Groundwater Defluoridation Using Cost-Effective Biosorbents and Natural Adsorbent Materials

Abstract

Millions of people worldwide depend on drinking water sources contaminated with excess fluoride, posing significant health risks. In regions where fluoride occurrence is widespread, particularly in small communities with scattered populations, defluoridation of potable water remains a major challenge. This study investigates the use of locally available low-cost adsorbentsSugarcane Bagasse, Coconut Husk, and Rice Husk for fluoride removal. The adsorbents were characterized, and experiments were conducted to evaluate the influence of pH, adsorbent dosage, and initial fluoride concentration on removal efficiency at a constant temperature of 30 ± 2 °C. Results indicated that fluoride removal efficiency initially increased with pH and then stabilized for Sugarcane Bagasse at an optimal dose of 0.5 g/100 ml and a contact time of 75 minutes. Furthermore, temperature studies revealed that the highest efficiency was achieved using Modified Bagasse of Sugarcane (MBC), followed by Aluminum Hydroxide-Coated Rice Husk and Modified Coconut Husk at 323 K. However, removal efficiency decreased with increasing initial fluoride concentration, attributed to the adsorption capacity limits of the materials. Overall, the study demonstrates the potential of these low-cost, locally available adsorbents as effective alternatives for defluoridation of drinking water.