title: Adsorption properties of congo red from aqueous solution onto N,O-carboxymethyl-chitosan.
abstract: N,O-carboxymethyl-chitosans (N,O-CMC) with different degree of substitution (DS) were synthesized under heterogeneous conditions by controlling the reaction temperature. The factors influencing adsorption capacity of N,O-CMC such as the DS of N,O-CMC, initial pH value of the dye solution and adsorption temperature for anionic dye congo red (CR) were investigated. Compared with chitosan (78.90 mg/g), N,O-CMC with the DS of 0.35 exhibited much higher adsorption capacity (330.62 mg/g) for CR at the same adsorption conditions. The adsorption kinetics and isotherms showed that the sorption processes were better fitted by pseudo-second-order equation and the Langmuir equation, respectively. The adsorption mechanism of N,O-CMC was also discussed by means of IR and XPS spectra. The results in this study indicated that N,O-CMC was an attractive candidate for removing CR from the dye wastewater.
authors.affiliation: Center of Eco-material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Aiqin
authors.initials: A
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D002236:Carbohydrate Conformation; D048271:Chitosan / Q000737:chemistry*; D003224:Congo Red / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D013055:Spectrophotometry, Infrared; D013696:Temperature; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry; D014877:Water Pollution, Chemical / Q000517:prevention & control
chemical_list: D014874:Water Pollutants, Chemical; D014867:Water; C077199:O,N-carboxymethylchitosan; D003224:Congo Red; D048271:Chitosan