title: Synthesis of alginate bioencapsulated nano-hydroxyapatite composite for selective fluoride sorption.
abstract: This article focuses on the development of eco-friendly adsorbent by alginate (Alg) bioencapsulating nano-hydroxyapatite (n-HAp) namely n-HApAlg composite for defluoridation studies in batch mode. n-HAp powder utilized as a promising defluoridating material, but it causes a significant pressure drop during field applications. To overcome such technological bottlenecks, n-HApAlg composite was synthesized. The defluoridation capacity (DC) of synthesized n-HApAlg composite possesses an enhanced DC of 3870 mg F(-)/kg when compared to n-HAp and calcium alginate (CaAlg) composite which possess DC of 1296 and 680 mg F(-)/kg, respectively. The biocomposite features were characterized using FTIR and SEM with EDAX analysis. The various adsorption influencing parameters like contact time, pH, co-anions, initial fluoride concentration and temperature were optimized. The adsorption process was enlightened by various isotherms and kinetic models. The suitability of the biocomposite at field conditions was also tested.
authors.affiliation: Department of Chemistry, Anna University, University College of Engineering, Dindigul, Reddiyarchatram, Dindigul 624 622, Tamilnadu, India.
authors.forename: Kalimuthu
authors.initials: K
authors.lastname: Pandi
authors.affiliation: Department of Chemistry, Anna University, University College of Engineering, Dindigul, Reddiyarchatram, Dindigul 624 622, Tamilnadu, India. Electronic address: drnviswanathan@gmail.com.
authors.forename: Natrayasamy
authors.initials: N
authors.lastname: Viswanathan
mesh_terms: D000327:Adsorption; D000464:Alginates / Q000737:chemistry*; D000838:Anions; D001639:Bicarbonates / Q000737:chemistry; D017886:Durapatite / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry* / Q000302:isolation & purification; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D053761:Nanocomposites / Q000737:chemistry*; D013816:Thermodynamics; D018508:Water Purification / Q000379:methods
chemical_list: D000464:Alginates; D000838:Anions; D001639:Bicarbonates; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D017886:Durapatite; D005459:Fluorides
keywords: Alginate; Biocomposite; Field studies; Fluoride; Nano-hydroxyapatite; Sorption