VUV/TiO_2/H_2O_2法去除水中微量硝基苯  

Removal of trace nitrobenzene in water by VUV/TiO_2/H_2O_2

作　　者：尹菁菁[1] 张彭义[1] 

机构地区：[1]清华大学环境科学与工程系,北京100084

出　　处：《中国环境科学》2008年第8期689-693,共5页China Environmental Science

基　　金：国家"863"项目(2002AA601250)

摘　　要：研究了过氧化氢(H2O2)强化的真空紫外光催化(VUV/TiO2/H2O2)方法对水中微量硝基苯(NB)的去除效果,同时考察了H2O2投加量、NB初始浓度、重碳酸盐和腐殖酸对NB降解的影响.采用负载在钛片上的二氧化钛(TiO2)薄膜为光催化剂,以能发射185nm真空紫外线(VUV)的紫外灯为光源.结果表明,去离子水中50μg/L的NB反应60s后去除率即达到97.9%.随H2O2投加量的增加,VUV/TiO2/H2O2对NB的降解速率先增后减;初始浓度低于170μg/L时,初始浓度对NB降解影响不大;重碳酸盐和腐殖酸对硝基苯降解有显著的抑制作用.VUV/TiO2/H2O2能快速有效地去除地表水(含碳酸盐和天然有机物)中的微量NB,5min内初始浓度为90μg/L的NB去除率达到94.1%,UV254在4min内也降低了53.3%.The removal of trace nitrobenzene （NB） in water by hydrogen peroxide-enhanced VUV photocatalytic process （VUV/TiO2/H2O2） was investigated, in which low-pressure mercury lamp emitting 185nm vacuum ultraviolet and titanium dioxide film coated on the titanium plate were respectively used as light source and photocatalyst. The effects of H2O2 dosage, NB initial concentration, bicarbonate and humlc acid on NB degradation were also investigated. It was showed that VUV/TiO2/H2O2was an effective method to remove trace NB in water. And 50μg/L NB in deionized water was removed by 97.9% within 60s. The apparent rate constant of NB by VUV/TiO2/H2O2 increased initially and then decreased with increase of H2O2 addition. The degradation of NB was little influenced when its initial concentration was less than 170μg/L. Bicarbonate and humic acid in water significantly inhibited the removal of NB. However, trace NB in surface water containing bicarbonate and natural organic matter could be removed fast and effectively by the VUV/TiO2/H2O2 process, and 94.1% nitrobenzene with initial concentration of 90pg/L was degraded within 5 rain and UV254 was also reduced 53.3% within 4min.

关 键 词：真空紫外光催化 光催化 硝基苯 重碳酸盐 腐殖酸 微污染物 

分 类 号：X131.2[环境科学与工程—环境科学] X52