Water nitrate removal with ion-exchanger grafted textiles

Two grafted textiles produced by the Institut Textile de France (Lyon), wer e examined to determine their characteristics for nitrate removal. Both wea k and strong basic groups linked to textiles were used as anion-exchangers (AET). Their exchange capacity was measured as approximate to 0.6 meq.g(-1) , a value lower than the one determined in the case of resins. Rapid exchan ge kinetics was observed for both textiles. Low nitrate concentrations coul d be removed easily. After studying of the counter-ion influence, it appear ed that nitrate removal was greater when the textiles were in the chloride form. However, the presence of other anions, such as sulphate, hydroxide an d chloride could compete in nitrate removal. Selectivity gradients were det ermined for the weak AET as SO42- > NO3- > Cl-. In the case of strong AET t hey were: OH- > SO42- > NO3- > Cl-. Regeneration was optimal in the presenc e of an excess of HCl for both textiles. These anion-exchanger textiles off er an interesting and advantageous alternative for water treatment by ion-e xchange technique.