Removal Of Taste And Odor Compounds And Humic Acid In Water With TiO₂-doped Photocatalytic Separation Membranes

Taste and Odour（T&O） materials of water source not only affect thequality of drinking water, even worse can affect human body conditions.Events of T&O which resulted from the deterioration of water sourcedirectly influence the normal life of citizen population and were closedwatched by society.Natural organic matter （NOM） can produce a host of disinfectionby-products（DBPs） and is a typical membrane fouling matter,HumicAcid（HA） is the most important part of the natural organic matter.Ultrafiltration（UF） allows the removal of particle, microorganism, varietyof water born viruses, colloid and certain amout of the dissolved organicmatter. It has become one of the best alternatives replacing conventionaldrinking water treatment technologies. However, UF is not veryeffectively to remove NOM due to comparatively large pore sizecompared with the size of NOM. Meanwhile, membrane fouling isanother factor which restricts its widespread application.In this study, the modified photocatalytic polyvinylidene fluoride （PVDF） membranes were prepared by adding different doses ofpolyethylene glycol （PEG） and TiO₂nanoparticles through the phaseinversion process （PIP） method, and were characterized by scanningelectron microscope （SEM）, atomic force microscope （AFM） and energydispersive spectroscopy （EDS）. The rejection and membrane fouling ofPVDF-PEG （P-P）、 PVDF-PEG-TiO₂（P-P-T）、 PVDF-LiCl（P-L） andPVDF-LiCl-TiO₂（P-L-T）membranes were investigated during filtrationof Taste&Odour（T&O） and humic acid （HA）.The following main results were obtained:The good hydrophilicity、good separation and good anti-foulingTiO₂-doped photocatalytic separation membranes were prepared byadding different doses of PVDF,PEG,LiCl and TiO₂.The membrane fouling of TiO₂-doped photocatalytic separationmembrane can be effectively decreased by UV irradiation. The removalrate of T&O materials were different under the UV irradiation, and theremoval mechanism were somewhat complex. Adsorption, Photo initiatedoxidation and photocatalytic degradated may be the reasons to removeT&O materials.pH can effectively influence the effect of TiO₂-doped photocatalyticseparation membrane photocatalytic degradated T&O. The lower of pH,the performance of photocatalytic degradation is good, and the fluxdecline rate is smaller. When pH equals to3.5, the better removal rate of DMTS,2-MIB, GSM, β-ionone, however, the removal rate ofβ-cyclocitral declined.The removal rate of HA can be improved with TiO₂-dopedphotocatalytic separation membrane and the membrane fouling alsodeclined.Different of UV intensities can different influence the fouling ofTiO₂-doped photocatalytic separation membrane. The results indicatedthat the higher UV intensity, the better flux decline rate.UV irradiation can different influence the flux decline rate indifferent initial concentration of HA. The results indicated that the initialconcentration of HA solution was lower during UF, the flux decline ofmembrane could be decreased more effectively by photocatalysis...