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- Olusegun, Sunday J., et al.
(författare)
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Comparative characteristics and enhanced removal of tetracycline and ceftriaxone by Fe3O4-lignin and Fe3O4-carbon-based lignin : Mechanism, thermodynamic evaluation, and DFT calculation
- 2023
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Ingår i: Journal of Molecular Liquids. - : Elsevier BV. - 0167-7322 .- 1873-3166. ; 371
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Tidskriftsartikel (refereegranskat)abstract
- In this study, eco-friendly Fe3O4-lignin (FeL) and Fe3O4-carbon-based lignin (FeCL) were synthesized, characterized, and applied for the adsorption of tetracycline (TRC) and ceftriaxone (CEF). Comparative characterization showed that the BET-specific surface area of FeCL is 27 m2/g more than that of FeL. The difference in their morphologies is insignificant, and the particle sizes range between 5 and 15 nm. There is a reduction in the oxygen content and hydroxyl group of FeCL as shown from the EDS and FTIR spectra respectively, compared with FeL. The adsorption capacity for the removal of TRC at 333 K is 156 and 148 mg g-1 by FeL and FeCL, respectively; while that of CEF are virtually the same. FeL and FeCL adsorption capacity for TRC increases with temperatures (endothermic), but decreases (exothermic) for CEF. The combination of experimental and computational approaches gave insight into the mechanisms of the adsorption process. The mechanisms of TRC and CEF adsorption by FeL and FeCL are the electrostatic attraction, hydrophobic, and 7C -7C interaction, while only FeL shows the possibility of hydrogen bond with both TRC and CEF. The study demonstrated that the synthesized material can be reused for up to 3 cycles without an alarming loss of efficiency capacity.
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| 2. |
- Olusegun, Sunday J., et al.
(författare)
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Removal of doxorubicin hydrochloride and crystal violet from aqueous solutions using spray-dried niobium oxide coated with chitosan-activated carbon : Experimental and DFT calculations
- 2024
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Ingår i: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 266
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Tidskriftsartikel (refereegranskat)abstract
- Spray -dried niobium oxide coated with chitosan-activated carbon (NIC) was synthesized and used to remove doxorubicin hydrochloride and crystal violet from aqueous solutions under different parameters such as solution pH (2, 4, 6, and 8), contact time (1 to 9 h), initial concentration (20 to 200 mg L -1 ), and competing ions (0.1 M of CaCl 2 and NaCl). The addition of 5 % chitosan-activated carbon to the matrix of niobium oxide slightly increased the specific surface area from 26 to 30 m 2 g -1 , with the introduction of a carboxylic functional group. This led to an increase in the amount of adsorbed doxorubicin hydrochloride (DOH) from 30 to 44 mg g -1 and that of crystal violet (CV) from 15 to 32 mg g -1 from the initial respective 100 mg L -1 at pH 8. The data from the concentration study fitted into Liu isotherm having adsorption capacity of 128 and 57 mg g -1 for DOH and CV respectively, while pseudo first and second order are more suitable for adsorption kinetics. The additional functional groups on the IR spectrum of NIC after the adsorption of DOH and CV confirmed the interaction between NIC and the adsorbates' molecules. The mechanism of adsorption was supported by DFT calculations.
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