Heavy metal removing by modified bentonite and study of catalytic activity

Kakaei, Saeed; Khameneh, Elham Sattarzadeh; Rezazadeh, Fardin; Hosseini, Majid

doi:10.1016/j.molstruc.2019.126989

Cited by 43 publications

(13 citation statements)

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“…are considered to play a significant role in controlling the direction and the magnitude of a certain adsorption and/or diffusion process. With respect to the adsorbents used in this study, one can conclude (simply speaking) that beidellite is a layered material with an expandable interlayer [ 15 ], allophane is an amorphous substance with a hollow “nanoball” structure that is intermitted by defect sites, the so-called perforations [ 17 ] and zeolite (natrolite and stilbite) is a crystalline material with a uniform three-dimensional pore structure [ 5 ].…”

Section: Resultsmentioning

confidence: 99%

“…However, these methods greatly vary in effectiveness and operational costs; thus there is still a high demand for the development of new, efficient, green and low cost adsorbent materials [ 9 , 10 , 11 ]. Silicate based adsorbents, such as clay minerals and zeolites, can be advantageous over non-siliceous materials or composite materials, because they provide a plenty of adsorption sites due to the very small particle size, high surface area, porous structure and presence of surface functional groups and exchangeable sites, rendering these components ideal for wastewater treatment [ 12 , 13 , 14 , 15 ].…”

Section: Introductionmentioning

confidence: 99%

“…The short-range-order aluminosilicate phase allophane also exhibits good sorption capacities for certain metal ions, such as Cs + , Ba 2+ , Co 2+ , Cu 2+ , Sr 2+ and Zn 2+ , owning to its unique physicochemical and surface (charge) properties, amphoteric ligand capacity and hollow “nanoball” structure [ 13 , 16 , 17 , 18 ]. Smectite group minerals, such as beidellite and montmorillonite, are also in use as adsorbents, ion exchangers and catalysts due to their low cost, high reactivity and worldwide distribution [ 15 , 19 , 20 ].…”

Section: Introductionmentioning

confidence: 99%

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Removal of Barium from Solution by Natural and Iron(III) Oxide-Modified Allophane, Beidellite and Zeolite Adsorbents

et al. 2020

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Efficient capture of barium (Ba) from solution is a serious task in environmental protection and remediation. Herein, the capacity and the mechanism of Ba adsorption by natural and iron(III) oxide (FeO) modified allophane (ALO), beidellite (BEI) and zeolite (ZEO) were investigated by considering the effects of contact time, temperature, pH, Ba2+ concentration, adsorbent dosage, the presence of competitive ions and adsorption–desorption cycles (regenerability). Physicochemical and mineralogical properties of the adsorbents were characterized by XRD, FTIR, SEM with EDX and N2 physisorption techniques. The Ba2+ adsorption fitted to a pseudo-first-order reaction kinetics, where equilibrium conditions were reached within <30 min. BEI, ALO and ZEO with(out) FeO-modification yielded removal efficiencies for Ba2+ of up to 99.9%, 97% and 22% at optimum pH (pH 7.5–8.0). Adsorption isotherms fitted to the Langmuir model, which revealed the highest adsorption capacities for BEI and FeO-BEI (44.8 mg/g and 38.6 mg/g at 313 K). Preferential ion uptake followed in the order: Ba2+ > K+ > Ca2+ >> Mg2+ for all adsorbents; however, BEI and FeO-BEI showed the highest selectivity for Ba2+ among all materials tested. Barium removal from solution was governed by physical adsorption besides ion exchange, intercalation, surface complexation and precipitation, depending mainly on the absorbent type and operational conditions. BEI and FeO-BEI showed a high regenerability (>70–80% desorption efficiency after 5 cycles) and could be considered as efficient sorbent materials for wastewater clean-up.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Removal of Barium from Solution by Natural and Iron(III) Oxide-Modified Allophane, Beidellite and Zeolite Adsorbents

et al. 2020

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“…Bentonite can be used as a catalyst support because of its strong interaction between metal and supports and has many reported applications in the catalytic field [7,8]. Moreover, bentonite indicated a good adsorption efficacy in the heavy metal ion adsorption of industrial water wastes [9]. Also, bentonite is considered to be an inorganic filler for the preparation of alkaline polymer composite with higher conductivity.…”

Section: Introductionmentioning

confidence: 99%

Structural, dielectric and electrical characterization of (Co)_x(Ni/bentonite) composites

Alotaibi

Abdel‐Baset

Bashal

2020

Journal of Taibah University for Science

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Based on commercial bentonite (bento) and two metal precursors, including NiCl 2 and CoCl 2 , diverse series of composites were prepared by incipient wet impregnation. The prepared composites were characterized by X-ray diffraction, scanning electron microscopy and energydispersive X-Ray spectroscopy. X-ray diffraction studies show that the crystallite size decreased as increasing the wt. % of cobalt. Moreover, the presence of Co in the EDX spectra for all bento concentrations, suggests its successful incorporation and probably the formation of Ni-Co oxide. The dielectric constant , the dielectric modulus (M , M) and the ac conductivity (σ ac) were also studied. It was found that decreases with frequency in all samples, a clear dielectric α relaxation observed from dielectric loss M. σ ac decreases by increasing Co content and the conduction mechanism is correlated barrier hopping (CBH). σ ac (T) is thermally activated and the activation energy Ea decreased with increasing Co content.

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“…Apart from this, it possesses both Lewis and Bronsted acidity, [56,62,63] thus it was explored as a heterogeneous catalyst in organic synthesis [62] . The other unique properties made it a favorable support for immobilization of metals nanoparticles, [57,59,64] metal oxides, [65,66] metal salts [56,60,63,67] and other modification of bentonite for various application [68–76] . Bentonite is widely distributed in the Kachchh region of India and mainly sodium and calcium bentonite are found in this area.…”

Section: Introductionmentioning

confidence: 99%

Fe(III)/Bentonite as a Heterogeneous Catalyst for the Synthesis of 3,4‐dihydropyrimidin‐2‐(1H)‐ones

Chopda

Dave

2020

ChemistrySelect

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Fe(III) immobilized over natural bentonite (bent) using the impregnation method. Prepared catalysts were well characterized by XRD, FT-IR and FeSEM. The catalytic activity of three catalysts 10, 20 and 30 % Fe(III)/bent evaluated for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones known as Biginelli reaction. The catalyst 30 % Fe(III)/bent exhibited a high yield of the product towards the synthesis of a variety of dihydropyrimidones (DHPMs). The high yield of dihydropyrimidone (DHPM) was obtained in model reaction in ethanol, acetonitrile, DMF and solvent-free condition. The reusability test indicated that 6 % of yield of product decreased after 5 th cycle. Highlights * 10, 20 and 30 % Fe(III) were supported over bentonite clay. The catalysts are well characterized by (XRD), FT-IR, FeSEM and EDS. All charactization method showed that Fe supported over bentonite. * The used catalysts were screened for Biginelli reaction for synthesis dihydropyrimidones. * 30 % Fe(III)/bent exhibited high yield of product towards model Biginelli reaction between benzaldehyde, ethylacetoacetate and urea in ethanol. * 30 % Fe(III)/bent exhibited high yield of product in CH 3 CN, DMF and solvent free-condition. * The catalyst 30 % Fe(III)/bent applied for synthesis of variety of dihydropyrimodone in good yield in CH 3 CN. * Reusability studies show that no great decline in activity after 5 th cycle.

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Heavy metal removing by modified bentonite and study of catalytic activity

Cited by 43 publications

References 43 publications

Removal of Barium from Solution by Natural and Iron(III) Oxide-Modified Allophane, Beidellite and Zeolite Adsorbents

Removal of Barium from Solution by Natural and Iron(III) Oxide-Modified Allophane, Beidellite and Zeolite Adsorbents

Structural, dielectric and electrical characterization of (Co)_x(Ni/bentonite) composites

Fe(III)/Bentonite as a Heterogeneous Catalyst for the Synthesis of 3,4‐dihydropyrimidin‐2‐(1H)‐ones

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Heavy metal removing by modified bentonite and study of catalytic activity

Cited by 43 publications

References 43 publications

Removal of Barium from Solution by Natural and Iron(III) Oxide-Modified Allophane, Beidellite and Zeolite Adsorbents

Removal of Barium from Solution by Natural and Iron(III) Oxide-Modified Allophane, Beidellite and Zeolite Adsorbents

Structural, dielectric and electrical characterization of (Co)x(Ni/bentonite) composites

Fe(III)/Bentonite as a Heterogeneous Catalyst for the Synthesis of 3,4‐dihydropyrimidin‐2‐(1H)‐ones

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Structural, dielectric and electrical characterization of (Co)_x(Ni/bentonite) composites