Water treatment is the process of improving water quality by removing contaminants and other undesired components, so that it becomes suitable for specific end-use. There are two types of water treatment, namely, drinking water treatment and industrial water treatment.The process used for removing contaminants from sewage and wastewater is known as wastewater treatment. The treatment aims at converting the wastewater into effluent so that it can be returned to water cycle. Water reclamation is the process of converting wastewater into water which can be reused. Wastewater treatment plant is the facility where the process takes place. There are various processes which are used for treatment of wastewater, such as phase separation, sedimentation, biochemical oxidation, etc. This book elucidates the concepts and innovative models around prospective developments with respect to water and wastewater treatment. Most of the topics introduced herein cover new techniques and the applications of water and wastewater treatment. This textbook will serve as a valuable source of reference for those interested in this field.