The removal of Pb (II) and Cd (II) with hydrous manganese dioxide: mechanism on zeta potential and adsorption behavior

Wu, Shanshan; Xie, Fencun; Chen, Sijie; Fu, Binbin

doi:10.1080/09593330.2019.1604814

Cited by 27 publications

(11 citation statements)

References 40 publications

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“…Existing studies have paid attention to the application capabilities of physical and chemical remediation technologies, including chemical precipitation, ion exchange, adsorption, membrane filtration technology, flotation, and electrochemical treatment techniques [14][15][16][17]. Although these treatment techniques can be employed to remove heavy metals, they may show some limitations in practice.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation on Bioremediation of Heavy Metal Contaminated Solution by Sporosarcina pasteurii under Some Complex Conditions

Huang

Zhang

Cui

2022

Water

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Bioremediation of contaminated solutions has attracted extensive attention in recent years due to its wide range of applicability to various types of contaminants and environmental friendliness. Previous studies adequately confirmed the potential of Sporosarcina pasteurii (i.e., S. pasteurii)-based bioremediation for heavy metal contaminated solutions, but they focused mainly on the bioremediation ability of single-heavy-metal contaminated solutions. This study focuses on S. pasteurii-based bioremediation under more complex pollution conditions. A series of laboratory experiments were performed to explore the efficiency and mechanism of S. pasteurii-based bioremediation to heavy metal contaminated solutions under various conditions, including single-heavy-metal pollution condition, heavy metal pollution under high mineral salinity context and multi-heavy-metal pollution scenarios. The results show that S. pasteurii can effectively remove heavy metals such as Cd, Cr(III), and Zn through biomineralization; for the typical range of mineral salinity (including NaCl and KCl) possibly encountered in practice in some contaminated solutions, such as leachate of landfills, the detrimental influence of high mineral salinity on efficiency of S. pasteurii-based bioremediation can be neglected; more importantly, S. pasteurii-based bioremediation can be considered as a potential option for remedying multi-heavy-metal contaminated solutions, though the addition of some heavy metals tends to produce a substantially detrimental influence on the bioremediation ability of S. pasteurii to other heavy metals.

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Section: Introductionmentioning

confidence: 99%

Experimental Investigation on Bioremediation of Heavy Metal Contaminated Solution by Sporosarcina pasteurii under Some Complex Conditions

Huang

Zhang

Cui

2022

Water

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“…In this process, the surface adsorption sites gradually decrease, and the adsorption capacity starts to approach the maximum. Moreover, the reduction of adsorption sites causes the adsorbed Cd 2+ to enter the interior of the mesopores, generating a considerable mass transfer resistance and finally reaching adsorption equilibrium with the adsorption rate maintained at k p,3 45 , 46 .…”

Section: Resultsmentioning

confidence: 99%

Cadmium adsorption performance and mechanism from aqueous solution using red mud modified with amorphous MnO2

Pang

Zhao

et al. 2022

Sci Rep

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In this study, red mud modified by manganese dioxide(MRM) was utilized as an adsorbent to effectively remove Cd2+ from aqueous solution. The characteristics were analysed by SEM–EDS, XRD, BET, FTIR and XPS. Different factors that affected the Cd2+ removal on MRM, such as dosage, initial pH, initial Cd2+ concentration, were investigated using batch adsorption experiments. Simultaneously, the adsorption kinetics, adsorption isotherms and adsorption thermodynamics of Cd2+ were also investigated using adsorption experiments data. The characterization results showed that MRM had a rougher, larger specific surface area and pore volume (38.91 m2 g−1, 0.02 cm3 g−1) than RM (10.22 m2 g−1, 0.73 cm3 g−1). The adsorption experiments found that the equilibrium adsorption capacity of MRM for Cd2+ was significantly increased to 46.36 mg g−1, which was almost three times that of RM. According to the fitting results, the pseudo-second-order kinetic model described the adsorption process better than the pseudo-first-order kinetic model. The Langmuir model fitted the adsorption isotherms well, indicating that the adsorption process was unimolecular layer adsorption and the maximum capacity was 103.59 mg g−1. The thermodynamic parameters indicated that the adsorption process was heat-trapping and spontaneous. Finally, combined XPS and FTIR studies, it was speculated that the adsorption mechanisms should be electrostatic attachment, specific adsorption (i.e., Cd–O or hydroxyl binding) and ion exchange. Therefore, manganese dioxide modified red mud can be an effective and economical alternative to the removal of Cd2+ in the wastewater treatment process.

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“…These results indicated that the alkyl epoxy atom could react with Cd(II) rapidly and a typical cadmium−oxygen (Cd−O) coordination bond is formed in Cd-MOF-PO. 69 Similar phenomena exist on the fluorescence of Cd-MOF toward some similar alkyl epoxy solvents such as dioxane (Diox) and tetrahydrofuran (THF). As shown in Figures S20−S25, upon the addition of Diox (0.5 mM) or THF (2.0 mM), the Cd-MOF suspension gives S−V constants of 9.2 × 10 3 and 7.7 × 10 3 M −1 , and the corresponding detection limits are determined to be 1.39 and 1.75 μM, respectively.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Meanwhile, two deconvolution peaks are recognized at 406.63 and 413.66 eV in the Cd 3d XPS spectrum of Cd-MOF-PO . These results indicated that the alkyl epoxy atom could react with Cd(II) rapidly and a typical cadmium–oxygen (Cd–O) coordination bond is formed in Cd-MOF-PO . Similar phenomena exist on the fluorescence of Cd-MOF toward some similar alkyl epoxy solvents such as dioxane (Diox) and tetrahydrofuran (THF).…”

Section: Resultsmentioning

confidence: 99%

Dynamic Metal–Iodide Bonds in a Tetracoordinated Cadmium-Based Metal–Organic Framework Boosting Efficient CO₂ Cycloaddition under Solvent- and Cocatalyst-Free Conditions

Qiao

et al. 2022

Inorg. Chem.

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Due to the inherent thermodynamic stability and kinetic inertness of CO2, heterogeneous catalytic conversion of CO2 to cyclic carbonates often requires harsh operating conditions, high temperature and high pressure, and the addition of cocatalysts. Therefore, the development of efficient heterogeneous catalysts under cocatalyst-free and mild conditions for CO2 conversion has always been a challenge. Herein, an infrequent tetracoordinated Cd-MOF was synthesized and used to catalyze CO2 cycloaddition reactions efficiently without the addition of any cocatalyst, and its catalytic mechanism was systematically investigated through a series of experiments, including fluorescence analysis, X-ray photoelectron spectroscopy, microcalorimetry, and density functional theory (DFT) calculation. Cd-MOF features a 3D supermolecule structure with 1D 11.6 × 7.7 Å2 channels, and the abundant Lewis acid/base and I– sites located in the confined channel boost efficient CO2 conversion with a maximum yield of 98.2% and a turnover number value of 1080.11 at 60 °C and 0.5 MPa, far surpassing most pristine MOF-based catalytic systems. A combined experimental and DFT calculation demonstrates that the exposed Cd(II) Lewis acid sites rapidly participate in coordination to activate the epoxides, and the resulting large steric hindrance facilitates leaving of the coordinated iodide ions in a reversibly dynamic fashion convenient for the rate-determining step ring-opening as a strong nucleophile. Such a pristine MOF catalyst with self-independent catalytic ring-opening overcomes the complicated operation limitation of the traditional cocatalyst-free MOF systems based on encapsulating/postmodifying cocatalysts, providing a whole new strategy for the development of simple, green, and efficient heterogeneous catalysts for CO2 cycloaddition.

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The removal of Pb (II) and Cd (II) with hydrous manganese dioxide: mechanism on zeta potential and adsorption behavior

Cited by 27 publications

References 40 publications

Experimental Investigation on Bioremediation of Heavy Metal Contaminated Solution by Sporosarcina pasteurii under Some Complex Conditions

Experimental Investigation on Bioremediation of Heavy Metal Contaminated Solution by Sporosarcina pasteurii under Some Complex Conditions

Cadmium adsorption performance and mechanism from aqueous solution using red mud modified with amorphous MnO2

Dynamic Metal–Iodide Bonds in a Tetracoordinated Cadmium-Based Metal–Organic Framework Boosting Efficient CO₂ Cycloaddition under Solvent- and Cocatalyst-Free Conditions

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The removal of Pb (II) and Cd (II) with hydrous manganese dioxide: mechanism on zeta potential and adsorption behavior

Cited by 27 publications

References 40 publications

Experimental Investigation on Bioremediation of Heavy Metal Contaminated Solution by Sporosarcina pasteurii under Some Complex Conditions

Experimental Investigation on Bioremediation of Heavy Metal Contaminated Solution by Sporosarcina pasteurii under Some Complex Conditions

Cadmium adsorption performance and mechanism from aqueous solution using red mud modified with amorphous MnO2

Dynamic Metal–Iodide Bonds in a Tetracoordinated Cadmium-Based Metal–Organic Framework Boosting Efficient CO2 Cycloaddition under Solvent- and Cocatalyst-Free Conditions

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Dynamic Metal–Iodide Bonds in a Tetracoordinated Cadmium-Based Metal–Organic Framework Boosting Efficient CO₂ Cycloaddition under Solvent- and Cocatalyst-Free Conditions