In this study, the degradation of molinate using heterogeneous and homogeneous photocatalytic methods has been investigated. The main objectives of the study were: I) to evaluate the kinetics of the pesticide disappearance in aqueous media of different composition such as river, lake and deionized water, II) to compare the photocatalytic efficiency of the two different types of photocatalysis, III) to examine the influence of various parameters such as initial concentration of pesticide or catalyst, pH value and presence of oxidants such as H₂O₂ and K₂S₂O₈ or different inorganic anions in the case of homogeneous process IV) to evaluate the degree of mineralization, V) to assess the detoxification efficiency of the studied processes.
Parameters such as iron’s and oxidant’s concentration and inorganic ions strongly affect the oxidation rate. In comparison to TiO₂ assisted photocatalysis, this system achieved slightly higher degradation rates.
The detoxification efficiency was found to be dependent on the system studied and, although it did not follow the rate of pesticide disappearance, it took place in considerable extent. From the point of view of practical application, it should be also noted that these methods give the opportunity of using the solar irradiation as well and they can be selected among the most popular solar technologies. Combining this fact with the effectiveness of the methods and the ability to be teamed up with other conventional technologies, photocatalysis could be considered as an alternative, promising method for the treatment of pesticide contaminated waters and wastewaters.