UV/H2O2对化工废水中2,6-二氯吡啶的降解研究  

Study on Degradation of 2,6-dichloropyridine in Chemical Wastewater by UV/H2O2

作　　者：谷振超 邬东 陈莉荣[1] GU Zhenchao;WU Dong;CHEN Lirong(School of Energy and Environment,Inner Mongolia University of Science and Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学能源与环境学院,内蒙古包头014010

出　　处：《湖南大学学报（自然科学版）》2021年第2期132-140,共9页Journal of Hunan University:Natural Sciences

基　　金：内蒙古自治区自然科学基金资助项目(2018BS02006,2017MS(LH)0212);内蒙古科技大学创新基金项目(2017QDL-B15)。

摘　　要：含氮杂环化合物随着化工行业的发展不断进入环境中,增加了对生态环境的威胁.考察了UV/H2O2对化工废水中含氮杂环化合物2,6-二氯吡啶(2,6-DCLPY)的降解特征,降解过程中的2,6-DCLPY浓度通过紫外分光光度法测定;并对2,6-DCLPY降解反应的影响因素包括初始2,6-DCLPY浓度、H2O2浓度、pH和共存阴离子等进行了研究.结果表明:2,6-DCLPY在UV/H2O2体系下的降解符合准一级反应动力学,该体系中羟基自由基(·OH)是降解2,6-DCLPY的主要活性物质,UV起协同作用;随着H2O2用量的提高,2,6-DCLPY的降解效率也逐渐提高,当H2O2和2,6-DCLPY的投加摩尔比为37∶1,pH为7.2时达到最高降解率77.3%.共存阴离子HCO-3和NO-3因能与·OH直接发生反应,对降解反应有显著的抑制作用.吡啶环上存在氨基等给电子基团有利于吡啶类污染物的降解,而氯等吸电子基团会抑制吡啶类污染物的降解.With the development of the chemical industry,nitrogen-containing heterocyclic compounds constantly enters the environment,which increases the threat to the ecological environment.The degradation characteristics of the nitrogen-containing heterocyclic compounds 2,6-dichloropyridine(2,6-DCLPY)in chemical wastewater by UV/H2O2 were investigated,and the concentration of 2,6-DCLPY in the degradation process was determined by ultraviolet spectrophotometry.The influencing factors of 2,6-DCLPY degradation reaction including initial 2,6-DCLPY concentration,H2O2 concentration,pH and coexisting anions were studied.The results showed that the degradation of 2,6-DCLPY under UV/H2O2 system accorded with quasi-first-order reaction kinetics.Hydroxyl radical(·OH)was the main active substance for degradation of 2,6-DCLPY,while UV played a synergistic effect.The degradation efficiency of 2,6-DCLPY gradually increased with the increasing H2O2 dosage,and the highest degradation rate could reach 77.3%when the molar ratio of H2O2 and 2,6-DCLPY was 37∶1 and the pH was 7.2.The coexisting anions HCO3-and NO3-can directly react with·OH,which leaded to significant inhibitory effect on the degradation reaction.The presence of electron-donating groups such as amino groups on the pyridine ring is conducive to the degradation of pyridine pollutants,while electron-withdrawing groups such as chlorine inhibits the degradation of pyridine pollutants.

关 键 词：光催化 UV/H2O2 2 6-二氯吡啶 含氮杂环化合物 羟基自由基 

分 类 号：X703[环境科学与工程—环境工程]