Performances of metals modified activated carbons for fluoride removal from aqueous solutions

doi:10.1016/j.cplett.2020.137705

Chemical Physics Letters

Volume 754, September 2020, 137705

https://doi.org/10.1016/j.cplett.2020.137705 Get rights and content

Highlights

•
Development and characterization of a novel AC-Al material.
•
Aluminum loading and impregnation time during synthesis has significant effect on fluoride adsorption.
•
The effect of certain operating parameters on the removal percentage were optimized.
•
The Langmuir, Temkin, Sips and Redlich-Peterson isotherm models fit adequately the experimental data with the maximal adsorption capacity was estimated at 13.03 mg.g^−1.

Abstract

The present research work focused on the activated carbon (AC) preparation from dates waste followed by its surface modification by incipient wetness impregnation using different metals: Ca, Co, Mg and Al. The obtained results showed that the AC-Al presented the best removal efficiency of the fluoride. The prepared activated carbons (AC) and (AC-Al) were characterized by several techniques. The optimization study of the AC-Al impregnation conditions was investigated by varying the impregnation time and the Al loading. Batch experiments were carried out to investigate the effect of certain operating parameters on the removal percentage. Several isotherm models were applied.

Graphical abstract

Introduction

In the region of the Algerian northern Sahara, encompassing Ouargla, Ghardaia, Touggourt, El Oued, Biskra and Hassi Messaoud, peoples in the eastern region consume groundwater from the terminal complex with a fluoride concentration above the World Health Organization standard (WHO) 1.5 mg.L⁻¹ [1] and will exceed 3–4 mg.L⁻¹ [2]. These waters are usually the only source for these regions [3]. The origin of the fluoride contamination in the main aquifers of the region is still not clear. In small doses in drinking water (0.5–1.5 mg.L⁻¹), fluoride promotes the dental and bones health. However, fluoride concentrations of 1.5 to 4 mg.L⁻¹ were responsible of the dental fluorosis [4] which is often appears as a change in tooth enamel, provoking dark patches [5]. This phenomenon is known as “Darmous” in the southern Algeria or “Mottled Enamel” in the Anglo-Saxon countries [2]. In addition, concentrations higher than 4 mg.L⁻¹, will cause the loss of the teeth and the bone fluorosis characterized by an hyper calcification of the bones. Skeletal fluorosis and possibly cancer have been diagnosed for fluoride concentrations above 10 mg.L⁻¹ [4]. A large percentage of inhabitants of the southern Algeria are affected by the endemic fluorosis with its two forms, dental and bone [6]. The Pasteur Institute reported this problem of the fluorosis firstly in 1932. Several surveys have been carried out, among them, those performed by the INSP (National Institute of Public Health) in 1980, which have revealed the appearance of the endemic fluorosis epidemic in the eastern part of the northern Sahara (El-Oued, Touggourt, Ouargla) [6]. This problem does not affect merely the south of Algeria, the vast region of India and some other countries such as Pakistan, Argentina, India, Korea, Russia, China, Mexico, Iran and part of Africa [7] are also affected by the high content of fluoride in the groundwater resources. Therefore, the reduction of the fluoride level in the water source at admissible concentrations is decisive to protect the public health. Many techniques have been applied for the fluoride removal from water. Several classical methods of fluoride removal were used such as adsorption, reverse osmosis, precipitation, electrodialysis and ion exchange…etc. Adsorption has always been recommended as the cost effective and convenient method [8]. Different adsorbents were used for the fluoride removal, especially activated carbon and nanotubes, Zeolithes, activated alumina, bone char, clays and resins [8]. Among the adsorbents, activated carbon is the most used because of its high surface area, highly microporous structure and easy availability [9]. Nevertheless, activated carbon has a relatively low adsorption capacity for anionic compounds especially if they are very soluble and reactive like the fluoride. Therefore, recent investigations have focused on modifying activated carbons surface with different metal oxides and hydroxides such as Aluminum [10], Iron [8], Calcium [11], Magnesium, Manganese [12] and some rare earth metals such as Zirconium [12] and Lanthanum [8]. These investigations have proved to be interesting for enhancing significantly the fluoride adsorption efficiency. Indeed, the surface modification will lead to the formation of new functional groups on the activated carbon surface, which will have a high affinity for fluoride anions leading to the improvement of the adsorption process efficiency. The aim of the present study is to prepare an activated carbon from date stems, which is an available agricultural waste in Algeria, with its surface modification by incipient wetness impregnation using different metals (Ca, Co, Mg and Al). Indeed, fluoride has high affinity for this metals which have acceptable cost compared to the rare earth metals which are insoluble under wide pH ranges [12]. In addition, the use of the date stems is not mentioned in the literature as a precursor for fluoride adsorption. This new material's adsorption efficiency, referred by AC-Al, has been verified by its application to remove fluoride from aqueous solutions. The new material was characterized and tested for fluoride removal in batch system. Study of the impregnation conditions and the effect of certain operating parameters, in particular the contact time, the pH solution, the dose of adsorbent and the initial concentration of fluoride on the adsorption capacity of the new material, has been tested. Isotherm analysis was also discussed.

Section snippets

Chemicals

Zinc chloride (ZnCl₂) used in this study was provided from VWR Chemicals. Calcium Nitrate hydrate (Ca(NO₃)_2,H₂O), Cobalt Nitrate hexahydrate (Co(NO₃)₃,6H₂O), Magnesium Nitrate hexahydrate (Mg(NO₃)₃,6H₂O) and Aluminum Nitrate nonahydrate (Al(NO₃)₃,9H₂O) were obtained from Alfa Aesar, Germany. The Sodium fluoride (NaF, 99%) was obtained from Merck, Germany. The solution pH was adjusted by using the solution of HCl or NaOH, procured by Sigma-Aldrich. Ultrapure water (resistivity ≥ 18 MΩ.cm) which

Textural properties

The characterization results of the activated carbons AC and AC-Al5 are presented in Table 1. The table gathers surface areas, pore sizes, volumes and distributions of the pores of the prepared activated carbons. Thus, the AC without surface modification presents an important porosity that was created during the calcination step, with a high specific surface area (1341 m².g⁻¹). This value decreased for the modified activated carbon AC-Al5 (561 m².g⁻¹) suggesting a good binding of Aluminum on

Conclusion

A novel material laws successfully produced by surface modification of an activated carbon prepared from date stems by fixing different metals: Ca, Co, Mg and Al onto the activated carbon (AC) surface. Indeed, the surface modification applied to the produced activated carbon had a positive effect on the fluoride removal efficiency from water. The highest fluoride removal was obtained for Al compared to the others impregnated metals. From the characterization results of the AC-Al5, it was

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

References (47)

A. Mullick et al.
Acoustic cavitation induced synthesis of zirconium impregnated activated carbon for effective fluoride scavenging from water by adsorption
Ultrason. Sonochem.
(2018)
Y.H. Li et al.
Adsorption of fluoride from water by amorphous alumina supported on carbon nanotubes
Chem. Phys. Lett.
(2001)
S. Roy et al.
Calcium impregnated activated charcoal: Optimization and efficiency for the treatment of fluoride containing solution in batch and fixed bed reactor
Process Saf. Environ. Prot.
(2017)
M.C. Macías-Pérez et al.
SO2 retention on CaO/activated carbon sorbents Part I: Importance of calcium loading and dispersion
Fuel.
(2007)
R. Araga et al.
Fluoride adsorption from aqueous solution using activated carbon obtained from KOH-treated jamun (Syzygium cumini) seed
J. Environ. Chem. Eng.
(2017)
J. Shu et al.
Simultaneous removal of ammonia and manganese from electrolytic metal manganese residue leachate using phosphate salt
J. Clean. Prod.
(2016)
N.S. Kumar et al.
Phenolic compounds biosorption onto Schizophyllum commune fungus: FTIR analysis, kinetics and adsorption isotherms modeling
Chem. Eng. J.
(2011)
H.A. Hasan et al.
Isotherm equilibria of Mn²⁺ biosorption in drinking water treatment by locally isolated Bacillus species and sewage activated sludge
J. Environ. Manage.
(2012)
T. Yang et al.
Characteristics of activated carbons prepared from pistachio-nut shells by physical activation
J. Colloid Interface Sci.
(2003)
K. Chullasat et al.
A facile optosensing protocol based on molecularly imprinted polymer coated on CdTe quantum dots for highly sensitive and selective amoxicillin detection
Sens. Actuat., B Chem.
(2018)

A. Heidari et al.

Evaluation of CO2 adsorption with eucalyptus wood based activated carbon modified by ammonia solution through heat treatment

Chem. Eng. J.

(2014)

C. Lu et al.

Comparisons of sorbent cost for the removal of Ni²⁺ from aqueous solution by carbon nanotubes and granular activated carbon

J. Hazard. Mater.

(2008)

L. Wang et al.

Adsorption of Pb(II) on activated carbon prepared from Polygonum orientale Linn.: Kinetics, isotherms, pH, and ionic strength studies

Bioresour. Technol.

(2010)

S.R. Shanmugam et al.

Treatment of aqueous phase of bio-oil by granular activated carbon and evaluation of biogas production

Bioresour. Technol.

(2017)

H.J. Niu et al.

Graphene-encapsulated cobalt nanoparticles embedded in porous nitrogen-doped graphitic carbon nanosheets as efficient electrocatalysts for oxygen reduction reaction

J. Colloid Interface Sci.

(2019)

Y. Tan et al.

One-step synthesis of nanostructured g-C3N4/TiO2 composite for highly enhanced visible-light photocatalytic H2 evolution

Appl. Catal. B Environ.

(2018)

S. Jagtap et al.

Synthesis and characterization of lanthanum impregnated chitosan flakes for fluoride removal in water

Desalination.

(2011)

Esmeralda Vences-Alvarez et al.

Fluoride removal in water by a hybrid adsorbent lanthanum–carbon

Journal of Colloid and Interface Science

(2015)

N.K. Mondal et al.

Removal of fluoride by aluminum impregnated coconut fiber from synthetic fluoride solution and natural water

Alexandria Eng. J.

(2015)

R. Leyva Ramos et al.

Adsorption of fluoride from aqueous solution on aluminum-impregnated carbon

Carbon

(1999)

World Health Organization, Guidelines for Drinking-water Quality,...

S. Achour et al.

Defluoruration des eaux du Sahara septentrional Algerien par adsorption sur des bentonites locales

Int. J. Environ. Stud.

(2009)

L. Youcef et al.

Defluoruration des eaux souterraines du sud Algerien par la chaux et le sulfate d’aluminium

Courrier du Savoir.

(2001)

Cited by (29)

Effective defluoridation using lanthanum-organic frameworks encapsulated hydrotalcite based bio-hybrid beads
2023, Journal of Solid State Chemistry
Herein, hydrotalcite (HT) integrated lanthanum-metal organic frameworks (LaMOFs) cross-linked alginate and chitosan (Alg-CS) biopolymers that are HT-LaMOFs@Alg-CS beads was prepared and successfully utilized for defluoridation investigations. The prepared HT-LaMOFs@Alg-CS beads were evaluated with the help of various instrument analyses. The adsorption capacity of the prepared HT-LaMOFs@Alg-CS beads for fluoride retention was investigated, across a broad choice of pH levels, and in the occurrence of interfering ions identified in water. The batch optimized condition for fluoride adsorption using HT-LaMOFs@Alg-CS beads were contact time (30 min), pH 7, initial fluoride concentration (10 mg/L), dosage (0.1 g) at room temperature. The fluoride adsorption capacity of HT-LaMOFs@Alg-CS beads is 4905 mgF⁻ kg⁻¹ within 20 min. To distinguish the defluoridation behavior on HT-LaMOFs@Alg-CS bio-hybrid beads, the adsorption isotherm, kinetics, and thermodynamic studies were performed. Thermodynamic results suggest that the fluoride adsorption route on the developed HT-LaMOFs@Alg-CS beads was endothermic process with spontaneous nature. The experimental data result of HT-LaMOFs@Alg-CS bio-hybrid beads for fluoride removal was majorly fitted Langmuir isotherm and pseudo-second-order kinetics. The reusability and real water sample examination results of the attained HT-LaMOFs@Alg-CS hybrid beads for defluoridation was demonstrated that the prepared HT-LaMOFs@Alg-CS beads were regenerable nature with more fitting at field level.
The use of eggshells, boiler stone, chalk and marl for the synthesis of novel hydroxyapatite modified biochars for the vanadium removal
2023, Chemical Engineering Journal
Synthesis, sorption–desorption studies and physicochemical analysis of novel hydroxyapatite modified biochars were performed. The hydroxyapatite used for the modification originated from the four sources: egg shells, boiler stone, chalk and marl. The obtained sorbents were used for vanadium ions removal from the aqueous solutions. It is dangerous impurity and its extensive use as a steel additive requires continual removal. The optimized sorption conditions: pH 3, time 240 min, temperature 293 K allowed to obtain satisfactory results, in particular for BC-HAp1 (hydroxyapatite modified biochar from egg shells) for which q_t is equal to 27.45 mg/g (concentration 100 mg/L). The calculated ΔH°, ΔS° and ΔG° reveal the nature of the sorption process. Washing the sorbents with hydrochloric acid after the sorption resulted in nearly 80% desorption efficiency. The physicochemical analysis of the sorbents allowed to suggest a complex, mixed mechanism of sorption involving physical and chemical interactions.
Fluoride removal from water using Zr-modified meso- and macroporous carbons: Effect of pore structure and adsorption conditions
2023, Chemical Engineering Journal Advances
We investigated the effects of the pore structure and adsorption conditions (pH and coexisting anions) on the fluoride (F^–) removal capacity of Zr-modified porous carbons. The porous carbons used in this study possessed well-defined pore structures created by the template technique with pore diameters of 10, 30, and 150 nm. These porous carbons were oxidized to functionalize them with oxygen-containing groups before being modified with Zr⁴⁺. Zr⁴⁺ modification improved the F^– removal capacity of porous carbons. The maximum amount of F^– adsorbed increased by approximately 3–10 times by Zr⁴⁺ modification. The F^– adsorption capacity depends on the pore size. The samples with larger pore diameters (smaller specific surface areas) exhibited higher F^– adsorption capacities than the samples with smaller pore diameters. This tendency can be explained using the theory of liquid imbibition in porous media. The adsorption capacities at pH 7.0 and 11.1 were lower than those at pH 3.1. This tendency can be interpreted based on competition between F^– and OH^– on adsorption sites and attractive/repulsive interactions between F^– and protonated/deprotonated adsorbent surfaces. The coexisting carbonate anions notably suppress the F^– adsorption. This suppressive effect can be explained by the competitive bonding of F^– and CO₃^2– to the adsorption sites.
Size-tunable graphitized carbon spheres for water defluoridation
2023, Colloids and Surfaces A: Physicochemical and Engineering Aspects
We fabricated non-catalytic carbon spheres with controllable dimensions (diameter 0.3–1.5 µm) by chemical vapour deposition at 1273 K using C₂H₂ (carbon source) and N₂ (dilutant) gas precursors. By varying the flow rates of precursor gases, spherical or pseudo-spherical morphologies with chain-like hierarchical structures are discerned. The X-ray diffraction data show hexagonally graphitized networks. The mechanism of carbon sphere formation is not yet fully resolved largely due to the ambiguity associated with the nucleation step, viz. pentagon or heptagon route. According to molecular dynamics calculations, the formation of carbon pentagons is energetically more favorable than heptagons. Pentagon structures seem to form by closing Fjord regions of the graphitized network as evidenced in IR bands at 635 cm⁻¹ and 796 cm⁻¹. The X-ray photon spectroscopic (XPS) measurements show adventitious oxygen on the carbon sphere’s surface sites with -COOH and -C-CO groups. The -COOH and -C-CO groups are polar; hence, the carbon spheres’ surface sites readily hydroxylate (where ${\equiv GOH}^{δ}$ represents surface sites with a fractional charge). The carbon sphere synthesized under $(\frac{C_{2} H_{2}}{N_{2}})$ = $\frac{5}{6}$ gas flow ratio (viz., CS3) shows the highest fluoride removal capacity, viz., 0.095 ± 0.01 mmol.m^2-. The comparable zeta potential values observed between the carbon spheres and fluoride laden carbon spheres point to an anion exchange of surface hydroxyl ions for F^- sorption. In agreement with the XPS data, the broad IR band at 3440 cm⁻¹ due to H-bonded surface hydroxyl stretching vibrations has resolved into three discrete bands, e.g., 3640, 3752, and 3738 cm⁻¹, which evidenced fluoride adsorption. Compared to activated carbon, the retention of fluoride on carbon spheres is over 60 times higher, which shows its potential in water treatment in removing fluoride.
Ambient evaporation-induced electricity generation in activated carbon-water interfaced three-dimensional hydrovoltaic device
2023, Journal of Power Sources
Green energy-based power generation is a most rising topic in scientific society. Carbon water interaction-based hydrovoltaic (HV) power generation is a futuristic current research theme to generate power; however, the actual process remains an open question. Here in this work, a novel three-dimensional (3D) tubular HV device is fabricated, and its voltage distribution is analyzed. Under ambient conditions, a single tubular activated carbon hydrovoltaic (TAC) device can generate a voltage of up to 0.9 V and a current of up to 0.7 mA. Moreover, the outstanding power deliver from TAC is nearly 600 μW for 1.2 g of active materials, and it is stable for more than ten days without any external light, wind, or heat. Further voltage improvement is tested with various factors such as light, heat, and humidity. Based on water flow-induced potential, 4 TACs can light an LED for successive ten days under ambient conditions (without any external energy supply). Moreover, the fabricated TAC device shows excellent self-life after one year of the experiment. Overcoming the two-dimensional (2D) HV devices, this self-charging 3D tubular high-power configuration is a low-cost HV device based on activated carbon and has advantages for practical applications.
Co-transport and deposition of fluoride using rice husk-derived biochar in saturated porous media: Effect of solution chemistry and surface properties
2023, Environmental Technology and Innovation
Fluoride (F $^{-}$ ) contamination in water is a global health concern, threatening the well-being of millions. This study investigated the role of ZnCl₂/FeCl₃-rice husk-modified biochar (Zn-BC and Zn/Fe-BC) in treating F $^{-}$ -contaminated surface and groundwater under the influence of varying solution chemistry, co-existing ions, and biochar-amended through column transport experiments. Modified biochar showed maximum F $^{-}$ adsorption, 99.01% and 91.90% using Zn/Fe-BC and Zn-BC, respectively, than 85.87% using raw biochar (R-BC). Raw/modified biochars were characterized with FESEM-EDAX, FTIR, XRD, particle size, surface area, electro-kinetic potential, and point of zero charge analyses. Langmuir and pseudo-second-order kinetic could explain that F $^{-}$ -biochar interactions are dominated by chemisorption at ambient temperature while physisorption at higher temperatures. The influence of salt concentrations and co-occurring ions reduced F $^{-}$ sorption using Zn/Fe-BC. Increased salt strengths led to reduced electrophoretic mobility of biochar particles, i.e., biochar–biochar particles attract each other and increase the hydrodynamic diameter, which ultimately reduces the active sites on biochar for F $^{-}$ adsorption. Co-transport and deposition of biochar and F $^{-}$ in saturated porous media revealed lower mobility of biochar, and maximum F $^{-}$ adsorption was observed at 10 mM salt strength. Biochar transport is governed by electrostatic interactions, whereas F $^{-}$ transport mainly occurs through chemisorption. In rural areas, hand pumps and tube wells are generally used as source of potable water for drinking and cooking purposes; thus, biochar-mediated sand columns can be utilized for defluoridation. Thus, Zn/Fe-BC can be utilized as a potential bio-adsorbent for F $^{-}$ -contaminated natural surface and groundwater with optimum preparation and treatment costs.

View all citing articles on Scopus

View full text

Research paperPerformances of metals modified activated carbons for fluoride removal from aqueous solutions

Highlights

Abstract

Graphical abstract

Introduction

Section snippets

Chemicals

Textural properties

Conclusion

Declaration of Competing Interest

Ultrason. Sonochem.

Chem. Phys. Lett.

Process Saf. Environ. Prot.

Fuel.

J. Environ. Chem. Eng.

J. Clean. Prod.

Chem. Eng. J.

J. Environ. Manage.

J. Colloid Interface Sci.

Sens. Actuat., B Chem.

Chem. Eng. J.

J. Hazard. Mater.

Bioresour. Technol.

Bioresour. Technol.

J. Colloid Interface Sci.

Appl. Catal. B Environ.

Desalination.

Journal of Colloid and Interface Science

Alexandria Eng. J.

Carbon

Defluoruration des eaux du Sahara septentrional Algerien par adsorption sur des bentonites locales

Int. J. Environ. Stud.

Defluoruration des eaux souterraines du sud Algerien par la chaux et le sulfate d’aluminium

Courrier du Savoir.

Research paper
Performances of metals modified activated carbons for fluoride removal from aqueous solutions