Removal of chromates from drinking water by anion exchangers

摘要

Strong-base anion-exchange resins were used for selective removal of Cr(VI) from tap water.The infuence on the process efficiency of parameters,such as the type of anion-exchange resin,the concentrations of Cl~- and SO_4~(2-) in the feed water,and the flow rate and pH of the feed water,was investigated.Regeneration was carried out by the reduction of the chromate with bisulfite under acidic conditions and the subsequent removal of the Cr from the column as the Cr~(3+) cation.The pH of the regenerant solution was then increased,causing Cr(OH)_3 to precipitate,and the precipitate was removed by filtration.