Radioactive Cobalt(II) Removal from Aqueous Solutions Using a Reusable Nanocomposite: Kinetic, Isotherms, and Mechanistic Study

Zhang, Xiaotao; Chen, Zhangjing

doi:10.3390/ijerph14121453

Cited by 29 publications

(11 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The pseudo-second order modelmeant that adsorption process was controlled by chemisorption which involved valency forces through sharing or exchange of electron between the solvent and the sorbate [ 43 , 44 , 45 ]. Because the pseudo-second order model contained the external liquid film diffusion, surface adsorption and intra-particle diffusion processes [ 46 , 47 , 48 , 49 ], this model could provide a more comprehensive and accurate description of the adsorption mechanism between tea waste and MB.…”

Section: Resultsmentioning

confidence: 99%

Removal Behavior of Methylene Blue from Aqueous Solution by Tea Waste: Kinetics, Isotherms and Mechanism

Liu

Fan

2018

IJERPH

View full text Add to dashboard Cite

Tea waste (biosorbent) was characterized by BET, SEM, FTIR, XPS, solid state 13C-NMR and applied to remove methylene blue (MB) from aqueous solution. The effect of different factors on MB removal, kinetics, isotherms and potential mechanism was investigated. The results showed that tea waste contains multiple organic functional groups. The optimum solid-to-liquid ratio for MB adsorption was 4.0 g·L−1 and the initial pH of the MB solution did not need to be adjusted to a certain value. The pseudo-second-order model could well fit the adsorption kinetic process. The adsorption process could be divided into two stages: a fast adsorption stage and a slow adsorption stage. The adsorption isotherm could be well described by Langmuir and Temkin isotherm models. The maximum adsorption amount could reach 113.1461 mg·g−1 based on Langmuir isotherm fitting. Desorption and reusability experiments showed that MB adsorption onto tea waste could be stable and could not cause secondary pollution. The interaction mechanism between tea waste and MB involved electrostatic attraction, hydrogen bond, ion exchange, π-π binding. The organic functional groups of tea waste played an important role during the MB removal process. Therefore, tea waste has the potential to act as an adsorbent to remove MB from aqueous solution.

show abstract

Section: Resultsmentioning

confidence: 99%

Removal Behavior of Methylene Blue from Aqueous Solution by Tea Waste: Kinetics, Isotherms and Mechanism

Liu

Fan

2018

IJERPH

View full text Add to dashboard Cite

show abstract

“…e adsorption process is controlled by the chemisorption involving valence forces through the sharing or exchange of electrons between the adsorbent and the adsorbate [32,33]. However, the pseudosecond-order model contains the external liquid film diffusion, intraparticle diffusion, and adsorption on the surface of the adsorbent; this model provides a more comprehensive and accurate description of the adsorption mechanism between wasted tea powder and MB [34][35][36]. Figure 9 shows the plot of intraparticle diffusion model for the adsorption of MB onto wasted tea powder.…”

Section: Adsorption Kineticsmentioning

confidence: 99%

Application of Wasted Oolong Tea as a Biosorbent for the Adsorption of Methylene Blue

Zhang

et al. 2019

Journal of Chemistry

View full text Add to dashboard Cite

Tea powder, a biosorbent prepared from wasted oolong tea, was collected as a prospective adsorbent for the adsorption of methylene blue (MB) from aqueous solution. e effect of factors on adsorption efficiency, isotherms, kinetics, and potential mechanism was carried out. Adsorption capacity of MB onto wasted tea powder increased with the MB concentration and contact time, whereas the increase in pH value and ion strength appeared to have a negative effect for the adsorption process. e adsorption efficiency increased rapidly and reached a stable state within 120 min. e optimal tea powder loading weight is suggested to be at 0.1 to 0.2 g, and the highest efficiency of 94.8% is achieved at 333 K. ere were no significant changes in adsorption efficiency when the effect of temperature is considered. e Langmuir isotherm model was found to be the best isotherm models to elucidate the adsorption mechanism in this study. e maximum adsorption capacities calculated at different temperatures by the Langmuir model ranging from 312.5 to 333.3 mg·g −1 were much close to the experimental results. From the kinetic analysis, the pseudo--second-order model was found to be the best model to describe the adsorption behavior. e calculated adsorption capacities at different initial MB concentrations by the pseudo-second-order model ranging from 92.34 to 400 mg·g −1 were well close to the experimental data. e fitting results obtained from the intraparticle diffusion model suggested that the intraparticle diffusion was not the only rate-controlling step and some other mechanisms along with the intraparticle diffusion were probably involved. e intraparticle diffusion of MB molecules into pore structures of wasted tea powder is the ratelimiting step for the adsorption process in this study. e repetitive cycle experiments indicated that the wasted oolong tea powder was efficiently regenerated using NaOH and thus be used for many times.

show abstract

“…The well-fitting result for second-order model demonstrates that the rate-limiting step is not the resistance of the boundary layer [ 72 ]. The adsorption process is controlled by chemisorption, which involves valence forces due to the sharing or exchange of electrons between the adsorbent and the adsorbate [ 73 , 74 ]. The second-order model includes the external liquid film diffusion, intraparticle diffusion, and adsorption on the surface of the adsorbent; this model provides a more comprehensive and accurate description of the adsorption mechanism between powder CeO 2 and CR [ 75 , 76 ].…”

Section: Resultsmentioning

confidence: 99%

Green Synthesis of Nanostructure CeO2 Using Tea Extract: Characterization and Adsorption of Dye from Aqueous Phase

Liu

et al. 2021

Bioinorganic Chemistry and Applications

View full text Add to dashboard Cite

Nanostructure CeO2 powders were synthesized using tea waste extract as gel precursor. The as-prepared samples were characterized by thermogravimetric analyzer (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Based on the TGA/DTG analysis, the intermediates of cerium chloride hydrates (CeCl3.4H2O and CeCl3.H2O) and cerium anhydrous (CeCl3) were produced, and the formation temperature of CeO2 was estimated to be 773 K. The cubic fluorite structure of CeO2 was detected to be the predominant species and was completely formed at the calcination temperature of 773K–1073 K with a crystal size between 8.8 and 11.4 nm based on the XRD measurement. Moreover, the main chemical state of ceria on the surface of the synthesized samples was confirmed to be tetravalent ceria by XPS. All samples show a strong Raman signal at a well-defined chemical shift of 463 cm−1 and a significant symmetry feature was observed, suggesting that the tetravalent ceria is the dominant species throughout the bulk sample. All the synthesized CeO2 calcined at different temperatures showed higher adsorption efficiency for Congo red (CR) compared with commercial CeO2. The adsorption efficiency maintained a steady state of more than 95% when the concentration of CR and adsorption temperature were varied in this study. The kinetic analysis showed that the second-order model was the appropriate model to interpret the adsorption behavior of synthesized CeO2. The calculated adsorption capacity derived from the second-order model is in good agreement with the experimental data. The isotherm analysis revealed that the Freundlich and D-R models fit well for the synthesized CeO2 and represent physisorption with a multilayer mechanism. The thermodynamic parameters, including the changes in Gibb’s free energy, enthalpy, and entropy, suggested that the adsorption of CR on the synthesized CeO2 sample was a spontaneous and endothermic process.

show abstract

Radioactive Cobalt(II) Removal from Aqueous Solutions Using a Reusable Nanocomposite: Kinetic, Isotherms, and Mechanistic Study

Cited by 29 publications

References 51 publications

Removal Behavior of Methylene Blue from Aqueous Solution by Tea Waste: Kinetics, Isotherms and Mechanism

Removal Behavior of Methylene Blue from Aqueous Solution by Tea Waste: Kinetics, Isotherms and Mechanism

Application of Wasted Oolong Tea as a Biosorbent for the Adsorption of Methylene Blue

Green Synthesis of Nanostructure CeO2 Using Tea Extract: Characterization and Adsorption of Dye from Aqueous Phase

Contact Info

Product

Resources

About