Electronic Thesis and Dissertation Repository


Master of Engineering Science


Chemical and Biochemical Engineering


Dr. Ajay K. Ray


As the increase in industrial technology continue to progress, it results in the increase in heavy metal pollution, creating harmful effects on humans, plants, and animals. Since toxic metals do not degrade easily, they accumulate over time, posing greater danger to living organisms. Removal of these heavy metals is therefore, of great importance. Though many research studies successfully utilized UV photocatalysis with TiO2 catalyst for the removal of Cd2+, none have performed the photoreduction of Cd2+ under visible light using eosin-y dye-sensitized TiO2. The objective of the present research is to study the photocatalytic reduction of Cd2+ from aqueous solution under solar (UV + visible) light spectrum, along with the adsorption of Cd2+ onto TiO2. In order to utilize visible light for the photocatlytic process, eosin-y dye-sensitized TiO2 is used as the photocatalyst. In order to obtain an accurate understanding of the dye-sensitization process, the effect of parameters such as: pH, initial TiO2 concentration, initial Cd2+ concentration, initial dye concentration, initial concentration of organic additives, and the light intensity were studied. Overall, a 95% reduction of Cd2+ was possible with dye-sensitized TiO2 under visible light and 98% reduction was obtained with UV light photoreduction of Cd2+ with TiO2 as catalyst.