Zeolite supported mono- and bimetallic oxides: Promising adsorbents for removal of As(V) in aqueous solutions

Şimşek, Esra Bilgin; Özdemir, Ercan; Beker, Ülker

doi:10.1016/j.cej.2013.01.070

Cited by 55 publications

(34 citation statements)

References 39 publications

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“…Al (Figure 3) shows the lowest phosphate removal at pH below than 2; and the highest with a plateau between pH 3 and 6 to decreases then from pH 6 to 11. The sorption mechanism of phosphate oxyanions (H2PO4 --HPO4 2--PO4 3-) is associated with the formation of complexes with the hydroxyl surface groups of the hydrated aluminum oxide layer impregnated on the zeolite structure (specific adsorption) [17,[43][44][45] or by means of columbic forces depending of the pHpzc (non-specific adsorption) [13,23,45].…”

Section: Phosphate and Ammonium Isothermsmentioning

confidence: 99%

“…However, they have been rarely used for phosphate sorption due to the constant negative charge on their surface [12]. In order to improve the ion exchange capacity of natural zeolites for anionic species the incorporation or impregnation of iron and aluminum oxides, are the most widespread and excellent candidates for phosphate removal [13][14][15][16][17][18]. Zeolites exhibit different properties which depend on the geological location and they deserve a detailed characterization [19,20].…”

Section: Introductionmentioning

confidence: 99%

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Simultaneous phosphate and ammonium removal from aqueous solution by a hydrated aluminum oxide modified natural zeolite

Guaya

Valderrama

Farrán

et al. 2015

Chemical Engineering Journal

263

106

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A natural zeolite (Z-N), rich in clinoptilolite, was modified (Z-Al) by incorporation of hydrated aluminum oxide (HAlO) for the simultaneous phosphate and ammonium removal. The incorporation of surface hydroxyl groups (≅Al-OH) into the zeolite structure, as active groups for phosphate removal, was characterized by acid-base titrations (pHPZC=4.5±0.2). The phosphate sorption increases from 0.6 mg-P/g for Z-N up to 7.0 mg-P/g while only a slight decrease on the ammonium sorption capacity from 33 mg-N/g of Z-N to 30 mg-N/g for Z-Al was observed. The HAlO modified zeolite sorption capacity for both phosphate and ammonium was slightly reduced by common ions typically present in secondary waste water effluents. Column experiments revealed higher enrichment factor for ammonium (120) than for phosphate (50) using 1 M NaOH as elution solution. A reduction of zeolite phosphate capacity with regeneration cycles was observed.

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Section: Phosphate and Ammonium Isothermsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Simultaneous phosphate and ammonium removal from aqueous solution by a hydrated aluminum oxide modified natural zeolite

Guaya

Valderrama

Farrán

et al. 2015

Chemical Engineering Journal

263

106

View full text Add to dashboard Cite

show abstract

“…Moreover, mixed aluminum and iron oxides can be used as catalysts for the oxidation of various organic pollutants from wastewaters [12,13]. In recent years, studies were focused on preparation of a new anionselective catalyst, especially using metal-oxides or surfactants, combining a good catalytic activity with a high stability against leaching.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of ultra-thin oxide layer in laser-treated 3× (Al/Fe)/Si multilayer structure

et al. 2014

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The conditions of ultra-thin oxide films synthesized as the Al/Fe multilayer structures after the surface treatment with femtosecond laser radiation were studied. Thin films composed of three (Al/Fe) bilayers were deposited by DC ion sputtering on (100) Si wafers to the total thickness of 410 nm. Laser irradiations were performed by 40-fs pulses of a Ti:Sapphire laser operating at 800 nm, at fluences slightly higher than the ablation threshold. The samples were characterized by Auger electron spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Progressed intermixing of components was achieved for the irradiation with fluence of 0.43 J cm -2 , when intermetallic phase was formed and all components were almost uniformly distributed through the entire multilayer structure. Exception is the subsurface region, to the thickness of 20 nm, where the distribution of constructive components and their oxide is changing with the distance from the surface, and this distribution depends on the applied laser fluences. An ultrathin oxide layer was formed at the surface, with the specific combination of the oxide phases, Al 2 O 3 and Fe 2 O 3 , depending on the applied fluences. Laser-induced modification was accompanied with the ablation of the material and the creation of parallel periodic structures. These effects of laser-induced morphological features are increased with increasing laser fluences, caused by the pronounced mobility of the materials. The special morphology of the laser-assisted synthesis of mixture of Al 2 O 3 and Fe 2 O 3 in the form of an ultra-thin oxide layer can improve their characteristics for functional applications, as catalysts and sensors.

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“…The previous study [7] concluded that the pretreated zeolites exhibited low or no adsorption capacities for As(V). However, major increases were observed for all metal oxide coated zeolites especially for bimetallic oxides coated ones.…”

Section: A Preparation Of Adsorbentsmentioning

confidence: 99%

“…Iron and aluminum oxides impregnated zeolites were prepared as described in previous study [7]: A defined amount of NC-Na was immersed in 200 ml of metal solution and pH of the solution was raised to 7.0 by addition of NaOH.…”

Section: A Preparation Of Adsorbentsmentioning

confidence: 99%

Kinetic Performance of Aluminum and Iron Oxides in the Removal of Arsenate from Aqueous Environment

Şimşek¹,

Beker²

2014

JOCET

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Abstract-Arsenate (As(V)) adsorption from aqueous solution onto clinoptilolite incorporating iron or aluminum oxides was investigated. The modified samples were characterized by nitrogen adsorption isotherms, TEM-EDX analysis. Kinetic models were applied to describe As(V) adsorption on each modified clinoptilolite samples. The kinetic data, explained best by the pseudo-second-order model by good regression coefficients.

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Zeolite supported mono- and bimetallic oxides: Promising adsorbents for removal of As(V) in aqueous solutions

Cited by 55 publications

References 39 publications

Simultaneous phosphate and ammonium removal from aqueous solution by a hydrated aluminum oxide modified natural zeolite

Simultaneous phosphate and ammonium removal from aqueous solution by a hydrated aluminum oxide modified natural zeolite

Synthesis of ultra-thin oxide layer in laser-treated 3× (Al/Fe)/Si multilayer structure

Kinetic Performance of Aluminum and Iron Oxides in the Removal of Arsenate from Aqueous Environment

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