Nanotechnology is an innovative research area which is being integrated with many other fields. Photocatalytic nanoparticles are of great concern now days, Titania being extensively studied one. It is being used for pollution remediation from air and water. The objective of the research was to develop sustainable technology for water disinfection. Modified Titania is used in the study which can disinfect water under visible light. Background theory is discussed in chapter 1 which also provides the achieved objectives. Chapter 2 describes the detailed knowledge of photocatalysis and severity of water contamination by bacteria. Chapter 3 discusses the detailed methodology adopted to achieve the objectives and evaluation procedure for the material. In chapter 4, obtained results are elaborated in great details and chapter 5 consists the drawn conclusions and further studies to be conducted. This book is a useful tool for the students and the researchers interested to proceed for drinking water treatment from contamination using photocatalytic nanoparticles.