PILOT-PLANT PHOTOMINERALIZATION OF S-TRIAZINES IN AQUEOUS-SOLUTION, BY PHOTOCATALYTIC MEMBRANES IMMOBILISING TITANIUM-DIOXIDE AND TRIALKYL VANADATES PHOTOCATALYSTS

A membrane module, utilizing photocatalytic membranes, has been employ ed in a pilot plant to investigate photomineralization of propazine, t erbuthylazine, simazine, prometryn, and ametryn, as model molecules of s-triazine herbicides, at concentrations (0.5-10 mu M) simulating tho se of contaminated aquifers, by using ozone as oxygen supplier. Photoc atalytic composite membranes immobilised 30+/-3 wt.% of TiO2 and 6 wt. % of a synergic mixture of tri-(t-butyl)and tri-(i-propyl)vanadate(V). Photomineralization was followed by total organic carbon (TOC) analys is. Quantum yields, as indicative of catalytic and photocatalytic mech anisms, were evaluated, discussed, and compared with that of atrazine photomineralization.