【作者】 焦贞华；

【导师】 李彦生；

【作者基本信息】 大连交通大学 ， 环境科学， 2008， 硕士

【摘要】 本文采用湿机械化学-离子交换法再生纳米TiO₂。文中针对的降解对象是甲基橙，实验过程中采用高锰酸钾高温氧化法测再生前后纳米材料光催化反应液的COD值；利用721分光光度计测定不同阶段反应液的色度；利用UV-2102 PCS型紫外-可见吸光光度计对反应液进行紫外可见吸光度的测定。通过对不同失活情况的纳米TiO₂再生前后的光催化活性的对比，考察此再生方法的再生效果，分析此再生过程原理。湿机械化学-离子交换法可以对失活的纳米TiO₂进行有效的再生，在动态紫外光催化实验中，再生后纳米TiO₂对的COD去除率由41％恢复到了65％，接近新鲜纳米TiO₂对COD的去除率68％，显色物质去除率由55％恢复到84％，接近新鲜纳米TiO₂对显色物质的去除率87％。通过对静态太阳光光催化的研究发现，此再生方法对去除纳米催化剂表面的不牢固和牢固吸附物质都十分有效，再生后的纳米TiO₂光催化甲基橙4次后反应液色度去除率为87％，远高于新鲜纳米TiO₂催化相同量的甲基橙后反应液色度去除率65％；再生后的纳米TiO₂光催化甲基橙10次后反应液色度去除率为37％，高于新鲜纳米TiO₂光催化甲基橙10次后反应液的去除率35％。湿机械化学-离子交换法可以对失效的纳米TiO₂进行多次再生，同样降解甲基橙一次和四次，再生过一次的纳米TiO₂降解率下降幅度为24％，再生两次的纳米TiO₂为26％，再生三次的纳米TiO₂为32％，均低于新鲜纳米TiO₂的下降幅度42％。并且为纳米催化剂在实际中长时间保持高催化性提供了途径，在静态紫外光催化甲基橙实验中，每催化一次甲基橙即对纳米TiO₂进行再生，再生后的TiO₂光催化甲基橙对色度的去除均维持在89％左右，对COD的去除率均在80％以上，接近新鲜纳米TiO₂首次用于催化甲基橙时的色度去除率89％和COD的去除率82％，保持了纳米TiO₂的高催化活性。湿机械化学-离子交换法的再生原理的原理是将离子交换作用和机械化学作用相结合，实现纳米TiO₂活性的恢复。这种再生方法不仅有效的恢复了纳米催化剂的活性，而且提高了纳米催化剂活性的保持能力，为纳米光催化剂的实际应用提供了一条新的途径。更多还原

【Abstract】 In the thesis, nano-TiO₂ was resuscitated by soft-mechanochemical ion exchange method. Methyl-orange was made as degradation object. COD, chroma and UV-Vis spectrophotometer were used as analysis methods in the experiments.By comparing photocatalytic activity of nano-TiO₂ before and after resuscitating, the effect of resuscitating was observed, the principle of resuscitating was analyzed.Soft-mechanochemical ion exchange method can resuscitate nano-TiO₂ which had lost activation. In the experimentation of dynamic UV-photocatalytic reaction, the removing percentage of COD is renewed from 41% to 65%, which is approach to 68% of the fresh nano-TiO₂. The removing percentage of chroma is renewed from 55% to 84%, which is approach to 87% of the fresh nano-TiO₂.This method can remove unfirm and firm absorbents which absorbed on the surface of nano-TiO₂. The removing percentage of the resuscitated nano-TiO₂ to chroma during fourth photocatalytic process is 87%, which is higher than 65% during eighth photocatalytic process of the fresh nano-TiO₂. The removing percentage of the resuscitated nano-TiO₂ to chroma during teneh photocatalytic process is 37%, which is higher than 35% during tenth photocatalytic process of the fresh TiO₂.This method also can resuscitate nano-TiO₂ many times. In the experiment , the degressive extent of nano-TiO₂ resuscitated one time photocatalyzed methyl-orange one time and four times was 24%, that of nano-TiO₂ resuscitated tow times was 26%, that of nano- TiO₂ resuscitated three times was 32%, all were lower than 42% of fresh nano-TiO₂’s. This method offers a method to keep higher photocatalytic activity in long time. In the experiment, nano-TiO₂ photocatalyzed methyl-orange one time was resuscitated. The removing percentages of the resuscitated nano-TiO₂ to chroma all were about 89%. The removing percentages to COD all were above 80%. Those approached to the fresh nano-TiO₂’s.The resuscitating process is what mechanochemical and ion exchange work together to resuscitate nano-TiO₂.Activity of nano-TiO₂ can be resuscitated and reused by soft-mechanochemical ion exchange method. The resuscitating conditions should be optimized and used in every photocatalytic process in order to purify the wastewater deeply.更多还原