Preparation of superfine down particles derived from down fiber wastes and their application as an efficient adsorbent toward acid brilliant scarlet 3R

Abstract

Low-cost superfine down particles (SDP) were evaluated as an adsorbent for the removal of acid brilliant scarlet 3R (ABS-3R) dye from aqueous solutions. Scanning electron microscopy, particle size distribution, Brunauer–Emmett–Teller specific surface area, X-ray diffraction, Fourier transform infrared spectroscopy, and amino-acid analysis were used to characterize the structural characteristics of the adsorbent material. The effects of adsorption process parameters, including initial pH, adsorbent dose, initial dye concentration, adsorption time, and temperature, were systematically studied in batch adsorption experiments. Further, adsorption equilibrium data were modeled by Langmuir, Freundlich, and Dubinin–Radushkevich isotherms. The adsorption process followed the Langmuir isotherm model and the maximum adsorption capacity was 158.23 mg/g at 318 K. Kinetic studies at different temperatures showed that the pseudo-second-order kinetic model fitted well in correlation to the experimental results in comparison to the pseudo-first-order model. The activation energy of the adsorption process was 59.52 kJ/mol, using the Arrhenius equation, which indicated the chemisorption nature of ABS-3R adsorption onto SDP. Thermodynamic study showed that adsorption of ABS-3R was a spontaneous and endothermic process. In summary, SDP was found to be an efficient and eco-friendly adsorbent, which might be suitable for the removal of dyes from aqueous solutions.