title: Removal of methylene blue dye from an aqueous media using superabsorbent hydrogel supported on modified polysaccharide.
abstract: The removal of methylene blue (MB) in water with the superabsorbent hydrogel (SH) formed by modified gum arabic, polyacrylate, and polyacrylamide was investigated. The SH exhibited excellent performance in MB absorption. The maximum absorption capacity was 48 mg of the dye per g of SH, representing 98% of the MB removed. Experimental parameters were used as follows: pH 8, hydrogel mass 50 mg, and initial concentration of MB 50 mg L(-1). In a procedure with an individual solution of orange II, an opposite effect related to the MB was observed: the hydrogel only absorbed water, resulting in an orange II-richer solution. The orange II concentration in solution increased about 50 times (relative to the initial concentration). In another experiment using an aqueous mixture of orange II and MB, the SH absorbed the MB exclusively. Compared to the MB, the orange II is separated from water by SH selectivity-absorption through an inverse process. This effect was attributed to the formation of a ionic complex between the imine groups of MB and the ionized carboxylic groups of SH.
authors.affiliation: Chemistry Department, Maringa State University, Av. Colombo 5790, CEP 87020-900, Maringa, Parana, Brazil.
authors.forename: Alexandre T
authors.initials: AT
authors.lastname: Paulino
authors.forename: Marcos R
authors.initials: MR
authors.lastname: Guilherme
authors.forename: Adriano V
authors.initials: AV
authors.lastname: Reis
authors.forename: Gilsinei M
authors.initials: GM
authors.lastname: Campese
authors.forename: Edvani C
authors.initials: EC
authors.lastname: Muniz
authors.forename: Jorge
authors.initials: J
authors.lastname: Nozaki
mesh_terms: D000042:Absorption; D000179:Acrylates / Q000737:chemistry; D000180:Acrylic Resins / Q000737:chemistry; D001391:Azo Compounds / Q000737:chemistry / Q000302:isolation & purification; D001557:Benzenesulfonates / Q000737:chemistry / Q000302:isolation & purification; D002264:Carboxylic Acids / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry / Q000302:isolation & purification*; D006170:Gum Arabic / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007097:Imines / Q000737:chemistry; D007220:Industrial Waste; D009682:Magnetic Resonance Spectroscopy; D008751:Methylene Blue / Q000737:chemistry / Q000302:isolation & purification*; D011134:Polysaccharides / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013784:Textiles; D013997:Time Factors; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D000099166:Polyacrylamides
chemical_list: D000179:Acrylates; D000180:Acrylic Resins; D001391:Azo Compounds; D001557:Benzenesulfonates; D002264:Carboxylic Acids; D004396:Coloring Agents; D006170:Gum Arabic; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007097:Imines; D007220:Industrial Waste; D008751:Methylene Blue; D011134:Polysaccharides; D014867:Water; D014874:Water Pollutants, Chemical; D000099166:Polyacrylamides; C014722:2-naphthol orange