Interlayer Space Of Montmorillonite Research Articles

Structure and Mobility of Lactose in Lactose/Sodium Montmorillonite Nanocomposites

This study aims at investigating the molecular level organization and molecular mobility in montmorillonite nanocomposites with the uncharged organic low-molecular-weight compound lactose commonly used in pharmaceutical drug delivery, food technology, and flavoring. Nanocomposites were prepared under slow and fast drying conditions, attained by drying at ambient conditions and by spray-drying, respectively. A detailed structural investigation was performed with modulated differential scanning calorimetry, powder X-ray diffraction, solid-state nuclear magnetic resonance spectroscopy, scanning electron microscopy, microcalorimetry, and molecular dynamics simulations. The lactose was intercalated in the sodium montmorillonite interlayer space regardless of the clay content, drying rate, or humidity exposure. Although, the spray-drying resulted in higher proportion of intercalated lactose compared with the drying under ambient conditions, nonintercalated lactose was present at 20 wt % lactose content and above. This indicates limitations in maximum loading capacity of nonionic organic substances into the montmorillonite interlayer space. Furthermore, a fraction of the intercalated lactose in the co-spray-dried nanocomposites diffused out from the clay interlayer space upon humidity exposure. Also, the lactose in the nanocomposites demonstrated higher molecular mobility than that of neat amorphous lactose. This study provides a foundation for understanding functional properties of lactose/Na-MMT nanocomposites, such as loading capacity and physical stability.

Effective intercalation of zein into Na-montmorillonite: role of the protein components and use of the developed biointerfaces.

Biohybrid materials based on the intercalation of zein, the major storage protein in corn, into sodium-exchanged montmorillonite were prepared following two synthesis strategies. The first one made use of zein dissolved in 80% (v/v) ethanol/water solution, the usual solvent for this protein, while the second method is new and uses a sequential process that implies the previous separation of zein components in absolute ethanol. This treatment of zein with ethanol renders a soluble yellow phase and an agglomerate of insoluble components, which are able to intercalate the layered silicate when an aqueous dispersion of montmorillonite is added to the ethanol medium containing both phases. The diverse steps in this second route were investigated individually in order to understand the underlying mechanism that drives to the intercalation of this complex hydrophobic biomacromolecule into the hydrophilic interlayer space of sodium-exchanged montmorillonite. In addition to physicochemical characterization of the resulting materials, these biohybrid interfaces were also evaluated as biofillers in the preparation of diverse ecofriendly nanocomposites.

Magnesium aluminium silicate–gentamicin complex for drug delivery systems

This paper presents the characteristics of magnesium aluminium silicate–gentamicin complexes for drug delivery systems. The work describes the results of studies on the successful introduction of gentamicin (an aminoglycoside antibiotic) into the interlayers of smectite clay and examines the possible use of intercalated smectite as a carrier for sustained drug release. Characterisation of magnesium aluminium silicate–gentamicin complexes was carried out by means of X-ray diffraction, Fourier transform infrared spectroscopy, thermal analysis and scanning electron microscopy with EDX analysis. The possibility of using the gentamicin intercalated smectite as a carrier for sustained release of the drug was investigated during in vitro study, in which the release rate of gentamicin from the smectite clay matrix was monitored based on absorption at 330 nm using a UV–Vis spectrometer and the kinetic of drug release was evaluated based on the zero-order, first-order, Higuchi and Korsmeyer–Peppas models. The results confirmed the efficiency of intercalation and indicate the potential for introducing gentamicin into the interlayer space of montmorillonite. Accordingly, the obtained material may thus be used as a drug carrier in modulated drug delivery systems.

Characterisation, in vitro release study, and antibacterial activity of montmorillonite-gentamicin complex material

The present paper concerns the potential use of montmorillonite as a drug carrier and focusses on the intercalation of the studied clay with gentamicin (an aminoglycoside antibiotic) at various temperatures (20, 50 and 80°C). The experiments were performed to identify the temperature required for the optimum intercalation of gentamicin into the interlayer of montmorillonite. The structural and microstructural properties of gentamicin and the potential for introducing it between smectite clay layers were investigated by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopic techniques, and SEM with EDS analysis. Additionally, the in vitro drug release behaviour of the montmorillonite-gentamicin complex and its antibacterial activity against Escherichia coli (E. coli) bacteria was investigated. Based on these studies, the impact of temperature on the intercalation of the drug between layers of smectite was evaluated. It was found that an intercalation temperature of 50°C resulted in the highest shift in the position of principle peak d(001) as measured by XRD, suggesting, that the greatest amount of gentamicin had been introduced into the interlayer space of montmorillonite at this temperature. Subsequently, the montmorillonite-gentamicin complex material obtained at 50°C revealed the greatest capacity for killing E. coli bacteria during an in vitro test.

Investigation on the co-modification process of montmorillonite by anionic and cationic surfactants

To study how anionic surfactant sodium dodecyl sulfonate (SDS) and cationic surfactant cetyltrimethylammonium chloride (CTAC) enter the interlayer spaces of montmorillonite, montmorillonite, CTAC and SDS were exchanged consecutively and simultaneously. Three parameters were investigated: reaction times, surfactants contents and addition sequences. The results of XRD, thermal analysis and sulfur analysis stated that SDS could not intercalate into montmorillonite interlayer space alone. However, it can enter the interlayer space of montmorillonite in the presence of CTAC. The addition sequences of cationic and anionic surfactants affect the d-value and thermal stability of anionic-cationic montmorillonite. The data obtained from elemental analysis clarified the steps of this multistep reaction sequence and a mechanistic scheme has been proposed: a portion of cationic surfactants intercalate into the interlayer spaces of montmorillonite by cation exchange firstly, and then the anionic surfactant enter the interlayer spaces of montmorillonite by the synergistic effect with cationic surfactants. Molecular simulation indicated the arrangement of cationic and anionic surfactants intercalated into montmorillonite interlayer space.

Mössbauer study of pH dependence of iron-intercalation in montmorillonite

57Fe Mossbauer spectroscopy and XRD have successfully been applied to show the incorporation of Fe ion into the interlayer space of montmorillonite via treatment with FeCl 3 in acetone. The 78K 57Fe Mossbauer spectra of montmorillonite samples reflected magnetically split spectrum part indicating the intercalation of iron into the interlayer of montmorillonite via the treatment with FeCl 3+acetone and washed with water until the initial pH=2.3 increased to pH=4.14. It was found that the occurrence of intercalated iron in the form of oxide-oxihydroxide in montmorillonite increases with the pH. Intercalation was confirmed by the gradual increase in the basal spacing d 001 with pH.

Montmorillonite-supported with Cu2O nanoparticles for damage and removal of Microcystis aeruginosa under visible light

The montmorillonite supported with Cu2O nanoparticles was prepared by reduction of Cu2+ absorbed by montmorillonite using glucose and ethylene glycol as reductant. X-ray diffraction and IR spectrum depicted the maintenance of the host structure of montmorillonite and the presence of crystallite Cu2O nanoparticles. X-ray diffraction and transmission electron microscopy demonstrated the Cu2O nanoparticles were either intercalated into the interlayer space of montmorillonite or dispersed homogeneously on the surface of montmorillonite, and the size of Cu2O nanoparticles were varying from 5 to 10nm. Energy dispersive X-ray showed the loading amount of Cu2O in montmorillonite interlayer was around 26.31%. Cu2O-montmorillonite was used for adsorbent, flocculant and photocatalyst to remove Microcystis aeruginosa, removing 90.4% of M. aeruginosa in 3h under visible light. The synergy of adsorption-flocculation and photocatalysis of Cu2O-montmorillonite promoted the aggregation of M. aeruginosa and then the cell damage mainly associated with cell membrane attack and inclusion degradation by photocatalysis of Cu2O, leading to the inhibition of physiological activity of M. aeruginosa. Cu2O-montmorillonite was an effective algae removal material for the emergency control of cyanobacteria bloom.

An inorganic-organic hybrid material from the co-intercalation of a cationic surfactant and thiourea within montmorillonite layers: application to the sensitive stripping voltammetric detection of Pb2+ and Cd2+ ions

A smectite-based inorganic-organic hybrid material was prepared by a one-step intercalation of cetyltrimethylammonium ions and thiourea within the interlayer space of montmorillonite (MT). The surface and textural properties of the resulting material were examined using several techniques (X-ray diffraction, elementary analysis and N 2 adsorption-desorption experiments (BET method)) that demonstrated the presence of both modifiers in the clay mineral structure. The presence of thiourea molecules in the modified MT greatly improved its ability towards the fixation of Pb 2+ and Cd 2+ ions when the organoclay material was used for sensing purposes as a glassy carbon electrode modifier. The electro-analytical procedure was based on the chemical accumulation of both analytes under open-circuit conditions, followed by the detection of the preconcentrated species using square wave voltammetry. Upon optimization of different parameters likely to influence the electrode response, linear calibration graphs were obtained in the concentration ranges from 0.1 to 1 μM and 0.01 to 0.1 μM for Cd 2+ and Pb 2+ , respectively, leading to low limits of detection (4.2 × 10 −10 M for Pb 2+ and 1.2 × 10 −9 M for Cd 2+ ). Un matériau hybride inorgano-organique à base de smectite a été préparé par intercalation en une seule étape d’ions cetyltrimethylammonium et de la thiourée entre des feuillets de montmorillonite (MT). Les propriétés surfaciques et texturales du matériau obtenu ont été analysées et caractérisées par diffraction de rayons X, analyse élémentaire et mesure d’isothermes d’adsorption–désorption d’azote par la méthode BET. Toutes ces techniques ont montré l’effectivité de la modification apportée à l’argile. Bien plus, la présence de la thiourée dans le minéral argileux a sensiblement augmenté son aptitude vis-à-vis de la fixation simultanée des ions Pb 2+ et Cd 2+ lorsque l’argile modifiée est utilisée comme modifiant d’une électrode de carbone vitreux. La procédure utilisée pour la détection électrochimique des ions analysés comprend deux étapes : l’accumulation en circuit ouvert, suivie de la détection des espèces fixées par voltammétrie à vagues carrées. Après optimisation des paramètres clés influençant le signal électrochimique des deux ions, des droites de calibration ont été obtenues dans des gammes allant de 0.1 à 1 μM et de 0,01 à 0.1 μM (respectivement pour les ions Cd 2+ et Pb 2+ ), conduisant à des limites de détection assez basses (4,2 × 10 −10 M pour Pb 2+ et 1,2 × 10 −9 M pour Cd 2+ ).

Nanocomposite based on erucic acid modified montmorillonite/sulfited rapeseed oil: Preparation and application in leather

Montmorillonite was modified by cis-13-docosenoic acid also known as erucic acid via intercalation reaction. The as-prepared erucic acid modified montmorillonite (EA-Mt), rapeseed oil, ethylene diamine, acrylic, and sodium bisulfite were employed to prepare the EA-Mt/modified rapeseed oil (EA-Mt/MRO) nanocomposite. X-ray diffraction (XRD) indicated that erucic acid successfully intercalated into the interlayer space of montmorillonite (Mt) with the basal spacing of Mt increasing from 1.24nm to 1.48nm. The thermal stability of EA-Mt/MRO nanocomposite was effectively improved after adding the EA-Mt by thermogravimetric analysis (TGA). Then, EA-Mt/MRO nanocomposite as fatliquoring agent was applied in the leather fatliquoring process of goatskin garment. Erucic acid intercalated Mt was dispersed on the collagen fibers of the leather as confirmed by SEM and EDX. The flame retardancy of the leather treated with EA-Mt/MRO nanocomposite was found to be improved in a significant way. Compared with that of leather treated with modified rapeseed oil (MRO), the highest LOI value of leather treated with EA-Mt/MRO reached 27.9% from 23.7% with 8% EA-Mt. The leather had superior softness, physical and mechanical properties.

Hydrogel template-assisted synthesis of nanometric Fe2O3 supported on exfoliated clay

A synthesis of metal oxide modified clays based on the hydrogel template assisted route was proposed. This novel method was verified by an intercalation of poly(acrylic acid) (PAA) into the interlayer space of montmorillonite (MT) using the in situ polymerization technique. The obtained hydrogel/clay composite with a MT/PAA mass ratio close to 1.0 exhibited an expanded layered structure and an excellent adsorption capacity for transition metal cations. These features were exploited to the modification of MT-PAA material with various amounts of Fe3+ cations by deposition at controlled pH = 2.5. The introduced Fe species favored the hydrogel burning, therefore in a subsequent step the organic template could be easily removed by calcination under oxidizing conditions at temperature protecting the clay against deep dehydroxylation. A gradual delamination of MT with an increase in the Fe content was observed after thermal treatment. This effect resulted in opening of the MT structure, manifested by a relatively high surface area and a large porosity. XRD, TEM, UV–Vis-DRS and XPS measurements exhibited that the formed α-Fe2O3 nanoparticles were highly dispersed on the exfoliated clay, which comprised a framework stabilizing the nanophase.

Copper(I) Confined in Interlayer Space of Montmorillonite: A Highly Efficient and Recyclable Catalyst for Click Reaction

CuI-exchanged solid based on montmorillonite material was investigated as catalyst in organic synthesis. The catalytic potential of this material was evaluated in the Huisgen [3 + 2]cycloaddition. This catalytic system has been examined and proved to be an efficient heterogeneous catalyst for this “click chemistry”-type transformation. The ensuing catalyst can be recycled and reused five times without dramatic yield loss.

Effect of Bacillus mucilaginosus D4B1 on the structure and soil-conservation-related properties of montmorillonite

Bacillus mucilaginosus is one of the common soil bacteria and is widely used as a microbial fertilizer to release potassium from K-rich soil minerals. But few researchers have discussed possible effects that the bacteria may have on montmorillonite. This study investigated the effect of B. mucilaginosus strain on the capability of montmorillonite to retain water/cations. After 20days of interaction with B. mucilaginosus D4B1, the expansion ratios of montmorillonite samples decreased from 83.2% to 76.7%, and the cation exchange capacities (CEC) decreased from 80.8 mmol/100g to 67.8 mmol/100g, suggesting the durative interaction with the bacteria may reduce the capabilities of incorporating water molecules and nutrient into the interlayer space of montmorillonite. Morphological changes of discrete layers and etch pits were observed with scanning electron microscope (SEM). In the synchrotron radiation X-ray diffraction (SR-XRD) profiles, the full-width at half maximum (FWHM) of 001 reflection increased to 0.24nm as compared to the abiotic sample (0.19nm), indicating a decreased structural order in bacteria-treated montmorillonite. Also, a new band at 1540cm−1 assigned to asymmetric stretching vibrations of carboxylate was detected by micro fourier-transform infrared spectroscopy (FTIR) in bacteria-treated samples, suggesting the alteration in the mineral structure of montmorillonite was possibly triggered by the organic acids produced by bacteria. Moreover, in bacteria involved dispersion, a significant decrease of the pH value was coupled with a consecutive increase of total protein concentration, indicating the continuous activities of the bacteria during 20days of interaction. Above all, the decreased water-holding or cations-exchange capacity of montmorillonite was related to the partial alteration in the mineral structure of montmorillonite by B. mucilaginosus D4B1. Such a durable interaction on structural alteration of soil clays would have detrimental impact on long-term sustainability of soil resources.

Effects of montmorillonite on phase transition and size of TiO2 nanoparticles in TiO2/montmorillonite nanocomposites

Nanostructured TiO2/montmorillonite (TiO2/Mt) materials have many applications in a variety of fields such as plastic degradation, photocatalysis, antibacterial agent development and water purification. In order to homogeneously disperse TiO2 nanoparticles within the interlayer space of montmorillonite, an in-situ interlayer reaction method was developed to prepare nanostructured TiO2/Mt materials. Briefly, cetyl trimethylammonium (CTA+) was first intercalated into the interlayer of the montmorillonite structure. Then tetrabutyl orthotitanate (TBOT) was introduced into the interlayer space of the CTA+/montmorillonite (CTA+/Mt) nanocomposites by solvation. TBOT in the nanocomposites underwent in-situ hydrolysis, de-hydroxylation and annealed at different temperatures. During annealing, CTA+ was burnt off and TiO2 formed in the interlayer space of montmorillonite. The average crystal size of TiO2 in TiO2/Mt was compared with that of both the pure TiO2 nanoparticles and the mixture of pure TiO2 and montmorillonite. The intermediate and final products were characterized by X-ray diffraction, FT-Raman spectroscopy and transmission electron microscopy. The results showed that the phase-change temperature for transformation of TiO2 nanoparticles in TiO2/Mt nanocomposites from anatase to rutile phase was higher than that for pure TiO2 nanoparticles and the mixture of pure TiO2 and montmorillonite. Pure TiO2 nanoparticles were all converted to rutile when the annealing temperature was increased to over 800°C. However, the anatase-TiO2 still existed in TiO2/Mt, even though the annealing temperature reached a much higher temperature of 1200°C. In addition, at the same annealing temperature, the average crystal size of TiO2 in TiO2/Mt nanocomposites was smaller than that of either the pure TiO2 or the mixture of pure TiO2 and montmorillonite.

Formation of layered columnar structure of montmorillonite by successive intercalation of polyvinyl alcohol and aluminum polyhydroxocomplexes

We proposed a new method for the formation of a layered columnar structure of carbon-containing montmorillonite by the successive intercalation of polyvinyl alcohol and aluminum polyhydroxocomplexes [Al13O4(OH)24(H2O)12]7+. Polyvinyl alcohol was shown to play an important role, serving as an efficient delaminating agent at the step of polycation intercalation into the interlayer space of montmorillonite and, at the step of pillar formation, to favor the formation of thermally stable layered-columnar structure. It was shown that, irrespective of the amount of polymeric intercalate (at its level of 3–20 wt %), the basal distance in the hybrid materials obtained upon a calcination temperature of 450°C is fixed at a value of d001 = 1.85 nm and greater than that of the conventional Al2O3-pillar montmorrilonite by the thickness of graphene monolayer. The textural characteristics of this layered columnar system can be controlled by the amount of polymer added and by the calcination temperature.

Adsorption of nisin and pediocin on nanoclays

Three different nanoclays (bentonite, octadecylamine-modified montmorillonite and halloysite) were studied as potential carriers for the antimicrobial peptides nisin and pediocin. Adsorption occurred from peptide solutions in contact with nanoclays at room temperature. Higher adsorption of nisin and pediocin was obtained on bentonite. The antimicrobial activity of the resultant bacteriocin-nanoclay systems was analyzed using skimmed milk agar as food simulant and the largest inhibition zones were observed against Gram-positive bacteria for halloysite samples. Bacteriocins were intercalated into the interlayer space of montmorillonites as deduced from the increase of the basal spacing measured by X-ray diffraction (XRD) assay. Infrared spectroscopy suggested non-electrostatic interactions, such as hydrogen bonding between siloxane groups from clays and peptide molecules. Transmission electron microscopy did not show any alteration in morphologies after adsorption of antimicrobial peptides on bentonite and halloysite. These results indicate that nanoclays, especially halloysite, are suitable nanocarriers for nisin and pediocin adsorption.

Comparative study on the use of cationic–nonionic-organo-montmorillonite in oil-based drilling fluids

This work involves a comparative study of cationic–nonionic-organo-montmorillonite (CNOMt), cationic-organo-montmorillonite (COMt) and nonionic-organo-montmorillonite (NOMt), aiming their use in oil-based drilling fluids. Firstly, CNOMt, COMt and NOMt were prepared in aqueous solution. Secondly, organo-montmorillonites were characterized by X-ray diffraction (XRD), differential thermal analysis (DTA), thermogravimetric analysis (TG), contact angle test, and swell index. The results indicated that cationic and nonionic surfactants could solely or synergistically intercalate into the interlayer spaces of montmorillonite. The order of their thermal stabilities was CNOMt>NOMt>COMt. The order of surface lipophilicity (or hydrophobicity) and swelling indices in oils was the same, i.e., CNOMt>COMt>NOMt. Finally, organo-montmorillonites were added into emulsions with different ratios of oil to water and their apparent viscosities were characterized. The results exhibited that both CNOMt and COMt viscosified the oil-based fluids better than NOMt did. In addition, the apparent viscosity of CNOMt was a little higher than that of COMt in the emulsion with oil/water ratio of 95:5 while the result was inverted in the emulsion with oil/water ratio of 80:20. From the standpoint of characterization results, CNOMt presented a new kind of potential rheological control additive of oil-based drilling fluids, especially for high oil/water ratio fluids, and CNOMt would perform excellent thermal stability.

ZnO–montmorillonite as Photocatalyst and Flocculant for Inhibition of Cyanobacterial Bloom

The cyanobacterial bloom in water has adversely affected water quality, local economies, and human health. Therefore, the removal and restricting the growth of harmful algae are of particular interest. In this study, ZnO–montmorillonite that could flocculate and restrict the growth of Microcystis aeruginosa, used as a probe of cyanobacterial, was prepared by hydrothermal solution intercalation method and characterized by means of XRD, IR, and TEM. In ZnO–montmorillonite, ZnO nanoparticles were either embedded in the interlayer space of montmorillonite or dispersed on montmorillonite surface. The determinations of chlorophyll a levels, total soluble protein content, and malondialdehyde concentration demonstrated that ZnO–montmorillonite had stronger flocculation effect on M. aeruginosa compared with natural montmorillonite and ZnO under visible light and had a better photocatalytic degradation effect on M. aeruginosa than ZnO under UV irradiation after 1 h. Under UV, 95 % removal efficiency was achieved for M. aeruginosa in 1 h using 50 mg L−1 ZnO–montmorillonite, and the proliferation of M. aeruginosa was totally inhibited due to the high photocatalytic activity and absorption flocculation ability of ZnO–montmorillonite. Furthermore, the cell structure was irreversibly damaged and the cell lysed. The synergy of absorption flocculation and photocatalysis of ZnO–montmorillonite promoted the removal of M. aeruginosa.

Formation of Cadmium Sulfide and Zinc Sulfide Mixture in the Interlayer Space of Montmorillonite

AbstractCadmium sulfide and zinc sulfide (CdS and ZnS) were incorporated in sodium and cetyltrimethylammonium montmorillonites by the precipitation of sulfides from soluble metal sources in the presence of montmorillonites. The resulting hybrids were characterized by XRD, themogravimetric/differential thermal analysis (TG‐DTA), TEM, Raman spectroscopy, and UV/Vis and photoluminescence spectroscopy. The absorption onsets owing to CdS and ZnS in cetyltrimethylammonium‐montmorillonite appeared in a shorter wavelength region (311–520 nm) relative to that (309–484 nm) of the two semiconductors in sodium montmorillonite, thus reflecting the difference in the particle sizes of CdS and ZnS in the hybrids. The appearance of the broad emission bands combined with the bands centered at 469, 451, 440, and 431 nm owing to CdS and ZnS were attributed to the existence of both CdS and ZnS in the products. The difference in the emission intensity of the hybrids is discussed in terms of the role of the cetyltrimethylammonium cation. The unique optical properties of the two products were thought to occur through the interactions of sulfides with their environment (montmorillonite and cetyltrimethylammonium cation).

Correlation between Electrical Properties and Potentiometric Response of CS-Clay Nanocomposite Membranes

The aim of this work is to study the relationship between electrical, structure, and potentiometric response to nitrate anions using Ion Selective Electrodes (ISE). These ISE are based on chitosan-montmorillonite nanocomposite membranes with different content of montmorillonite. Membrane properties have been studied using SEM, FTIR, and impedance spectroscopy measurements. With the advent of impedance spectroscopy one is allowed to obtain the DC conductivity dependence on montmorillonite concentration and the percolation threshold. Additionally, the potentiometric response to nitrate anions of ISE based on chitosan-clay nanocomposite has been investigated. It is shown that the properties and performance of these membrane electrodes depend upon the clay wt% and that the best sensitivity to nitrate ions (with detection limit 7×10−5 M) is obtained near the percolation concentrationca. 8 ± 2.5 wt% of clay. This observation is traceable to higher clay content (higher agglomeration) that tends to decrease the intercalation and absorption of the number of chitosan chains in the interlayer space of montmorillonite.

Effective phosphate adsorption by Zr/Al-pillared montmorillonite: insight into equilibrium, kinetics and thermodynamics

Zirconium-pillared montmorillonite (Zr-Mt) and zirconium/aluminum-pillared montmorillonite (Zr/Al-Mt) were prepared by intercalating Zr4+ and Zr4+/Al3+ polyhydroxy-cations into the interlayer spaces of natural montmorillonite (Mt). Zr-Mt and Zr/Al-Mt exhibited greater specific surface areas and pore volumes, as compared with Mt. In particular, the enhancement in the phosphate removal performance of Zr/Al-Mt was more significant in terms of phosphate adsorption capacity and rate, in relation to Zr-Mt. Herein, several important parameters, such as contact time, temperature, initial solution pH and competing anion, were investigated in detail to evaluate the phosphate adsorption performances of Zr/Al-Mt. The pseudo-second-order kinetic model fitted our acquired phosphate adsorption data best, in comparison with the use of the pseudo-first-order or the pseudo-third-order kinetic model. The Langmuir model appeared to fit the adsorption process better than that of the Freundlich model, with a maximum phosphate adsorption capacity of 17.2mg P/g at 25°C. The thermodynamic parameters (ΔG°, ΔH° and ΔS°) were also determined, which revealed that the phosphate adsorption process was spontaneous and endothermic in nature. A high adsorption capacity was observed at pH=3.0, which decreased by increasing pH. The presence of competitive ions, e.g. Cl−, NO3−, and SO42−, slightly impacted the phosphate adsorption; whereas the introduction of CO32− caused the greatest adverse effect. The study on the Zr/Al-Mt leaching strongly suggested that the risk of Zr4+ leakage during adsorption process be negligible within a wide pH range of 3.0–9.0. After three adsorption-desorption cycles, there was no significant loss in the adsorption performance of Zr/Al-Mt.