Preparation And Activity Of Metal Supported Heterogenous Catalyst In Catalytic Ozonation Of TNT

Catalytic ozonation of refractory organic model compound by the heterogenous catalysts is receicing increasing attention from environmental scientists. Research had confirmed the strength and performance of the catalysts were directly depending on autocatalysis and applied model compound. War industry produced a great deal of TNT waste water in our country every year;it may endanger human being and creature in many ways. However, traditional technology of water treatment can not result in contaminates mineralization;Catalytic ozonation can be an effective process for waster water. More study is needed on preparating proper catalyst.The targets of TNT mineralization were invaluated by changing of the TNT concentration, ozone decompostion and byproducts. Through experiment, active species and support were selected , supported metal oxide heterogenous catalyst were prepared, and the activity and selectivity of the catalysts for TNT were evaluated, the mechanism were conferred .The results indicated: metal ( iron, copper, zine etc)hydrous oxide and the compound hydrous oxide have certain catalytic ozonation ability, the activty of the hydrate ferrous oxide(HFO) is most remarkable, Choose the HFO as the effective active species, its main carystal is α -FeOOH , rational peparation parameter were: T=120℃, partical diameter 0.074-0.125 μm. γ-Al₂O₃, granular active carbon(GAC), power active carbon(PAC), 5A molecular sieves supports have a better adsorption and the catalytic ability, especially the PAC modified by H₂O₂ show remarkable adsorption and the catalytic ability, and it was choosed as catalyst supports. Metal oxide Supported heterogenous catalyst was prepared by thrice precipitation-adsorption at 1% impregnant, and HFO content was 50mg/g. The rational parameter of catalytic ozonation TNT by metal oxide Supported heterogenous catalyst were: catalyst 0.9g, ozone 0.08 m³/h, neutral pH . As catalyst had a long time activity and small rion drain, it was suitable for TNT waster water treatment practically .Catalyst can enhance 83% of ozone decomposition rate, and it may change the mechanism of reaction, the catalytic ozonation reaction mechanism propablely to be hydroxyl radical mechanism.