An improved method for defluoridation

Fluoride is a naturally occurring toxic mineral present in drinking water and the root cause of many diseases and disorders. Present international drinking water standard set by World Health Organisation (WHO) for fluoride is 1.5 ppm. In order to find the wide spread concentration of fluoride in drinking water of fluoride contaminated aquifer, 30 bore well water samples have been collected from different villages of Natrampalli Union which comes under Tiruvannamalai Circle, Tamil Nadu, India. In the present work, an attempt to remove fluoride by the use of coagulant, Poly Aluminium Chloride (PAC) was made and is compared with the most common existing technique "Nalgonda Technique" where there was a reversible reaction. The coagulant used in Nalgonda technique is Alum [(Al2SO4)3]. Results of the present work show that Poly Aluminium Chloride (PAC) can be an effective coagulant for the removal of fluoride from water with a higher removal efficiency of about 75 - 85% in less detention time and also observed that the fluoride removal was dependent on initial fluoride concentration and dose of coagulants.