Coated sand filtration: an emerging technology for water treatment

The use of oxide coated sand filtration as an alternative to current costly methods for water treatment has been reviewed. The paper highlights the importance of iron, aluminium and manganese oxides, including sand coated with these oxides, for removal of heavy metals and other impurities from water. The literature review showed that oxide coated sand is able to remove heavy metals (both anions and cations) and other impurities (e.g. natural organic matter, microorganisms, sulphate, manganese, etc.) from surface water or groundwater. In this review an extensive list of the use of oxide (iron, aluminium and manganese) coated sand in water treatment by adsorption and filtration processes has been compiled to provide a summary of available information. The information available on the capacity of coated sand for pollutant uptake is very scarce, however some data on the capacity of coated sand for heavy metals uptake have been compiled and presented. The coated sand could be an alternative emerging technology for water treatment without any side effects or treatment process alterations.