Dissolved inorganic contaminants in water can he cationic, anionic, or neutral forms of ions, atoms, or molecules of any element in the periodic table.All contaminant ions and most dissolved non-ions a Relatively insensitive to flow and total dissolved soli Low effluent concentration possible In reverse osmosis, bacteria and particles are removed as well DisadvantagesHigh capital and operating costs High level of pretreatment required Membranes are prone to fouling Rnim stream is M W % of feed flw