Fluoride present in the form of minerals, which dissolves in ground water and contaminates it. This paper deals with the mimosideae family fruit carbons are used for the removal of fluoride by the process of adsorption. The activated carbon was prepared by carbonisation of Enterolobium saman fruit carbon (ESC) and Prosofis juliflora fruit carbon (PJC) in muffle furnace and treated with 2.5 x 10-1M nitric acid and thermally activated in air oven. The activated carbon was characterized and chemical analysis was done by X-ray fluorescence. Batch experiments were carried out to establish the various parameters. The adsorption was examined by studying the impact of various parameters such as 1) initial concentration (1–7mg/L). Maximum (76 - 82%) removal fluoride concentration up to 5mg/L after this the removal percentage was low. 2) pH (5-9) higher removal percentages in neutral media. 3) Dose (1-7mg/L). After 4mg/L removal adsorption capacity was very low 4) time (10 min – 90 min). Maximum adsorption was observed between 40-60min. and 5) Particle size (45μ-150μ) 45μ sized carbon shows higher adsorption capacity (90.8 %, 80.2% for ESC and PJC). Recycling studies and regeneration of the fluoride loaded carbons were performed with 1.0 x 10-1 NaOH mol/l (72%), Na2CO3, KOH and 1.0 x 10-2 H2SO4 mol/l solutions (68-58%). Adsorption data fits well to Langmuir isotherm and Freundlich isotherms and sorption kinetics Natarajan & Khalaf, intra particle diffusion model follows first order nature of adsorption. All experimental results were compared with the studies of commercial activated carbon (CAC) and comparative results indicate ESC and PJC shows 3 to 4 times higher adsorption capacity than CAC.
International Letters of Chemistry, Physics and Astronomy (Volume 56)
M. Kishore "Potable Water Defluoridation by Lowcost Adsorbents from Mimosideae Family Fruit Carbons: A Comparative Study", International Letters of Chemistry, Physics and Astronomy, Vol. 56, pp. 71-81, 2015