Any process that improves the quality of water and makes it acceptable for specific uses, such as drinking, irrigation, industrial water supply, etc. is termed as water treatment. It involves the removal of contaminants or the reduction in their concentration. The techniques and technologies used for water treatment vary according to use. Some of the processes used in the treatment of municipal drinking water include pre-chlorination, aeration, sedimentation, filtration, disinfection, etc. The principal methods of industrial wastewater treatment are cooling water treatment and boiler water treatment. Water supplied to domestic properties is treated via water softening or ion exchange. This book provides significant information of water treatment techniques and technologies to help develop a good understanding of the management of contaminated water. It is a collective contribution of a renowned group of international experts. It aims to serve as a resource guide for students and experts alike.