Use of Metal-Composite Incorporatedcoated Bio-Polymer Beads for the Removal of Fluoride Ions From Aqueous Media

Abstract

Attached

Access to safe drinking w ater has declined over the last decades in almost every part o f the world. A m ong m any different water pollutants, fluorides play a major role. Accumulation o f fluoride ions into natural w ater bodies largely happens through waste w ater discharge from industrial practices and weathering mineralization. Consumption o f excess amounts o f fluoride ions can cause both dental and skeletal fluorosis. Even though, the acceptable values for fluoride ions in drinking water recom m ended by W HO is 1.5 mg/L, recom m ended value o f fluoride for topical countries such as Sri Lanka is 1.0 mg/L. This research highlights the implementation o f m etal incorporated/coated bio-polymer system for the removal o f fluorides ions from aqueous media. Naturally existing, low cost and highly abundant polym er materials such as Alginate, Carboxy M ethyl Cellulose (CMC) and Chitosan have been used as the m atrix material o f fluoride removal system. Since rare earth metals such as La, Ce and Zr show strong affinity towards fluoride, a tri-metal composite o f those m etals were synthesized using one step coprecipitation method. Characterized tri m etallic composite was incorporated into a natural polym er to enhance fluoride removal efficiency. 1:1 ratio o f tri metal composite incorporated alginate, CM C and chitosan beads and tri-m etal coated alginate and CM C beads were synthesized separately. Freshly prepared 10 mg/L o f fluoride solution w as used to determine percent removal o f fluorides and the am ount o f fluoride adsorbed per unit. All adsorption experiments were carried out in 250 mL plastic beakers w ith 100.00 ±0.01 m L test solution at pH 7.00±0.1 and room tem perature (28 ± 1°C). Rapid adsorption o f Fluoride was observed within the first sixty minutes and equilibrium was established within 2 hours. The amount o f fluoride adsorbed per unit for CM C, Alginate, Chitosan and tri-m etal incorporated alginate, CM C and chitosan w ere 2.47±0.09, 2.95±0.11, 1.01±0.80 mg/g and 4.703±0.09,4.67±0.08 and 1.07±0.03mg/g while tri-metal coated'alginate and CMC were 3.77±0.004 and 2.98±0.06 mg/g. These composites were further studied using FT-IR techniques. Carboxy M ethyl Cellulose-CM C, W orld H ealth OrganizationW HO, Fourier transform infrared spectroscopy- FTIR