Study Of Photocatalytic Degradation Of Environmental Hormone PAEs

The adsorption of diethyl phthalate (DEP) on the surface of nanoscale titaniumdioxide, effects of pH value of solutions, initial concentrations of DEP and additivesurfactant on photocatalytic degradation of DEP, kinetic dynamics of photocatalyticdegradation of DEP were studied in aqueous TiO₂ suspensions under UV lightirradiation in the present paper. Photocatalytic degradation of DEP was pseudofirst-order reaction kinetics. The reactant was degraded fast when its initialconcentration was low. TiO₂ had certain adsorption ability to DEP. TiO₂ could adsorbmost DEP in partial neutral solution. Degradation rate of DEP was not effectedobviously by additives of nonionic surfactant nonylphenol poly( oxyethylene ) ether( OP-10 ) and anionic surfactant sodium dodecyl benzenesulfonate ( DBS ). Speed ofdegradation of DEP was not enhanced obviously, but degradation of DBS wasspeeded up in the presence of DEP. Degradation rate of DEP was depressed byadditive of cationic surfactant cetyl trimethyl ammonium bromide ( CTAB ). Themore CTAB was added in, the slower DEP was degraded. Degradation speed ofCTAB became slowly with the increase of CTAB initial concentration. Adsorptionmodel was given in the present paper.The photocatalytic degradation of DEP in water was also studied with sepiolitesupported nanoscale TiO₂ as catalyst. Two kinds of carrier catalysts were prepared.One of them was A101/sepiolite catalyst manufactured by directly mixing TiO₂ andsepiolite, the other was TBT/sepiolite catalyst in which nanoscale TiO₂ was preparedwith Ti(OC4H9)4 through sol-gel method and then supported on sepiolite. The resultsof experiments showed that the rate of photocatalytic degradation was affected by theamount of catalyst and the load of TiO₂. For A101/sepiolite catalyst, the load of TiO₂has great effect on its photocatalytic activity and the rate of DEP's degradation, whilefor TBT/sepiolite catalyst, the amount of catalyst has leading influence on itsphotocatalytic activity and DEP's degradation. The morphography and crystal form ofthe supported catalyst was analyzed by x-ray diffraction ( XRD ) and scanningelectronic microscope ( SEM ).