Photocatalytic oxidation: the process and its practical applications

Photocatalytic oxidation (PCO) is a novel wastewater treatment process which converts contaminants into environmentally acceptable and products such as CO₂ and H₂O. Production of dilute acids such as HCl and HNO₃ during the PCO of organic compounds is also possible, depending on the type of organic degraded. PCO is a promising wastewater treatment technology in which organic contaminants typically can be completely converted to end products such as CO₂ and H₂O. the rate dependence of PCO on the initial concentrations of the organic substrate, as well as oxygen, is described by Langmuir Hinshelwood kinetics. There is an optimum value of photocatalyst specific surface area at which maximum removal of organics is observed. The PCO rate increases nonlinearly with the incident light intensity. Studies using sunlight as the energy source have yielded promising results, which suggest that the PCO process can be made more cost efficient, paving the way for practical uses.