非生物改性对厌氧微生物产物光化学活性影响  

Effect of abiotic modification on photochemical activity of anaerobic microbial products

作　　者：范思涵 于国熙 来超超 何欢[1] 黄斌[1] 潘学军[1] FAN Sihan;YU Guoxi;LAI Chaochao;HE Huan;HUANG Bin;PAN Xuejun(Faculty of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming 650500,Yunnan,China)

机构地区：[1]昆明理工大学环境科学与工程学院,云南昆明650500

出　　处：《化工进展》2023年第4期2180-2189,共10页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(21866017,42067056);云南省基础研究计划(202101BE070001-013)。

摘　　要：厌氧溶解性微生物产物(soluble microbial products,SMP)广泛存在于天然深层水体,经水体扰动可迁移至表层水域。在此过程中厌氧SMP将受到一系列非生物转化过程的影响,如自然光及氧化还原介质,进而导致其理化性质发生改变,最终影响其光化学活性。本研究分别从厌氧微生物菌群(anaerobic microorganisms,An)和希瓦氏菌(Shewanella oneidensis,S)中提取了An-SMP和S-SMP,在模拟自然光和氧化还原的条件下改性48h,并评估非生物改性对厌氧SMP光化学活性的影响。结果表明:原始An-SMP的芳香度、腐殖化程度和分子量均高于S-SMP。自然光改性后,两种SMP的紫外吸光度和芳香度降低,芳香C==C结构被破坏,腐殖化程度降低,生成了更多的亲水性含氧官能团。氧化还原改性后,两种SMP吸光度出现增色效应,腐殖化程度升高,更多的蛋白类物质向腐殖质类物质转化,使氧化还原改性对SMP光化学性质的影响更为显著。SMP对17α-乙炔基雌二醇(EE2)光转化起促进作用,且经氧化还原改性后的SMP对EE2光解的介导作用明显优于经光改性的SMP。其中对EE2光解过程起主要作用的活性氧物质包括激发三线态SMP(^(3)SMP^(*))和羟基自由基(·OH)。本研究为明确自然水体中SMP介导有机污染物光转化的影响提供了理论研究基础。Anaerobic soluble microbial products(SMP)are widespread in the deep-water environment and could migrate to the upper water by water disturbance processes.The physicochemical properties of anaerobic SMP would be altered during migration by various abiotic transformation processes,such as photo irradiation and redox processes,which would further change its photochemical activity.Herein,anaerobic SMP extracted from anaerobic microorganisms(An-SMP)and that from Shewanella oneidensis(S-SMP)were modified by photo irradiation and redox processes for 48h to evaluate the effects of these abiotic modifications on the photochemical activity of anaerobic SMP.The results of the characterization showed that the aromaticity,humification degree,and molecular weight of the original An-SMP were higher than those of S-SMP.The UV absorbance,aromaticity,degree of humification,and aromatic C==C structure of both of SMP decreased after the photo-modification,while hydrophilic oxygen-containing functional groups increased.After the redox-modification process,the hyperchromic effect of both of SMP absorbance was observed,as well as the increase of humification degree and the conversion of proteinlike substances to humic substances.Compared to photo-modification,redox-modification showed more significant effects on the photochemical properties of SMP.Furthermore,the photo-transformation of 17α-ethinylestradiol(EE2)was promoted by the SMP,and the redox-modified SMP exhibited superior photochemical properties than that of photo-modified SMP.The mechanism study indicated that the active oxygen substances were responsible for the photolysis of EE2,especially the^(3)SMP^(*)and·OH.This study provided a theoretical basis to clarify the effect of abiotic transformation processes on the phototransformation of organic pollutants mediated by SMP in natural water.

关 键 词：厌氧溶解性微生物产物 光改性 氧化还原改性 光化学 活性氧物质 

分 类 号：X131.2[环境科学与工程—环境科学]