摘要
采用过一硫酸盐(PMS)直接氧化降解废水中的氮杂环化合物吡啶,考察了PMS投加量、pH、共存阴离子(Cl^(-)、HCO_(3)^(-)、NO_(3)^(-))和腐殖酸(HA)对吡啶降解效果的影响。结果表明,PMS直接氧化去除吡啶的过程符合拟一级反应动力学。当吡啶初始浓度为8.0 mg/L、pH为7.0、反应温度为25℃、PMS投加量为4.0 mmol/L时,反应150 min后对吡啶的降解率可达到93.66%。水中Cl^(-)、HCO_(3)^(-)、NO_(3)^(-)和HA的存在均对吡啶的降解没有明显影响。自由基鉴定实验结果显示,PMS体系中未产生硫酸根自由基(SO_(4)^(-)·)和羟基自由基(·OH),有少量单线态氧(^(1)O_(2))生成,PMS的直接氧化作用是吡啶降解的主要因素。通过GC-MS分析检测到PMS直接氧化降解吡啶的中间产物为N,N-二甲基丙烯酰胺、草酸、乙酸等低毒性有机化合物。
Peroxymonosulfate(PMS)was directly applied to oxidize nitrogen heterocyclic compound pyridine in wastewater.The effects of PMS dosage,pH,coexisting anions(Cl^(-),HCO_(3)^(-),NO_(3)^(-))and humic acid(HA)on degradation of pyridine were investigated.The direct oxidation of pyridine by PMS conformed to pseudo first-order reaction kinetics.When the initial concentration of pyridine was 8.0 mg/L,the pH was 7.0,the reaction temperature was 25℃,and PMS dosage was 4.0 mmol/L,the removal efficiency of pyridine reached 93.66%after 150 minutes of reaction.The presence of (^(1)O_(2)),HCO_(3)^(-),NO_(3)^(-)and HA in water had no significant effect on pyridine degradation.Free radical identification showed that no sulfate radical(SO_(4)^(-)·)and hydroxyl radical(·OH)were generated,and a small amount of singlet oxygen(^(1)O_(2))was formed in the PMS system.The direct oxidation of PMS was the main mechanism of pyridine degradation.GC-MS analysis showed that the intermediate products of pyridine directly oxidized by PMS were N,N-dimethylacrylamide,oxalic acid,acetic acid,and other low?toxic organic compounds.
作者
王鹏莺
苏冰琴
彭娅娅
温宇涛
郭越
李瑞
WANG Peng-ying;SU Bing-qin;PENG Ya-ya;WEN Yu-tao;GUO Yue;LI Rui(College of Environmental Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Municipal Engineering Graduate Education Innovation Center of Shanxi Province,Taiyuan 030024,China)
出处
《中国给水排水》
CAS
CSCD
北大核心
2022年第13期64-70,共7页
China Water & Wastewater
基金
国家自然科学基金资助项目(22008167)
山西省自然科学基金资助项目(201801D121274)。
关键词
过一硫酸盐
直接氧化
吡啶
氮杂环化合物
反应机制
peroxymonosulfate
direct oxidation
pyridine
nitrogen heterocyclic compound
reaction mechanism
