Systemic fluorosis is an endemic problem in several developing countries. In India 15 states are endemic for fluorosis, of which 5 have indicated hyperendemicity for fluorosis in all districts. WHO standards permit only 1 mg/l as a safe limit for human consumption People in several districts of Rajasthan are forced to consume water with fluoride concentrations of up to 44 mg/l which has resulted in permanent deformities, joint pains, general debility and misery. About 60% of fluoride intake is through water. Considerable work on fluoride removal from water has been done all over the world. However a safe, efficient, free from residual aluminium in treated water, and cost effective defluoridation technique/process is not available and needs to be developed in order to prevent the occurrence of fluorosis. This paper describes the development of a defluoridation process which differs from the known processes in its simplicity, cost effectiveness and results in traces of residual aluminium in treated water. The parameters like fluoride concentration, temperature, pH, alkalinity, humidity and total dissolved solids of input water do not affect this process. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved.
