Defluoridation of Groundwater Using Low-cost Adsorbents

Abstract

Excessive fluoride in groundwater poses significant health risks to millions of people worldwide, necessitating effective and accessible defluoridation methods. This study investigates the use of column filtration for removing fluoride from groundwater. The study employs a systematic approach to evaluate the performance of different adsorbent materials in a fixed-bed column setup. Various materials were tested as adsorbents in column, including Brick powder, Neem leaf powder, Lime, Sawdust, and Vetiver. The research examines the effects of key operational parameters such as bed depth, flow rate, and initial fluoride concentration on the overall removal efficiency. Experiments were conducted using groundwater to assess the method's effectiveness. Results indicated that column filtration can effectively reduce fluoride concentrations to below the World Health Organization's recommended limit of 1.5 mg/L. This report contributes to the development of efficient, cost-effective, and sustainable solutions for groundwater defluoridation. All adsorbents used were inexpensive materials, available easily in nature and locally at village or rural level. Some of the adsorbents were very effective in removal of fluoride ion and can be used as defluoridating agents but they impart color and turbidity to the groundwater. Among all the adsorbents used, Vetiver demonstrated higher removal efficiency of 78% followed up by limestone 77% removal but hindered by its precipitation. Sawdust and brick powder were also efficient up to a certain extent of 72% and 69% respectively in adsorbing fluoride ions. Neem leaves powder was found to be least effective in adsorbing showing about 50% removal efficiency.