NaClO催化氧化法对酸性大红3R废水的脱色降解

Decolorization and degradation of acid red 3R wastewater by NaClO catalytic oxidation

采用NaClO催化氧化法对酸性大红3R废水进行脱色降解,探讨了反应条件对出水脱色率和Ni^(2+)溶出量的影响,分析了染料的降解机理。结果表明,该方法对染料的脱色效果优异,脱色率随着染料浓度的增加而降低,随着pH、有效氯和催化剂投加量的增加而升高。连续流实验的脱色率达到90%以上,运行约3000 min,催化剂没有出现失活现象。原子氧/单线态氧在染料降解过程中起了重要作用,在降解产物中未发现有毒的氯代有机化合物。采用扫描电子显微镜(SEM)、X射线衍射(XRD)和X射线光电子能谱(XPS)对浸渍法制备的催化剂表层进行表征,结果表明催化层较为均匀且致密地包裹在Al_(2)O_(3)小球表面,其中含有β-NiOOH和β-Ni(OH)_(2)物相,化学吸附氧占比高。研发的新工艺在印染废水处理中具有一定的应用潜力。

The decolorization and degradation of acid red 3R wastewater by NaClO catalytic oxidation were systematically studied.The effects of reaction conditions on decolorization rate and Ni^(2+) dissolution in effluent were discussed,and the degradation mechanism of the dye was analyzed.The results showed that this method had a good decolorization effect.The decolorization rate decreased with dye concentration,and increased with pH,available chlorine and catalyst dosage.The decolorization rate of continuous flow experiment was over 90%,and the catalyst was not deactivated after about 3000 min operation.Atomic oxygen/singlet oxygen played an important role in the degradation of acid red 3R,and no toxic chlorinated organic compounds were found in the degradation products.SEM,XRD and XPS were used to characterize the surface layer of the catalyst prepared by impregnation method.The results showed that the catalytic layer was uniformly and densely coated on the surface of Al_(2)O_(3) beads,which containedβ-NiOOH andβ-Ni(OH)_(2) phases,and the proportion of chemisorbed oxygen was high.The developed new technology had certain application potential in printing and dyeing wastewater treatment.