,dc-HA had greater number of oxygen-containing groups with an increase of carbonyl index from 0.001 to 0.077.In addition,given higher·OH yields from the redox process,dc-HA had a better ability to degradate PS-MPs.【Conclusion】The differences between HA from different sources are primarily attributed to variations in their oxygen-containing functional groups,with the number of oxygen-containing groups being roughly positively correlated with their radical generation capacity and pollutant degradat

关 键 词：腐殖酸 分子结构 氧化还原循环 羟基自由基 聚苯乙烯微塑料 

分 类 号：X705[环境科学与工程—环境工程]