Application of Photocatalytic Hybrid Composites in Waste Water Treatment

Since the mid-1990s, numerous studies on the treatment of natural and industrial waters by photocatalysis have been reported. Once optimized, the photocatalytic process can completely degrade numerous inorganic and organic compounds and make the difference when large surfaces of water, such as lakes or seas, are polluted as a result, for example, of catastrophic events and criminal actions. In this study, a photocatalytic floating hybrid device was developed for the remediation treatment of surface waters containing organic pollutants and their vapors, such as fuels, oils and chemical products, which may be impractical and expensive to remove using conventional filtration or coagulation methods. The innovative device proposed here is a multilayer polymeric/TiO2 composite with a hydrophobic/superhydrophobic side, necessary to ensure the device flotation during its application in water, and a photocatalytic layer as active agent for pollutant degradation. The hydrophobic side was obtained by synthesizing a Polyacrylic-based polymer being oxygen permeable and having high photo-chemical, mechanical and thermal resistance by a novel procedure involving the use of fluorinated co-monomers and controlling the polymeric foil morphology during solvent casting deposition, making the material suitable for indoor and outdoor applications [1,2,3]. On the other side of the polymeric foil, the photo-active titania-based film, obtained by an ad hoc multi-layer spray-coating procedure developed both to preserve the polymeric support properties and favor the adhesion of inorganic coatings onto organic surface, degrades adsorbate pollutants upon light exposure [4].