Ion exchange materials protect nature and man from the harmful effects of heavy metals. These materials are used in agriculture, industry, wastewater treatment, purification of aqueous solutions, analytical chemistry, medicine, and pharmacology. This book presents a comprehensive overview of heavy metal ions sorption carried out with ion-exchange materials of polysaccharide nature using modern methods of research. Cellulose materials are the most common: affordable and biodegradable with practically unlimited renewability. This book covers the modification of cellulose materials and the introduction of chelating groups into their structure to produce a new generation of sorption materials.