Adsorption mechanisms of metal cations from water on an oxidized carbon surface

Moreno‐Castilla, Carlos; Álvarez-Merino, M.A.; Pastrana‐Martínez, Luisa M.; López-Ramón, M.V.

doi:10.1016/j.jcis.2010.01.062

Cited by 43 publications

(31 citation statements)

References 17 publications

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“…At high P/Po values, the isotherm show a small capillary condensation step and presents a hysteresis loop that is of H4 type. The hysteresis loop, observed for P/Po > 0.5 can be due to capillary condensation in narrow slit-shaped mesopores [27] concluding the presence of both micro-porosity and a small part of meso-porosity [28]. The volume of N 2 adsorbed at high relative pressure although not significant, is attributed to the presence of substantial presence of mesopores [29,30].…”

Section: Materials Characterizationmentioning

confidence: 99%

Adsorption of Arsenate by Nano Scaled Activated Carbon Modified by Iron and Manganese Oxides

et al. 2017

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Abstract:The presence of arsenic in water supplies is a major problem for public health and still concerns large parts of population in Southeast Asia, Latin America and Europe. Removal of arsenic is usually accomplished either by coagulation with iron salts or by adsorption with iron oxides or activated alumina. However, these materials, although very efficient for arsenic, normally do not remove other undesirable constituents from waters, such as chlorine and organo-chlorine compounds, which are the results of water chlorination. Activated carbon has this affinity for organic compounds, but does not remove arsenic efficiently. Therefore, in the present study, iron modified activated carbons are investigated as alternative sorbents for the removal of arsenic(V) from aqueous solutions. In addition, modified activated carbons with magnetic properties can easily be separated from the solutions. In the present study, a simple and efficient method was used for the preparation of magnetic Fe 3 (Mn 2+ )O 4 (M:Fe and/or Mn) activated carbons. Activated carbons were impregnated with magnetic precursor solutions and then calcinated at 400 • C. The obtained carbons were characterized by X-ray diffraction (XRD), nitrogen adsorption isotherms, scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), Fourier Transform Infrared Spectrometry (FTIR) and X-ray photoelectron spectroscopy (XPS) measurements. Their adsorption performance for As(V) was evaluated. The iron impregnation presented an increase in As(V) maximum adsorption capacity (Q max ) from about 4 mg g −1 for the raw carbon to 11.05 mg g −1 , while Mn incorporation further increased the adsorption capacity at 19.35 mg g −1 .

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Section: Materials Characterizationmentioning

confidence: 99%

Adsorption of Arsenate by Nano Scaled Activated Carbon Modified by Iron and Manganese Oxides

et al. 2017

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“…To appreciate the Ni(II) contribution to the total immersion enthalpy the solid adsorbent quantities and water must be kept constant that acts as a solvent of smaller amount of ions that have a positive electrical charge [13]. Figure 3 shows the negative values of enthalpy change and exothermic character, which are greater for the two solids that were in contact with the HNO 3 solution for 6 and 9 hours.…”

Section: Resultsmentioning

confidence: 99%

“…This expression indicates that the variations of the partial quantities, in this case the change in the enthalpy differential, with regard to the system composition are not independent of a temperature and constant pressure [13]. Using (6) we can calculate the differential enthalpy change for solid and solvent in the mixture and this in function of ion Ni(II) mass fraction presents a behavior contrary to the ion Ni(II) differential enthalpy change, Δ DIF Ni(II) , as what happens with the partial molar properties in the development of the mixture thermodynamics.…”

Section: Resultsmentioning

confidence: 99%

Enthalpic Contribution of Ni(II) in the Interaction between Carbonaceous Material and Aqueous Solution

Giraldo

Moreno–Piraján

2017

Journal of Chemistry

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Solid adsorbents were prepared from corn cob that was modified with a solution of HNO 3 6 M at different contact times. The solids are characterized by physical N 2 adsorption at 77 K to know their surface area by applying the BET model and surface chemistry is determined using the Bohem method. Once we have prepared the adsorbents we determine the immersion enthalpy, Δ im , of the solids in Ni(II) aqueous solutions of different concentrations between 20 and 800 mg⋅L −1 , with values for Δ im between 10.0 and 35.3 J⋅g −1 . From the results obtained for the immersion enthalpy in function of the ion Ni(II) concentration we calculate the contribution to the immersion enthalpy that corresponds to the ion when it is treated with the system adsorbent-solution as a mixture in which the solid, the solvent, and the adsorbate are involved. The solution thermodynamics allows for establishing the enthalpic changes that bring the ion in function of the concentration and the intensity of the interaction of solid-metal ion that is favored by the presence of acid groups in the solid.

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“…It is generally considered that the removal of an ion is mainly attributed to the interaction of surface groups and the ion, through various mechanisms, such as: formation of metal complexes like COOH-M and / or donor-acceptor reactions of electrons (Petit et al 2010;Moreno-Castilla et al 2010), that is, by establishing specific interactions, therefore, these mechanisms are favored when the solid undergoes an oxidation process as in the case of the sample GACoxN, which has a higher adsorption capacity with respect to other ones, this capacity decreased in heat-treated samples after the process oxidation ratifying the importance of the presence of oxygenated surface groups, although it is important to note that the adsorption capacity of GAC1173 sample is lower, it is also suggested to contemplate within the mechanisms of adsorption interactions that are not only specific but also of the dispersive type, to a lesser extent but to complement the adsorption process.…”

Section: Thermodynamic Of the Interactions Between Gas-solid And Solimentioning

confidence: 99%

Thermodynamic of the Interactions Between Gas-Solidand Solid-Liquid on Carbonaceous Materials

García-Cuello¹,

Vargas-Delgadillo²,

Murillo-Acevedo³

et al. 2011

Thermodynamics - Interaction Studies - Solids, Liquids and Gases

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Adsorption mechanisms of metal cations from water on an oxidized carbon surface

Cited by 43 publications

References 17 publications

Adsorption of Arsenate by Nano Scaled Activated Carbon Modified by Iron and Manganese Oxides

Adsorption of Arsenate by Nano Scaled Activated Carbon Modified by Iron and Manganese Oxides

Enthalpic Contribution of Ni(II) in the Interaction between Carbonaceous Material and Aqueous Solution

Thermodynamic of the Interactions Between Gas-Solidand Solid-Liquid on Carbonaceous Materials

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