中文摘要：

研究1,3-二溴-5,5-二甲基海因（DBDMH）水溶液中的有效溴、溴离子和溴酸根离子在紫外（UV）辐照下的转化过程,并探讨pH、光照波长和氨氮等因素对次溴酸溶液的光促歧化反应的影响。研究结果表明：普通消毒剂量的DBDMH水溶液（质量浓度为3.2 mg/L）紫外辐照5 min后可产生质量浓度较大的溴酸根离子（〉25.9μg/L）;溴酸根离子是次溴酸光促歧化反应的中间产物;在实验条件下,紫外光波长越短,越有利于有效溴的光解和溴酸根的生成,而pH的影响较小;氨氮通过与有效溴反应形成溴氨抑制溴酸根离子的生成。

英文摘要：

1,3 dibromo-5,5 dimethylhydantoin（DBDMH） decomposition with ultraviolet（UV） irradiation was studied by following the transformation of available bromine,bromide and bromate.Detailed experiments were conducted to fully explore the effect of pH,wavelength and ammonia on photo-induced disproportionation of hypobromous acid.The results show that more than 25.9 μg/L of bromate forms with initial 3.2 mg/L DBDMH close to the normal dosage of swimming pool disinfection.Generally,a shorter wavelength leads to a higher production rate of bromate and a higher decomposing rate of free bromine.The effect of pH is ignorable.Ammonia is able to completely suppress the formation of bromate by reacting with free bromine to form bromamines.