Chapter 20 - Photocatalytic treatment of wastewater using nanoporous aerogels: Opportunities and challenges

Abstract

Water pollution is continuously raising concern around the world. The uncontrolled and massive discharge of waste components from domestic and various industrial sectors lead to the declining of water quality, and thus impair the aquatic and human health. Among the water pollutants, heavy metals and organic compounds are two major classes of hazardous pollutants present in the water environment, and they typically co-exist specially in industrial wastewater. Semiconductor photocatalysis has been arose as an effective method for water pollutant treatment and also known as green technology due to its cleanliness and sustainability. This chapter is designed to focus on the usability of aerogels as photocatalysts, in order to remove organic and inorganic pollutants from water. Aerogels are three dimensional porous materials, and are known as one of the most considerable adsorbents, because of their special characteristics such low density, high porosity, large surface area and self-supporting configuration. All of these features of aerogels certainly outperform those of conventional photocatalytic materials. Various synthesis methods and classification of aerogel photocatalysts are presented in detail. Furthermore, the potential of aerogels for photocatalytic removal of various organic and inorganic contaminants is presented with possible generalized mechanisms. Aerogels may encounter various challenges and their use is still having a long way to ensure for mature practicing. In the end the challenges associated with aerogel photocatalysis of pollutant and forthcoming outlook are summarized in order to improve their specific potential and successful field application in future.