WATER: RECYCLING AND PURIFICATION

Water: recycling and purification Sabrina Carola Carroccio National Research Council (CNR), Catania, Italy The focus of the presentation is on the application of nanotechnology to water treatment [1]. Worldwide 1.2 billion people suffer inadequate access to clean water. Nanotechnology is expected to improve water purification with lower cost and energy. An intense research work is needed to identify robust methods for purifying water by minimizing the use of chemicals and impact on the environment. These were the major motivations for undertaking this research activity, aiming to develop novel industrial and service assets. We describe the mineralization of organic pollutants and the antibacterial efficiency of several photocatalytic nanomaterials and nanocomposites, along with an evaluation of the nanotoxicology aspects related to the use of nanomaterials in the environment. Some examples are shown about the oxidation process and the elimination of organic pollutants and bacteria from water induced by the use of TiO2 and ZnO based nanomaterials [2-4]. Nanotech based water purification, up-scalable to industrial production, might determine an impact on the economy and society through a technological breakthrough. Further methodologies, relative to advanced oxidation and elimination of pollutants, concern the design of graphene (G) based materials for photocatalysis applications [5]. In this context, the assembly of organic photosensitizers active in the visible-light range, combined with the unique properties of G-based materials, is becoming a hot topic in water remediation. We illustrate a new concept of design of hybrid nanostructured materials by using graphene 3D and polyporphyrins for visible light photocatalysis. This assembly method promotes an intimate and extensive contact between the G and the photosensitizer polymers, allowing to obtain high photocatalytic efficiency. At the same time, same critical issues deriving from the use of carbon based materials for water treatment are circumvented.