| Activated carbon fiber (ACF) is an excellent adsorbent with tremendous adsorptive capacity, rapid regeneration process and facility of operation. However, ACF has weak regeneration ability for macromolecular substance or high boiling point substance. In many cases the adsorptive environment contains these difficultly regenerating substances which would accumulate on the surface of ACF and block the entrance of the micropore. Thus, ACF may loss its adsorptive capacity for any substance. Moreover, ACF is expensive, only repetitive use could improve its cost performance and increase its competitive power in market. Our objective is to improve the regeneration ability of ACF for macromolecular or high boiling point substances. Photocatalytic oxidization technology has been introduced to remove the substances adsorbed on the surface of ACF. Because the photocatalytic oxidization not only has wide-ranging applied substances but also can degrade compounds rapidly and thoroughly.We developed two types of photocatylytic ACF adsorbent by combining the TiO2 photocalyst via sol-gel method. (1). TiO2 is directly supported on the surface of ACF. Ti(OC4H9)4 was used as the precursor of TiO2. Mixing Ti(OC4H9)4, alcohol, acetic acid,water and AcAc, undergoing a aging process of a week, the TiO2 sol was obtained. ACF felts were dipped into this sol for several minutes and then were disposed in a supercentrifuge machine to remove the redundant sol and control the amount of sol by centrifugal force. After centrifugation, the TiO2 sol coated ACF felts were heat treated in a carbonization furnace at 550癈 for 3 hours and anatase TiO2 coated ACF felts were obtained. The regeneration ability of this TiO2 coated ACF felts were investigated by using PVA and citric acid as macromolecular and high boiling point substances. TiO2 coated ACF felts were be soaking in to the PVA or citric acid aqueous solution to reach the saturated adsorption state, then the saturated adsorbent were irradiated under the UV light. The results show that the TiO2 on the ACF's surface can degrade the organic compounds adsorbed on the ACF effectively under the irradiation of UV light. The special surface area and the adsorption capacity of ACF only decrease in the first photocatalytic regeneration slightly and maintain constant for the following regeneration process. The feasibility and superiority of regenerating ACF by photocatalysis were confirmed. Meanwhile, we investigated the morphology of TiO2 on the ACF's surface by analyzing the nitrogen adsorption isotherm and SEM photos. The results indicated that the shape of TiO2on ACF's surface was spherical segment with the diameter of about 250nm. (2). Improving the regeneration ability can enhance the total service lifeof ACF by increasing the repetitive use time, on the other hand, extending the service life of a single operation can prolong the total service life as well. Moreover, considering that TiO2 directly coated ACF would destroy the adsorption capacity of ACF in a certain extent, we employed TiO2 coated glass fiber mesh to give ACF the photocatalytic ability. Using the sol-gel procedures, we prepared titanium dioxide (TiOi) thin films on the surface of glass fiber mesh via using the tetra-n-butyl titanate (Ti(OC4H9)4) as precursor. After heat treatment at 550 degree centigrade for 3 hours, amorphous TiO2 films were transformed to anatase as comfirmed by the XRD analysis. Wrapped the ACF felts with this glass mesh coated with TiO2 films, the sandwich-like photocatalytic adsorbents were obtained. The decolorization capability and the decolorization kinetics of this photocatalytic adsorbent for methylene blue were investigated via determining the absorbance measurements of the methylene blue solution. Both static and dynamic reaction were performed with irradiation of two 40w UV lamp with dominant wavelength of 253.7nm. The results show that TiO2 and ACF in the photocatalytic adsorbent improve the performance in coordination: TiO2 prolong the service life of ACF and ACF accelerate th...
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