TY - JOUR
T1 - Removal of Azo dyes – tartrazine, carmoisine, and allura red – from wastewater using spirulina biomass-immobilized alginate beads
T2 - Equilibrium, kinetics, thermodynamics, desorption, and reusability
AU - Saloglu, Didem
AU - Sahin, Oya Irmak
N1 - Publisher Copyright:
© 2021 Desalination Publications. All rights reserved.
PY - 2021/4
Y1 - 2021/4
N2 - In the present study, Spirulina microalgae-immobilized alginate beads (Alg-SP) were used as novel adsorbents for the adsorption of tartrazine, carmoisine, and Allura Red azo-dyes from wastewa-ter. Synthesized Alg-SP beads were characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry analyses. Maximum azo-dye removal percentages were achieved using 100 mg of Alg-SP beads with a ratio of 3.0% (w/v) within 2 h, and tartrazine, carmoisine, and Allura Red removal performances were determined to be 98%, 93%, and 82%, respectively. The adsorp-tion data for azo-dyes onto Alg-SP beads were evaluated by several isotherm equations such as Langmuir, Freundlich, Dubinin–Radushkevich, Temkin, Halsey, and Harkins–Jura isotherm mod-els, but were best described by the Langmuir and Harkins–Jura models as they gave the highest correlation. Pseudo-first-order, pseudo-second-order, Elovich, Weber–Morris, and Bangham models were investigated and dye adsorption onto Alg-SP beads was represented by pseudo-second-order and Elovich kinetic models. After the adsorption process, the beads can easily be regenerated by NaOH and effectively reused over three cycles. Consequently, Spirulina microalgae-immobilized alginate beads have considerable potential for the adsorption of dyes from wastewater.
AB - In the present study, Spirulina microalgae-immobilized alginate beads (Alg-SP) were used as novel adsorbents for the adsorption of tartrazine, carmoisine, and Allura Red azo-dyes from wastewa-ter. Synthesized Alg-SP beads were characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry analyses. Maximum azo-dye removal percentages were achieved using 100 mg of Alg-SP beads with a ratio of 3.0% (w/v) within 2 h, and tartrazine, carmoisine, and Allura Red removal performances were determined to be 98%, 93%, and 82%, respectively. The adsorp-tion data for azo-dyes onto Alg-SP beads were evaluated by several isotherm equations such as Langmuir, Freundlich, Dubinin–Radushkevich, Temkin, Halsey, and Harkins–Jura isotherm mod-els, but were best described by the Langmuir and Harkins–Jura models as they gave the highest correlation. Pseudo-first-order, pseudo-second-order, Elovich, Weber–Morris, and Bangham models were investigated and dye adsorption onto Alg-SP beads was represented by pseudo-second-order and Elovich kinetic models. After the adsorption process, the beads can easily be regenerated by NaOH and effectively reused over three cycles. Consequently, Spirulina microalgae-immobilized alginate beads have considerable potential for the adsorption of dyes from wastewater.
KW - Adsorption
KW - Alginate
KW - Azo dyes
KW - Spirulina
UR - http://www.scopus.com/inward/record.url?scp=85105503376&partnerID=8YFLogxK
U2 - 10.5004/dwt.2021.27010
DO - 10.5004/dwt.2021.27010
M3 - Article
AN - SCOPUS:85105503376
SN - 1944-3994
VL - 220
SP - 431
EP - 445
JO - Desalination and Water Treatment
JF - Desalination and Water Treatment
ER -