title: Development of sustainable dye adsorption system using nutraceutical industrial fennel seed spent-studies using Congo red dye.
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.
authors.affiliation: a Department of Chemistry , University of Malaya , Kuala Lumpur , Malaysia.
authors.forename: Syed Noeman
authors.initials: SN
authors.lastname: Taqui
authors.affiliation: a Department of Chemistry , University of Malaya , Kuala Lumpur , Malaysia.
authors.forename: Rosiyah
authors.initials: R
authors.lastname: Yahya
authors.affiliation: a Department of Chemistry , University of Malaya , Kuala Lumpur , Malaysia.
authors.forename: Aziz
authors.initials: A
authors.lastname: Hassan
authors.affiliation: b LAQV-REQUIMTE, Department of Chemistry, Faculty of Science and Technology , Universidade NOVA de Lisboa , Caparica , Portugal.
authors.forename: Nayan
authors.initials: N
authors.lastname: Nayak
authors.affiliation: c Department of Studies in Chemistry , University of Mysore , Manasa Gangotri, Mysuru , India.
authors.forename: Akheel Ahmed
authors.initials: AA
authors.lastname: Syed
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D003224:Congo Red / Q000737:chemistry*; D019587:Dietary Supplements; D030001:Foeniculum; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification
chemical_list: D014874:Water Pollutants, Chemical; D003224:Congo Red
keywords: Congo red; adsorption studies; nutraceutical industrial fennel seed spent