3.1. UV and UV/H2O2
Direct UV light was used to determine the degree of photolysis
of formaldehyde and methanol. It was found that the
degradation percentage of formaldehyde and methanol using UV
alone are 1.5 and 2%. Both substances were not well degraded
with the photolysis reaction. When UV-irradiation was combined
with hydrogen peroxide, the degradation of formaldehyde
and methanol increased significantly compared to that when
using direct photolysis. Fig. 1(a and b) show the decrease of
formaldehyde and methanol as a function of irradiation time.
The experimental conditions of each experiment are shown in