PRELIMINARY STUDY ON ADSORBING FLUORIDE ION (F-) IN WASTE WATER BY DENATURED PYROLUXITE ORE FROM VIETNAM
Pyrolusite ore from Cao Bang province was denatured to adsorb fluoride in waste water.There were 3 methods studied for denaturing Pyrolusite in this paper to be: temperature,HNO3 acid and Al2 (SO4)3. The method using HNO3 acid (0,5 M, shaking time for 4 hours) wasthe best for denaturing Pyrolusite (adsorbing efficiency: 44 %; adsorbing capacity: 0.15mg/kg). The best conditions for adsorbing fluoride of denatured Pyrolusite were pH to be 2and shaking time to be 4 hours.Two waste water samples were applied to investigate fluoride adsorbed ability of denaturedPyrolusite. The efficiency for adsorbing fluoride ranged from 16.9 to 19.6 % and adsorbingcapacity was 0.12 mg/kg.
Keywords: Denatured Pyroluxite ore, adsorb, fluoride, waste water