摘要
测定了木质颗粒活性炭 (GAC)和负载在GAC上的羟基氧化铁 (FeOOH)催化水中臭氧分解的速率常数并探讨了催化臭氧分解的途径 .以水中几种氧化物表面羟基密度和表面零电荷pH值 (pHzpc)为表征氧化物表面性质的参数 ,考察了 2个参数对催化臭氧氧化水中硝基苯的影响 .GAC和负载在GAC上的FeOOH使水中臭氧一级分解速率常数分别提高了 6 8%和10 8% ,用叔丁醇捕获掉生成的羟基自由基后 ,前者的分解速率常数降低了 9% ,后者降低了 2 0 % .GAC在催化臭氧分解时主要起到吸附剂和还原剂的作用 ,FeOOH催化臭氧分解过程中促进了羟基自由基生成 .氧化物表面羟基密度和催化臭氧氧化水中硝基苯的效果之间没有直接的关系 ,由氧化物的 pHzpc决定的表面电荷状态与催化氧化效果有关 ,表面接近电中性时对催化氧化硝基苯有利 .高密度的表面羟基会使表面羟基之间形成较强的氢键 ,使催化作用减弱 .
In this paper, the decomposition rate of ozone in water was measured over GAC and ferric hydroxide/GAC (FeOOH/GAC) catalyst and the mechanism of ozone catalytic decomposition was discussed. The catalytic ozonation activity of trace nitrobenzene in water was determined on several metal oxides and correlated with their surface density of hydroxyl groups and pH_ zpc (pH of zero point of charge). The results show that: ① The pseudo-first order rate of ozone decomposition increased by 68 and 108 percent for GAC and FeOOH/GAC catalysts respectively; ② When t-butanol was added, the rate constant decreased by 9 % for GAC and 20% for FeOOH/GAC; ③ There was no direct correlation between surface density of hydroxyl groups and the activity of catalytic ozonation of nitrobenzene; ④ The oxide surface at nearly zero charged point was favorable for the catalytic ozonation of nitrobenzene.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2005年第2期78-82,共5页
Environmental Science
基金
国家自然科学基金资助项目 (5 0 3 780 2 8)
