A Modular Stand-Alone Photocatalytic Reactor for Waste Water Purification: The HPSolar Project

In this work we present the construction and performances of a photocatalytic reactor developed for the HPSolar project, the purpose of this reactor is the treatment of water in order to remove pollutants like drugs or pesticides that are not removed effectively by present water treatments. The reactor is modular and composed by multiple elementary cells where the photocatalyst is a thin layer of tungsten trioxide biased positively with respect to a metallic cathode; this polarization is switched periodically in order to restore the functionality of the anode. The cells are completely self-reliant because are powered by four solar cells laying behind the semi-transparent anode while a microcontroller integrated into each cell applies the biasing cycles. The abatement measurements on atenolol and carbamazepine show that this device can remove 70% of the drugs from a sample of water within 5 and 7 hours respectively.