REMOVAL OF LEAD BY USING Na-A ZEOLITE SYNTHESIZED FROM SPENT SILICA - ALUMINA การกาจ งเคราะหจากซ ล-อะลว

This research was carried out in order to investigate the adsorption efficiency of lead removal using sodalite and Na-A zeolite synthesized from spent silica–alumina. The starting material composition used in this experiment was: Al2O3: 1.926 SiO2: 3.165 Na2O: 128 H2O. The optimum condition used to synthesize zeolite was at 90 o C for 4 hr. The experiment was carried out by using sodalite and Na-A zeolite as an adsorbent for removing lead from aqueous solution. The adsorption was carried out in batch experiment. The results indicated that the optimum condition of sodalite and Na-A zeolite for lead adsorption was at the concentration of 30 ppm, pH 4 with the contact time of 60 min for sodalite and 30 min for Na-A zeolite. The efficiency of lead removal was about 98-99%. The adsorption isotherm of sodalite and Na-A zeolite was shown to be in a linear form and related to the Langmuir isotherm. The adsorption phenomenon was monolayer. The maximum lead adsorption capacity for sodalite was at 224 mg lead/g. While the maximum lead adsorption capacity for Na-A zeolite was only 46 mg lead/g.