Surface modification of pumice enhancing its fluoride adsorption capacity: An insight into kinetic and thermodynamic studies

Sepehr, Mohammad Noori; Sivasankar, V.; Zarrabi, Mansur; Kumar, Mukesh

doi:10.1016/j.cej.2013.04.089

Cited by 123 publications

(54 citation statements)

References 79 publications

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“…The decrease in sorption capacity at pH > 5 can be due to the competition for the active sites by OH − ions and the electrostatic repulsion of anionic nitrate by the negatively charged surface of nanoalumina and IMP. Different pH pzc (pH point of zero charge) values ranging from 5 to 9 for aluminum based oxides/ hydroxide [17,28,29] and 6-7 for pumice [30,31] are reported in the literature. When pH < pH zpc , the surface of the sorbent has got more positive charge which causes the electrostatic attraction between positively charged surface ions and nitrate ions [31].…”

Section: Effect Of Solution Phmentioning

confidence: 99%

“…Different pH pzc (pH point of zero charge) values ranging from 5 to 9 for aluminum based oxides/ hydroxide [17,28,29] and 6-7 for pumice [30,31] are reported in the literature. When pH < pH zpc , the surface of the sorbent has got more positive charge which causes the electrostatic attraction between positively charged surface ions and nitrate ions [31]. Because pH values of soil and groundwater were generally between 5 and 9 [32,33], therefore these adsorbents could be used for removal of nitrate effectively.…”

Section: Effect Of Solution Phmentioning

confidence: 99%

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Isotherm and kinetic studies on the adsorption of nitrate onto nanoalumina and iron-modified pumice

Golestanifar

Asadi

Alinezhad

et al. 2016

Desalination and Water Treatment

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A B S T R A C TThe use of nanoalumina and iron-modified pumice (IMP) as adsorbents for removal of nitrate from aqueous solution was investigated. Adsorption experiments were carried out as a function of the pH, contact time, and concentration of nitrate. Both adsorbents were effective for the nitrate removal in a pH range of 4-6, and optimum removal of nitrate ions occurred in a pH 5.0. The adsorption of nitrate on both adsorbents reached equilibrium within 50 min. Nitrate sorption kinetics was well fitted by pseudo-second-order model. The maximum nitrate uptake capacities for nanoalumina and IMP were found to be 70.8 and 86.7 mg g −1 , respectively. The kinetic results showed that the nitrate sorption to nanoalumina and IMP followed pseudo-second-order kinetics with a correlation coefficient greater than 0.99. The equilibrium data for both the adsorbents for nitrate removal were fitted to Langmuir and Freundlich isotherms, but the experimental data were found to be little better fitted by the Langmuir model. These results indicate that nanoalumina and IMP are interesting alternatives for nitrate removal from the aqueous solution.

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Section: Effect Of Solution Phmentioning

confidence: 99%

Section: Effect Of Solution Phmentioning

confidence: 99%

Isotherm and kinetic studies on the adsorption of nitrate onto nanoalumina and iron-modified pumice

Golestanifar

Asadi

Alinezhad

et al. 2016

Desalination and Water Treatment

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show abstract

“…In order to determine the kinetic parameters of MG adsorption on the AB, the pseudo-first-order, pseudosecond-order models were applied to fit the experimental data. The linear form of the pseudo-first order rate equation is given as [13,14]:…”

Section: Resultsmentioning

confidence: 99%

Sorptive Removal of Methyl Green from Aqueous Solutions using Activated Bentonite

2017

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Bentonite clay from Maghnia (North West Algeria) has been acid-activated. The activated bentonite was employed as adsorbent for the removal of methyl green from aqueous solutions using adsorption method. The influence of several parameters (kinetics, contact time, sorbent amount, adsorbate concentration and pH) on the adsorption capacity was evaluated and discussed. The Langmuir adsorption model was applied to experimental equilibrium data and the isotherm constant was calculated. The results indicated that the adsorption was favourable at neutral pH. This model provided the best fit to the experimental data with high correlation coefficient (R 2 = 0.996). The monolayer adsorption capacity of activated bentonite found to be 353.33 mg/g. It was seen that pseudo-first order equation describes the adsorption kinetics. The results indicated that this bentonite-type clay is potential to be used as an economical adsorbent for the removal of methyl green dye.

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“…The peak at 3700 cm -1 corresponds to the stretching vibrations of OH bonds attached to polyhedral Al [33]. The broad band between 3000 and 3600 cm -1 is due to the stretching of OH groups [34,35], while the band at 2925 cm -1 and its shoulder at 2864 cm -1 are related to CH stretching and bending vibrations [13]. The absorption bands at 1640  1520 cm -1 can be associated to vibrations of OH groups of ketones, aldehydes, carboxylic acids and aromatic skeletal vibrations of cellulose [13,36].…”

Section: Characterization Of Denim-based Adsorbents and Surface Intermentioning

confidence: 97%

Synthesis of denim waste-based adsorbents and their application in water defluoridation

Mendoza-Castillo

Reynel-Ávila

Bonilla-Petriciolet

et al. 2016

Journal of Molecular Liquids

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This study evaluates the application of denim fiber scraps as a precursor for the synthesis of adsorbents for water treatment via pyrolysis and their application in water defluoridation. The best pyrolysis conditions for the synthesis of this novel adsorbent have been identified and a metal doping route with different salts of Al 3+ , La 3+ and Fe 3+ was proposed to improve its fluoride adsorption behavior. Different spectroscopic and microscopic techniques (i.e., FTIR, XPS, XRF, SEM) were used to characterize the precursor and adsorbents, and to analyze the surface interactions involved in the fluoride removal mechanism. Experimental results showed that these adsorbents were effective for fluoride adsorption showing uptakes up to 4.25 mg/g. The Si-Ometal-F interactions appear to be highly relevant for the fluoride removal. This study highlights the potential of denim textile waste as a raw material for the production of added-value products, thus minimizing their associated disposal cost. It also highlights the performance of denim textile waste as a precursor of adsorbents for addressing relevant environmental concerns such as fluoride pollution.

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Surface modification of pumice enhancing its fluoride adsorption capacity: An insight into kinetic and thermodynamic studies

Cited by 123 publications

References 79 publications

Isotherm and kinetic studies on the adsorption of nitrate onto nanoalumina and iron-modified pumice

Isotherm and kinetic studies on the adsorption of nitrate onto nanoalumina and iron-modified pumice

Sorptive Removal of Methyl Green from Aqueous Solutions using Activated Bentonite

Synthesis of denim waste-based adsorbents and their application in water defluoridation

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