H_2O_2多点添加对Fe^(2+)/H_2O_2体系ORP影响的研究

Influence of Multi-Point Addition of H_2O_2 on ORP of Fe^(2+)/H_2O_2 System

Fenton体系中H_2O_2的添加方式直接影响着H_2O_2对·OH的消耗程度.本文采用多点投加装置,研究H_2O_2多点投加对Fe2+/H_2O_2体系氧化还原电位(Oxidation-Reduction Potential,ORP)的影响规律。研究发现,当添加点数增加时,溶液终态ORP增大。Fe^(3+)/Fe^(2+)电对是体系ORP的主要贡献物质。OH被捕捉后,体系ORP升高,可能是Fe^(3+)/Fe^(2+)的循环状态发生改变。温度升高,H_2O_2对·OH消耗增强,使得Fe^(3+)/Fe^(2+)的转化过程发生变化,溶液ORP升高。H_2O_2加入溶液的时间尺度,会影响体系ORP的增长过程及终态值,实验发现时间尺度为4 min时最佳,原因在于其它体系中Fe^(2+)不能充分转变成Fe^(3+),因而体系ORP增长较慢,稳定时体系ORP数值较低。

In Fenton system,invalid consumption of hydroxyl radicals was directly influenced by adding ways of H2O2 Therefore,influence of multi-point addition of H2O2 on ORP of Fe^2＋/H2O2system was experimentally studied and analyzed in this work.Results indicate that final ORP of system was higher when H2O2 was added by more points.Fe^3＋/Fe^2＋ was the main contribution substances.When hydroxyl radicals were captured,ORP of system would increase,which was attributed to change of circulation state of Fe^3＋/Fe^2＋.Invalid consumption of hydroxyl radicals by H2O2 was enhanced with increased temperature,which caused change of circulation state of Fe^3＋/Fe^2＋.Change process of ORP and final ORP was impacted by adding time scale of H2O2-When H2O2 was added within 4 min,Fenton system achieved highest final ORP,which showed in other conditions,Fe^2＋ could not be transferred to Fe^3＋ adequately;final ORP was lower and needed a longer time to reach stable level.