Immobilized Tio2/Activated Carbon Bilayer System For The Removal Of Phenol Via Photocatalytic-Adsorptive Processes
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Date
2012-04
Authors
Bahrudin, Noor Nazihah
Journal Title
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Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Titanium dioxide (TiO2) and activated carbon (AC) had been combined in an immobilized bilayer arrangement on glass plates for the removal of phenol. The immobilized monolayer AC/ENR50/PVC and bilayer TiO2/AC/ENR50/PVC systems have been successfully fabricated via a dip-coating method. The adhesives used in both activated carbon and TiO2 dip-coating solutions were ENR50/PVC blends. The purpose of the fabrication was to photocatalytically remove phenol from aqueous solution as opposed to the conventional suspension method. Adsorption kinetic and isotherm studies of TiO2/AC/ENR50/PVC and AC/ENR50/PVC were also conducted whereby both systems followed second order kinetic model of Lagergren’s but for isotherm study, the TiO2/AC/ENR50/PVC system obeyed Langmuir whereas the AC/ENR50/PVC system obeyed Freundlich. The optimum AC/ENR50/PVC loading was 2.5 mg cm-2 while the optimum TiO2/ENR50/PVC loading on the AC/ENR50/PVC layer was 0.32 mg cm-2. It was found that the TiO2/AC/ENR50/PVC bilayer system operated simultaneously via the incorporation of the two processes i.e adsorption of phenol into the AC/ENR50/PVC layer and photocatalytic degradation of phenol by the TiO2/ENR50/PVC layer. The single layer of TiO2/ENR50/PVC followed pseudo first order rate constant of Langmuir-Hinshelwood equation whereas the single layer of AC/ENR50/PVC showed the pseudo second order rate constant. Therefore, TiO2/AC/ENR50/PVC followed the pseudo second order rate constant since the adsorption process was more favourable than the photocatalytic process in the bilayer system. The effects of some operational parameters such as pH of the solution, light intensity and O2 supply were also studied and were found to be optimized at pH 6, 6.0 Wm-2 of UV leakage and 100 mL min-1 of aeration rate, respectively. The comparison between TiO2/AC/ENR50/PVC and TiO2/ENR50/PVC was based on the removal efficiency for all the parameters studied. The mineralization of phenol was observed through COD test. The reusability and COD tests were also done under solar irradiation for practical applications. SEM-EDX, BET, FT-IR, CHN, PL and TGA are some physical characterizations used to describe the process phenomenon before and after applications.
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Keywords
Titanium dioxide, activated carbon combined in an immobilized bilayer , arrangement on glass plates for the removal of phenol