Study Of Photocatalytic Degradation Of Dimethyl Sulfoxide And The Impact Parameters

As the development of industry, plenty of organic compounds have been sent to environment, causing severe problems to people's health. The toxicity of dimethyl sulfoxide (DMSO) itself is not very high, but as a widely used industrial solvent and additives, the researches on the effective treatments of DMSO is still a topic meaningful. It's hard to degrade by traditional biochemical method because of its lowly biodegradable characteristic, so the researchers have focused on the treatment by chemical oxidation and advanced oxidation processes.Persulfate ions can act as an electron acceptor who can prohibit the recombination of electron/hole and in the same time improve the production of the radicals (? OH and ?SO42-). So it's useful to add this ion in the sysytem photocatalytic for improvements.Firstly, the study of degradation of DMSO by catalysts immobilized on the alumnium and stainless steel was made. Then comparation of two kinds of titanium dioxide particles who has different crystal structures has been investigated. And the comparation of different kinds of catalysts was made .Then research of the stability of persulfate ions (S2O82-) has been made in this titanium dioxide/ ultraviolet (TiO2/UV) system using Degussa P25 suspension as the catalyst because it has shown better performance for the degradation of DMSO in preceding research. Then research of the degradation of DMSO has been made in this photocatalytic system in presence of persulfate ions. Influences of these parameters have been compared: different concentration of persulfate ions, different dose of catalyst added, different concentration initial of DMSO and different pH condition on the degradation of DMSO in syetem TiO2/UV in presence of persulfate ions. Finally, the study has been made in comparation of the sulfur compounds during the reaction in this two system photocatalytic: with presence of persulfate ions and without presence of persulfate ions.The results show that, for the immobilized catalysts, there are some parameters that can have influence to the degradation of DMSO. The suspension of catalysts has a higher rate of DMSO remove compared with immobilized catalysts. And he catalyst P25 of the company Degussa has shown better performance for the treatment of DMSO. In the kinetic studies, it shows that the degradation of persulfate ions in system photocatalytic correspond with the model Langmuir- Hishelwood of 1 order. It is the same for the degradation of DMSO in presence of persulfate ions. The presence of sulfate ions can improve activity of the system photocatalytic. It has influences on the concentration and evolution of sulfur intermediates too. In general, the presence of persulfate can help to improve the photocatalytic activity of the system. And the addition of oxidants in the photocatalytic system is a promising research topic.