摘要
采用两种基于紫外的高级氧化技术—紫外/过氧化氢(UV/H_(2)O_(2))和紫外/过硫酸盐(UV/PS)降解亚硝基二甲胺(NDMA),并考察氧化剂投加量、pH、溶解氧、光照强度等反应条件对NDMA降解效果的影响。结果表明,UV/PS和UV/H_(2)O_(2)对NDMA的去除率在一定范围内都会随着氧化剂投加量和光照强度的增加而升高,且增加光照强度对NDMA去除率的促进效果要好于增加氧化剂投加量。对于UV/PS,弱酸性条件下对NDMA的去除效果最好,K_(obs)为0.0104 min^(-1);而对于UV/H_(2)O_(2),强碱性条件下对NDMA的去除效果最佳,K_(obs)为0.0153 min^(-1)。对反应机理的分析表明,NDMA受到紫外光辐射或者是氧化性自由基(·OH或·SO_(4)^(-))进攻时,分子中的N—N键断裂,生成二甲胺和亚硝酸盐,二甲胺会被进一步降解生成甲胺且最终被降解生成甲酸盐;而亚硝酸盐最终被氧化为硝酸盐。
Two UV-based advanced oxidation processes-UV/hydrogen peroxide(UV/H_(2)O_(2))and UV/persulfate(UV/PS)were used to remove nitrosodimethylamine(NDMA)from water,and the effects of reaction conditions such as oxidant dosage,pH value,dissolved oxygen,and light intensity on the degradation of NDMA were investigated.The NDMA removal efficiency was increased with the increasing oxidant dosage and light intensity by both UV/H_(2)O_(2)and UV/PS.Moreover,the promotion effect of increasing light intensity was better than that of increasing oxidation dosage.For UV/PS,the best NDMA removal efficiency was achieved under weak acidic condition with K_(obs) of 0.0104 min^(-1).For the UV/H_(2)O_(2),the best removal efficiency of NDMA was achieved under strong alkaline condition with K_(obs) of 0.0153 min^(-1).The analysis of the reaction mechanism a showed that NDMA was attacked first by UV radiation or oxidative radicals(·OH or·SO_(4)^(-))and the N-N bond in the molecule was broken,which resulted in DMA and nitrite.DMA was further degraded to MA,and MA was finally degraded to formate.Nitrite was finally oxidized to nitrate.
作者
查晓松
金苏雯
赵倩
黄培楠
张琳
翁元捷
ZHA Xiaosong;JIN Suwen;ZHAO Qian;HUANG Peinan;ZHANG Lin;WENG Yuanjie(School of Environmental Science and Engineering,Xiamen University Tan KahKee College,Zhangzhou 363105,China;Key Laboratory of Estuary Ecology and Environmental Health of Fujian Province,Xiamen University Tan KahKee College,Zhangzhou 363105,China)
出处
《水处理技术》
CAS
CSCD
北大核心
2022年第9期32-37,共6页
Technology of Water Treatment
基金
福建省自然科学基金项目资助(2020J05017)
漳州市自然科学基金项目资助(ZZ2019J11)
福建省教育厅中青年教师教育科研项目(JAT19017)。
关键词
亚硝基二甲胺
紫外高级氧化技术
影响因素
反应机理
nitrosodimethylamine
UV-based advanced oxidation processes
influence factors
reaction mechanism
