การกำจัดฟลูออไรด์ออกจากน้ำใต้ดินโดยแร่ไพโรลูไซต์จากเหมืองในจังหวัดเชียงใหม่

Abstract

This study investigated the removal of fluoride from groundwater by pyrolusite. The pyrolusites studied were divided into two types: water-washed and acid-washed. The results of the study found that the pH at point of zero charge is approximately 4 for both types of pyrolusites. The study of isotherms of pyrolusite adsorption revealed that both types of pyrolusites correspond to the Fruendlish model. The study on the fluoride adsorption kinetics of water-washed pyrolusite corresponded to the pseudo-first-order kinetics reaction and time to reach equilibrium was 30 minutes. Besides, the study on the fluoride adsorption kinetics of acid-washed pyrolusite was consistent with the pseudo-first-order reaction and time to reach equilibrium was 60 minutes. Finally, the removal of fluoride from groundwater by water-washed and acid-washed pyrolusites were 0.0593 and 0.0607 mg fluoride per g pyrolusite, respectively.