摘要
用共沉淀法和液相还原法制得Fe_(3)O_(4)负载nZVI复合材料(Fe_(3)O_(4)-nZVI),以Fe_(3)O_(4)-nZVI为非均相催化剂与H_(2)O_(2)耦合构建类Fenton体系,将其用于降解废水中的氯酚(CPs),如,对氯苯酚(4-CP)、2,4-二氯苯酚(2,4-DCP)及2,4,6-三氯苯酚(2,4,6-TCP).SEM、EDS、XPS、XRD和VSM表征结果表明,Fe_(3)O_(4)-nZVI是可通过磁回收循环利用的纳米级复合材料,且可促进Fe2+和Fe_(3)+循环并增加HO·的产量.动力学拟合参数表明,Fe_(3)O_(4)-nZVI类Fenton体系对3种CPs的降解过程均符合拟一级动力学方程(R2>0.9).在25℃,Fe_(3)O_(4)和nZVI物质的量比1:1,溶液初始pH=3,H_(2)O_(2)浓度15mmol/L,CPs初始浓度40mg/L,Fe_(3)O_(4)-nZVI投加量0.6g/L的优化条件下,Fe_(3)O_(4)-nZVI类Fenton体系对4-CP、2,4-DCP和2,4,6-TCP的降解率分别为96.28%、98.77%和98.03%.3种CPs的降解速率顺序为k4-CP>k2,4-DCP>k2,4,6-TCP,表明随着苯环上氯取代基的增加,CPs的降解速率随之减小.淬灭实验和质谱结果表明HO·氧化和取代脱氯是CPs降解的主要方式.
The ferriferrous oxide supported nano zero-valent iron(Fe_(3)O_(4)-nZVI)was prepared by co-precipitation and liquid phase reduction method,and used as heterogeneous catalysts with H_(2)O_(2) of Fenton-like systems to degrade chlorophenols(CPs)in wastewater,such as p-chlorophenol(4-CP),2,4-dichlorophenol(2,4-DCP)and 2,4,6-trichlorophenol(2,4,6-TCP).The characterisation results of SEM,EDS,XPS,XRD and VSM showed that Fe_(3)O_(4)-nZVI was a nanoscale magnetic composite that could be recycled by magnetic recovery and could promote the circulation of Fe2+and Fe_(3)+and increase the yield of HO·.The fitting parameters of kinetics showed that the degradation process of three kinds of CPs in Fe_(3)O_(4)-nZVI Fenton-like system fitted the pseudo-first-order kinetics model(R2>0.9).Under the optimization conditions,which were reaction temperature 25℃,Fe_(3)O_(4):nZVI=1:1(mol:mol),pH=3,H_(2)O_(2)15mmol/L,CPs 40mg/L,and Fe_(3)O_(4)-nZVI 0.6g/L,the degradation rates of 4-CP,2,4-DCP and 2,4,6-TCP by Fe_(3)O_(4)-nZVI Fenton-like systems were 96.28%,98.77%and 98.03%,respectively.The degradation rates of three kinds of CPs were in the order of k4-CP>k2,4-DCP>k2,4,6-TCP.The degradation rates of CPs decreased with the increase of chlorine atoms on the benzene ring.The quenching experiments and mass spectrometry results indicated that HO·oxidation and substitution dechlorination played a critical role on degrading CPs.
作者
钟金魁
李闻青
谢亚瑞
李静
委嘉禾
ZHONG Jin-kui;LI Wen-qing;XIE Ya-rui;LI Jing;WEI Jia-he(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Key Laboratory of Yellow River Water Environment of Gansu Province,Lanzhou 730070,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第11期5746-5756,共11页
China Environmental Science
基金
国家自然科学基金资助项目(22166022)
甘肃省科技计划项目(20JR2RA002)
兰州交通大学创新创业项目(CXXL20230087)。
