n-ZVM (zero valent metals) can be used to both desalinate and treat water (including water disinfection). Desalination can be undertaken at atmospheric temperatures in existing water tanks and water bodies without requiring an energy supply. This chapter describes the different approaches that can be used: (i) potable water production; (ii) partial desalination using N₂/N₂ + H₂ modified particles and pellets; (iii) desalination in a reducing environment; (iv) partial desalination using CO_x/N₂/H₂-modified particles and pellets; (v) combined redox and eutectic desalination; (vi) rapid partial desalination in an oxidising environment; (vii) rapid desalination at elevated temperatures (25–75 °C). n-ZVM is suitable for the desalination of irrigation water, livestock feed water, emergency relief water, reject brine associated with reverse osmosis desalination plants, saline waste water, and impoundments associated with shale gas/oil production.