Batch and Column Operations for the Removal of Fluoride from Aqueous Solution Using Bottom Ash

  • S.T. Ramesh
  • R. Gandhimathi
  • P.V. Nidheesh
  • Manoj Taywade
Keywords: Adsorption, Bottom ash, Batch study, Fixed-bed column study, Kinetics, Isotherms


Millions of people rely on drinking water that contains excess fluoride. In fluoride endemic areas, especially small communities with staggered habitat, defluoridation of potable water supply is still a problem. In this study, adsorption potential of bottom ash was investigated for defluoridation of drinking water using batch and continuous fixed bed column studies. Batch sorptive defluoridation conducted under experimental conditions such as pH, temperature, particle size, agitation time and dosage. Adsorption isotherms have been modeled by Langmuir and Freundlich isotherms. The fluoride sorption capacity at breakthrough point for bottom ash was greatly influenced by bed depth. The results were then analyzed using the Bed Depth Service Time (BDST) Model and various performance parameters like Adsorption Capacity, Critical Bed Depth, and Adsorption Rate Constant were evaluated. With the observed data Thomas model and Yoon Nelson Model fitted well and constants are found.