Surface modification of natural zeolite by chitosan and its use for nitrate removal in cold regions

Surface modifications of natural zeolite were performed by coating it with a chitosan layer. The chitosan coated zeolite (Ch-Z) was protonated with either sulfuric or hydrochloric acid and tested for its suitability to capture nitrate from water at 20 and 4 °C. The surface characterization of the Ch-Z was done by SEM, FTIR, TGA and nitrogen adsorption tests. The results of these tests showed evidence of chitosan coating onto zeolite particles. Ch-Z has comparable capacity to other weak anion exchangers with a nitrate ion exchange capacity 0.74 mmol NO3 g− 1 (protonated with HCl).