Photocatalytic oxidation of
formaldehyde (HCHO) in K2SO4
solution using ZnO or SiO2 as catalyst under ambient
conditions is studied. The effects of UV illumination time, catalyst (herein, ZnO or SiO2)
content (m/V), HCHO initial concentration, pH, and K2SO4
concentration on the photocatalytic oxidation of HCHO are determined. The presence of SiO2 (1.0 g/L) can enhance the photocatalytic
oxidation of HCHO (2.0´10-2 g/L)
from ~7.1% to ~19.2% after illumination time of 24 hours. The photocatalytic oxidation of HCHO is dependent on pH value, but independent of ionic strength. The results are
important for the application of natural sand (SiO2) in the
treatment of HCHO pollution in the eutrophic solutions, and for
the evaluation of the elimination of organic pollutants by photocatalytic
oxidation in the environmental pollution cleanup.