Wastewater Treatment by Photocatalytic Process Using Photocatalyst-coated Materials

In Thailand, there are many industrial factories. Each factory has different production
processes which produce various types of wastewater. The color of wastewater comes from
organic and inorganic pollutants. If the wastewater is not properly handled, it will affect humans
and the environment.[2] The main purpose of this study is to reduce the color of wastewater by a
photocatalytic process with TiO2-coated materials (i.e., glass, ceramic tile, and stainless steel)
using the sol-gel method under UV irradiations. The results showed that the optimum substrate
and light source that yielded the highest color removal efficiency were TiO2-coated glass sheets
under UV irradiation. The actual wastewater from the textile industry was tested in this study,
and a high removal efficiency was obtained (92.2%). In addition, the reusability of the TiO2-
coated glass sheet was also evaluated. It was found that the TiO2-coated glass sheet showed the
same efficiencies for 5 times of reuse. This process can also decrease the time in the wastewater
treatment process, which is not necessary to remove TiO2 from the treated wastewater before
releasing it into public water sources.