摘要
吡虫啉(IMI)作为第1代新烟碱类农药,在环境中残余量大、残留时间长,降低其在环境中的含量十分必要。采用凝胶法制备ZnCo_(2)O_(4)双金属氧化物催化剂,利用扫描电镜(SEM)、X射线衍射(XRD)、傅里叶红外光谱(FTIR)及X射线光电子能谱分析(XPS)等手段对催化剂进行了表征。通过ZnCo_(2)O_(4)活化过一硫酸氢钾(PMS)产生SO4·-降解IMI,考察了PMS用量、催化剂用量、污染物浓度、pH及常见阴离子(Cl-、CO32-、NO32-)等因素对ZnCo_(2)O_(4)/PMS体系中IMI降解的影响,探索主要活性自由基及降解产物,并对催化剂重复使用性能进行研究。结果表明,在IMI浓度为20 mg·L^(-1)、ZnCo_(2)O_(4)投加量为0.4 g·L^(-1)、PMS投加量为15 mmol·L^(-1)时,体系在60 min可实现95%以上的IMI降解率;随着IMI初始浓度的增加、体系pH相应增加,IMI降解率有所下降;在5~30 mmol·L^(-1)内,PMS的投加量与IMI降解率呈正相关关系;催化剂用量在0.4 g·L^(-1)以下时,IMI降解率随催化剂用量的增加而增大;Cl-、CO32-对IMI的降解有抑制作用,NO32-无明显作用;体系中主要起作用的自由基为SO4·-;使用GCMS检测到IMI降解产物有5种;催化剂重复使用3次时IMI降解率稳定在80%以上。
As the first-generation neonicotinoid pesticide,imidacloprid(IMI)has a large residual amount and high persistence in the environment,it is of great significance to remove it from environment.A bimetal oxide catalyst-ZnCo_(2)O_(4)was prepared by the gel method,and it was characterized by scanning electron microscope(SEM),X-ray diffraction(XRD),Fourier infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).Peroxymonosulfate(PMS)was activated by ZnCo_(2)O_(4)to generate SO4·-for the oxidative degradation of IMI,the effects of the PMS concentration,catalyst concentration,IMI concentration,pH and coexisting anions(Cl-,CO32-,NO32-)on IMI degradation were investigated.The active free radicals degradation products and the performance of the recycled catalyst were also studied.The results show that when the IMI concentration was 20 mg·L^(-1),the dosage of ZnCo_(2)O_(4)catalyst was 0.4 g·L^(-1),and the dosage of PMS was15 mmol·L^(-1),IMI degradation rate was over than 95%within 60 min.As the initial concentration of IMI increased,and the pH of the system increased accordingly,IMI degradation rate decreased.The degradation rate of IMI was positively correlated with the dosage of PMS in a range of 5~30 mmol·L^(-1).when the amount of the catalyst was below 0.4 g·L^(-1),the degradation rate increased with the increase of the catalyst amount.Cl-and CO32-had inhibitory effects on the degradation rate of IMI,whileNO32-had slight effect.The main free radical in the system was SO4·-,5 kinds of degradation products of IMI were detected by GCMS.The IMI degradation rate could maintain more than 80%after 3 times-recycling of the catalyst.
作者
刘婧宇
亢昕
李东鹏
孙铸宇
宋新山
赵晓祥
LIU Jingyu;KANG Xin;LI Dongpeng;SUN Zhuyu;SONG Xinshan;ZHAO Xiaoxiang(College of Environmental Science and Engineering,Donghua University,Shanghai 201620,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2021年第4期1227-1241,共15页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(21906016)
国家重点研发计划(2019YFC0408604)
中央高校基本科研业务费专项资金(2232020D-25)。
