PHOTO-TREATMENT OF AQUEOUS SOLUTIONS OF FIVE MEDICINES

In this work we investigated the effect of sunlight and its combination with TiO2 and sea-salt for the removal of five medicines, i.e. Zinadol, Zyrtec , Pricefil, Pariet and Panadol. Aqueous solutions of the ready for consumption medicine were subjected to direct photolysis and TiO2 photocatalysis with and without untreated sea-salt in the average concentration that it is encountered in the sea (3.5% w/w). The samples were exposed to sunlight for up to a few months and they were analysed via UV measurements and TOC analyses. Direct photolysis of the medicines resulted in some degradation of all medicine solutions in all cases but in the case of Panadol. The photocatalyst TiO2 seemed to play a more complex role, depending on the employed medicine and on whether NaCl was present or not. In all photocatalytic measurements without NaCl, UV absorption was constantly reducing; however, TOC was usually increasing after being reduced for some time, thus indicating desorption of intermediate products in the aqueous solution. This was not the case however, in NaCl-containing photolytically treated solutions; NaCl increased their resistance to degradation. Therefore, these medicines cannot be removed naturally from sea-water. Photocatalysis seems to be a very good method for Panadol minaralisation.