title: Adsorption of Remazol Red 198 onto magnetic N-lauryl chitosan particles: equilibrium, kinetics, reuse and factorial design.
abstract: OBJECTIVE
  The discharge of colored effluents from industries is an important environmental issue and it is indispensable to remove the dyes before the water gets back to the rivers. The magnetic adsorbents present the advantage of being easily separated from the aqueous system after adsorption by positioning an external magnetic field.
  
  
  METHODS
  Magnetic N-lauryl chitosan (L-Cht/γ-Fe(2)O(3)) particles were prepared and characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, and vibrating sample magnetometry. Remazol Red 198 (RR198) was used as a reactive dye model for adsorption on L-Cht/γ-Fe(2)O(3). The adsorption isotherms were performed at 25°C, 35°C, 45°C, and 55°C and the process was optimized using a 2(3) factorial design (analyzed factors: pH, ionic strength, and temperature). The desorption and regeneration studies were performed in a three times cycle.
  
  
  RESULTS
  The characterization of the material indicated that the magnetic particles were introduced into the polymeric matrix. The pseudo-second order was the best model for explaining the kinetics and the Langmuir-Freundlich was the best-fitted isotherm model. At room temperature, the maximum adsorption capacity was 267 mg g(-1). The material can be reused, but with a decrease in the amount of adsorbed dye.
  
  
  CONCLUSIONS
  L-Cht/γ-Fe(2)O(3) is a promising material to remove RR198 and probably other similar reactive dyes from aqueous effluents.
authors.affiliation: NIQFAR CCS, Universidade do Vale do Itajaí, Itajaí, SC, Brazil.
authors.forename: Aline
authors.initials: A
authors.lastname: Debrassi
authors.forename: Thaisa
authors.initials: T
authors.lastname: Baccarin
authors.forename: Carla Albertina
authors.initials: CA
authors.lastname: Demarchi
authors.forename: Nataliya
authors.initials: N
authors.lastname: Nedelko
authors.forename: Anna
authors.initials: A
authors.lastname: Ślawska-Waniewska
authors.forename: Piotr
authors.initials: P
authors.lastname: Dłużewski
authors.forename: Marta
authors.initials: M
authors.lastname: Bilska
authors.forename: Clóvis Antonio
authors.initials: CA
authors.lastname: Rodrigues
mesh_terms: D000327:Adsorption; D001391:Azo Compounds / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry*; D007700:Kinetics; D060328:Magnetic Phenomena; D008855:Microscopy, Electron, Scanning; D009282:Naphthalenesulfonates / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013783:Textile Industry; D013818:Thermogravimetry; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D009282:Naphthalenesulfonates; D014874:Water Pollutants, Chemical; C575088:remazol red 198; D048271:Chitosan