磺胺嘧啶和磺胺二甲基嘧啶在纳米Fe3O4-nZVI类Fenton体系中的降解效果
Degradation effect of sulfadiazine and sulfamethazine in nano Fe3O4-nZVI Fenton-like system
钟金魁 1谢亚瑞 2李闻青 2谢欣卓 2张子涵2
作者信息
- 1. 兰州交通大学环境与市政工程学院,兰州,730070;甘肃省黄河水环境重点实验室,兰州,730070
- 2. 兰州交通大学环境与市政工程学院,兰州,730070
- 折叠
摘要
用Fe3O4负载纳米零价铁(Fe3O4-nZVI)作为非均相催化剂,与H2O2耦合构建类Fenton体系,以降解水中磺胺嘧啶(SDZ)和磺胺二甲基嘧啶(SMT).通过SEM、EDS、XRD和XPS对Fe3O4-nZVI材料进行了表征,并考察了Fe3O4-nZVI类Fenton体系中H2O2浓度、Fe3O4-nZVI投加量、初始pH及Fe3O4-nZVI循环使用次数对SDZ和SMT降解效果的影响.结果表明,在25 ℃,SDZ和SMT初始浓度均为10mg·L-1,H2O2 浓度分别为 10 mmol·L-1(SDZ)和 15 mmol·L-1(SMT),Fe3O4-nZVI投加量为 0.8g·L-1,初始pH为3的优化条件下,在180 min时,Fe3O4-nZVI类Fenton体系对水中SDZ和SMT的降解率分别为97.45％和95.51％,Fe3O4-nZVI重复利用4次后,对SDZ和SMT的降解率仍保持在87％以上,表明该材料具有良好的磁回收利用性能.拟一级动力学拟合参数R2均在0.93以上,表明Fe3O4-nZVI类Fenton法对SDZ和SMT的降解过程均符合拟一级动力学方程.且在各因素最优条件下,SDZ的反应速率常数均大于SMT的反应速率常数,这可能与二者的理化性质及分子结构有关,即磺胺类抗生素(SAs)的pKa值和水溶解度越小,疏水性越强,杂环基团上的甲基取代基数目越少,SAs越容易被降解.
Abstract
Fe3O4-supported nano-zero-valent iron(Fe3O4-nZVI)was used as a heterogeneous catalyst and coupled with H2O2 to construct a Fenton-like system for the degradation of sulfadiazine(SDZ)and sulfamethazine(SMT)in water.The Fe3O4-nZVI materials were characterized by SEM,EDS,XRD and XPS.The effect of H2O2 concentration,Fe3O4-nZVI dosage,initial pH and Fe3O4-nZVI recycling times on the degradation of SDZ and SMT in Fe3O4-nZVI Fenton-like system was investigated.The results showed that under the optimized conditions of the temperature of 25 ℃,the initial concentration of SDZ and SMT of 10 mg·L-1,the concentration of H2O2 of 10 mmol·L-1(SDZ)and 15 mmol·L-1(SMT),the dosage of Fe3O4-nZVI of 0.8 g·L-1,and the initial pH of 3,the degradation efficiencies of SDZ and SMT in the Fe3O4-nZVI Fenton-like system are 97.45％and 95.51％at 180 min,respectively.The degradation efficiencies of SDZ and SMT are still above 87％after Fe3O4-nZVI reused for 4 times,indicating that the Fe3O4-nZVI composite material has a good magnetic recycling performance.The fitting parameters R2 of pseudo-first-order kinetics are all above 0.93,indicating that the degradation process of SDZ and SMT by Fe3O4-nZVI Fenton-like method fits to the pseudo-first-order kinetics equation.Moreover,under the optimal condition of all factors,the reaction rate constant of SDZ is higher than that of SMT,which may be related to their physicochemical properties and molecular structure,that is,the smaller the pKa value and water solubility of sulfonamide antibiotics(SAs),the stronger the hydrophobicity,and the fewer the number of methyl substitutions on the heterocyclic group,the easier SAs is to be degraded.
关键词
Fe3O4-nZVI/类Fenton法/磺胺嘧啶/磺胺二甲基嘧啶/抗生素Key words
Fe3O4-nZVI/Fenton-like technology/sulfadiazine/sulfamethazine/antibiotics引用本文复制引用
基金项目
国家自然科学基金(22166022)
甘肃省科技计划项目(20JR2RA002)
兰州交通大学大学生创新创业训练计划项目(CXXL20230080)
出版年
2024
NETL
NSTL
万方数据