Inorganic contaminants dissolved in the water can be removed by distillation or chemical exchange. Organic contamination has been treated by biological and chemical remediation, and new treatment methods are being tried every day. You recycle water by using it over and over again. This sometimes requires removing contaminants that have been introduced by a particular use before putting the water back into the natural hydrologic cycle for eventual reuse. The type of reuse determines what clean-up treatment may be warranted.
Ice is cold, hard water.
Both water and ice consist of hydrogen and oxygen molecules. No one knows for sure what would happen if the snow and ice in the polar regions all melted. Sea level would rise, which would flood coastal regions. Climate would be affected worldwide. Isostatic rebound would occur where ice masses were removed from continents, causing the land surface there to rise.