title: Development of a sodium alginate-based organic/inorganic superabsorbent composite hydrogel for adsorption of methylene blue.
abstract: Batch adsorption experiments were carried out for the removal of methylene blue (MB) cationic dye from aqueous solution using organic/inorganic hydrogel nanocomposite of titania incorporated sodium alginate crosslinked polyacrylic acid (SA-cl-poly(AA)-TiO2). The hydrogel was prepared by graft copolymerization of acrylic acid (AA) onto sodium alginate (SA) biopolymer in the presence of a crosslinking agent, a free radical initiator and TiO2 nanoparticles. The hydrogel exhibited a high swelling capacity of 412.98g/g. The factors influencing adsorption capacity of the absorbents such as pH of the dye solutions, initial concentration of the dye, amount of absorbents, and temperature were investigated and used to propose a possible mechanism of adsorption. The adsorption process concurs with a pseudo-second-order kinetics and with Langmuir isotherm equation. A very high adsorption capacity (Qmax=2257.36 (mg/g)) and a correlation coefficient of 0.998 calculated from isotherm equations show the high efficiency of the absorbent and thus expected to be a good candidate as an absorbent for water treatment.
authors: Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa.
authors: Sourbh
authors: S
authors: Thakur
authors: Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa.
authors: Sadanand
authors: S
authors: Pandey
authors: Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa; Centre for Nanomaterials Science Research, University of Johannesburg, South Africa. Electronic address: oarotiba@uj.ac.za.
authors: Omotayo A
authors: OA
authors: Arotiba
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000327:Adsorption; D000464:Alginates / Q000737:chemistry*; D004396:Coloring Agents / Q000302:isolation & purification*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008751:Methylene Blue / Q000302:isolation & purification*; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D013816:Thermodynamics; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods
chemical_list: D000180:Acrylic Resins; D000464:Alginates; D004396:Coloring Agents; D006603:Hexuronic Acids; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C006903:carbopol 940; D020723:Glucuronic Acid; D014025:Titanium; D008751:Methylene Blue
keywords: Acrylic acid; Adsorption; Methylene blue; O/I hydrogel nanocomposite; Sodium alginate; Water pollution