摘要
Fenton反应中 ,由于各种介质价态及形态的改变 ,氧化还原电位 (ORP)也随之发生变化 .在滴加H2 O2 过程中 ,H2 O2 /[Fe2 +]0 的摩尔比小于 0 75时 ,ORP的升高是一个快速过程 ;大于 0 75后 ,ORP的变化趋于缓慢 .当体系中没有加入有机物时 ,随着过量H2 O2的加入 ,Fe2 +以微量且较稳定的浓度存在 ,体系的ORP也保持较稳定的状态 ;当加入石油烃后 ,伴随着H2 O2 浓度降至微量 ,少量Fe3+能被有机自由基还原成Fe2 +,相对应的ORP也出现下降 .不同H2 O2 浓度对应不同的ORP曲线 ,H2 O2 浓度愈高 ,ORP最大值出现得也愈迟 .通过研究ORP的变化规律 。
Transformations of both chemical valence and species of reagents brought about variation of redox potential(ORP)in Fentions reaction.When H 2O 2 is titrated into an Fe 2+ bearing solution,ORP increased rapidly with increasing H 2O 2 at a molar ratio of H 2O 2/[Fe 2+ ] 0 below 0 75.Above the ratio,however,the increasing rate of ORP evidently slowed down.In the absence of organic substrate,the ORP remained as a constant value for a longtime following a fast increase with addition of H 2O 2.When hydrocarbon is added into the solution,however,there exists the maximum ORP,and increase of Fe 2+ was observed after it arrived at the minimum point.Different H 2O 2 do ses corresponded to different ORP curves.Longer time was needed to reach the maximum point of ORP for a higher concentration of H 2O 2.
出处
《环境化学》
CAS
CSCD
北大核心
2004年第2期135-139,共5页
Environmental Chemistry
基金
国家重大科技专项 863项目 (批准号 :2 0 0 2AA60 1 3 1 0 )
