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By the operation of sands filter system in treating ground water contains high concentration of ammonia (2-2.8mg/L),iron (0.9-2mg/L) and manganese (1.2-1.7mg/L),on the surfaces of quartz sands,formed the co-oxides filter membrane.The removal of ammonia in filter before and after the inactivation of membrane coated sands and the transformation of nitrogen in filter bed was studied.The Morphology and the chemical composition of the membrane coated sands were studied by SEM and EDS,and the structure of membrane material was characterized by XRD.The specific area and pore properties of quartz sands before and after the formation of filter membrane were studied by BET method.The XPS characterization was introduced to identify the chemsorb sites of dissolved oxygen and ammonia on the membrane surface.The results show that the membrane material consists of iron and manganese oxides was amorphous;both specific area and pore volume of the sands got increased as the membrane formed;Removal of ammonia in filter was a catalytic oxidation process,and 90% of capacity of ammonia treatment was recovered in the 116h operation after the membrane coated sands got inactivated,which was due to the restoration of the surface structure of membrane.The dissolved oxygen was mostly possible adsorbed on Mn atoms occur as Mn2O3 and MnO2,and the Fe atoms occur as FeO while on the membrane surface,the Mn atoms in states of Mn2O3 and MnO,and the Fe atoms in states of Fe2O3 and FeO may be the chemsorb sites of ammonia.