Zeolite Particles Research Articles

Synergistic adsorption of creatinine and p-cresol from simulated serum using zeolites in electrospun fibrous mixed-matrix membranes

In this study, fibrous polyethersulfone (PES) mixed-matrix membranes were prepared by electrospinning, to which fine adsorbents including two zeolites, activated carbon, and graphene oxide were added. They were applied as a hemoperfusion unit for efficient clearance of creatinine and p-cresol from simulated serum. Physicochemical and morphological properties of the prepared fibrous membranes were firstly investigated. Batch adsorption tests revealed that the equilibria of uremic toxins on all fibrous membranes were attained within 4 h. The adsorption isotherms of creatinine and p-cresol in simulated serum (37 °C and pH 7.4), with and without 30 g/L of BSA, could be better described by the Langmuir equation, compared to the Freundlich equation. In contrast to pure adsorbent and PES membrane alone, synergistic adsorption (defined in equation (7) in the text) of creatinine and p-cresol using the fabricated mixed-matrix membranes was observed. In particular, the strongest synergism occurred in creatinine adsorption using the zeolite-incorporated PES membranes, mainly due to the comparable dimensions of the fibers and zeolite particles. The operating stability of as-prepared fibrous membranes was assessed by checking their adsorption ability before and after they were sonicated. The hemolysis tests and viability measurements of human umbilical vein endothelial cells finally indicated that the prepared PES-based mixed matrix membranes were hemo- and bio-compatible.

Zeoliti i njihova primjena u zaštiti bilja

Zeolites are a large group of aluminosilicate minerals that appear in non-metamorphic rocks or are synthesized by humans. Interest in the use of zeolites in agricultural production has been growing in recent years, primarily because they are environmentally friendly. They are used to protect the plants from insects in open areas, as well as in warehouses. Research is being conducted on the effectiveness of zeolite in controlling the insect eggs, larvae, and adults, the cause of plant diseases, and weeds. The movement of insects on the treated parts of the plant is difficult because the zeolite particles are caught by their hairs, making it difficult for them to feed, so they eventually die. Aluminum-rich zeolites are mostly used as the means for drying the surface parts of plants, considering that water is needed for the infections caused by the fungi and bacteria, or they create a thin layer on a leaf surface that prevents the germination of spores and the development of certain plant diseases. Zeolites have a potential to be slowly released, and therefore they ensure that the active substance of the herbicide has a longer duration of effectiveness, whereby a potential for leaching and environmental pollution is being reduced.

Reduction of rainwater turbidity using zeolite

In this work, we showed that rainwater harvesting offers a potential solution for overcoming clean water emergencies. However, rainwater that has been held for more than two months will be hazy and mossy in appearance. Rainwater must, therefore, first be treated to make it clearer. Rainwater was treated using clinoptilolite-type zeolite. We used two sizes of zeolite particles: large (0.02 cm) and small (0.002 cm). The zeolite was activated in an oven at 225 °C for 3 hours. After 50 hours of immersion, it was found that large-sized zeolite could lower the turbidity of rainwater by up to 86.2% without increasing the TDS (Total Dissolved Solids) value. Small-sized zeolite might reduce the turbidity of rainwater by 8% for the same immersion time. These findings show that larger zeolites are more efficient at reducing rainwater turbidity. Large-sized zeolite does not require any further processing to be made smaller before use because it is readily available on the market. Furthermore, it showed that the zeolite-based rainwater treatment process employs the pseudo-second-order kinetic model.

Influence of impeller clearance, impeller size and baffles on copper sorption on zeolite NaX: Do the size and position really matter?

Even though optimal mixing parameters may significantly influence the sorption process and its costs, the influence of hydrodynamics on sorption in a batch reactor hasn't yet been adequately studied. In this study, the hydrodynamic conditions produced by pitched blade turbine (PBT) impellers of various diameters and positions in baffled and unbaffled reactors were investigated. The objective was to investigate their influence on the just suspended impeller speed (NJS), power consumption per zeolite mass and the sorption process at the same temperature, initial copper solution concentration, and zeolite particle size in all the experiments conducted. The results show that NJS generally decreases as impeller diameter increases and is lower in the reactor without baffles. A transient multiphase computational fluid dynamics model was developed to provide valuable insight into the complex flow kinetics and it was found that the further the impeller is from the bottom of the baffled reactor the wider is the secondary suspension flow and the intensity of the flow below the impeller decreases. For this reason, complete suspension of the NaX zeolite particles in the solution was achieved at a higher PBT impeller speed. Due to the swirling motion of the suspension, this phenomenon is not observed in the unbaffled reactor for all the impellers used besides the smallest one. The power consumption per zeolite mass, at the state of complete zeolite suspension, increases in baffled reactor and decreases in unbaffled reactor with increasing impeller diameter having significantly lower values in the unbaffled reactor. The significantly lower power consumption per zeolite mass in an unbaffled system could be attributed to, not only the generally lower NJS values, but also to the resistance force which baffles make to the tangential fluid flow. The Ritchie model and Mixed surface reaction and diffusion controlled adsorption kinetic model were used for the kinetic analysis of the experimental kinetic data. The kinetic results indicate that the process is faster when the impeller is at the standard of bottom clearance, regardless of the presence of the baffles.

Degradation Kinetic Studies of BSA@ZIF-8 Nanoparticles with Various Zinc Precursors, Metal-to-Ligand Ratios, and pH Conditions.

Nanosized zeolitic imidazolate framework particles (ZIF-8 nanoparticles [NPs]) have strong potential as effective carriers for both in vivo and in vitro protein drug delivery. Synthesis of ZIF-8 and stability of protein encapsulation within ZIF-8 are affected by several factors, notably the metal ion source and molar ratio. To systematically investigate these factors, we investigated such effects using BSA as a model test protein to synthesize BSA@ZIF-8 NPs at various metal-to-ligand (M:L) ratios. SEM, FTIR, XRD, and DLS were applied to characterize the morphology and structure of BSA@ZIF-8 NPs and their effects on protein loading capacity. Degradation kinetics and protein release behavior of BSA@ZIF-8 NPs were evaluated at pH 5.0 (to simulate the tumor environment) and pH 7.4 (to mimic the blood environment). Our objective was to define optimal combinations of the high protein loading rate and rapid release under varying pH conditions, and we found that (i) the yield of BSA@ZIF-8 NPs decreased as the M:L ratio increased, but the protein content increased. This highlights the need to strike a balance between cost-effectiveness and practicality when selecting ZIF-8 NPs with different molar ratios for protein-based drug formulation. (ii) BSA@ZIF-8 NPs exhibited cruciate flower-like shapes when synthesized using Zn(NO3)2 as the zinc precursor at M:L ratios of 1:16 or 1:20. In all other cases, the NPs displayed a regular rhombic dodecahedral structure. Notably, the release behavior of the NPs did not differ significantly between these morphologies. (iii) When Zn(OAc)2 was used as the zinc precursor, the synthesized ZIF-8 NPs exhibited a smaller size compared to the Zn(NO3)2-derived ZIF-8 NPs. (iv) The release rate and amount of BSA protein were higher at pH 5.0 compared to pH 7.4. (v) Among the different formulations, BSA@ZIF-8 with an M:L ratio of 1:16 at pH 5.0 was observed to have a shorter time to reach a plateau (0.5 h) and higher protein release, making it suitable for locally rapid administration in a tumor environment. BSA@ZIF-8 prepared from Zn(OAc)2 at an M:L ratio of 1:140 showed the slower release of BSA protein over a 24-h period, indicating its suitability for sustained release delivery. In conclusion, our findings provide a useful basis for the practical application of ZIF-8 NPs in protein-based drug delivery systems.

Effects of zeolite loaded with silver, copper, or zinc ions on antimicrobial properties of the ethylene‐vinyl acetate copolymer

AbstractThe improvement of antimicrobial activity of ethylene‐vinyl acetate (EVA) resin is of significant importance from the hygienic point of view. Hence, the present work aimed to improve antimicrobial performance of the polymer with the aid of a novel, effective and low‐cost additive. Accordingly, the effects of incorporating Mobil‐twenty‐two zeolite loaded with silver, copper and zinc salts to EVA on antimicrobial activity of the polymer was investigated in this study. The used zeolite was hydrothermally synthesized and doped with silver, copper, or zinc nitrates. The loaded zeolite particles were added to EVA through melt mixing. The prepared composite samples were then compression molded to obtain thin films with a thickness of about 0.1 mm. X‐ray diffraction experiments and scanning electron microscopy revealed successful synthesis of Mobil‐twenty‐two zeolite and its metal‐salt loading. Moreover, favorable distribution of the loaded zeolite in the polymer matrix was proved by scanning electron microscopy images. Also, stress–strain test unveiled that the addition of the zeolite particles enhances Young's modulus and tensile strength of the polymer while decreases its elongation at break. In addition, among the studied samples, the one containing 2 wt.% of silver‐loaded zeolite showed the highest Young's modulus of 105 ± 4.7 MPa. however, its modulus was only about 2% higher than that of the sample containing 2 wt.% of copper/zinc‐doped zeolite. Moreover, the two mentioned samples showed the highest elongation at break among the samples containing 2 wt.% of the loaded zeolites. Besides, the lowest observed elongation at break was 491% ± 16.2 belonging to the composite sample containing 2 wt.% of copper‐loaded zeolite. Furthermore, the film samples containing either of the loaded zeolite particles exhibited antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans, with maximum bacterial and fungal inhibitions of about 56% and 54% in the case of the film samples containing 2 wt.% of silver‐ and copper/zinc‐doped zeolite, respectively. Overall, it was concluded that copper and/or zinc‐loaded zeolites, the effects of which is comparable to that of silver‐loaded zeolite, have the potential for application as low cost additives to induce antimicrobial activity to EVA, while maintaining its beneficial mechanical properties.

The structure and packaging properties of films made by Poly(lactic acid)/ lactide grafted Zeolite

Graft modification is used to achieve homo-dispersion of zeolite in the PLA resin. First zeolite was treated with acid and ultrasound, and then it was modified by grafting lactide onto it. XRD and FTIR demonstrated that the in situ grafting reaction of lactide to the surface of zeolite took place at 140 °C, under the conditions of mass ratio of 4-dimethylaminopyridine, lactide and zeolite of 2:1:1 and reacting for 24 h. The particle size distribution proved that the modified zeolite particles were significantly smaller, and TGA proved the highest grafting rate under the conditions of 4-dimethylaminopyridine, lactide, and zeolite with the mass ratio of 2:2:1 for 24 h. Finally, the PLA matrix was filled with graft-modified zeolite and epoxidized soybean oil was used as a plasticizer to prepare modified PLA blown films. The results showed that lactide grafted zeolite could be more homo-dispersed in the PLA matrix, and the tensile strength of the composite film was improved to 65.73 MPa, the elongation at break was improved to 35.33 %, the crystallinity was improved to 46.91 %, and the thermal stability of the composites was also improved compared with that of pure PLA. The water vapor permeability of the composite film became 2.73 × 10−7 g·m/(m2·h·Pa), and the oxygen permeability of the composite film became 6.63 × 10−7 cm3 cm/(cm2·s·Pa), which can be used as modified atmosphere packaging film.

Self-assembly of hierarchical ZSM-5 particles on rice husk template as hybrid catalysts for boosting methanol aromatization

Herein, natural rice husks with hierarchically porous structures were used as a platform to assemble ZSM-5 particles (denoted as hierarchical ZSM-5) to improve diffusion properties in the methanol-to-aromatics (MTA) reactions. Rice husk could work as the platform to immobilize zeolite grains and provide additional silicon sources for the growth of zeolite particles. Sodium hydroxide amount and SiO2/Al2O3 ratio strongly determined the acid properties, and the rotational crystallization condition favored the zeolite formation. Improved diffusion properties of hierarchical ZSM-5 particles were confirmed by comprehensive pore analysis and benzene diffusion experiments, showing an excellent diffusion property towards aromatic molecules. Compared with commercial microporous zeolite in the catalytic MTA reaction, hierarchical ZSM-5 exhibited superior aromatics selectivity (40.8 vs. 35.8 %), higher liquid hydrocarbon yield (22.3 vs. 14.7 wt%), and longer lifetime (60 vs. 40 h). These results offer new insights into the controllable synthesis of Hier-ZSM-5 with a hierarchically porous structure using biomass as templates.

Complex Effect of Portland Cement Modified with Natural Zeolite and Ground Glass Mixture on Durability Properties of Concrete

This article analyses the combined effect of a mixture of natural zeolite and ground soda lime silicate glass on the durability properties of concrete. The specimens were prepared by replacing 25% of the cement with a mixture of zeolite and glass at different proportions with zeolite particles of two different sizes and cured for 28 and 90 days. Chloride migration, the depth of water penetration under pressure, and freeze–thaw cycle tests were performed, and compressive strength was determined. The combined effect of the mixture on the composition and microstructure of the cement matrix was studied by analysing the results of XRD, TGA, SEM-BSE, and porosity tests. The test results showed that irrespective of the cement “dilution” effect, the mixture of additives had a beneficial combined effect: increased durability of concrete, a denser structure of the cement matrix, the formation of calcium aluminate hydrates, faster rate, and higher degree of hydration.

LTA zeolite particles functionalized with nanomagnetite for effective recovery of dysprosium from liquid solutions

Rare earth elements (REEs) as Dysprosium (Dy) are critical elements for the fabrication of components in many green energy technologies, from electric vehicles to wind turbines. Consequently, there is an increasing interest in creating sustainable and effective materials for the recovery and recycling of these elements. Zeolite materials have demonstrated a high affinity and selectivity for REEs. Thus, this paper aims to study the use of a synthetic LTA zeolite functionalized with nanomagnetite for Dy absorption, including a complete characterization of the synthetic zeolite, the kinetics and the factors affecting the adsorption efficiency. The maximum adsorption capacity reaches a value around 35 mg of Dy per gram of zeolite. The results from the adsorption isotherms and kinetic study revealed a good agreement with both Langmuir and Temkin models and pseudo-second-order kinetics. Furthermore, the thermodynamic analysis suggests that the adsorption of Dy onto the zeolite is a spontaneous and favorable process. The findings from this work could provide insights into the design and optimization of zeolite-based processes for REE recovery and recycling, contributing to the development of a more sustainable and circular economy.

Impact of Long-Term Exposure to High Chlorine and to Low pH Solutions during Chlorine Regeneration of Ammonia-Loaded Zeolite

An earlier study has shown that chlorine solutions were capable of effectively regenerating an ammonium-loaded zeolite column; however, the chlorine concentrations were high (1000 mg Cl2/L), and for two hours of the regeneration cycle, the pH was approximately 3. This led to concerns regarding the long-term durability of the zeolite. The objective of this study is to investigate the durability of a zeolite by conducting long-term batch exposure tests using (a) high concentration chlorine solutions and (b) low pH solutions. Particle size analysis, SEM images, N2 gas adsorption tests, FTIR characterization and batch loading tests showed that 35-day exposure to 1000 mg Cl2/L solutions did not significantly impact the zeolite studied. This chlorine exposure is equivalent to 840,000 ppm-h, which is three orders of magnitude higher than the values recommended by the supplier. The 90-day-long low pH exposure tests showed that pH = 4 solutions only slightly impacted the zeolite’s characteristics and ammonium uptake; however, the pH = 3 exposure led to discernable changes, and the pH = 2 exposure led to an even greater impact. At pH = 2, there was a breakdown of some external part of the zeolite particles, leading to a 7.1-fold increase in the fines and a 56% reduction in the ammonium uptake. The decrease in the ammonium uptake was proportional to the percent of fines.

Improving the Pervaporation Performance of PDMS Membranes for Trichloroethylene by Incorporating Silane-Modified ZSM-5 Zeolite.

The hydrophobic nature of inorganic zeolite particles plays a crucial role in the efficacy of mixed matrix membranes (MMMs) for the separation of trichloroethylene (TCE) through pervaporation. This study presents a novel approach to further augment the hydrophobicity of ZSM-5. The ZSM-5 zeolite molecular sieve was subjected to modification using three different silane coupling agents, namely, n-octyltriethoxysilane (OTES), γ-methacryloxypropyltrimethoxysilane (KH-570), and γ-aminopropyltriethoxysilane (KH-550). The water contact angles of the resulting OTES@ZSM-5, KH-570@ZSM-5, and KH-550@ZSM-5 particles exhibited significant increases from 97.2° to 112.8°, 109.1°, and 102.7°, respectively, thereby indicating a notable enhancement in hydrophobicity. Subsequently, mixed matrix membranes (MMMs) were fabricated by incorporating the aforementioned silane-modified ZSM-5 particles into polydimethylsiloxane (PDMS), leading to a considerable improvement in the adsorption selectivity of these membranes towards trichloroethylene (TCE). The findings indicate that the PDMS membrane with a 20 wt.% OTES@ZSM-5 particle loading exhibits superior pervaporation performance. When subjected to a temperature of 30 °C, flow rate of 100 mL/min, and vacuum of 30 Kpa, the separation factor and total flux of a 3 × 10-7 wt.% TCE solution reach 328 and 155 gm-2·h-1, respectively. In comparison to the unmodified ZSM-5/PDMS membrane, the separation factor demonstrates a 41% increase, while the TCE flux experiences a 6% increase. Consequently, this approach effectively enhances the pervaporation separation capabilities of the PDMS membrane for TCE.

Magnetic Zeolite: Synthesis and Copper Adsorption Followed by Magnetic Separation from Treated Water

Zeolites are widely used in diverse applications, including the removal of heavy metals from wastewater. However, separating fine-sized zeolite particles from treated water is often a challenge. In this work, a novel method utilizing a colloidal polyvinyl alcohol (PVA) solution to bind iron oxide nanoparticles to a Linde Type A (LTA) zeolite was used to synthesize magnetic zeolite. Different zeolite–iron oxide nanoparticle loadings (10:1, 10:0.5, and 10:0.1) were used in batch adsorption experiments to investigate adsorption capacities and kinetics for Cu removal from an aqueous solution. The results showed that the magnetic zeolite maintained much of its adsorbent properties while facilitating a simplified process design. Thus, the adsorption capacity of pure LTA zeolite was found to be 262 mg/g for magnetic zeolite, with a 10:1 ratio—151 mg/g; 10:0.5—154 mg/g; and 10:0.1—170 mg/g. Magnetic separation was subsequently employed to remove the magnetic zeolite from the treated solution.

Electrode-supported high-tortuosity zeolite separator enabling fast-charging and dendrite-free lithium-ion/metal batteries

Lithium-metal batteries (LMBs) are poised to be the next-generation high-energy density storage media of choice for various applications; however, they are currently plagued by failure due to dendrite propagation at high charge/discharge rates. One of the most sought-after technologies for dendrite propagation prevention in LMBs is solid state batteries, but they face commercialization challenges due to low room temperature ionic conductivity and high manufacturing cost. Here, we report the use of plate-shaped zeolite particles with intraparticle crystalline micropores to form an electrode-coated separator by a scalable blade-coating methodology. These separators with minimal polymer content are non-flammable and highly wettable to organic-based liquid electrolytes. They have high pore tortuosity and shear modulus resulting from the unique physical properties and morphology of the plate-shaped zeolite particles. LMB cells made of a LiNi0.5Co0.2Mn0.3O2 (NMC) cathode, coated with the plate-shaped zeolite separator, LiPF6-carbonate electrolyte, and lithium metal anode, show good charge-discharge characteristics and effectiveness in preventing dendrites from propagating through the separator even at high (3 C-rate) rates. When compared to LMB cells with a tortuously porous separator of similar pore size and porosity made of dense plate-shaped γ-alumina particles without intraparticle pores, cells with the zeolite separator show better charge/discharge characteristics, lower solid electrolyte interface (SEI) and charge-transfer resistances, and more effective dendrite propagation prevention. Results suggest that the intraparticle pores of the zeolite separator particles homogenize the Li-ion flux at the separator-anode interface in a much better manner than γ-alumina particles. There is promising commercial potential for the electrode-coated zeolite separator with highly tortuous pores for lithium batteries with a lithium-metal anode.

ZSM-5 Templated Porous Carbon: Synthesis and Characterization

Microporous zeolite ZSM-5 is prepared by the hydrothermal method, and its structure is tuned by changing the hydrothermal conditions. Then zeolite particles with uniform size and dispersion are etched into the hollow porous structures with an alkali solution to form zeolite templates. Porous carbon materials with ordered pore channels are acquired by the carbon deposition method (CVD). The detailed steps include introducing suitable carbon sources into the pore channels of the as-prepared zeolite templates, followed by carbon vapor deposition and continuous optimization of the deposition conditions, and finally, removing the template. The hollow porous structure of the carbon material facilitates the exposure of catalytic active sites and the improvement of diffusion kinetics. The hollow porous carbon (HPC) formed by carbon deposition perfectly inherits the structure and pore attributes of the hollow hierarchical zeolite ZSM-5. It can be further used as a carbon-based catalyst support.

Large-scale production of nano-sized LTA-type zeolite particles by beads-milling and recrystallization method

Large-scale production of nano-sized LTA-type zeolite particles by beads-milling and recrystallization method

Zeolite Coated Separators for Improved Performance and Safety of Lithium Metal Batteries

Lithium (Li) metal batteries are attractive due to their high gravimetric and volumetric energy densities. However, they can fail catastrophically due to dendritic nucleation, growth, and penetration through the polypropylene (PP) or polyethylene (PE) separators. Poor electrolyte wetting and non-uniform Li ion flux are known to affect Li dendrite formation, especially since the PP/PE separators have non-uniform pore size distribution and typical organic electrolytes do not wet them well. In this work, we demonstrate that a porous zeolite coating on a commercial PP separator can improve electrolyte wettability and through plane ionic conductivity, giving rise to more uniform Li flux. Consequently, coated separator can delay dendrite penetration and enhance cell performance and safety. We tested Celgard 2400 (uncoated) and zeolite-coated separator (coated) in high energy NMC||Li cells for their rate capability and cycle life performance. Rate capability test for these cells shows that the additional resistance due to the zeolite coating can negatively impact the cell performance at high C-rates. However, cells with the coated separator outperform those with uncoated separator in the cycle life test with improved capacity retention. Symmetric cell studies performed to understand the differences in Li plating morphology indicate initial lower overpotential for the coated separator cells, revealing improved electrolyte wetting and relatively uniform Li flux. Scanning electron microscopy (SEM) reveals zeolite-coating microstructure with evenly distributed zeolite particles and cycled Li metal electrode morphologies. SEM images show much smoother Li plating morphology on Li metal surface in the cells with coated separators. This study highlights the potential of using zeolite-coated separators to enhance lithium metal battery (LMB) performance and safety.

Adsorption and Desorption Behaviors of Ammonia on Zeolites at 473 K by the Pressure-Swing Method.

Adsorption and desorption behaviors of ammonia on the zeolites were investigated using the pressure-swing method to utilize the ammonia adsorbent at 473 K. For various (Y, A, L, and mordenite) types of zeolites, the effects of their pore sizes, countercation species, and number of adsorption sites on the ammonia adsorption behavior were evaluated. The adsorption capacity increased with increasing the pore size. The differences in the countercation species and the number of adsorption sites contributed to the ammonia adsorption process on the zeolites. Sodium cations strongly adsorb ammonia molecules. The adsorption/desorption of ammonia expanded and shrunk the zeolite crystal, suggesting that the pores in the zeolite were enlarged by the adsorption of ammonia molecules. Despite repetitive lattice expansion and shrinkage, the morphologies of the zeolite particles were not degraded. These results confirm that the zeolite showed high durability for the adsorption and desorption of ammonia at 473 K.

Electrocoagulation Combined with Synthetic Zeolite—Does the Size of Zeolite Particles Matter?

Although electrocoagulation combined with zeolite (ECZ) shows higher efficiency in wastewater treatment, the actual contribution of zeolite particle size has not been fully explored. In this work, the influence of particle size of synthetic zeolite SZ (<90, 90–160, and 160–600 μm) on ECZ treatment of compost leachate with very high organic load is investigated together with different electrode materials (Fe, Al, and Zn), current densities (0.003, 0.009 and 0.018 A/cm2), and contact times (10, 20 and 30 min). The results positively highlight that the largest particle size should be used in ECZ, as it leads to a lower increase in pH and temperature, a higher decrease of chemical oxygen demand (COD) and turbidity, and a lower electrode consumption, while causing more damage to the electrode surface. The estimated energy costs ranged from 3.960 kW/m3–1313.657 kW/m3. The Taguchi L9 orthogonal configuration showed the highest COD and turbidity decrease under the conditions of 160–600 µm zeolite particles. The powder X-ray diffractometer (PXRD) analysis shows that interplanar spacing decreases when smaller and medium SZ particle sizes are used, while this effect was not observed with larger zeolite particle size. SEM-EDS shows that oxygen, silicon, and aluminium are the predominant elements in electrogenerated sludge coupled with zeolite.

Polyacrylonitrile (PAN)/Freeze-dried Chitosan (FCS)-NaY zeolite triple layer nanostructure fibrous adsorptive membrane (PAN/FCS-NaY TNAM) for Cu(II) and Pb(II) ions removal from aqueous solutions

In this study, an innovative PAN/FCS-NaY TNAM was fabricated using an electrospinning technique for Cu(II) and Pb(II) removal from contaminated water. Top and bottom fibrous layers (M1) were fabricated using a combination of FCS and PAN blends. Middle layer (M2) was electrospun from pure PAN solution and loaded with NaY zeolite particles. The physicochemical properties of the material and fibrous samples were investigated through SEM, FTIR-ATR, DSC, AFM, DMTA analysis, and contact angle measurement. The effective parameters, including initial ions concentration, time, reusability, and pH on the dynamic adsorption performance of the prepared membrane and its stability in the aqueous medium for Cu(II) and Pb(II) ions removal were investigated at a pressure of 0.006 bar. Dynamic metal ions adsorption was modeled using dynamic filtration prediction models such as Thomas and Yoon-Nelson. The fabricated nanostructure fibrous membranes with the removal percentage of Cu(II) and Pb(II) ions (94.6% and 98.7%, respectively) under the optimal operating conditions (initial concentration: 50 ppm, time: 10 min, and pH: 4.6), high compatibility in modeling dynamic filtration (R2 > 0.99), high pure water flux (298 LMH), suitable reusability (four-cycle without significant reduction in adsorption) as well as long-term stability, can be as potential filters in water treatment applications.