Photochemical oxidation of thiophene in n-octane/water extraction system by using air as oxidant was studied.Results obtained here can be used as the reference of oxidative desulfurization of gasoline because thiophene is one of the main sulfur-containing components in fluid catalytic cracking gasoline.A 500 W high pressure Hg lamp （wave length 365 nm, 0.19 kW·m -2 ） was used as the light source for irradiation and air was introduced by a gas pump for supplying O2.Thiophene dissolved in n-octane was photodecomposed and removed into the water phase at ambient temperature and atmospheric pressure.Thiophene can be photo-oxidized directly to sulfone,sulfoxide, or ethanedioic acid,SO 2- 4 ,CO2.The photo-oxidation kinetics of thiophene with O2 was first-order with rate constant of 4.42×10 -5 s -1 and half-time of 4.36 h.The desulfurization yield of thiophene in n-octane was 58.9% for a 5 h photo-irradiation under the conditions with air flow at 150 ml·min -1 and water/oil ratio at 1∶1.The sulfur content could be reduced from 800 μl·L -1 to less than 330 μl·L -1 .
Photocatalytic activities of TiO2 and NaY zeolites-supported TiO2 were investigated with omethoate as a model pollutant.The physical and chemical states of NaY zeolite-supported TiO2 were evaluated via XRD,FTIR,BET and SEM.Photodegradation of omethoate was studied with H2O2 as oxidant and TiO2 supported on NaY zeolite as photocatalyst.Parameters involved in the photo-catalysis of omethoate,i.e.,the calcination temperature of the photocatalyst,initial omethoate concentration,the amount of TiO2 loaded on NaY zeolite,photocatalyst dosage and H2O2 concentration were investigated in detail.The results show that TiO2/NaY zeolite prepared by means of sol-gel method exhibited a good photocatalytic activity for the degradation of omethoate.Optimum conditions included the calcination temperature of photocatalyst 550℃,initial omethoate concentration 500 mg/L,the amount of TiO2 loaded on NaY zeolite 35%（mass fraction）,the amount of photocatalyst 5 g/L,H2O2 concentration 30 mL/L and an irradiation time of 180 min.The removal of omethoate was up to 93%.Kinetics parameters of the photocatalytic degradation of omethoate were measured and calculated.The result shows the kinetics of photocatalytic degradation of omethoate is first-order.
