Sorption of Hg(II) by modified K10 montmorillonite: Influence of pH, ionic strength and the treatment with different cations

Santos, Vanessa Cristina Gonçalves dos; Grassi, Marco Tadeu; Abate, Gilberto

doi:10.1016/j.geoderma.2014.08.018

Cited by 31 publications

(8 citation statements)

References 43 publications

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“…The X-ray diffractogram of the acid-activated K10 Mt exhibited a lowintensity reflection peak at 2θ ¼ 5.74 (1.54 nm) (Figure 1), in agreement with diffractograms described for this material in other publications (dos Santos et al, 2015;Yang et al, 2015;Almasri et al, 2018). According to Wallis et al (2007), this low intensity is a consequence of processes starting with the exchange of the interlayer cations by H þ , followed by delamination (producing disorientated aggregates), dissolution of the individual platelets, and formation of low crystallinity highly porous hydrous phase.…”

Section: Characterizationssupporting

confidence: 89%

Fe(III)-polyhydroxy cations supported onto K10 montmorillonite for removal of phosphate from waters

Leite

Nascimento

Masini

2020

Heliyon

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Since phosphate is strongly related to eutrophication of environmental waters, several research groups quest for materials that can efficiently remove phosphate from wastewaters before it contaminates lakes and reservoirs. In the present work, a commercial clay mineral (K10 montmorillonite) modified with Fe 3þ polyhydroxy cations was investigated as an adsorbent for phosphate. The incorporation of the polycations did not alter the main conformational characteristics of the montmorillonite, as verified by specific surface area measurements, X-ray diffractometry, FTIR, electron microscopy, and zeta potential titrations. On the other hand, the materials supporting Fe 3þ polyhydroxy cations exhibited a significant enhancement of adsorption capacity, as determined by Langmuir-Freundlich isotherms, from 39 AE 2 to 104 AE 15 μmol g À1 . The different ratios of OH À to Fe 3þ did not affect the adsorption capacities. The adsorption kinetics was best described by the pseudo 2 nd order model, approaching the equilibrium after 120 min of contact time. A variation of pH between 4.6 and 8.5 did not affect the adsorption percentages. The adsorption capacities increased with the increase of the ionic strength, thus suggesting that the formation of inner-sphere complexes prevails over electrostatic interactions as the adsorption mechanism. The materials removed phosphate from three polluted water samples having phosphate concentrations between 0.0919 and 1.211 mg L À1 . The remaining phosphate concentration was below the limit of quantification of the analytical method (0.063 mg L À1 in P, or 2.0 μmol L À1 ). The presence of 10 mg L À1 humic of fulvic acid did not affect the performance of the materials. In conclusion, the modification of clay minerals with Fe 3þ polyhydroxy cations is useful in producing low-cost adsorbents for phosphate.

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Section: Characterizationssupporting

confidence: 89%

Fe(III)-polyhydroxy cations supported onto K10 montmorillonite for removal of phosphate from waters

Leite

Nascimento

Masini

2020

Heliyon

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“…Chitosan-montmorillonite beads were prepared by crosslinking with pentasodium tripolyphosphate for the removal of Cu (II) studied by Pereira et al [95]. Some more toxic metal removal studies was performed by Dos Santos et al [20] and Wang et al [127]. For the removal of Co (II) by modified chitosan-montmorillonite and removal of Hg(II) by influence of pH, ionic strength and treatment with different cations [69].…”

Section: Discussionmentioning

confidence: 99%

Clay nano-adsorbent: structures, applications and mechanism for water treatment

2019

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Nanotechnology plays an important role in current environmental practices for remediation of contaminants in environment. From last few years, nano-clay has found more attention because of its unique characteristics and properties. Clay and clay minerals are very important naturally occurring mineral playing key role in environmental protection. Clay basically originates from raw minerals, having different types of geometry and morphology. These clay minerals have been used in disposal and storage of hazardous chemicals as well as for remediation of contaminated water. In several industries, clay minerals have been used as raw materials for hundreds of industrial applications due to its abundant availability and inexpensive nature. Because of unique properties and high removal efficiency, clay is used as nano-adsorbent in many adsorption processes. Nano-clays act as a promising property enhancer found highly effective and efficient for water purification. The use of clay minerals as adsorbents for adsorption of various hazardous substances like-heavy metals, dyes, antibiotics, biocide compounds, and other organic chemicals has been widely studied by a large number of researchers. In the present review paper, authors highlights the nano-composites and their preparation methods, adsorption mechanism and has compiled the past and current research works carried out by different researchers on innovation in nanoclay, upcoming advancement, and/or mechanism for removal of contaminants by different nanoclays for water purification.

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“…In many cases the pseudo-first order model failed to describe the adsorption kinetic data Gupta 2006, 2011;Akar et al 2009;Chen and Zhao 2009;Koswojo et al 2010;Kurniawan et al 2011;Toor and Jin 2012;Vanamudan et al 2014;Wang et al 2014;Dos Santos et al 2015). Kurniawan et al (2011) found the inconsistency of the fitted value of parameter k 1 with its physical meaning, the value of k 1 , increase with the increasing of initial solute concentration, hence the pseudo-first order model is not the correct choice to represent the kinetic experimental data.…”

Section: The Pseudo-first Order Kineticmentioning

confidence: 99%

“…In most adsorption systems using clay minerals and its modified forms as the adsorbents, the pseudo-second order kinetic model could represent the experimental data much better than the pseudo-first order kinetic Gupta 2006, 2011;Tsai et al 2007;Akar et al 2009;Chen and Zhao 2009;Koswojo et al 2010;Kul and Koyuncu 2010;Kurniawan et al 2011;Toor and Jin 2012;Auta and Hameed 2012;Lv et al 2014;Vanamudan et al 2014;Wang et al 2014;Dos Santos et al 2015). A potential advantage of the pseudo-second order equation as an expression estimating the q e values is its small sensitivity to the influence of the random experimental error (Plazinzki et al 2009).…”

Section: The Pseudo-second Order Kineticmentioning

confidence: 99%

The Kinetic Studies in the Adsorption of Hazardous Substances Using Clay Minerals

Ismadji

Soetaredjo

Ayucitra

2015

SpringerBriefs in Molecular Science

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For the design of the adsorption system, reliable adsorption kinetic data are required. Different concepts are employed to develop a reliable adsorption kinetic model. Most of the available models were developed according to mass transfer principles or the concept of chemical reaction occurring on the surface of a solid. The models based on the surface-reaction kinetic step as controlling the sorption rate have also been proposed, these models include pseudo-first order kinetic (also called as Lagergren model), pseudo-second order kinetic, and Elovich equation. This chapter discusses various aspects of pseudo-first order kinetic and pseudo-second order kinetic in representing the adsorption kinetic data of some hazardous compounds onto clay minerals. The pseudo-first order kinetic is the earliest known equation to describe the rate of sorption in the liquid phase system. The behavior of time constant parameters k 1 and k 2 of pseudo-first order kinetics and pseudo-second order kinetics as a function of initial concentration as well as the temperature is discussed in this chapter. One of the kinetic models which also widely used to represent the sorption kinetic data is an intraparticle diffusion model also briefly discussed in this chapter.Keywords Adsorption kinetic · Pseudo-first · Pseudo-second · Intraparticle diffusion Adsorption kinetics are expressed as the solute removal rate that controls the residence time of the solute in the solid-solution interface. Reliable sorption kinetic data are of substantial value for adsorption separation system design. Various models have been developed to adequately describe the kinetics of sorption of the solid-liquid system. However, due to its complexity compared to the description of adsorption equilibria, the progress of development of various sorption kinetics appears to be limited. In general, the adsorption of solute from aqueous solution

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Sorption of Hg(II) by modified K10 montmorillonite: Influence of pH, ionic strength and the treatment with different cations

Cited by 31 publications

References 43 publications

Fe(III)-polyhydroxy cations supported onto K10 montmorillonite for removal of phosphate from waters

Fe(III)-polyhydroxy cations supported onto K10 montmorillonite for removal of phosphate from waters

Clay nano-adsorbent: structures, applications and mechanism for water treatment

The Kinetic Studies in the Adsorption of Hazardous Substances Using Clay Minerals

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