Papers by Author: Nuttaporn Pimpha

Abstract: Nitric acid modified water treatment sludge (NS) was used as an adsorbent for methylene blue (MB) removal from aqueous solution in a batch experiment system. Surface area and pore volume were characterized by BET-N₂ method. Zeta potential measurements of the NS showed a negatively charge which has the potential to attract positively charged molecules. The effect of initial MB concentration and initial pH solution were investigated. When the initial MB concentration was increased, the percentage of MB removal decreased accordingly while the amount of adsorbed MB on NS at equilibrium time (q_e) increased. For the effect of initial pH solution, the adsorption of MB was increased with increase in pH. The maximum removal was observed at pH 11. The result indicates that NS can be used as low cost adsorbent in wastewater treatment for cationic dye removal.

Abstract: Titanium dioxide nanofibers were fabricated by electrospinning technique. The titania solutions were obtained from adding various types of Ti precursor (Ti(OBu)4, Ti(OiPr)4, and Ti(OPr)4) to an ethanol solution containing polyvinyl pyrrolidone (PVP). Acetic acid was used to stabilize the solution and to control the hydrolysis reaction. The porous and well-defined crystalline structure was obtained after calcined at 450oC for 1 h. The thermal behavior, phase composition including crystallite size, as well as the morphology of as-synthesized nanofibers was obtained from thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The average diameter of these nanofibers was in the range from 100 to 400 nm depending on titania precursor. The photocatalytic activity of TiO2 fibers were evaluated for NOx degradation in a gaseous phase. The results demonstrated that at the same catalyst loading, the photocatalytic activity of TiO2 nanofiber was higher than the commercial Degussa P-25.