Electrolytic Defluoridation (EDF) Technique

Electrolytic Defluoridation (EDF) Technique


In India, an estimated 62 million people, including 6 million children suffer from fluorosis due to consumption of excess fluoride contaminated water.  As per BIS 10500, 2004 and WHO guideline the desirable limit of fluoride in drinking water is 1.0 mg/L, which can be extended to 1.5 mg/L in the absence of alternate source. 

Electrolytic defluoridation process  is a water purification system suitable for fluoride affected area with water containing excess fluoride. The defluoridation process is based on the principle of electrolysis, using aluminium plate electrodes placed in the raw water containing excess fluoride.  During the electrolysis, anode gets ionized and fluoride is removed by complex formation, adsorption, precipitation, coagulation and settling.





Adiwasi Kanya Shiksha Parisar , Chindwara Dist. (M.P.)


Sargapur, Seoni Dist. (M.P.)


Usarwara,  Dist. Durg. (C.G.)


Dongargaon, Chandrapur Dist. (M.S.)


Adiwasi Kanya School , Chindwara Dist. (M.P.)


Salient Features

  • Removal of fluoride by active species of hydroxide of aluminium produced by passing DC power through aluminium electrodes
  • Simple to fabricate, easy to operate with  minimum maintenance
  • Suitable for treatment of raw water with fluoride concentration upto 10 mg/L
  • Produces potable water with palatable taste as against the other  available chemical treatment methods
  • Quantity of sludge produced is much less (60-70%) than conventional treatment methods
  • Simultaneous  reduction in bacterial contamination in treated water
  • Cost of treated water  Rs. 25-30  per 1000 liter
  • Capacity : 2000 L per batch in 3- 3.5 hours



  • Received  International Project Innovation Award (PIA) – Development
  • Instituted by International Water Association (IWA) in 2011
  • Chosen among 30 successful technologies and received DST-Lockheed Martin India Innovation Growth Award - 2012


Present Status

  • Know-How transferred to 9 firms for installation of EDF plants in the fluoride affected areas in the country
  • CSIR-NEERI has installed EDF demonstration plants in M.P. and C.G. states with the financial support from MDWS, GOI and UNICEF 
  • Nearly 200 EDF plants have been installed and more  plants will be installed in fluoride affected areas of various states by  State Water Supply Departments.