Application of modified zeolite for ammonium removal from drinking water

Clinoptilolite was processed, first, by sodium chloride solution, and then mixed with Na(2)SiO(3) and powdered activated carbon. The mixture went through extrusion forming and calcination to prepare the Silicate-Carbon Modified Zeolite (SCMZ) that was used for removing ammonium from drinking water. The SCMZ was analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetry(TG), and its BET surface was compared with that of natural zeolite. This study was performed using column experiments, and batch tests were performed under a range of conditions to assess the effect of solution pH, filtration rate, initial ammonium concentration and regeneration methods on the performance and capacity of the zeolite in ammonium removal. Results indicate that the adsorption capacity of SCMZ was 0.115 mg NH(4)(+)-N/g, when the pH of the solution was 7, filtration rate was 10 m/h and initial ammonium concentration was 5 mg/L, and was much higher than that of natural zeolite. This breakthrough product made from SCMZ filtering media would have high ammonium-removal efficiency when regenerated by three cycles through sodium chloride solution. (C) 2010 Elsevier B.V. All rights reserved.