This investigation centers on the evaluation and possible development of physical chemical methods for the conversion of urine into water suitable for drinking or other uses in fallout shelters and other isolated sites. The capacity of the multiple and mixed bed ion exchange for the demineralization of urine and of activated carbon for the removal of urea, foaming agents, and color were evaluated. Reaction rates and products were determined for the oxidation of urea with calcium hypochlorite and with nitrous acid. The hydrolysis of urea without buffer using the enzyme urease was explored. A strongly acidic sulfonated polystyrene exchange resin was found to be effective for the removal of urea from urine. Experiments on the precipitation of chloride and carbonate, either present in urine or a reaction product, with silver salts were conducted.