Details
| Original language | English |
|---|---|
| Pages (from-to) | 5982-5991 |
| Number of pages | 10 |
| Journal | Ceramics international |
| Volume | 50 |
| Issue number | 4 |
| Early online date | 3 Dec 2023 |
| Publication status | Published - 15 Feb 2024 |
Abstract
In this study, two laterites (LA)-based geopolymers were synthesized using alkalination (GPAL) and phosphoric acid-activation (GPAC) approaches and applied to scavenge malachite green (MG) dye from aqueous (non-saline) and saline water. The precursor (LA) and geopolymers were characterized by XRF, XRD, TG/DTA SEM, and FTIR techniques. Alkalination and acid-activation resulted in morphologically distinguishable geopolymers with different porosity structures. The dissolution of mineral phases and chemical composition was dependent on the activation medium, resulting in Na-polyferrosialate and polyferrophosphosialate geopolymers for GPAL and GPAC, respectively. The adsorption kinetics data were best described by the pseudo-first-order (PFO) model wherein the adsorption rate, denoted by rate constant (k1), increased with an increase in ionic strength (salinity). The equilibrium data were best modelled by the Sips isotherm. GPAL had a higher maximum adsorption capacity (Qms) than GPAC in both aqueous (non-saline) and saline water. The adsorption capacities were increased in saline solution relative to aqueous solutions without NaCl, from 12.4 to 54.1 mg/g and from 57.1 to 92.0 mg/g for GPAC and GPAL, respectively. The adsorption mechanism entailed electrostatic interactions, hydrogen bonding and hydrophobic interactions. Salinity decreased the solubility of MG and increased the hydrophobic interactions and affinity of MG, implied by apparent equilibrium constant (Ka), resulting in increased adsorption density (Qms). These results indicate that alkaline-based geopolymers are better candidates for scavenging MG dye from water, especially in saline environments.
Keywords
- Acid-activation, Adsorption, Alkalination, Laterite, Malachite green, Salinity
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Ceramics and Composites
- Chemical Engineering(all)
- Process Chemistry and Technology
- Materials Science(all)
- Surfaces, Coatings and Films
- Materials Science(all)
- Materials Chemistry
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In: Ceramics international, Vol. 50, No. 4, 15.02.2024, p. 5982-5991.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Elimination of malachite green from aqueous and saline water by laterite-derived Na-polyferrosialate and polyferrophosphosialate geopolymers
T2 - A comparative study
AU - Sylvain, Tome
AU - Tamaguelon, Hermann Dzoujo
AU - Shikuku, Victor
AU - Nana, Achile
AU - Etoh, Marie Annie
AU - Rüscher, Claus
AU - Etame, Jacques
N1 - Funding Information: The work presented in the paper has been carried out DAAD postdoc scholarship namely Research Stays for University Academics and Scientists , 2022 Award ID No: 57588362 to the first author and DAAD is greatly acknowledged. The authors are grateful Institut für Mineralogie of Leibniz Universität Hannover for extending all the facility to carry out the different characterization analyses.
PY - 2024/2/15
Y1 - 2024/2/15
N2 - In this study, two laterites (LA)-based geopolymers were synthesized using alkalination (GPAL) and phosphoric acid-activation (GPAC) approaches and applied to scavenge malachite green (MG) dye from aqueous (non-saline) and saline water. The precursor (LA) and geopolymers were characterized by XRF, XRD, TG/DTA SEM, and FTIR techniques. Alkalination and acid-activation resulted in morphologically distinguishable geopolymers with different porosity structures. The dissolution of mineral phases and chemical composition was dependent on the activation medium, resulting in Na-polyferrosialate and polyferrophosphosialate geopolymers for GPAL and GPAC, respectively. The adsorption kinetics data were best described by the pseudo-first-order (PFO) model wherein the adsorption rate, denoted by rate constant (k1), increased with an increase in ionic strength (salinity). The equilibrium data were best modelled by the Sips isotherm. GPAL had a higher maximum adsorption capacity (Qms) than GPAC in both aqueous (non-saline) and saline water. The adsorption capacities were increased in saline solution relative to aqueous solutions without NaCl, from 12.4 to 54.1 mg/g and from 57.1 to 92.0 mg/g for GPAC and GPAL, respectively. The adsorption mechanism entailed electrostatic interactions, hydrogen bonding and hydrophobic interactions. Salinity decreased the solubility of MG and increased the hydrophobic interactions and affinity of MG, implied by apparent equilibrium constant (Ka), resulting in increased adsorption density (Qms). These results indicate that alkaline-based geopolymers are better candidates for scavenging MG dye from water, especially in saline environments.
AB - In this study, two laterites (LA)-based geopolymers were synthesized using alkalination (GPAL) and phosphoric acid-activation (GPAC) approaches and applied to scavenge malachite green (MG) dye from aqueous (non-saline) and saline water. The precursor (LA) and geopolymers were characterized by XRF, XRD, TG/DTA SEM, and FTIR techniques. Alkalination and acid-activation resulted in morphologically distinguishable geopolymers with different porosity structures. The dissolution of mineral phases and chemical composition was dependent on the activation medium, resulting in Na-polyferrosialate and polyferrophosphosialate geopolymers for GPAL and GPAC, respectively. The adsorption kinetics data were best described by the pseudo-first-order (PFO) model wherein the adsorption rate, denoted by rate constant (k1), increased with an increase in ionic strength (salinity). The equilibrium data were best modelled by the Sips isotherm. GPAL had a higher maximum adsorption capacity (Qms) than GPAC in both aqueous (non-saline) and saline water. The adsorption capacities were increased in saline solution relative to aqueous solutions without NaCl, from 12.4 to 54.1 mg/g and from 57.1 to 92.0 mg/g for GPAC and GPAL, respectively. The adsorption mechanism entailed electrostatic interactions, hydrogen bonding and hydrophobic interactions. Salinity decreased the solubility of MG and increased the hydrophobic interactions and affinity of MG, implied by apparent equilibrium constant (Ka), resulting in increased adsorption density (Qms). These results indicate that alkaline-based geopolymers are better candidates for scavenging MG dye from water, especially in saline environments.
KW - Acid-activation
KW - Adsorption
KW - Alkalination
KW - Laterite
KW - Malachite green
KW - Salinity
UR - http://www.scopus.com/inward/record.url?scp=85179031219&partnerID=8YFLogxK
U2 - 10.1016/j.ceramint.2023.11.252
DO - 10.1016/j.ceramint.2023.11.252
M3 - Article
AN - SCOPUS:85179031219
VL - 50
SP - 5982
EP - 5991
JO - Ceramics international
JF - Ceramics international
SN - 0272-8842
IS - 4
ER -