Abstract:
The major objective of this research was to investigate a removal efficiency of the odour by
photocatalysis of titanium dioxide coated on activated carbon (TiO/AC). The equipment consists of
three main parts: heat exchanger, electrostatic precipitator and TiO/AC. The experiment was
carried out at the voltages of 0, 4 and 8 kV, relative humidities of 30, 40 and 50%, air velocity of
0.5 m/s and temperature of 40?C. The formaldehyde at concentrations of 4.14, 9.24 and 14.11 ppm
was used as odour representative. The experimental results showed that the overall removal
efficiency of the odour leaving from the equipment was not increased with increasing voltage, but it
can be improved by increasing a relative humidity. In addition, it was also found that this system
can remove formaldehyde in larger quantity at high concentration than at low concentration. The
best condition for removal of formaldehyde in this experiment was at 50% relative humidity with no
electric field applied. Considering the removal efficiency in each part of the equipment, it was found
that the removal efficiency of heat exchanger part was higher than that of the TiO/AC part at
formaldehyde concentration of 4.14 ppm. When the formaldehyded concentration increased to 9.24
and 14.11 ppm, the efficiencies of both parts were nearly equal. Using the best condition to treat
formaldehyde at concentration of 0.77 ppm (concentration level that found in industry), it was
revealed that this system can remove formaldehyde with the efficiency of 38.4%.