邻苯二甲酸二丁酯降解过程的单体同位素分析  

Compound specific isotope analysis of dibutyl phthalate during degradation processes

作　　者：张丹 曹素珍 段小丽 姚俊 ZHANG Dan;CAO Su-zhen;DUAN Xiao-li;YAO Jun(School of Energy and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China;School of Water Resources and Environment,China University of Geosciences,Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学能源与环境工程学院,北京100083 [2]中国地质大学(北京)水资源与环境学院,北京100083

出　　处：《中国环境科学》2018年第7期2714-2721,共8页China Environmental Science

基　　金：国家自然科学基金资助项目(41430106;41573080);国家自然科学基金国际(地区)合作与交流资助项目(41720104007;41711530150;41711530224);环保部公益专项(201509049);科技部国际合作项目(S2016G2135)

摘　　要：研究对比了邻苯二甲酸二丁酯(DBP)在不同降解过程(水解、UV/H_2O_2光解、直接光解、过硫酸钾光氧化)中的碳、氢同位素组成变化、分馏特征及二维同位素(Δδ~2H-Δδ^(13)C)的相关性.水解反应中DBP分子产生了显著的碳同位素分馏,未发现氢同位素分馏,而且碳同位素富集因子ε_C为(-2.7±0.4)‰,表明DBP水解时发生C—O键断裂,氢原子不参与反应.而UV/H_2O_2光解和直接光解反应(pH值分别为2、7和10)中,DBP分子呈现了相似的二维同位素相关性Λ值[(9±2)^(11±2)],推测经历了相同的反应过程.过硫酸钾光氧化降解时,明显偏大的Λ值(31±3)说明反应可能发生C—H键断裂.结果表明:二维单体同位素分析(2D-CSIA)技术可以有效区分DBP的水解、光解、光氧化3种不同类型的降解过程,有助于分析其降解路径.A systematic investigation on carbon and hydrogen isotopic compositions,isotope fractionations and dual isotope correlations(Δδ^2H-Δδ^13C)during different degradation processes(hydrolysis,UV/H2O2,direct photolysis and UV-activated persulfate oxidation)of dibutyl phthalate(DBP)was performed in this study.Significant carbon isotope enrichment and no hydrogen isotope fractionation were observed during hydrolysis.The carbon isotope enrichment factor(εC)was determined as(-2.7±0.4)‰.The difference between carbon and hydrogen isotope patterns indicated the C-O bond cleavage in the hydrolytic reaction without H atoms involvement.During photodegradation of DBP induced by UV/H2O2 and direct photolysis at different pH values(pH 2,7 and 10),correlationΛvalues of dual isotope were observed in a similar range of[(9±2)^(11±2)]and indicated similar reaction mechanism.UV-activated persulfate oxidation yielded the distinctΛvalue of(31±3),which was likely associated with the C-H bond cleavage.Therefore,two-dimensional compound specific isotope analysis(2D-CSIA)highlighted the potential to discriminate three types of degradation processes(hydrolysis,photolysis and UV-activated persulfate oxidation)of DBP and to deduce degradation pathways.

关 键 词：邻苯二甲酸二丁酯 同位素分馏 光解 过硫酸钾氧化 单体同位素分析 

分 类 号：X592[环境科学与工程—环境工程]