Pesticides: Necessary, but not unproblematic
Pesticides can be inorganic (e.g., copper and sulfur) or organic. The organic pesiticides are often artificially produced substances, which are characterized by their high effectiveness against parasites. This property also makes them particularly toxic to aquatic organisms.
In order to reduce the concentration of organic pesticides in the water, a photocatalytic method, which has already proven itself in the laboratory, will be established within the PHOTOPUR project. The principle of this method is the generation of reactive oxygen species (radicals), which react with the organic pesticides and thus destroy them.
The reactive oxygen species are formed when a photocatalyst (a semiconductor material) is irradiated with ultraviolet light (e.g., sunlight). The water contaminated with pesticides is simply poured over an photocatalytically active area (the photocatalyte), while the latter is exposed to sunlight.