Synthesis of Micro- and Nano-sized Composites Based on Silica for Removal and Detection of Toxic Substances

Abstract

Environmental chemistry is multidiscipline science that deals with the reaction, transport and fate of chemical species in 4 pillars of environment (hydrosphere, atmosphere, geospheres and biospheres and how they affect the human activities and the whole ecosystem. It combines various chemical principles to achieve the ultimate goal of creating clean and sustainable environment. In this dissertation, Synthesis of Micro- and Nano-sized Composites Based on Silica for Removal and Detection of Toxic Substances were described in detail. Iron oxide coated silica gels were employed to remove arsenic oxyanions from artificial groundwater to permissible safety limit defined by WHO. Arsenic adsorption kinetics, isotherm and interference effect from various were also discussed. Various metal ions-modified silica gel offer high sensitivity, straight-forward colorimetric detection of toxic industrial pollutants such as hydrogen sulfide gas and ammonia gas. The method can also be applied to detect sulfur ion in human plasma blood or in aqueous solution. The proposed method described here may eliminate the requirement of complex and expensive equipment, complicated sample preparation and, most importantly, offers portability which can be directly used on-site/in-situ for forensic application.