Effects of pH on photocatalysis of trichlorophenol
- Bangkok : Asian Institute of Technology, 1993
- 66 leaves + 1 online resource
- Thesis ; no. EV-93-25 .
- Asian Institute of Technology. Thesis ; no. EV-93-25 .
A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering
Thesis (M.Eng.) - Asian Institute of Technology, 1993
The effects of pH on the photocatalytic decomposition of 2,4,6-trichlorophenol (TCP) with UV illuminated titanium dioxide powder in aqueous suspension were investigated. A first order reaction with respect to 2, 4, 6-TCP concentration was obtained. Higher degradation rate was observed under alkaline condition than acidic condition. The role of adsorption of 2,4,6-TCP onto the TiO2 surface was found insignificant in photocatalysis. The reaction rate was enhanced by the addition of sodium chloride at pH 10. But at pH 5 a decrease in reaction rate was observed. The photocatalytic decomposition of deaerated TCP solution with or without sodium chloride addition gives lower degradation rate than with dissolved oxygen at different pH. A mechanism for the reaction based on photogeneration of hydroxyl radical was proposed. For a 20 mg/L of 2,4,6-TCP the average rate of solar degradation resulted in a decrease in concentration to 2 mg/L within 160 min. Higher potentiality of solar energy for the purification of water containing 2, 4,6-TCP was found.