Alumina And Ammonia-Modified Cnt Are Used To Enhance The Activities Of Catalytic Ozonation For The Degradation Of Carboxylic Acids

This paper includes two parts. The first part introduces the impact of the crystalline phases and morphology of the catalysts on the catalytic activities of alumina. The catalytic activity of the samples was tested by using degradation of PA in aqueous solution in the presence of ozone. The other part presents the catalytic activity of a series of ammonia-modified multi-walled carbon nanotubes which was prepared via hydrothermal method. It was evaluated by degradation of OA in aqueous solution.A series of different of crystal phases and morphology of Al2O3powder was prepared by appropriate calcinations. For correlating the physicochemical properties of the catalysts with the heterogeneous catalytic degradation of PA in the presence of ozone, the Al2O3powders were characterized by the means of XRD, TEM, BET measurements and the determination of the amount of surface hydroxyl groups. The crystal phases and morphology of the catalysts were studied by. We can conclude that large surface areas and the a-phase of Al2O3facilitate the degradation of PA with ozone. We also discovered morphology effects were found to be negligible in our experiments.Another series of ammonia-modified multi-walled carbon nanotubes was prepared via hydrothermal method. The catalytic activity of the samples was evaluated by degradation of oxalic acid in aqueous solution in the presence of ozone. The structure and surface properties of the catalysts have been well characterized by TEM, FTIR and Boehm titration. It was found that reaction process can be fitted to zero-order reaction kinetics. The zero-order apparent rate constant had a positive relation with the basic groups and pHPZC of the catalysts. On this basis, it is concluded that the significant enhancement of oxalic acid degradation by hydrothermal treatment with ammonia should be because the method promote the formation of basic groups and the increase of pHPZc-The main objective of this study is on enhancing the removal of refractory wastewater by catalytic ozonation, and it could accumulate the data of catalytic activity.