Mechanism Of Fluoride Removal Research Articles

Efficient removal of fluoride from water by CaO/Ca12Al14O33/Ca5Al6O14 composites: Performance and mechanism

CaO/Ca12Al14O33/Ca5Al6O14 composites were synthesized through calcination of Ca-Al layered double hydroxides (CaAl-LDHs). The structures of the CaAl-LDHs and the composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen adsorption–desorption isotherms. Batch experiments were carried out to study the influence of various experimental parameters such as initial fluoride concentration, contact time, pH and the coexisting anions on the adsorption of fluoride. The fluoride adsorption follows the Freundlich isotherm model. With the World Health Organization (WHO) guideline of 1.5 mg L−1, the adsorption capacity was 52.78 mg g−1. The kinetic data were fitted to the pseudo-second-order model. The change of pH (3–10) has almost no influence on the fluoride removal. High concentration of the coexisted sulfate, carbonate and phosphate anions slightly inhibited the fluoride removal. The fluoride removal mechanism study suggested that CaO transformed into CaF2 after fluoride adsorption, which play key roles in fluoride removal. The hydrolysis of Ca12Al14O33 and Ca5Al6O14 resulted the formation of Ca3Al2(OH)12. Fluoride anions participated in this hydrolysis process and resulted in the formation of Ca3Al2(OH)12-xFx, which was revealed by XRD, X-ray photoelectron spectroscopy analysis (XPS) and SEM elemental mapping images.

Novel MOF(Zr)–on-MOF(Ce/La) adsorbent for efficient fluoride and phosphate removal

A one-pot method with formic acid regulation was adopted to fabricate a novel MOF(Zr)–on-MOF(Ce/La) adsorbent for fluoride and phosphate removal. Compared to traditional adsorbents, MOF(Zr)–on-MOF(Ce/La) boasted abundant active sites and a wide application range, with adsorption capacities of 173.2 and 92.85 mg g−1 for fluoride and phosphate, respectively. Comprehensive characterization techniques like SEM-EDS, BET, XRD, FTIR, and TGA were employed to analyze the material’s properties. Adsorption experiments investigated multiple effect factors. BET analysis disclosed a specific surface area of 332 m2 g−1, mainly composed of micropores and mesopores. The adsorbent showed rapid adsorption rates for both ions, with low reliance on adsorption time. The adsorption process was exothermic and spontaneous, favored by higher temperatures. Kinetic and thermodynamic studies favored the pseudo-second-order kinetic and Langmuir models, suggesting monolayer chemical adsorption. Through combined analyses including XPS, XRD, and studies on kinetics and thermodynamics, the fluoride removal mechanism involved electrostatic interaction and ion exchange, while phosphate removal encompassed ion exchange, electrostatic interactions, and complexation. Field wastewater experiments met Chinese standards, and recycling experiments revealed sustained removal efficiencies of 90.20 % for fluoride and 87.27 % for phosphate after two regeneration cycles, highlighting the significant potential of this approach in alleviating fluoride and phosphorus pollution.

Development of innovative and green adsorbents for in situ cleanup of fluoride-polluted groundwater: Mechanisms and field-scale studies

In this study, the magnesium oxide (MgO)-based adsorbents [granulated MgO aggregates (GA-MgO) and surface-modified MgO powder (SM-MgO)] were developed to remediate a fluoride-contaminated groundwater site. Both GA-MgO and SM-MgO had porous, spherical, and crystalline structures. Diameters for GA-MgO and SM-MgO were 1–1.7 mm and 1–10 μm, respectively. The pseudo second-order dynamic adsorption and the Freundlich isotherm could be applied to express the chemical adsorption phenomena. The monolayer adsorption was the dominant mechanism at the initial adsorption period. During the latter part of fluoride adsorption, the multilayer adsorption became the dominant mechanism for fluoride removal from the water phase, which also resulted in the increased adsorption capacity. Higher hydroxide, phosphate, and carbonate concentrations caused a decreased fluoride removal efficiency due to the competition of sorption sites between fluoride and other anions with similar electronic properties. Fluoride removal mechanism using GA-MgO and SM-MgO as the adsorbents was mainly carried out by the chemical adsorption. Reaction paths contained two main processes: (1) formation of magnesium hydroxide after the reaction of MgO with water, and (2) the hydroxyl group of the magnesium hydroxide was replaced by fluoride ions to form magnesium fluoride precipitation. Results from column tests show that up to 61 and 73% of fluoride removal (initial fluoride concentration = 9.3 mg/L) could be obtained after 50 pore volumes of groundwater pumping with GA-MgO and SM-MgO injection, respectively. The GA-MgO system could be applied to contain and remediate fluoride-contaminated groundwater, and SM-MgO could be applied as an immediate fluoride removal alternative to achieve a rapid pollutant removal for emergency responses. Up to 71% of fluoride removal (fluoride concentration = 10.8 mg/L) could be obtained with GA-MgO injection after 30 days of operation. The developed GA-MgO system is a potential and green remediation alternative to contain the fluoride plume significantly.

Facile synthesis of Aluminium fumarate metal–organic framework and hydroxyapatite composite with improved adsorption characteristics for efficient fluoride removal from water

An aluminium fumarate (AlFu)-hydroxyapatite (HAP) composite (AlFu-HAP) with numerous functional groups for fluoride binding was synthesised by a simple solid–solid mixing process. The produced AlFu-HAP composite with numerous functional groups results in outstanding adsorption capability in the sequence AlFu-HAP > AlFu > HAP. This composite was studied under different pH, initial fluoride concentrations, temperatures, and contact times. The adsorption kinetics and isotherms were pseudo-second-order model and Freundlich adsorption isotherm, respectively. XRD, SEM, FTIR, Raman spectroscopy, and XPS analysis of the samples before and after the adsorption reaction indicate that the fluoride removal mechanism was controlled by anion exchange of the OH– group in AlFu-HAP and F- in water. At high concentrations (150–200 mg F-/L) in groundwater and industrial effluent, the AlFu-HAP showed > 90 % fluoride removal. Thus, the current study will provide an effective strategy for developing an AlFu-HAP composite adsorbent to be used for the effective elimination of fluoride from wastewater.

Synthesis of stable flowerlike MgAl-LDH@MIL-88A and its adsorption performance for fluoride

MgAl-LDH@MIL-88A as an effective adsorbent was successfully prepared by a simple stirring method in water bath through loading MIL-88A onto the surface of flowerlike MgAl-LDH, which was synthesized via solvothermal method. Interestingly, the results of characterizations showed that the MIL-88A could still grow, but extrude the brucite-like layers of MgAl-LDH. The influences of initial solution pH, contact time, temperature, and co-existing ions on the adsorption performance of MgAl-LDH@MIL-88A were studied systematically by batch static adsorption experiments. It was found that MgAl-LDH@MIL-88A represented the highest adsorption loading of fluoride (14.00 mg g−1) at initial pH 7.0 in 420 min. The uptake process was described appropriately by the pseudo-second-order, the Temkin and the Freundlich isotherm models. The thermodynamic parameters confirmed the endothermic and spontaneous nature of adsorption. MgAl-LDH@MIL-88A was the green adsorbent as the residual mental contents ([Mg2+] = 1.095 mg L−1, [Fe3+] = 0.007 mg L−1, [Al3+] = 0.076 mg L−1) after adsorption met the Chinese sanitary standard for drinking water (GB 5749-2006). The mechanism of fluoride removal by MgAl-LDH@MIL-88A involved the electrostatic interactions between Fe3+ of MIL-88A and fluoride, and ligand exchange among hydroxyl groups of MgAl-LDH, carboxylate groups of the C4H4O4 and fluoride.

Fluoride Removal from Drinking Water Using Aluminium Oxide Coated Charcoal – effectiveness of repetitive regenerations

There are many techniques to remove fluoride from drinking water. However, adsorption was found to be very effective and easy to apply. Along with this line, many studies were done to find an effective and affordable fluoride adsorbent. Activated Alumina (AA), Aluminum oxide coated sand (AOCS), pumice (AOCP), bauxite (AOCB) and charcoal (AOCC) were recently investigated. Nevertheless, AOCC found to be more promising for two reasons: it is cheap and can be regenerated. This paper aims to further contribute to feasibility of AOCC for fluoride removal in order to reduce the operation cost. Batch and continuous flow filter runs were conducted AOCC regenerated batch-wise, and used for the next filter run. AOCC was consequently regenerated three times. The results showed a considerable increase in AOCC fluoride adsorption capacity after each regeneration cycle. Characterization of virgin charcoal, virgin AOCC and regenerated AOCC after the first, the second and the third regeneration cycle, showed that virgin charcoal has highest specific surface area and micro porosity. For virgin AOCC and regenerated AOCC after the first, the second regeneration cycle a reduction in the specific surface area occurred, coupled with a reduction of micro porosity. AOCC after third regeneration cycle showed an increase in specific surface area likely due to aluminum hydroxide deposits on re-coated AOCC surface. Most of the pores after the third regeneration cycle were found to be meso pores. This means that, specific surface area alone cannot explain the increase in the AOCC adsorption capacity after regeneration. The paper recommends investigating the fluoride removal mechanism onto AOCC in order to produce affordable fluoride removal material from drinking water.

Applications of biomass-based materials to remove fluoride from wastewater: A review.

Fluoride is one of the essential trace elements for the human body, but excessive fluoride will cause serious environmental and health problems. This paper summarizes researches on the removal of fluoride from aqueous solutions using newly developed or improved biomass materials and biomass-like organic materials in recent years. These biomass materials are classified into chitosan, microorganisms, lignocellulose plant materials, animal attribute materials, biological carbonized materials and biomass-like organic materials, which are explained and analyzed. By comparing adsorption performance and mechanism of adsorbents for removing fluoride, it is found that carbonizing materials and modifying adsorbents with metal ions are more beneficial to improving adsorption efficiency and the adsorption mechanisms are various. The adsorption capacities are still considerable after regeneration. This paper not only reviews the properties of these materials for fluoride removal, but also focuses on the comparison of materials performance and fluoride removal mechanism. Herein, by discussing the improved adsorption performance and research technology development of biomass materials and biomass-like organic materials, various innovative ideas are provided for adsorbing and removing contaminants.

Single-step removal of calcium, fluoride, and phenol from contaminated water by Aquabacterium sp. CZ3 via facultative anaerobic microbially induced calcium precipitation: Kinetics, mechanism, and characterization

Confronting the complex contaminated water, Aquabacterium sp. CZ3 could perform microbially induced calcium precipitation (MICP) under facultative anaerobic condition using phenol as supplementary carbon source. Strain CZ3 exhibited a remarkable ability to remove nitrate, fluoride, calcium and phenol with removal rates of 100.00, 87.50, 66.24 and 100.00%, respectively. The Modified Gompertz model was used for kinetic analysis to determine the optimum conditions for denitrification and degradation of phenol. The mechanism of anaerobic MICP was enhanced by measuring the self-aggregation properties of the isolates. The mechanism of fluoride removal was identified as co-precipitation and adsorption by characterization analysis of the bioprecipitation. Furthermore, the changes in soluble metabolites under phenol stress explained the utilization of phenol as a co-substrate by microorganisms. This is a novel report on phenol degradation by anaerobic MICP, which provides a theoretical basis for expanding its practical application.

Defluoridation performance comparison of aluminum hydroxides with different crystalline phases

Abstract Aluminum hydroxide is an eye-catching and extensively researched adsorbent for fluoride removal and its defluoridation performance is closely related to the preparation method and crystalline phase. In this research, the defluoridation performances of aluminum hydroxides with different crystalline phases are compared and evaluated in terms of fluoride removal capacity, sensitivity to pH values and residual Al contents after defluoridation. It is found that the defluoridation performance of different aluminum hydroxides follows the order of boehmite > bayerite > gibbsite. The fluoride adsorption on aluminum hydroxides follows the pseudo-second-order kinetic model and Langmuir isotherm model, and the maximum defluoridation capacities of boehmite, bayerite and gibbsite are 42.08, 2.97 and 2.74 mg m−2, respectively. The pH values and FTIR analyses reveal that the ligand exchange between fluoride and surface hydroxyl groups is the fluoride removal mechanism. Different aluminum hydroxides have different surface hydroxyl group densities, which results in the different defluoridation capacities. This work provides a new idea to prepare aluminum hydroxide with outstanding defluoridation performance.

Development, characterization and mechanisms study of protonated sawdust biochar-chitosan composite bead biosorbent for defluoridation of contaminated groundwater

Protonated Sawdust Biochar Chitosan Composite Bead (PSCCB) biosorbent was prepared to compare its defluoridation capacity against raw chitosan from synthetic fluoride solution. Chitosan sawdust biochar beads were chemically modified via crosslinking and protonation to utilize amine and hydroxyl functional groups to enhance defluoridation. Adsorbents were characterized by BET, SEM, XRD, FTIR and zero point charge analysis. High pore volume of PSCCB yielded higher surface area of 57.97 m2/g after modification. Batch experiments revealed that PSCCB has an excellent defluoridation capacity of more than 90% at pH 7 within an equilibrium time of 60 min. Experimental data of PSCCB fitted well with Langmuir isotherm model and followed pseudo second order kinetic model. The maximum monolayer adsorption capacity of PSCCB was 4.413 mg/g. The dominant mechanism of fluoride removal was proposed as formation of hydrogen bonds with protonated amines in PSCCB. Field trials were conducted on groundwater samples collected from three distinct locations.

Efficient removal of fluoride from neutral wastewater by green synthesized Zr/calcium sulfate whiskers: An experimental and theoretical study

A convenient and effective method was developed to fabricate zirconium-based calcium sulfate whiskers (Zr-CSWs), an environmentally friendly adsorption material designed to clean excessive fluoride from wastewater. Zr-CSWs, which potentially provide high adsorption activity toward fluoride in wastewater, overcome an aggregation problem typical of Zr-based species that may block the pore structure of the supporting material and degenerate its treatment performance. The results indicate that Zr-CSWs show excellent equilibrium adsorption capacity compared to other Zr-based materials in practical water solutions with pH values of 6–7. The adsorption of fluoride on Zr-CSWs was further evaluated in accordance with the Langmuir equation and the pseudosecond-order model. Coexisting anions had a minor effect on the removal of fluoride, and a strong alkali solution regenerated the used adsorbent. Density functional theory (DFT) calculations were performed to determine the mechanism of fluoride removal. The calculations demonstrated that the removal of fluoride by Zr-CSWs was mainly achieved by ion exchange between fluoride ions and OH - on the surface of the adsorbent, where a protonation process created low-coordination Zr atoms. • Zirconium decorated calcium sulfate whisker (Zr-CSW) was prepared in a simple and low-cost way. • Zr-CSW has high capacity and good selectivity for the removal of fluoride in water. • The adsorption follows Langmuir model and pseudosecond-order dynamic equation. • The mechanism for fluoride removal has been revealed by density of functional theory (DFT).

Behavior and mechanism of fluoride removal from aqueous solutions by using synthesized CaSO4·2H2O nanorods

The defluoridation of aqueous solutions is of great importance to environmental governance and long-term human development. Although common calcium-containing materials may fix fluoride, the interaction between CaSO4·2H2O and fluoride has seldom been reported. This research aimed to explore and assess the feasibility of removing fluoride with CaSO4·2H2O. Three kinds of CaSO4·2H2O materials (purchased powders, synthesized whiskers, and synthesized nanorods) were characterized via scanning electron microscopy (SEM), X-ray diffraction, and N2 adsorption–desorption analyses. In contrast to the CaSO4·2H2O powders and whiskers, the CaSO4·2H2O nanorods, which had small sizes, poor crystallinity, high pore volume, and large Brunauer–Emmett–Teller surface area, could furnish numerous active sites for fluoride removal. Comparative adsorption experiments confirmed that the CaSO4·2H2O nanorods had an advantage in fluoride removal. The batch adsorption experiment results obtained for the CaSO4·2H2O nanorods showed that fluoride removal was achievable over the pH range of 5–11.32 without an additional pH adjustment. Adsorption kinetic research indicated that the adsorption process conformed to the pseudo-second-order kinetic model. The existence of competitive ions, such as CO32− and PO43−, exerted obvious interference in fluoride removal. The SEM–energy dispersive spectroscopy, Fourier transform infrared spectrometry, and X-ray photoelectron spectroscopy results of defluorinated products revealed that the fluoride removal mechanism of the CaSO4·2H2O nanorods could be ascribed to precipitation and chemisorption, with precipitation being dominant. This research confirmed that the CaSO4·2H2O nanorods are a feasible material for fluoride removal.

Separation of Excess Fluoride from Water Using Amorphous and Crystalline AlOOH Adsorbents.

Aluminum hydroxide is an effective defluoridation adsorbent; however, the poor defluoridation performance limits its wide application. In this work, amorphous and crystalline AlOOH adsorbents are synthesized through hydrolysis of Al salts, and their defluoridation performances are evaluated in terms of adsorption capacity and rate, sensitivity to pH value, and water quality after defluoridation. The defluoridation performance of AlOOH is closely related to the hydrolysis pH value, but hardly to the type of Al salts. The adsorbent can remove >95% fluoride in the first 2 min and reach adsorption equilibrium within 2 h, and the maximum defluoridation capacity is 41.9 mg/g. Furthermore, the adsorbent exhibits an excellent defluoridation efficiency at a wide pH range of 4.5–10.5. After fluoride removal, the adsorbents prepared at pH values of 6 and 7 exhibit low residual Al concentration. The Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) results confirm that the fluoride removal mechanism is the ligand exchange between fluoride and hydroxyl groups. The excellent defluoridation capacity and low residual Al demonstrate that AlOOH is a potential adsorbent for fluoride separation from water.

Design and synthesis of amine functionalized graphene oxide for enhanced fluoride removal

Graphene oxide (GO) possesses appreciable defluoridation capacity (DC) of 2451 mgF- kg−1. To enhance the DC and its properties, amine functionalized graphene oxide (AGO) was developed for fluoride removal. In addition, the prepared AGO have the vital DC of 4001 mgF- kg−1. The sophisticated instrumentations techniques namely SEM, TGA, FTIR, XRD, XPS and Raman analysis were explored for AGO and individual materials. The optimization of the responsible parameters (shaking time, solution pH, AGO dosage, interfering anions, temperature and initial fluoride ion concentration) for fluoride adsorption was employed under batch conditions. The influence of adsorption isotherms (Freundlich, Dubinin-Radushkevich (D-R) and Langmuir), kinetics (particle/intraparticle diffusion and pseudo-first/second-order models) and thermodynamic studies (ΔH°, ΔS° and ΔG°) of AGO was investigated. The fluoride removal mechanism of AGO was found to be electrostatic attraction. The reusability and field study of AGO was also scrutinized.

Fluoride removal by thermally treated egg shells with high adsorption capacity, low cost, and easy acquisition.

In this study, the use of eggshells was suggested as an adsorbent for fluoride removal, and their mechanism of fluoride removal was investigated. The eggshells underwent thermal treatment to improve their adsorption capacity; 800 °C was found to be the optimal temperature for treatment. Eggshells thermally treated at 800 °C (ES-800) were mainly composed of Ca (82.4%) and C (15.9%), and the peaks of ES-800 obtained from X-ray diffraction (XRD) corresponded to calcite, portlandite, and lime. Fluorine adsorption by ES-800 reached 70% of the equilibrium adsorption amount within 15 min and gradually increased until 24 h. The maximum adsorption capacity of ES-800 at pH 7 and 25 °C was 258.28 mg/g, which is 18 times larger than that of activated alumina; this is classified as the best available technology by the United States Environmental Protection Agency. Both enthalpy and entropy increased in the process of fluoride adsorption onto ES-800. Fluoride adsorption of ES-800 decreased from 59.16 to 11.85 mg/g with an increase in pH from 3 to 11. Fluoride adsorption decreased in the presence of anions, whose impact follows the order: HPO43- > HCO3- >> SO42- > Cl-. XRD, and X-ray photoelectron spectroscopy analysis revealed that fluoride removal was achieved by the formation of calcium fluorite (CaF2). Thus, it can be concluded that eggshells can function as highly efficient adsorbents for fluoride removal, replacing bone char and activated alumina; further, their adsorption capacity can be improved by thermal treatment.

Feasibility of using calcined Patinopecten yessoensis shells for fluoride removal and investigation of the fluoride removal mechanism

Feasibility of using calcined Patinopecten yessoensis shells for fluoride removal and investigation of the fluoride removal mechanism

Dynamic experiment on de-fluoridation of Manganese-loaded Activated Alumina

This work used Manganese-loaded Activated Alumina (MAA) as the adsorbent to analyze the effect of column height and filtration rate on the removal of fluoride and iron ions, and clarified the fluoride removal mechanism by using dynamic experiments when the fluoride and iron in drinking water exceed the standard at the same time. The results showed that the height of the column and the filtration rate have a significant impact on the operation of the system. It was the best operating condition for the system that the filtration rate was 1m/h and the column height was 300mm. After the system run for 102 hours, the fluoride ion effluent concentration exceeded the standard, which was 1.02mg / L; the concentration of iron ions in the effluent reached the standard stably after the system run for 1 hour, and the concentration was not more than 0.18mg/L. When the filtration rate was 1m/h and the column height was 150mm, the stable running time of fluoride removal of MAA column was 2.5 times that of ordinary activated alumina (AA); the start-up time of MAA to remove iron ions was one-twelfth of AA. The effect of removing fluoride and iron by MAA was significantly better than AA.

A study of suitability of limestone for fluoride removal by phosphoric acid-crushed limestone treatment

Limestone samples collected from different locations have been characterised using IR spectroscopy, X-ray diffraction, energy dispersive X-ray spectroscopy and Brunauer-Emmett-Teller analysis and correlated with their fluoride removal abilities by phosphoric acid (PA)-crushed limestone treatment (PACLT). The effects of varying initial fluoride [F]0 and initial phosphoric acid [PA]0 concentrations, contact time and coexisting anions on fluoride removal and pH of treated water have been studied. PHREEQC was used to analyse the mechanism of fluoride removal and effects of impurities in limestone on the defluoridation process. Three of the limestone samples were found suitable for PACLT, with the treated water conforming to WHO guideline. With all limestone samples, defluoridation increased with increasing [PA]0 and decreasing [F]0. Fluoride removal and pH of treated water attained stability within 3 h. The influence of coexisting anions on fluoride removal was low for all limestone samples and followed the order sulfate > chloride > nitrate. The surface area and total pore volume above 2.55 m2/g and 0.0094 cm3/g respectively, and density below 2.68 g/cm3 are required for a limestone sample for defluoridation from 10 mg/L [F]0 to 1.5 mg/L with 0.68 mM [PA]0. PHREEQC analysis suggests the mechanism of defluoridation to be a combination of precipitation and adsorption, and that the presence of acidic metal oxides in limestone, viz., Fe2O3 and Al2O3 contributes in fluoride removal and lowers the pH of treated water from the predicted equilibrium pH of 7.93 in presence of PA. The results may be useful for predicting suitability of limestones for PACLT.

Physicochemical characteristics and mechanism of fluoride removal using powdered zeolite-zirconium in modes of pulsed& continuous sonication and stirring

The current work reports the first application of the fluoride removal using zeolite-zirconium powder in three modes of pulsed sonication, continuous sonication, and stirring. The properties of powdered zeolite-Zr were specified using surface analysis techniques (surface area: 109.71 m2/g and pore volume: 0.08 cm3/g). For all the studied modes, the highest removal rate was observed at pH 7, contact time of 80 min, and zeolite-Zr dose of 3 g/L. Adsorption-desorption experiments were carried out in 6 steps and the fluoride removal was reached to 80% for the final step. The effect of co-existing anions was also studied and chloride and nitrate did not have much effect on efficiency. The powdered zeolite-Zr demonstrated the high ability to remove fluoride from actual wastewater. The data of the present study were well suited to the model of the Freundlich isotherm and the pseudo-second-order kinetic. The pulsed sonication with a maximum adsorption capacity of 32.98 mg/g has been able to demonstrate better performance in comparison with the continuous sonication and stirring mode.

Fe–Al–Mn@chitosan based metal oxides blended cellulose acetate mixed matrix membrane for fluoride decontamination from water: Removal mechanisms and antibacterial behavior

The scientific community is yet to find a cost-effective solution for the widespread problem of fluoride contamination in groundwater. In this study, cellulose acetate based mixed matrix membrane (MMM) was prepared through a phase inversion method using mixed metal oxides nanoparticles-polymer composite (Fe–Al–Mn@chitosan) as nanofiller. Adsorption is the commonly known mechanism of fluoride removal through MMMs and also a reason for its limited performance in real applications. Fe–Al–Mn@chitosan loaded cellulose acetate-based mixed matrix membrane (1 m2) is capable to treat 4000 L fluoride contaminated water. It has been observed that fluoride ions rejection occurs initially through adsorption. Subsequently, membrane surface experiences electrostatic repulsion due to the development of negative surface charges. Excellent defluoridation performance was obtained due to the electrostatic repulsion between F− and negatively charged MMM surface. The antibacterial test reveals that the MMM is less susceptible to microbial attack compared to cellulose acetate membranes. Fluoride rejection through membrane confirms that mixed oxide nanoparticles-polymer-composite loaded MMM is capable of removing F− from water quite efficiently.