TiO₂ Pillared Bentonite And Its Photocatalytic Adsorption Activity Of Oil-wastewater

Oil-wastewater is provided with complicated structure,high density and more substance which is hard to degrade,and it contains lots of inorganic salts,sulfide and many kinds of bio-toxicity organic compounds.It is hard to treat with common methods.TiO₂ semi-conductor photocatalysis used recent years is an advanced technique of water-treatment which can destroy organic pollutant,without secondary-pollution,low consumption of energy and material,simple process.So it is a hopeful method of water-treatment.But traditional TiO₂ semi-conductor photocatalysis is restrict.Because the photocatalyst is easy to aggregate,loses activity and goes against recovery.In this paper,with these methods(XRD,FT-IR,TG-DTA,BET and DRS), Fe-TiO₂-pillared bentonite is prepared,and the influence of calcination temperature and a mount of iron ion-doped on the structure and degradated activity are studied.(1) TiO₂-pillared bentonite composites with iron ion doping are prepared.Results show that iron ion lie in the shape of noncrystal,which have no effect on the d001 basal spacings.Compared with TiO₂-pillared bentonite,BET special surface area has been increased slightly.For Fe³⁺-doped TiO₂-pillared bentonite,1.5%Fe³⁺ content have the highest adsorptive and photocatalytic activity.After adsorption process,the oil,COD and TOC decontamination of oil wastewater is 92.5%,85%and 80%, respectively.The oil,COD and TOC decontamination of oil wastewater is 98.5%, 96%and 82%in photocatalytic process with irradiation time 4h,respectively.(2) It has been found that TiO₂-pillared bentonite has the best samdwich and TiO₂ nanoparticles,the crystal type of which is Anatase,are distributed into the layers of bentonite.The d001 basal spacings,BET special surface area,the thermal stability and adsorptive and photocatalytic activity of composites are all enhanced compared with bentonite.Results indicate that TiO₂-pillared bentonite,which is calcinated at 473K,exhibite the highest adsorptive and photocatalytic activity,while the TiO₂-pillared bentonite,which is calcinated at 773K exhibite the lowest adsorptive and photocatalytic activity.After adsorption process,the oil,COD and TOC decontamination of oil wastewater is 63.5%,78%and 65%,respectively.The oil, COD and TOC decontamination of oil wastewater is 77%,70%and 82%in photocatalytic process with irradiation time 4h,respectively.