摘要
以实验室制备的水合氧化铁 (IHO)为催化剂 ,研究了其催化臭氧氧化去除水中痕量难氧化有机物———硝基苯的效能 ,通过研究叔丁醇对催化反应的影响以及氧化物催化性能之间的对比 ,间接推断了催化反应的机理 .探讨了催化剂投量、水质因素和催化剂重复使用对催化氧化硝基苯的影响 .发现IHO对臭氧氧化水中的痕量硝基苯有明显的催化活性 ,在本实验条件下 ,以蒸馏水为本底 ,反应 2 0min时催化氧化硝基苯的去除率比单独臭氧氧化高出 4 4 8% .这种催化作用遵循羟基自由基的途径 ,氧化物羟基含量多对催化反应有利 .本实验条件下催化剂投量最佳为 1 0 0mg/L ,水溶液的 pH值接近氧化物零电荷pH值 (pHzpc)时催化作用最明显 ,水中重碳酸根浓度为 2 38mmol/L时催化作用受到显著抑制 .催化剂重复使用了 5次 ,其催化活性基本没有变化 。
Laboratory produced iron hydroxide was tested for its activity in catalytic ozonation of trace nitrobenzene (NB) in water. The catalysis mechanism was deduced from the effect of tert butanol on the reaction and the difference of catalytic activity between several typical transition metal oxides. Effects of catalyst dose, pH, bicarbonate ion, and times of catalyst reuse on NB removal were also examined. The iron hydroxide showed high catalytic activity on ozonation of NB with removal rate of NB dissolved in distilled water increased by 44.8% at reaction time of 20min. The catalysis follows a hydroxyl radical pathway and is affected by density of hydroxyl groups on the oxide. An optimal catalyst dosage of 100mg/L existed in this experiment. Solution pH near pH of zero charged surface of the oxide favored NB removal and bicarbonate concentration of 2 38mmol/L significantly reduced it. The oxide was used for five times with no significant change of its activity and no dissolution was observed.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2004年第4期43-47,共5页
Environmental Science
基金
国家自然科学基金资助项目 ( 5 0 0 0 80 0 4)
