摘要
印染废水治理是水系环境治理的重点,而亚甲基蓝是印染废水中典型的有机污染物。本研究选用掺杂Zn2+的纳米TiO2作为光催化剂对亚甲基蓝进行降解研究。XRD谱图分析表明,Zn2+的掺入可改变纳米TiO2锐钛矿型和金红石型的组成。制备工艺参数对样品光催化降解亚甲基蓝的活性具有很大影响,纯TiO2样品在450℃焙烧时的活性较其他温度的高;而掺杂Zn2+的样品则在500℃焙烧时的光催化活性相对最佳。催化剂的加入量过高或过低都不利于光催化活性的提高,催化剂的加入量为1g/L时,光催化剂对亚甲基蓝的降解效果最好;Zn2+掺入量为0.5%时,掺杂粉体的光催化活性相对较高。随着掺杂量的进一步增加,光催化活性降低。被降解有机物浓度过高时,紫外光较难到达催化剂表面,光的利用率降低,导致催化剂活性降低。亚甲基蓝的初始浓度为5mg/L时的降解速率较快。
Printing and dyeing waste water is one of the key concerns of sewage treatment. The methylene blue is the typical organic pollutant in dyeing waste water. The methylene blue solution will be degraded by TiO2 particles doped Zn^2＋ as the photo- catalyst. The XRD pattern analysis shows that the doped ion Zn^2＋ has changed the ratio of anatase to rutile. Parameters during the preparation of the catalyst affect the photocatalytic degradation rate of methylene blue greatly. The pure TiO2 calcined performs the best at 450℃. The TiO2 doped Zn^2＋ calcined performs the best at 500℃. That catalyst dosage should be neither too high nor too low, which is not conducive to the improvement of photocatalytic activity. The degradation ratio of methylene blue is the highest when the concentration of catalyst is 1 g/L. The photocatalytic activity of catalyst is relatively high when the concentration of Zn^2＋ is 0.5%. As the doping amount of Zn^2＋ further increases, the photocatalytic activity is decreased. It becomes more difficult for ultraviolet light to reach the catalyst surface when the concentration of organic compounds is high. The utilization efficiency of light, is reduced, so the catalyst activity is getting lower. The degradation is relatively fast when the methylene blue initial concentration is 5 mg/L.
出处
《科技导报》
CAS
CSCD
北大核心
2009年第19期104-107,共4页
Science & Technology Review
