Preparation Of Bismuth Oxide And Its Efficiency For Catalytic Ozonation Of Dimethyl Phthalate In Water

Water is the source of life,The serious shortage of water resources in China,coupled with reform and opening up in the past 40 years,has resulted in serious waste and pollution of water resources.In the problem of water pollution,the persistent organic compounds in water supply are not only difficult to remove,but also can be enriched from drinking water and edible fish,shrimp and poultry to human body through the biological chain,thus seriously affecting human health.Therefore,the removal of POPs in water is particularly important.It is more urgent to study new,economic and efficient removal methods.Among these pollutants,methyl ortho phthalate two?DMP?is a kind of o-phenyl two formate?PAEs?,which is often touched in our daily life,because it can improve the elastic-plastic properties of the material,often added to plastic toys,food packaging bags,takeout boxes,personal care products.Ozone catalytic oxidation is a kind of advanced oxidation technology?AOPs?rising in recent years.It can produce strong oxidable hydroxyl radicals?·OH?in the reaction process,decompose harmful organic substances in water to produce CO2 and H2O.Catalytic ozonation technology is usually divided into homogeneous catalytic ozonation and heterogeneous catalytic ozonation.Heterogeneous catalytic ozonation is beneficial to recovery without secondary pollution.In this paper,DMP in water was removed by heterogeneous oxidation with bismuth oxide as catalyst.The modified bismuth oxide was prepared by adding different surfactants.The catalysts were tested XRD,SEM,FTIR,BET,XPS to determine the crystal form,valence,morphology,type of chemical bond,pore size and specific surface area of the catalyst.And the effects of ozone dosage,initial concentration of DMP,catalyst dosage,system temperature and p H on the removal of DMP were investigated,and then the reaction mechanism of catalytic ozonation of DMP in water was discussed.It was found that the removal efficiency of DMP in water by catalytic ozonation with catalyst Bi₂O₃-EG-450? was significantly higher than that by ozonation alone.When the influence factors of these two systems were investigated,it was found that the ozone dosage,p H and temperature of solution were all positively related to the removal efficiency of DMP,with the enhancement of theinfluence factors,the removal efficiency of DMP would be improved.While the catalyst dosage and the initial concentration of DMP have a positive correlation with the DMP removal rate in a certain range.If the catalyst dosage exceeds a certain range,the reaction will be inhibited and the DMP removal rate will decrease.