Fluoride removal from aqueous solution by Al(III)–Zr(IV) binary oxide adsorbent

doi:10.1016/j.apsusc.2015.09.012

Applied Surface Science

Volume 357, Part A, 1 December 2015, Pages 91-100

https://doi.org/10.1016/j.apsusc.2015.09.012 Get rights and content

Highlights

•
Al₂O₃–ZrO₂ adsorbent was prepared via coprecipitation followed by calcination.
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A maximum adsorption capacity of Al₂O₃–ZrO₂ adsorbent was114.54 mg/g.
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The adsorption mechanism of the adsorbent involved the ligand and ion-exchange.

Abstract

In this study, a novel binary oxide adsorbent of Al₂O₃–ZrO₂ was prepared via coprecipitation followed by calcination method, and the calcination temperatures were investigated. The adsorbent was characterized by XRD, EDX and XPS. The batch adsorption experiments were carried out at different parameters, such as solution pH, adsorbent dose, contact time, initial fluoride concentration and adsorption temperature, to evaluate the fluoride removal performance. The results showed that the adsorption isotherm was better described by the linear Langmuir model, and a maximum adsorption capacity was 114.54 mg/g. The adsorption kinetics was well fitted by the linear pseudo-second-order, and the correlation coefficient value (R²) was 0.997. The thermodynamic parameters of ΔH⁰, ΔS⁰ and ΔG⁰ were calculated, which showed that the fluoride adsorption process was spontaneous and exothermic. And the possible adsorption mechanism of the adsorbent for fluoride could involve the ligand-exchange and ion-exchange based on the results in the study.

Graphical abstract

Al₂O₃–ZrO₂ adsorbent was prepared via coprecipitation. The adsorption isotherm is better described by the linear Langmuir model with a maximum adsorption capacity of 114.54 mg/g.

Introduction

Fluorine is one of the necessary trace elements for both human beings and animals, which may be beneficial or detrimental to health depending on its concentration in drinking water [1], [2]. On the one hand, fluoride can avoid dental caries with a relative quantity in the body. On the other hand, excessive ingestion of fluoride can result in various diseases such as dental caries, skeletal fluorosis and brain damage [3], [4]. To date, millions of people are influenced by excess fluoride in drinking water all over the world. Therefore, the concentration of fluoride in drinking water should be controlled in a reasonable level. The World Health Organization has recommended that the limit of fluoride concentration in drinking water is between 0.5 and 1.5 mg/L [5]. In China, the concentration of fluoride in drinking water is amended to 1.0 mg/L and the allowable emission concentration of fluoride in wastewater of uranium industry should be below 10 mg/L [6]. Accordingly, it is very important to decrease the fluoride concentration in wastewater.

In recent years, wastewater with high fluoride concentration discharges from various industries, such as metallurgy factories, semiconductor factories and mines, can hardly decrease in nature condition [7]. Therefore, various treatment techniques are used to remove fluoride in wastewater, such as ion exchange [8], chemical precipitation [9], electrodialysis [10], electrocoagulation [11], and adsorption [12]. Among these methods, adsorption is widely used due to its easy operation, good selectivity and low cost [13]. Many adsorbents, such as activated alumina, synthetic ion exchangers, hydroxyapatite, bone charcoal, have been investigated for defluoridation [14], [15], [16]. But the low adsorption capacity, high cost and bad selectivity severely limit their large range applications. Hence searching for adsorbents with pronounced performance and cost-effective is necessary in recent years.

La(III), Ce(IV), Zr(IV) oxides have been reported to remove fluoride with high adsorption [17], [18]. However, the above metals are expensive, in order to reduce the cost and keep high fluoride adsorption capacity, some cheaper metals are mix with them to form hybrid oxides. The hybrid oxides such as Fe(III)–Zr(IV) [19], Fe(III)–Ce(IV) [20], Al(III)–Ce(IV) [21], Fe(III)–Al(III)–Ce(IV) [22], have been prepared and showed pronounced adsorption performance. Zr-based materials have been paid more attention in fluoride removal for its high affinity with electronegative fluoride [23]. Meanwhile, Al-based materials are the common adsorbent used in fluoride removal for the low cost and environmental impact [18]. Al(III)–Zr(IV) binary oxide (Al₂O₃–ZrO₂) was prepared with combining the advantages of two adsorbent in this study. Up to now, Al₂O₃–ZrO₂ adsorbent has not yet been reported for fluoride removal.

In this study, the novel Al₂O₃–ZrO₂ adsorbent for fluoride removal from aqueous solution was prepared through precipitation combined with calcination method. The adsorbent was investigated by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), and X-ray photo-electron spectroscopy (XPS). The effects of calcination temperature, solution pH, adsorbent dose, contact time, initial fluoride ion concentration, and adsorption temperature on the adsorption performance of adsorbent were investigated. Moreover, in order to understand the adsorption process well, Langmuir isotherms, Freundlich isotherms, pseudo-first-order kinetic, pseudo-second-order kinetic and thermodynamic were discussed in detail. Finally, the adsorption mechanism of fluoride on Al₂O₃–ZrO₂ was analyzed.

Section snippets

Materials

Sodium fluoride (NaF), aluminum chloride hexahydrate (AlCl₃·6H₂O), zirconium nitrate pentahydrate (Zr(NO₃)₄·5H₂O) and sodium hydroxide (NaOH) were obtained from Chengdu Kelong Chemicals Company and used without further purification. Besides, all chemicals were of analytical grade. Stock solution of 1000 mg/L F⁻ was prepared by dissolving 2.2105 g NaF in 1000 mL deionized water, and diluting the stock solution to required concentrations before used.

Preparation of Al₂O₃–ZrO₂ adsorbent

AlCl₃·6H₂O and Zr(NO₃)₄·5H₂O were dissolved in

Effect of calcination temperature

The fluoride adsorption capacity of metal oxides can be affected by pre-treatment on the precursor at different calcination temperatures [22], [24]. Hence, the effects of different calcination temperatures on the fluoride removal by Al₂O₃–ZrO₂ absorbent are investigated, and the results are presented in Fig. 1. The adsorption capacity is slightly altered in the range of 41.27–45.67 mg/g between the calcination temperatures of 600–800 °C and 1000–1200 °C, but the adsorption capacity significantly

Conclusions

The Al₂O₃–ZrO₂ adsorbent was successfully prepared for fluoride removal from aqueous solutions via coprecipitation combined with calcination method. XRD patterns proved that the Al₂O₃–ZrO₂ adsorbent was successfully obtained and the optimum calcination temperature was 700 °C. Batch experiments were investigated for the adsorption property of Al₂O₃–ZrO₂ adsorbent, and the optimum adsorption conditions of pH and contact time were 2.0 and 4 h. The adsorption isotherm and kinetic were well fitted by

Acknowledgements

The authors thank the financial support from Nuclear Power Development Special item (13zg610301) and Professional Scientific Research Innovation Team Building Fund Projects of Key Research Platform of Southwest University of Science and Technology (Nos. 14tdsc02 and 13zxbk01). We acknowledge the technology support of Engineering Research Center of Biomass Materials, Ministry of Education.

References (46)

Q.S. Zhou et al.
Fluoride adsorption from aqueous solution by aluminum alginate particles prepared via electrostatic spinning device
Chem. Eng. J.
(2014)
V. Sivasankar et al.
Fluoride removal from water using activated and MnO₂-coated Tamarind Fruit (Tamarindus indica) shell: batch and column studies
J. Hazard. Mater.
(2010)
J.J. García-Sánchez et al.
Removal of fluoride ions from drinking water and fluoride solutions by aluminum modified iron oxides in a column system
J. Colloid Interface Sci.
(2013)
T. Nur et al.
Batch and column adsorption and desorption of fluoride using hydrous ferric oxide: solution chemistry and modeling
Chem. Eng. J.
(2014)
N. Chen et al.
Studies on fluoride adsorption of iron-impregnated granular ceramics from aqueous solution
Mater. Chem. Phys.
(2011)
T. Wajima et al.
Adsorption behavior of fluoride ions using a titanium hydroxide-derived adsorbent
Desalination
(2009)
S.Y. Zhang et al.
Removal of fluoride from groundwater by adsorption onto La(III)–Al(III) loaded scoria adsorbent
Appl. Surf. Sci.
(2014)
Z. Amor et al.
Fluoride removal from brackish water by electrodialysis
Desalination
(2001)
J. Zhu et al.
Fluoride distribution in electrocoagulation defluoridation process
Sep. Purif. Technol.
(2007)
F. Ji et al.
Dynamic adsorption of Cu(II) from aqueous solution by zeolite/cellulose acetate blend fiber in fixed-bed
Colloids Surf. A
(2013)

Y.L. Tang et al.

Fluoride adsorption onto activated alumina: modeling the effects of pH and some competing ions

Colloids Surf. A

(2009)

N. Viswanathan et al.

Removal of fluoride from aqueous solution using protonated chitosan beads

J. Hazard. Mater.

(2009)

M. Bhaumik et al.

Removal of fluoride from aqueous solution by polypyrrole/Fe₃O₄ magnetic nanocomposite

J. Hazard. Mater.

(2011)

H. Liu et al.

Preparation of Al–Ce hybrid adsorbent and its application for defluoridation of drinking water

J. Hazard. Mater.

(2010)

T. Zhang et al.

Equilibrium and kinetics studies of fluoride ions adsorption on CeO₂/Al₂O₃ composites pretreated with non-thermal plasma

Chem. Eng. J.

(2011)

X.M. Wu et al.

Fluoride removal performance of a novel Fe–Al–Ce trimetal oxide adsorbent

Chemosphere

(2007)

J. Wang et al.

Excellent fluoride removal performance by CeO₂–ZrO₂ nanocages in water environment

Chem. Eng. J.

(2013)

N. Das et al.

Defluoridation of drinking water using activated titanium rich bauxite

J. Colloid Interface Sci.

(2005)

V. Tomar et al.

Adsorptive removal of fluoride from water samples using Zr–Mn composite material

Microchem. J.

(2013)

H. Paudyal et al.

Adsorptive removal of fluoride from aqueous solution using orange waste loaded with multi-valent metal ions

J. Hazard. Mater.

(2011)

J. Wang et al.

A sorbent of carboxymethyl cellulose loaded with zirconium for the removal of fluoride from aqueous solution

Chem. Eng. J.

(2014)

S.K. Swain et al.

Development of new alginate entrapped Fe(III)–Zr(IV) binary mixed oxide for removal of fluoride from water bodies

Chem. Eng. J.

(2013)

K.O. Adebowale et al.

Kinetic and thermodynamic aspects of the adsorption of Pb²⁺ and Cd²⁺ ions on tripolyphosphate-modified kaolinite clay

Chem. Eng. J.

(2008)

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Fluoride removal from aqueous solution by Al(III)–Zr(IV) binary oxide adsorbent

Highlights

Abstract

Graphical abstract

Introduction

Section snippets

Materials

Preparation of Al2O3–ZrO2 adsorbent

Effect of calcination temperature

Conclusions

Acknowledgements

Chem. Eng. J.

J. Hazard. Mater.

J. Colloid Interface Sci.

Chem. Eng. J.

Mater. Chem. Phys.

Desalination

Appl. Surf. Sci.

Desalination

Sep. Purif. Technol.

Colloids Surf. A

Colloids Surf. A

J. Hazard. Mater.

J. Hazard. Mater.

J. Hazard. Mater.

Chem. Eng. J.

Chemosphere

Chem. Eng. J.

J. Colloid Interface Sci.

Microchem. J.

J. Hazard. Mater.

Chem. Eng. J.

Chem. Eng. J.

Chem. Eng. J.

Preparation of Al₂O₃–ZrO₂ adsorbent