Affiliations 

  • 1 a Department of Chemistry , University of Malaya , Kuala Lumpur , Malaysia
  • 2 b LAQV-REQUIMTE, Department of Chemistry, Faculty of Science and Technology , Universidade NOVA de Lisboa , Caparica , Portugal
  • 3 c Department of Studies in Chemistry , University of Mysore , Manasa Gangotri, Mysuru , India
Int J Phytoremediation, 2017 Jul 03;19(7):686-694.
PMID: 28121459 DOI: 10.1080/15226514.2017.1284746

Abstract

Fennel seed spent (FSS)-an inexpensive nutraceutical industrial spent has been used as an efficient biosorbent for the removal of Congo red (CR) from aqueous media. Results show that the conditions for maximum adsorption would be pH 2-4 and 30°C were ideal for maximum adsorption. Based on regression fitting of the data, it was determined that the Sips isotherm (R2 = 0.994, χ2 = 0.5) adequately described the mechanism of adsorption, suggesting that the adsorption occurs homogeneously with favorable interaction between layers with favorable interaction between layers. Thermodynamic analysis showed that the adsorption is favorable (negative values for ΔG°) and endothermic (ΔH° = 12-20 kJ mol-1) for initial dye concentrations of 25, 50, and 100 ppm. The low ΔH° value indicates that the adsorption is a physical process involving weak chemical interactions like hydrogen bonds and van der Waals interactions. The kinetics revealed that the adsorption process showed pseudo-second-order tendencies with the equal influence of intraparticle as well as film diffusion. The scanning electron microscopy images of FSS show a highly fibrous matrix with a hierarchical porous structure. The Fourier transform infrared spectroscopy analysis of the spent confirmed the presence of cellulosic and lignocellulosic matter, giving it both hydrophilic and hydrophobic properties. The investigations indicate that FSS is a cost-effective and efficient biosorbent for the remediation of toxic CR dye.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.