METHOD FOR PREPARING ADSORBENT CAPABLE OF SIMULTANEOUSLY ADSORBING NITROGEN, PHOSPHORUS AND ORGANIC COMPOUNDS

摘要

PURPOSE: A method for preparing an adsorbent having zeolite function of ion exchange property, activated carbon function of excellent organic matter adsorption performance and phosphoric acid ion precipitant function from coal ash is provided. CONSTITUTION: In a method for preparing an adsorbent by using a principal raw material of coal ash containing 50 to 56 wt.% of SiO2, 20 to 32 wt.% of Al2O3 and 3 to 25 wt.% of non-burnt carbon generated from coal thermal power plant in a large quantity, the method comprises first process of synthesizing adsorbent and activating non-burnt carbon by hydrothermal reaction of the coal ash with 1 to 5 M of NaOH solution and 1 to 3 M of ZnCl2 or Ca(OH)2 in an autoclave at temperature of 100 to 200 deg.C for 5 to 24 hours; and second process of adding 20 to 50 % MgCl2 solution or lime cream, lime slurry and lime milk to slurry of the synthesized adsorbent so that the mixed solution is neutralized to a pH 10 to 12 to give the adsorbent a function capable of strongly precipitating and recovering phosphates showing anionic property and improve filtering characteristics of the adsorbent at the same time.