Abstract:
Nano-titanium dioxide (nano-TiO2) photocatalyst was synthesized through sol-gel
method. A sol-gel solution was prepared using the formulation of 1 TTIP: 2 C2H5OH: 5.
H20. A simple batch reactor was designed and used for process studies. The
photocatalytic degradation of methylene blue was studied under different operating
parameters. The initial methylene blue concentration, catalyst dosage and pH value of
methylene blue were studied as important process variables. The nano-TiO2 catalyst was
characterized by using Scanning Electron Microscopy (SEM) and Energy Dispersive
X-ray Spectroscopy (EDX) analysis. The degradation of Methylene Blue (MB)
concentration under UV radiation is more efficient compared to without ultraviolet (UV)
radiation. The highest percentage of degradation was achieved when the concentration
of methylene blue was at 20ppm. The degradation of MB increased with an increase in
catalyst dosing up to an optimum loading of 0.75g. Degradation efficiency decreased in
the order of pH2 > pH5 > pH7 > pH9. The photocatalytic degradation of methylene blue
shows a pseudo-first order kinetics. The highest apparent rate constant, kapp was
achieved at the initial concentration of 20ppm, which is 0.0183min-1. The kinetics
evaluation on methylene blue degradation was also studied to determine the rate
constant, k and adsorption equilibrium constant, K. The value of k and K were estimated
by using non-linear regression in POLYMATH software.
