FeOOH/H2 O2催化降解碱性品红的研究

摘要

采用FeOOH/H2 O2体系对一种碱性阳离子染料进行催化降解。考察了H2 O2浓度、FeOOH的投加量、碱性品红的浓度、pH对碱性品红降解的影响。结果表明，反应的较优条件是H2 O2浓度为60 mmol/L，FeOOH投加量1.0 g/L；碱性品红浓度高的降解速率比较慢，浓度低的降解速率快；pH=1时，碱性品红去除率为90.9%；pH=9时，碱性品红去除率为98.9%。机理研究表明，当溶液pH小于FeOOH的零电荷点时，FeOOH表面带正电荷，与带正电荷的碱性品红之间相互排斥降低了对碱性品红的吸附作用，同时部分 Fe离子发生溶解，溶解的铁离子与H2 O2形成Fenton 体系；当溶液 pH 大于 FeOOH 的零电荷点时，FeOOH 带负电荷，碱性品红因静电力被吸附在FeOOH表面，同时与产生的羟基自由基发生反应。%The eatalytie degradation of fuehsin using FeOOH/H2 O2 system was investigated. The effeets of H2 O2 eoneentration,FeOOH dosage,fuehsin eoneentration and pH on fuehsin degradation were diseussed in detail. The results showed that the optimum eonditions were as follows:H2 O2 eoneentration 60 mmol/L and FeOOH dosage 1. 0 g/L;The degradation rate of fuehsin in high eoneentration was slow,on the eon-trary,that in low eoneentration was fast;The removal rate of fuehsin was 90. 9% at pH=1,but whieh was 98 . 9% at pH=9;The meehanistie studies suggested that absorption of fuehsin was redueed due to the re-pulsion between positively eharge of fuehsin and positively eharged surfaee of FeOOH eaused when the so-lution pH was less than the point of zero eharge of FeOOH. Meanwhile,part of ferrie ions dissolved then Fenton system was formed by H2 O2 and dissolved ferrie ion;On the eontrary,when the solution pH was more than the point of zero eharge of FeOOH,the fuehsin was absorbed on the surfaee of negatively eharge surfaee of FeOOH by eleetrostatie foree and reaeted with produeed hydroxyl radieals.