The UV/Cl2 process is commonly used to achieve a multiple-barrier disinfection and main-tain residuals.The study chose methylamine as a precursor to study the formation of high-toxic halonitromethanes(HNMs)in the presence of bromide ions(Br-)during UV/Cl2 dis-infection.The maximum yield of HNMs increased first and then decreased with increasing concentration of Br-.An excessively high concentration of Br-induced the maximum yield of HNMs in advance.The maximum bromine incorporation factor(BIF)increased,while the maximum bromine utilization factor(BUF)decreased with the increase of Br-concentra-tion.The maximum yield of HNMs decreased as pH value increased from 6.0 to 8.0 due to the deprotonation process.The BUF value remained relatively higher under an acidic condi-tion,while pH value had no evident influence on the BIF value.The maximum yield of HNMs and value of BUF maximized at a Cl2:Br-ratio of 12.5,whereas the BIF value remained rel-atively higher at low Cl2:Br-ratios(2.5 and 5).The amino group in methylamine was first halogenated,and then released into solution as inorganic nitrogen by the rupture of C-N bond or transformed to nitro group by oxidation and elimination pathways.The maximum yield of HNMs in real waters was higher than that in pure water due to the high content of dissolved organic carbon.Two real waters were sampled to verify the law of HNMs forma-tion.This study helps to understand the HNMs formation(especially brominated species)when the UV/Cl2 process is adopted as a disinfection technique.

Lin Deng;Wei Luo;Xiao Chi;Tingting Huang;Longjia Wen;Huiyu Dong;Mingxian Wu;Jun Hu

Department of Municipal Engineering,Southeast University,Nanjing 211189,China;Zhejiang Haihe Environmental Technology Co.,Ltd.,Jinhua 321000,China;Research Center for Eco-Environmental Sciences,University of Chinese Academy of Sciences,Chinese Academy of Sciences,Beijing 100085,China;Zhejiang Truelove Blanket Technology Co.,Ltd.,Jinhua 322000,China;College of Environment,Zhejiang University of Technology,Hangzhou 310014,China

环境科学学报（英文版）

[1]Lin Deng;Wei Luo;Xiao Chi;Tingting Huang;Longjia Wen;Huiyu Dong;Mingxian Wu;Jun Hu-.Formation of halonitromethanes from methylamine in the presence of bromide during UV/Cl2 disinfection)[J].环境科学学报（英文版）,2022(07):28-36

halonitromethanes,BUF

Formation,from,methylamine,presence,bromide,during,UV,Cl2,disinfection,process,commonly,used,achieve,multiple,barrier,tain,residuals,study,chose,precursor,formation,toxic,HNMs,ions,Br,maximum,yield,increased,first,then,decreased,increasing,concentration,An,excessively,induced,advance,bromine,incorporation,BIF,while,utilization,value,due,deprotonation,remained,relatively,higher,acidic,condi,had,evident,influence,maximized,whereas,low,ratios,amino,group,was,halogenated,released,into,solution,inorganic,nitrogen,by,rupture,bond,transformed,oxidation,elimination,pathways,real,waters,that,pure,content,dissolved,carbon,Two,were,sampled,verify,law,This,helps,understand,especially,brominated,species,when,adopted,technique

0.410159