二溴硝基甲烷在紫外光照条件下的光降解

Degradation of dibromonitromethane under UV irradiation

以二溴硝基甲烷为研究,采用单一控制变量法研究了光照强度、初始物浓度、自由氯、溴离子、pH值等影响因子对二溴硝基甲烷光降解的影响,探讨了二溴硝基甲烷的光降解动力学规律.结果表明:二溴硝基甲烷在紫外光条件下的降解遵循一级反应动力学规律,其光降解效率随二溴硝基甲烷初始浓度的增加而减小,随光照强度和pH值增加而增加;溴离子的存在能促进二溴硝基甲烷的光降解;添加自由氯能够显著加快二溴硝基甲烷的光降解效率,并且会使二溴硝基甲烷在光降解的过程中转化为以一溴一氯硝基甲烷为主的其他卤代硝基甲烷.此研究结果可为水处理过程中控制二溴硝基甲烷的形成、降低水质安全风险提供参考.

The effects of light intensity,initial concentration,free chlorine,bromine ion and pH value on the photodegradation of dibromonitromethane(DBNM)were studied by single variable control method,and the photodegradation kinetics of DBNM was discussed.The results showed that the photodegradation of DBNM under UV treatment followed first-order kinetics.The photodegradation rate of DBNM decreased with the increasing of initial concentration,increased with the increasing of light intensity and pH value.The presence of bromine ions would slightly promote the photodegradation of DBNM.The addition of free chlorine could significantly accelerate the photodegradation rate of DBNM,and could transform DBNM into the other halonitromethanes(HNMs)which were mainly composed of bromochloronitromethane(BCNM)during the degradation process.The results of this study could provide a reference for controlling the formation of DBNM during water treatment and reducing the risk of water quality safety.