title: Synthesis of assorted metal ions anchored alginate bentonite biocomposites for Cr(VI) sorption.
abstract: Biocomposites were synthesized by dispersing bentonite (Bent) clay in a biopolymer namely alginate (Alg) and cross-linked with bi (Ca(2+)), tri (Ce(3+)) and tetravalent (Zr(4+)) metal ions viz., Ca@AlgBent, Ce@AlgBent and Zr@AlgBent composites respectively. The synthesized biocomposites were characterized by various instrumental techniques like FTIR, SEM and EDAX. Cr(VI) sorption capacities (SCs) of the biocomposites Ca@AlgBent, Ce@AlgBent and Zr@AlgBent were examined by batch process. Various adsorption influencing factors viz., contact time, dosage of the sorbent, pH of the medium, temperature, presence of common co-ions and initial Cr(VI) concentration were studied. Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherm models were adopted to examine the adsorption equilibrium. Kinetics of the sorption process was carried out by pseudo-first-order and pseudo-second-order models. The nature of the sorption process was explained using thermodynamic parameters like ΔS°, ΔG° and ΔH° and a possible mechanism for the sorption of Cr(VI) onto the biocomposites was given. The application of the biocomposites at field conditions was also examined by testing it with industrial water. The regeneration studies were carried to know about the reusability of the biocomposites.
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.
authors.forename: Soodamani
authors.initials: S
authors.lastname: Periyasamy
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 / Q000737:chemistry*; D001546:Bentonite / Q000737:chemistry*; D060326:Chemistry Techniques, Synthetic; D002857:Chromium / Q000737:chemistry* / Q000302:isolation & purification; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D009942:Organometallic Compounds; D002857:Chromium; D001546:Bentonite; C074702:chromium hexavalent ion; D020723:Glucuronic Acid
keywords: Adsorption; Biocomposite; Chromium; Field study; Metal loaded