Adsorption equilibrium modeling and solution chemistry dependence of fluoride removal from water by trivalent-cation-exchanged zeolite F-9

Maurice S. Onyango, Yoshihiro Kojima, Aoyi Ochieng, Eileen C. Bernardo, Hitoki Matsuda

Research output: Contribution to journalArticle

426 Citations (Scopus)

Abstract

Fluoride in drinking water above permissible levels is responsible for human dental and skeletal fluorosis. In this study, therefore, the large internal surface area of zeolite was utilized to create active sites for fluoride sorption by exchanging Na+-bound zeolite with Al3+ or La3+ ions. Fluoride removal from water using Al3+- and La3+-exchanged zeolite F-9 particles was subsequently investigated to evaluate the fluoride sorption characteristics of the sorbents. Equilibrium isotherms such as the two-site Langmuir (L), Freundlich (F), Langmuir–Freundlich (LF), Redlich–Peterson (RP), Tóth (T), and Dubinin–Radushkevitch (DR) were successfully used to model the experimental data. Modeling results showed that the isotherm parameters weakly depended on the solution temperature. From the DR isotherm parameters, it was considered that the uptake of fluoride by Al3+-exchanged zeolite proceeded by an ion-exchange mechanism (E=11.32−12.13 kJ/mol), while fluoride–La3+-exchanged zeolite interaction proceeded by physical adsorption (E=7.41−7.72 kJ/mol). Factors from the solution chemistry that affected fluoride removal from water were the solution pH and bicarbonate content. The latter factor buffered the system pH at higher values and thus diminished the affinity of the active sites for fluoride. Natural groundwater samples from two Kenyan tube wells were tested and results are discussed in relation to solution chemistry. In overall, Al3+-exchanged zeolite was found to be superior to La3+-exchanged zeolite in fluoride uptake within the tested concentration range.
Original languageEnglish
Pages (from-to)341-350
Number of pages10
JournalJournal of Colloid and Interface Science
Volume279
Issue number2
DOIs
Publication statusPublished - 2004

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Zeolites
Fluorides
Cations
Positive ions
Isotherms
Adsorption
Water
Sorption
Sorbents
Potable water
Groundwater
Ion exchange
Ions
Bicarbonates
Drinking Water
Temperature

Cite this

@article{eea545c4e29b4c1490dfdf6fb90bd2eb,
title = "Adsorption equilibrium modeling and solution chemistry dependence of fluoride removal from water by trivalent-cation-exchanged zeolite F-9",
abstract = "Fluoride in drinking water above permissible levels is responsible for human dental and skeletal fluorosis. In this study, therefore, the large internal surface area of zeolite was utilized to create active sites for fluoride sorption by exchanging Na+-bound zeolite with Al3+ or La3+ ions. Fluoride removal from water using Al3+- and La3+-exchanged zeolite F-9 particles was subsequently investigated to evaluate the fluoride sorption characteristics of the sorbents. Equilibrium isotherms such as the two-site Langmuir (L), Freundlich (F), Langmuir–Freundlich (LF), Redlich–Peterson (RP), T{\'o}th (T), and Dubinin–Radushkevitch (DR) were successfully used to model the experimental data. Modeling results showed that the isotherm parameters weakly depended on the solution temperature. From the DR isotherm parameters, it was considered that the uptake of fluoride by Al3+-exchanged zeolite proceeded by an ion-exchange mechanism (E=11.32−12.13 kJ/mol), while fluoride–La3+-exchanged zeolite interaction proceeded by physical adsorption (E=7.41−7.72 kJ/mol). Factors from the solution chemistry that affected fluoride removal from water were the solution pH and bicarbonate content. The latter factor buffered the system pH at higher values and thus diminished the affinity of the active sites for fluoride. Natural groundwater samples from two Kenyan tube wells were tested and results are discussed in relation to solution chemistry. In overall, Al3+-exchanged zeolite was found to be superior to La3+-exchanged zeolite in fluoride uptake within the tested concentration range.",
author = "Onyango, {Maurice S.} and Yoshihiro Kojima and Aoyi Ochieng and Bernardo, {Eileen C.} and Hitoki Matsuda",
year = "2004",
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language = "English",
volume = "279",
pages = "341--350",
journal = "Journal of Colloid and Interface Science",
issn = "0021-9797",
publisher = "Academic Press Inc.",
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Adsorption equilibrium modeling and solution chemistry dependence of fluoride removal from water by trivalent-cation-exchanged zeolite F-9. / Onyango, Maurice S.; Kojima, Yoshihiro; Ochieng, Aoyi; Bernardo, Eileen C.; Matsuda, Hitoki.

In: Journal of Colloid and Interface Science, Vol. 279, No. 2, 2004, p. 341-350.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Adsorption equilibrium modeling and solution chemistry dependence of fluoride removal from water by trivalent-cation-exchanged zeolite F-9

AU - Onyango, Maurice S.

AU - Kojima, Yoshihiro

AU - Ochieng, Aoyi

AU - Bernardo, Eileen C.

AU - Matsuda, Hitoki

PY - 2004

Y1 - 2004

N2 - Fluoride in drinking water above permissible levels is responsible for human dental and skeletal fluorosis. In this study, therefore, the large internal surface area of zeolite was utilized to create active sites for fluoride sorption by exchanging Na+-bound zeolite with Al3+ or La3+ ions. Fluoride removal from water using Al3+- and La3+-exchanged zeolite F-9 particles was subsequently investigated to evaluate the fluoride sorption characteristics of the sorbents. Equilibrium isotherms such as the two-site Langmuir (L), Freundlich (F), Langmuir–Freundlich (LF), Redlich–Peterson (RP), Tóth (T), and Dubinin–Radushkevitch (DR) were successfully used to model the experimental data. Modeling results showed that the isotherm parameters weakly depended on the solution temperature. From the DR isotherm parameters, it was considered that the uptake of fluoride by Al3+-exchanged zeolite proceeded by an ion-exchange mechanism (E=11.32−12.13 kJ/mol), while fluoride–La3+-exchanged zeolite interaction proceeded by physical adsorption (E=7.41−7.72 kJ/mol). Factors from the solution chemistry that affected fluoride removal from water were the solution pH and bicarbonate content. The latter factor buffered the system pH at higher values and thus diminished the affinity of the active sites for fluoride. Natural groundwater samples from two Kenyan tube wells were tested and results are discussed in relation to solution chemistry. In overall, Al3+-exchanged zeolite was found to be superior to La3+-exchanged zeolite in fluoride uptake within the tested concentration range.

AB - Fluoride in drinking water above permissible levels is responsible for human dental and skeletal fluorosis. In this study, therefore, the large internal surface area of zeolite was utilized to create active sites for fluoride sorption by exchanging Na+-bound zeolite with Al3+ or La3+ ions. Fluoride removal from water using Al3+- and La3+-exchanged zeolite F-9 particles was subsequently investigated to evaluate the fluoride sorption characteristics of the sorbents. Equilibrium isotherms such as the two-site Langmuir (L), Freundlich (F), Langmuir–Freundlich (LF), Redlich–Peterson (RP), Tóth (T), and Dubinin–Radushkevitch (DR) were successfully used to model the experimental data. Modeling results showed that the isotherm parameters weakly depended on the solution temperature. From the DR isotherm parameters, it was considered that the uptake of fluoride by Al3+-exchanged zeolite proceeded by an ion-exchange mechanism (E=11.32−12.13 kJ/mol), while fluoride–La3+-exchanged zeolite interaction proceeded by physical adsorption (E=7.41−7.72 kJ/mol). Factors from the solution chemistry that affected fluoride removal from water were the solution pH and bicarbonate content. The latter factor buffered the system pH at higher values and thus diminished the affinity of the active sites for fluoride. Natural groundwater samples from two Kenyan tube wells were tested and results are discussed in relation to solution chemistry. In overall, Al3+-exchanged zeolite was found to be superior to La3+-exchanged zeolite in fluoride uptake within the tested concentration range.

U2 - 10.1016/j.jcis.2004.06.038

DO - 10.1016/j.jcis.2004.06.038

M3 - Article

VL - 279

SP - 341

EP - 350

JO - Journal of Colloid and Interface Science

JF - Journal of Colloid and Interface Science

SN - 0021-9797

IS - 2

ER -