高强紫外光强化降解消毒副产物氯乙酸的效能及作用机制  

Performance and Mechanism of High Photon Flux of UV Light for Enhanced Degradation of DBP Chloroacetic Acids

作　　者：李婷 张岍 邢丁予 李家练 艾为党 LI Ting;ZHANG Qian;XING Dingyu;LI Jialian;AI Weidang(Shenzhen Shenshui Longgang Water〈Group〉Co.,Ltd.〈LGWG〉,Shenzhen518055,China;Bureau of Public Works of Longgang Shenzhen Municipality,Shenzhen518055,China;School of Civil and Environmental Engineering,Harbin Institute of Technology,Shenzhen518517,China;Space Science and Technology Institute〈Shenzhen〉,Shenzhen518055,China)

机构地区：[1]深水龙岗水务集团有限公司,广东深圳518055 [2]深圳市龙岗区建筑工务局博士后创新基地,广东深圳518055 [3]哈尔滨工业大学<深圳>土木与环境工程学院,广东深圳518517 [4]深圳市绿航星际太空科技研究院,广东深圳518055

出　　处：《净水技术》2021年第8期44-51,共8页Water Purification Technology

基　　金：人因工程国防科技重点实验室开放基金资助项目(SYFD170051808K);深圳市龙岗区区级重点实验室认定扶持项目(ZSYS2017001)。

摘　　要：氯乙酸是一种化学性质稳定的氯化消毒副产物,传统高级氧化技术对氯乙酸的降解效率低、矿化不彻底,拟采用强度高达3.13×10-6 Einstein/(cm2·s)(强度约合1000 mW/cm2,比传统高级氧化工艺中使用的紫外光强度高两个数量级以上)的紫外光作为光源,考察其对3种氯乙酸(一氯乙酸、二氯乙酸和三氯乙酸)的降解效果、影响因素和矿化过程。研究结果表明,与传统紫外光降解技术相比,高强紫外光可高效降解氯乙酸,前者在360 min内对氯乙酸的去除率不足5%,后者可在50 min内实现99%以上的降解,且3者的降解速率关系为:三氯乙酸>二氯乙酸>一氯乙酸。高强紫外光对氯乙酸的降解过程遵循伪一级动力学,光强、pH和DO这3个光解反应影响因素中,pH对氯乙酸光解过程影响不大,但光强和DO对光解速率影响显著,光解的反应速率随紫外光子通量的提高呈一次线性增加,随着DO由1 mg/L增加至9 mg/L,光解速率提高1倍。此外,高强紫外光对氯乙酸的矿化过程彻底,几乎不产生中间产物,氯乙酸的矿化过程可能主要是通过脱卤和脱羧基两个反应路径实现,DO和pH对光解过程的影响从侧面佐证了氯乙酸高强紫外光光解路径。该结果表明,高强紫外光可有效降解光稳定物质氯乙酸,可为氯化消毒副产物的高效去除提供技术借鉴。Chloroacetic acids(CAAs)are typical disinfection by-products in drinking water treatment process.Due to its photostability and high water solubility,it’s hard to be degraded by traditional advanced oxidation processes.High photon flux with 3.13×10-6 Einstein/(cm2·s)(approximate 1000 mW/cm2,2 orders higher than conventional photon flux UV)was used as light source to degrade the CAAs.Degradation effect,effect parameters and mineralization process of CAAs(MCAA,DCAA and TCAA)degradation was investigated.Compared to traditional UV process with less than 5%CAAs degradation within 360 min,high photon flux UV was efficiently for CAAs decomposition with more than 99%removal within 50 min,and degradation rates were in order of TCAA>DCAA>MCAA.Photolysis process of CAAs with high UV light intensity followed pseudo-first-order reaction kinetics model,and kinetics were positively affected by photon flux and DO,but unaffected by pH,where kinetics linearly increased by the increasing of photon flux and significantly increased double with DO from 1 mg/L to 9 mg/L.In addition,CAAs could achieve completely mineralization under high photon flux UV,and there was barely no intermediate products during the degradation process.It was speculated that the process of CAAs mineralization may be implemented through dehalogenation and decarboxylation pathways,and the effects of DO and pH on CAAs degradation also laterally supported this speculation.Results indicated that high photon flux UV was promising for photostable CAAs decomposition and could provide technical reference for typical disinfection by-products removal.

关 键 词：高强紫外光 消毒副产物 氯乙酸 高效矿化 降解路径 

分 类 号：TU991.25[建筑科学—市政工程]