溴离子对紫外/氯联用工艺中天然有机质转化和卤代副产物生成的影响  

Effect of Bromide Ions on the Transformation of Natural Organic Matter and the Formation of Halogenated Byproducts in the UV/chlorine Oxidation Process

作　　者：阮小雪 向滢颖 杨欣[1] RUAN Xiaoxue;XIANG Yingying;YANG Xin(School of Environmental Science and Engineering,Sun Yat-sen University,Guangzhou 510006,China;Zhongshan Association for Science and Technology,Zhongshan 528400,China;Nanyang Environment&Water Research Institute,Nanyang Technological University,Singapore 637141,Singapore)

机构地区：[1]中山大学环境科学与工程学院,广东广州510006 [2]中山市科学技术协会,广东中山528400 [3]南洋理工大学南洋环境水务研究院,新加坡637141

出　　处：《能源环境保护》2025年第1期99-112,共14页Energy Environmental Protection

基　　金：国家自然科学基金资助项目(22176225)。

摘　　要：紫外/氯联用作为一种高级氧化工艺,可利用其产生的多种活性物种去除微污染物和强化消毒效果。在此过程中,水体中存在的天然有机质(NOM)和溴离子会导致氯代和溴代消毒副产物的生成,从而对生态安全和人类健康构成潜在风险。由于检测技术的限制,之前的研究大多只关注常规消毒副产物,针对紫外/氯联用工艺中NOM在分子层面的转化以及未知卤代副产物生成的研究非常缺乏。本研究采用傅里叶变换离子回旋共振质谱技术(FT-ICR MS),从分子层面解析溴离子对紫外/氯联用工艺中NOM转化以及卤代副产物生成的影响。研究发现,紫外/氯联用工艺中,溴离子转化生成次溴酸和含溴自由基(例如Br^(·)、BrO^(·)、Br_(2)^(·-)和BrOH^(·-)),使得NOM中更多的CHO化合物发生转化,特别是芳香性较高的物质,并生成主要为单宁酸类及富含羧基的脂环类CHO化合物。NOM经紫外/氯联用工艺处理后,共检出222个含溴化合物(CHOBr),与单独氯化处理后生成的CHOBr化合物相比具有明显更低的含碳数和芳香性指数。通过对其前体物的解析发现CHOBr化合物对应的前体物主要是NOM中O/C值较低或H/C值较高的物质,包括NOM中的木质素类似物、高度不饱和类和酚类化合物,而发生取代反应的前体物比发生加成反应的前体物的芳香值更低。单独氯化生成的大部分CHOBr化合物会在后氯化阶段被去除,但紫外/氯生成的大量CHOBr化合物在后氯化阶段依然存在。有溴离子存在时,紫外/氯联用工艺中识别出的CHOCl化合物数量远远低于无溴离子存在时的数量。在没有Br^(-)参与的紫外/氯联用工艺中,识别出333个一氯化合物。当体系中加入Br^(-)后,紫外/氯联用体系中只识别出33个一氯化合物。研究同时也检出了既含Cl又含Br的化合物。本研究从分子层面表征了紫外/氯联用工艺中新型含溴副产物的生成,并阐明了其前体物的转�The UV/chlorine advanced oxidation process(AOP),which generates various highly reactive radical species,effectively degrades micropollutants and inactivates microorganisms.The ubiquitous presence of natural organic matter(NOM)in water leads to the generation of chlorinated disinfection byproducts,while the presence of bromide induces the generation of brominated disinfection byproducts,which are known to pose threats to ecological safety and human health.However,research has primarily focused on conventional disinfection byproducts due to the complexities associated with NOM,the diversity of halogenated byproducts,and the limitations of analytical techniques.In this study,Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS)was applied to elucidate the influence of bromide ions on the transformation of NOM and the generation of halogenated byproducts in the UV/chlorine AOP.The introduction of bromide in the UV/chlorine AOP facilitated the generation of hypobromous acid and bromine-containing radicals(such Br_(2)^(•-)as Br^(•),BrO^(•),and BrOH^(•-)).This alteration in radical speciation led to significant transformations of CHO compounds in NOM,particularly those with higher aromaticity.The newly generated CHO compounds were mainly tannin-like and alicyclic molecules rich in carboxyl groups.A total of 222 bromine-containing compounds(CHOBr)were detected after the UV/chlorine AOP.Compared with the CHOBr compounds detected in dark chlorination,these CHOBr compounds had significantly lower carbon numbers and AImod values.Analysis of the precursors of these CHOBr,considering both addition.reactions(AR)and substitution reactions(SR)as pathways,showed that these precursors had low O/C ratios or high H/C ratios.These precursors were predominantly lignin-like compounds and highly unsaturated and phenolic compounds.The SR precursors had lower aromaticity compared to AR precursors.The majority of CHOBr compounds generated during chlorination were removed during the post-chlorination process,while mo

关 键 词：紫外/氯联用 高级氧化工艺 天然有机质 溴离子 卤代消毒副产物 FT-ICR MS 

分 类 号：X52[环境科学与工程—环境工程] X703