The book explores the significant contribution of magnetic nanoparticles (MNPs) as great adsorbents for the adsorption of multifarious pollutants from water sources. With the advance of technology, using magnetic nanoparticles has become one of the practical approaches to purifying water from various pollutants. The book provides an in-depth overview of the magnetic properties of nanoparticles, synthesis methods, and their applications in the adsorption of heavy metals, organic compounds, and other pollutants in water. Readers will get an insight into the essential aspects of this technology and how its adoption might enhance water quality for environmental sustainability and human health. This book is appropriate for researchers, scholars, and practitioners in environmental chemistry and water technology due to its comprehensive yet easily understandable discussions.