title: One pot synthesis of metal ion anchored alginate-gelatin binary biocomposite for efficient Cr(VI) removal.
abstract: Biopolymers are widely used for the removal of chromium from aqueous medium but it possesses limitations like poor sorption capacity and low stability. To overcome the limitations of biopolymers and to improve their properties, the present study was designed in such a way to develop a novel sorbent with enhanced chromium sorption capacity and better stability by synthesizing metal ion cross-linked binary biocomposites using biopolymers like alginate and gelatin cross-linked with Ca2+, Ce3+ and Zr4+ ions namely Ca@AlgGel, Ce@AlgGel and Zr@AlgGel composites. The functional groups, agglomeration, surface area, surface morphology, elemental analysis and thermal stability of the composites were investigated by FTIR, TEM, BET, SEM with EDAX and TGA analysis. The chromium removal studies of the biocomposites were carried out in batch mode. The sorption process was optimized by varying the influencing aspects like contact time, dosage, presence of common ions, pH, initial chromium concentration and temperature. The maximum sorption capacity of Ca@AlgGel, Ce@AlgGel and Zr@AlgGel composites were found to be 19.40, 24.50 and 25.40 mg/g, respectively. The sorption data was fitted by using Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherms. Thermodynamic parameters indicate the nature of chromium sorption. The suitability of the composite materials was also tested under the field conditions.
authors.affiliation: Department of Chemistry, Velammal College of Engineering and Technology, Madurai - 625 009, Tamilnadu, India.
authors.forename: Venkatrajan
authors.initials: V
authors.lastname: Gopalakannan
authors.affiliation: Department of Chemistry, Anna University, University College of Engineering - Dindigul, 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 / Q000138:chemical synthesis* / Q000737:chemistry*; D060326:Chemistry Techniques, Synthetic; D002857:Chromium / Q000737:chemistry* / Q000302:isolation & purification*; D004785:Environmental Pollutants / Q000737:chemistry* / Q000302:isolation & purification*; D005780:Gelatin / Q000737:chemistry*; D020723:Glucuronic Acid / Q000138:chemical synthesis / Q000737:chemistry; D006603:Hexuronic Acids / Q000138:chemical synthesis / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D013696:Temperature; D013816:Thermodynamics
chemical_list: D000464:Alginates; D004785:Environmental Pollutants; D006603:Hexuronic Acids; D002857:Chromium; D020723:Glucuronic Acid; D005780:Gelatin
keywords: Binary composite; Biopolymers; Chromium sorption; Isotherms