Adsorption of mercury ions from synthetic aqueous solution using polydopamine decorated SWCNTs

Ghasemi, Seyedeh Sima; Hadavifar, Mojtaba; Maleki, Behrooz; Mohammadnia, Esmail

doi:10.1016/j.jwpe.2019.100965

Cited by 71 publications

(26 citation statements)

References 80 publications

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“…The calculated parameters of Thomas and Adams-Bohart model are presented in Table 7 . Comparison of the fitness of dynamic adsorption data with the models were based on the higher values of R 2 , Consequently, Table 7 shows that the experimental data were best fitted by Thomas model with R 2 above 0.964, compared to the Adams-Bohart model with the highest R 2 of 0.887, thereby corresponding to pseudo-second order rate driving force 80 . Above all, the results obtained for the continuous adsorption corresponds to results of batch adsorption based on assumption of Thomas model for pseudo-second order kinetics which remarks that adsorption process was mass transfer controlled at the interface, not by chemical reaction 49 .…”

Section: Resultsmentioning

confidence: 99%

Adsorption of Cr(VI), Ni(II), Fe(II) and Cd(II) ions by KIAgNPs decorated MWCNTs in a batch and fixed bed process

Egbosiuba

Abdulkareem

Kovo

et al. 2021

Sci Rep

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The efficient removal of toxic metals ions from chemical industry wastewater is considered problematic due to the existence of pollutants as mixtures in the aqueous matrix, thus development of advanced and effective treatment method has been identified as a panacea to the lingering problems of heavy metal pollution. In this study, KIAgNPs decorated MWCNTs nano adsorbent was developed using combination of green chemistry protocol and chemical vapor deposition techniques and subsequently characterized using UV–Vis, HRTEM, HRSEM, XRD, FTIR and XPS. The adsorptive efficiency of MWCNTs-KIAgNPs for the removal of Cr(VI), Ni(II), Fe(II), Cd(II) and physico-chemical parameters like pH, TDS, COD, BOD, nitrates, sulphates, chlorides and phosphates from chemical industrial wastewater was examined in both batch and fixed bed systems. The result exhibited successful deposition of KIAgNPs on the surface of MWCNTs as confirmed by the microstructures, morphology, crystalline nature, functional groups and elemental characteristics of the MWCNTs-KIAgNPs. Optimum batch adsorption parameters include; pH (3 for Cr(VI) and 6 for Ni(II), Fe(II) and Cd(II) ions), contact time (60 min), adsorbent dosage (40 mg) and temperature (318 K). The binding capacities were obtained as follows; Cr6+ (229.540 mg/g), Ni2+ (174.784 mg/g), Fe2+ (149.552) and Cd2+ (121.026 mg/g), respectively. Langmuir isotherm and pseudo-second order kinetic model best described the experimental data in batch adsorption, while the thermodynamic parameters validated the chemisorption and endothermic nature of the adsorption process. In continuous adsorption, the metal ions were effectively removed at low metal influent concentration, low flow rate and high bed depth, whereby the experimental data were designated by Thomas model. The high physico-chemical parameters in the wastewater were successfully treated in both batch and fixed bed systems to fall within WHO permissible concentrations. The adsorption/desorption study illustrated over 80% metal removal by MWCNTs-KIAgNPs even after 8th adsorption cycle. This study demonstrated excellent performance of MWCNTs-KIAgNPs for chemical industry wastewater treatment.

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Section: Resultsmentioning

confidence: 99%

Adsorption of Cr(VI), Ni(II), Fe(II) and Cd(II) ions by KIAgNPs decorated MWCNTs in a batch and fixed bed process

Egbosiuba

Abdulkareem

Kovo

et al. 2021

Sci Rep

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“…Nevertheless, negative ∆H 0 values represent the exothermic nature of the adsorption of MB by rGO adsorbent, say, a negative enthalpy (−2.20 kJ mol −1 ) implies that temperature increase had negative impact on the adsorption of MB, resulting in higher adsorption at lower temperatures. Negative ∆H 0 values, particularly, indicate that high temperature during adsorption process causes low adsorption efficiency [79]. The positive value of ∆S 0 = 0.069 confirms the good affinity of MB toward the rGO nanosheets, and the increased randomness at the rGO-water interface during the adsorption process [52].…”

Section: Adsorption Thermodynamicsmentioning

confidence: 93%

“…Indeed, the adsorption process is assigned to physisorption in nature when the ΔG 0 value is in the range from 0 to −20 kJ mol −1 , while ΔG 0 values in the range from −80 to −400 kJ mol −1 suggest a chemisorption process [52]. The partition between these two categories is vague [79]. Then, based on isotherm models it was seen that in this (MB-rGO) process both monolayer adsorption (chemisorption) and multilayer adsorption (physisorption) can occur.…”

Section: Adsorption Thermodynamicsmentioning

confidence: 99%

The Adsorption of Methylene Blue on Eco-Friendly Reduced Graphene Oxide

et al. 2020

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Recently, green-prepared oxidized graphenes have attracted huge interest in water purification and wastewater treatment. Herein, reduced graphene oxide (rGO) was prepared by a scalable and eco-friendly method, and its potential use for the removal of methylene blue (MB) from water systems, was explored. The present work includes the green protocol to produce rGO and respective spectroscopical and morphological characterizations, as well as several kinetics, isotherms, and thermodynamic analyses to successfully demonstrate the adsorption of MB. The pseudo-second-order model was appropriated to describe the adsorption kinetics of MB onto rGO, suggesting an equilibrium time of 30 min. Otherwise, the Langmuir model was more suitable to describe the adsorption isotherms, indicating a maximum adsorption capacity of 121.95 mg g−1 at 298 K. In addition, kinetics and thermodynamic analyses demonstrated that the adsorption of MB onto rGO can be treated as a mixed physisorption–chemisorption process described by H-bonding, electrostatic, and π − π interactions. These results show the potential of green-prepared rGO to remove cationic dyes from wastewater systems.

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“…Case S2 illustrates the breakthrough behavior of mercury adsorption on a nano-adsorbent [38]. Case S3…”

Section: Additional Casesmentioning

confidence: 99%

Improved fixed bed models for correlating asymmetric adsorption breakthrough curves

Apiratikul

Chu²

2021

Journal of Water Process Engineering

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Breakthrough curves of water contaminants are usually analyzed using simple fixed bed models such as the Bohart-Adams, Thomas, and Yoon-Nelson equations, which are by design symmetric. Because breakthrough data often follow an asymmetric pattern, the use of models that do not account for asymmetry could lead to poor fits, consequently resulting in erroneous estimates of breakthrough and exhaustion times. To address this issue, the Bohart-Adams, Thomas, and Yoon-Nelson models were modified by a logarithmic transformation to enhance their data fitting ability. The three modified models were found capable of providing robust fits to seven separate sets of previously reported asymmetric breakthrough data of water contaminants (fluoride, methylene blue, salicylic acid, lead, mercury, nickel, and arsenic), with reported residual root mean square error (RRMSE) values ranging from 0.019 to 0.046. In consequence, the new models were found capable of providing reliable estimates of breakthrough and exhaustion times corresponding to any predetermined concentration level. By contrast, the three original models were found to perform poorly, reporting inferior RRMSE values ranging from 0.038 to 0.086 for data fits and providing grossly inaccurate estimates of breakthrough and exhaustion times. The new models contain only parameters that appear in the original models, and are highly flexible, being able to assume virtually all monotonically increasing sigmoid shapes. They represent a far more accurate alternative to the original models.

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Adsorption of mercury ions from synthetic aqueous solution using polydopamine decorated SWCNTs

Cited by 71 publications

References 80 publications

Adsorption of Cr(VI), Ni(II), Fe(II) and Cd(II) ions by KIAgNPs decorated MWCNTs in a batch and fixed bed process

Adsorption of Cr(VI), Ni(II), Fe(II) and Cd(II) ions by KIAgNPs decorated MWCNTs in a batch and fixed bed process

The Adsorption of Methylene Blue on Eco-Friendly Reduced Graphene Oxide

Improved fixed bed models for correlating asymmetric adsorption breakthrough curves

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