title: Evaluation of adsorption characteristics of an anionic azo dye Brilliant Yellow onto hen feathers in aqueous solutions.
abstract: PURPOSE AND AIM: Removal of an anionic azo dye Brilliant Yellow has been carried out from its aqueous solutions by using hen feathers as potential adsorbent.
  
  
  METHODS
  Hen feathers procured from local poultry were cut, washed, and activated. Detailed chemical and physical analysis of hen feathers and its characterization through scanning electron microscopy, X-ray diffraction, and infrared measurements have been made. Procured dye has been adsorbed over under batch measurements and adsorption process is monitored using UV spectrophotometer.
  
  
  RESULTS
  Optimum parameters for the adsorption of Brilliant Yellow over hen feathers have been determined by studying the effect of pH, temperature, concentration of dye, and amount of adsorbent. On the basis of Langmuir adsorption, isotherms feasibility of the ongoing adsorption has been ascertained and thermodynamic parameters have been calculated. Attempts have also been made to verify Freundlich, Tempkin, and Dubinin–Radushkevich adsorption isotherm models. It is found that during adsorption, uniform distribution of binding energy takes place due to interaction of the dye molecules and the ongoing adsorption process is chemisorptions. The kinetic measurements indicate dominance of pseudo-second-order process during the adsorption. The mathematical treatment on the kinetic data reveals the rate-determining step to be governed through particle diffusion at 8 × 10−5 M and involvement of film diffusion mechanism at higher concentration at temperatures at all the temperatures.
  
  
  CONCLUSIONS
  The developed process is highly efficient and it can be firmly concluded that hen feather exhibits excellent adsorption capacity towards hazardous azo dye Brilliant Yellow.
authors.affiliation: Department of Chemistry, Maulana Azad National Institute of Technology, Bhopal 462052, India. aljymittal@gmail.com
authors.forename: Alok
authors.initials: A
authors.lastname: Mittal
authors.forename: Vijay
authors.initials: V
authors.lastname: Thakur
authors.forename: Vibha
authors.initials: V
authors.lastname: Gajbe
mesh_terms: D000327:Adsorption; D000818:Animals; D020240:Apraxia, Ideomotor; D001391:Azo Compounds / Q000378:metabolism*; D001557:Benzenesulfonates / Q000378:metabolism*; D002645:Chickens; D004396:Coloring Agents / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005241:Feathers / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D001391:Azo Compounds; D001557:Benzenesulfonates; D004396:Coloring Agents; D014874:Water Pollutants, Chemical; C059622:Direct Yellow 4 dye