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Adsorption Characteristics of Allura Red AC onto Sawdust and Hexadecylpyridinium Bromide-Treated Sawdust in Aqueous Solution.
- Source :
-
ACS omega [ACS Omega] 2020 May 28; Vol. 5 (22), pp. 13358-13374. Date of Electronic Publication: 2020 May 28 (Print Publication: 2020). - Publication Year :
- 2020
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Abstract
- The Allura red AC (ARAC) dye adsorption onto natural sawdust (NSD) and hexadecylpyridinium bromide-treated sawdust (MSD) was investigated in aqueous solution as a function of contact time, solution pH, particle size, adsorbent dosage, dye concentration, temperature, and ionic strength. The adsorbents were characterized by Fourier transform infrared spectroscopy and X-ray diffraction crystallography. The dye adsorption onto both adsorbents was confirmed by field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. The maximum dye adsorption was found within 120 min at pH 2.0 for NSD and pH 3.0 for MSD, respectively, with a particle size of 0-75 μm and an adsorbent dosage of 0.07 g/50 mL ARAC dye solution (50 μmol/L). The batch adsorption kinetic data were followed by the pseudo-second-order kinetic model rather than the pseudo-first-order and Elovich kinetic models. Equilibrium adsorption isotherms were explained by the Langmuir isotherm model, and the maximum extent of adsorption was found to be 52.14 μmol/g for NSD and 151.88 μmol/g for MSD at 55 °C. The values of activation energy ( E <subscript>a</subscript> ) and thermodynamic parameters (Δ G <superscript>⧧</superscript> , Δ H <superscript>⧧</superscript> , Δ S <superscript>⧧</superscript> , Δ G °, Δ H ° and Δ S °) proved that the ARAC dye adsorption onto both adsorbents NSD and MSD is a spontaneous-endothermic physisorption process. ARAC (98-99%) was released from dye-loaded adsorbents in aqueous solution (pH ≥ 12) within 120 min. The adsorbents NSD and MSD were reused for a second time without significant loss of their adsorption efficiency.<br />Competing Interests: The authors declare no competing financial interest.<br /> (Copyright © 2020 American Chemical Society.)
Details
- Language :
- English
- ISSN :
- 2470-1343
- Volume :
- 5
- Issue :
- 22
- Database :
- MEDLINE
- Journal :
- ACS omega
- Publication Type :
- Academic Journal
- Accession number :
- 32548522
- Full Text :
- https://doi.org/10.1021/acsomega.0c01493