腐殖质及其模型化合物的H2O2光化学生成研究  

Hydrogen peroxide photoproduction by humic substances and their model compounds

作　　者：李建华 张亚 吴欣安 王梦杰 施沁人 彭建彪 高士祥[3] LI Jian-hua;ZHANG Ya;WU Xin-an;WANG Meng-jie;SHI Qin-ren;PENG Jian-biao;GAO Shi-xiang(Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse,School of Environmental and Biological Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;Nanjing Institute of Environmental Sciences,Ministry of Ecology and Environmental of the People’s Republic of China,Nanjing 210042,China;State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Nanjing University,Nanjing 210023,China;School of Environment,Henan Normal University,Key Laboratory for Yellow River and Huai River Water Environmental and Pollution Control,Ministry of Education,Henan Key Laboratory for Environmental Pollution Control,Xinxiang 453007,China)

机构地区：[1]南京理工大学环境与生物工程学院,江苏省化工污染控制与资源化重点实验室,江苏南京210094 [2]生态环境部南京环境科学研究所,江苏南京210042 [3]南京大学环境学院,污染控制与资源化研究国家重点实验室,江苏南京210023 [4]河南师范大学环境学院,黄淮水环境污染与防治教育部重点实验室,河南省环境污染控制重点实验室,河南新乡453007

出　　处：《中国环境科学》2020年第12期5337-5342,共6页China Environmental Science

基　　金：国家自然科学基金资助项目(21577059)。

摘　　要：在模拟太阳光下研究了多种腐殖质及其模型化合物的过氧化氢(H2O2)生成动力学,并对其生成机制进行了探讨.结果表明不同来源或不同形式的腐殖质在模拟太阳光照射下均能产生H2O2.不同腐殖质生成H2O2速率差异不大,范围为6.379~15.784nmol/(L⋅min),腐殖酸生成H2O2速率略快于富里酸.对于腐殖质模型化合物,邻苯二酚、间苯二酚、对苯二酚、苯醌、邻茴香胺、对茴香胺、水杨酸和2,6-二甲氧基-1,4-苯醌等8种模型化合物没有产生明显的H2O2,而藜芦醇、对氨基苯甲酸、3,5-二羟基苯甲酸(DHBA)、2,5-二羟基-1,4-苯醌、苯酚、苯甲酸和苯胺等7种化合物均可检测到H2O2产生.但其产生H2O2的速率差异较大,相差1~2个数量级,生成H2O2速率最快的化合物为2,5-二羟基-1,4-苯醌和DHBA,较慢的为苯酚、苯甲酸和对氨基苯甲酸.基于腐殖质生成H2O2机制,推测典型模型化合物DHBA的H2O2生成机制可能为光照条件下该化合物跃迁为单重激发态,该激发态发生分子内电子转移,生成还原性自由基中间体,该中间体和O2反应,生成了超氧负离子(O2·^-),随后与水中H+反应生成了H2O2.The present study systematically investigated H2O2 generation kinetics and potential mechanism from irradiated humic substances(HS)and their model compounds under simulated sunlight.Our results indicated that all the selected HS with different sources or forms can produce H2O2 under irradiation,and no significant difference was observed between them,with the generation rate ranging from 6.379 to 15.784nmol/(L⋅min).The H2O2 generation rate from humic acid(HA)was slightly faster than that from fulvic acid(FA).In the case of humus model compounds,7compounds including veratryl alcohol,p-aminobenzoic acid,3,5-dihydroxybenzoic acid(DHBA),2,5-dihydroxy-1,4-benzoquinone,phenol,benzoic acid and aniline could produce detectable H2O2,while other compounds including catechol,resorcinol,hydroquinone,quinone,o-anisidine,p-anisidine,salicylic acid and 2,6-dimethoxy-1,4-benzoquinone can’t.Nevertheless,the H2O2 generation rate from the model compounds varies from each other,with one or two orders of magnitude.Among them,2,5-dihydroxyl-1,4-benquione and DHBA exhibited the highest H2O2 yields,while phenol,benzoic and p-aminobenzoic acid showed a relative low H2O2 generation potential.Based on the generation mechanism of H2O2 from HS,a possible H2O2 formation mechanism from a typical model compound,i.e.DHBA,was proposed.DHBA was believed to excite to a singlet state,after an intramolecular electron transfer process,giving a reducing intermediate.The intermediate could further react with O2 to form O2·^-and subsequently generate H2O2.

关 键 词：过氧化氢 腐殖质 腐殖质模型化合物 光化学生成 水体 

分 类 号：X52[环境科学与工程—环境工程] X131.2