摘要
在2.0≤pH≤5.1、0.2mmol·L-1≤[H2O2]0≤100mmo·lL-1和0.05mmo·lL-1≤[Fe(Ⅲ)]0≤0.5mmol·L-1的试验条件下,考察了不含有机物的反应体系中[H2O2]0/[Fe(Ⅲ)]0、[Fe(Ⅲ)]0、pH及Fe(Ⅲ)水解形态等因素对类-Fenton反应中Fe(Ⅲ)催化分解H2O2动力学的影响.结果表明,在[Fe(Ⅲ)]0一定时,H2O2分解存在最佳[H2O2]0/[Fe(Ⅲ)]0摩尔比;当[H2O2]0一定时,Fe(Ⅲ)催化H2O2分解可用二级动力学反应进行描述,其二级动力学常数kd为22.21L·mol-1·min-1;Fe(Ⅲ)催化H2O2分解的最佳pH为3.0;H2O2的分解速率随着Fe(Ⅲ)水解时间的增加而降低,Fe(Ⅲ)存在形态对H2O2催化分解起主导作用.
In this paper, the effects of [ H2O2 ]0/[ Fe （ Ⅲ ） ]0, [ Fe （ Ⅲ ） ]0, pH and hydrolysis species of Fe （ Ⅲ ） on the kinetics of H2O2 decomposition in the Fenton - like system free of organic substrates had been investigated. Experiments were carried out over a wide range of experimental conditions （2.0 ≤ pH ≤ 5.1,0. 2 mmol· L^-1 ≤ [ H2O2 ]0 ≤ 100 mmol· L^-1 , and 0. 05 mmol· L^-1 ≤ [ Fe（ Ⅲ ） ]0 ≤0. 5 mmol· L^-1 ）. The experimental results showed that there was an optimum molar ratio of [ H2O2 ] 0/ [ Fe （ m ） ] 0 when the initial concentration of Fe （ Ⅲ ） kept constant. When the H2O2concentration kept constant, the initial rate of catalytic decomposition of H2O2 by Fe（ Ⅲ ） abided by a second-order kinetic law with the second-order rate constant ka of 22.21 L· mol^- 1. min^ - 1. The optimum solution pH for the reaction was observed at around 3. 0. The decomposition rate of H2O2 decreased with the increasing of hydrolysis time of Fe（Ⅲ ） , and the hydrolysis species of Fe（ Ⅲ ） played an important role in the rates of catalytic decomposition of H202 by Fe（ Ⅲ ） in the Fenton-like system.
出处
《环境科学学报》
CAS
CSCD
北大核心
2007年第7期1197-1202,共6页
Acta Scientiae Circumstantiae
基金
国家自然科学基金资助项目(No.50478049
50678104)
广东省自然科学基金资助项目(No.04011215)~~
