Layered double hydroxides have been known for over 150 years since the discovery of the mineral and Organic – Inorganic hybrid ion-exchangers are considered as next generation composite material that will encompass a wide variety of applications. There has been considerable interest in the use of these materials to remove different ions by both surface adsorption and ion-exchange. Their high uptake levels of pollutants can be accounted for by their large surface area and high ion-exchange capacities. These materials exhibit excellent water treatment properties. The need for treatment of water is becoming more urgent for drinking purpose, even in developed countries. The increasing populations of developing countries are encroaching more on previously undisturbed watersheds. In view of above facts, the present book discusses the synthesis and physicochemical characterization of hybrid thorium (IV) phosphates and layered double hydroxides for the removal of lead and nitrate from water. This book, therefore, provides a new metric of success for students, researchers and scientists, who are working in the field of environmental application of various clays and hybrid ion-exchangers.