Removal of pharmaceuticals, particularly antidepressants, from aqueous environments using environmentally friendly adsorbents remains a challenge. This study developed a hybrid cryogel composed of sodium acrylate and carboxymethyl chitosan (NaPA-CMCs) through cryogelation and evaluated its effectiveness in removing antidepressants using a fixed-bed column. Fluoxetine (FLX) served as the target contaminant, with citalopram (CIT) and venlafaxine (VEN) used for competitive adsorption tests. The effects of pH, flow rate (Q), bed height (H), and initial concentration (C₀) on breakthrough curves were evaluated. FLX removal reached its highest level of 59.03

Fluoxetine (FLX) contamination in aquatic environments presents significant ecological risks, highlighting the need for effective removal methods. In this study, we developed a bio-based, macroporous molecularly imprinted cryogel (MIC/NaPA-CMCs) for continuous-flow FLX adsorption. The cryogel, synthesized from sodium polyacrylate and carboxymethyl chitosan by cryopolymerization at −18 °C for 24 h, used genipin and N,N′-methylenebis(acrylamide) as crosslinkers, with FLX as the template molecule. Selective recognition cavities were generated by template removal using an acidified solvent (5% methanol/0.1 M HCl, 1:1 v/v). A non-imprinted cryogel (NIC/NaPA-CMCs) was prepared for comparison. Characterization included Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analysis, and point-of-zero-charge (pHPZC) determination. MIC/NaPA-CMCs exhibited a pHPZC of 4.9 and a specific surface area of 36.8 m²/g. In continuous fixed-bed adsorption experiments (pH 8.5, bed height 0.4 cm, 20 ± 2 °C), increasing FLX inlet concentration (10-40 mg/L) and flow rate (1.5-2.5 mL/min) resulted in earlier breakthrough and lower adsorption capacities. The maximum adsorption capacity reached 22.05 mg/g at 20 mg/L and 1.5 mL/min, decreasing to 6.61 mg/g at 2.5 mL/min. Breakthrough data fit well to the Thomas and Yoon-Nelson models (R² > 0.990), indicating internal diffusion-limited kinetics. Competitive adsorption with citalopram (CIT) confirmed the selectivity of MIC/NaPA-CMCs, with higher FLX uptake and a relative selectivity coefficient (K′ > 1) compared to the non-imprinted cryogel. Further studies are required to assess adsorption performance and selectivity in real wastewater or environmental matrices for practical application.

The growing consumption of semi-and fully prepared products has increased demand for packaging materials that protect goods from production to consumption while minimizing losses. Currently, most packaging materials are derived from petroleum-based polymers, which are generally non-biodegradable and contribute to environmental pollution. Paper is considered a promising alternative, provided that its barrier and mechanical properties are improved. In this study, cellulose filaments were examined for their potential to enhance the barrier properties through a water-based coating formulation containing cationic starch, montmorillonite, and alkyl ketene dimer as matrix components. The methodology involved preparing coating formulations with varying cellulose filaments concentrations, applying these to paper substrates, and evaluating the coated papers for mechanical and barrier performance. The results showed a significant improvement in the overall performance of the coated paper. For the formulation containing 2 wt% cellulose filaments, the tensile, tear, and burst indices increased by 27.8%, 41.2%, and 29.2%, respectively. In addition, significant improvements in barrier properties were observed, with the Cobb value decreasing from 21.1 to 5.8 g/m2 and the water vapor transmission rate reducing from 409.1 to 158.2 g/m2 & sdot;day. The coated paper also exhibited strong hydrophobicity, with water contact angles exceeding 117 degrees. These findings demonstrate the potential of cellulose filaments as an effective coating additive for improving the mechanical, physical, and barrier properties of paper, offering a promising approach for developing sustainable paper-based packaging materials for non oxygen-sensitive applications.

As the demand for critical rare earth elements increases, their recovery from e-waste has become a sustainable alternative to traditional mining. Cerium, widely used in strategic technologies, remains challenging to recover efficiently. In this study, a three-layer bio-based composite adsorbent containing cellulose, phosphorylated cellulose, and electrospun chitosan nanofibers was developed to selectively adsorb and recover Ce3+ ions from aqueous solutions. The composite's constituents strongly influenced its adsorption performance: phosphorylated cellulose introduced phosphate groups that enhanced Ce3+ binding through electrostatic interactions, while chitosan nanofibers provided amino and hydroxyl sites that improved chelation, porosity, and mechanical integrity. The optimized combination of these components achieved a balance between functionality, permeability, and stability. Characterization (e.g., scanning electron microscopy, energy-dispersive X-ray spectroscopy, image analysis) confirmed the uniform distribution of active layers and the presence of functional groups responsible for adsorption. Batch adsorption tests revealed a high adsorption capacity of over 64 mg/g within 60 min, following a pseudo-first-order kinetic model and the Langmuir isotherm behavior. Thermodynamic analysis indicated an exothermic process, and the composite exhibited selectivity toward Ce3+ and Nd3+ over Cu2+. Cerium was effectively desorbed and recovered, and the material maintained over 83% of its performance after four cycles, demonstrating its strong potential for sustainable rare earth recovery in line with circular economy principles.

Performance and recyclability of paper coatings depend on precise control of polymer, surfactant, filler compositions as well as oil to water ratios to produce stable dispersions and defect-free films. These factors determine fiber polymer interactions and coating removability during repulping, which are critical for efficient fiber recovery and recyclable packaging. This study examines PLA organoclay aqueous dispersions stabilized by sodium dodecyl sulfate (SDS), emphasizing particle size, zeta potential, and solids content. Using a full factorial design (2(4)) and stepwise regression, predictive equations have been established to identify the dominant formulation factors and illustrate their combined effects through response surface modeling. The most promising formulation within the tested range (PLA 10.65 wt%, SDS 0.10 wt%, organoclay 3 wt%, oil-to-water ratio 1.4) was selected from the JMP Profiler using a multi-criteria optimization, simultaneously maximizing solids content while maintaining submicronic particle size. This formulation yielded similar to 13% solids, kinetically stable dispersions, and defect-free coatings. Under laboratory-scale settings, repulpability tests revealed effective disintegration (94.7% +/- 1.5% fiber recovery) without foaming. Overall, this study proposes a formulation-driven optimization technique for producing recyclable, bio-based PLA-organoclay coatings for recyclable paper packaging, guided by a design of experiments strategy.

Paper packaging coated with synthetic materials raises major environmental and health concerns. As a response, new promising approaches consist of using sustainable coatings based on nano-biocomposites. In this work, polylactic acid (PLA)/organoclays (OC) aqueous dispersions thickened by xanthan gum were applied on paper using the bar coating technique. Morphological and topographical analyses using scanning electron microscopy and laser confocal microscopy showed a smooth polymeric layer completely covering the fibrous and porous surface of the paper, resulting in a substantial improvement in the barrier properties. Water vapor transmission rates and water absorptivity had undergone a major decrease when coatings containing 3 and 5 wt% OC were used, while no significant difference was observed between the 1 wt% OC formulation and pure PLA. Moreover, coated paper showed no air porosity with 0 mL/min values recorded for all samples, thus confirming the morphology observations of the surfaces and cross-sections. Additionally, the contact angle measurements indicated a slight decrease in the hydrophobicity of the base paper when coated with PLA and 1 wt% OC. However, this reduction was reversed with the addition of 3 and 5 wt% OC, restoring the hydrophobicity.Highlights Polylactic acid (PLA)/organoclay (OC) coatings sealed and covered completely the paper's surface. Water resistance of the base paper had a major improvement due to the coatings. The porous surface of the paper was successfully sealed, leading to no air porosity. Adding 3 and 5 wt% OC resulted in excellent barrier performances. PLA/OC coatings have the potential to replace synthetic paper coatings.

Single-use plastic packaging has become a serious problem for many countries, including Canada, with millions of tons consumed annually without considering end-of-life impact. Researchers are developing sustainable alternatives to non-biodegradable plastic. While cellulose microfibers (MFC) and nanocrystalline cellulose (NFC) are common raw materials for film production, their preparation requires costly chemical treatments that cause environmental pollution. Kruger Inc. developed a method to produce cellulose filaments (CFs) with high fibrillation using only mechanical treatment. This study uses CFs to produce packaging films through handsheet forming, with cationic starch (CS) and Alkylketene Dimer (AKD) as additives for enhanced water, water vapor, and oxygen resistance. We analyzed morphological, barrier, mechanical, and optical properties using various techniques, including SEM, WVTR, WVP, OTR, contact angle, Cobb 60, burst index, tensile index, tear index, and transmittance. The films showed promising properties, with WVTR decreasing to 49.42 g/m2·day, WVP to 2.82 × 10-6 g·m/m2·day·Pa, OTR to 3.3 cc/m2·day, and Cobb value to 32.2 g/m2. After adding 3 % CS, films demonstrated good mechanical performance with a tensile index of 80.49 N·m/g, burst index of 10.93 kPa·m2/g, and tear index of 0.66 mN·m2/g. These results prove CFs' effectiveness with CS and AKD in forming films with excellent properties. CFs show potential compared to other biopolymers due to their eco-friendliness and cost-effectiveness. The production method is simple, scalable, and yields biodegradable films composed of biomass-derived materials.

The traditional use of single-use plastics in the packaging sector is limited by pollution, non-recyclability, and non-biodegradability. Replacing it with recyclable, biodegradable, and compostable materials such as cellulose has become vital. In this study, mixtures of refined kraft pulp and cellulose filaments were used to produce paper with good barrier properties. The results showed that cellulose filaments significantly improved the barrier properties of the handsheets without the use of other chemical agents. The water vapor transmission rate (WVTR) of samples produced from refined kraft pulp alone was 177 g/m2. day, which significantly decreased to 77 g/m2. day by the addition of 80 % cellulose filaments owing to the formation of a complex network of physical and chemical bonds between the fibers. The water barrier also improved significantly as the Cobb60 value decreased from 87 to 57 g/m2 when 80 % cellulose filaments were used. Furthermore, all the samples produced had a recyclability percentage of more than 89 %, which is an essential requirement in the packaging industry.

A new 3D composite adsorbent material has been developed using forest and fishing residues to extract Ce3 + from water. Untreated and phosphorylated Kraft pulps were combined to create the composite core, onto which chitosan nanofibers were electrospun on both sides. The material's morphology and strength properties were analyzed using SEM, EDX, FTIR, total charges, and mechanical tests. Batch tests were used to evaluate the material's Ce3+ adsorption capacity. The composite material maintained its structural integrity in water at a pH level of 6.8. The maximum Ce3+ adsorption achieved was 63.41 mg/g in 60 min at room temperature and a pH of 6.8. The adsorption occurred through chelation with chitosan and electrostatic interactions with phosphoryl groups. This innovative material shows promise for recovering Ce3+ from water, contributing to the circular economy and reducing e-waste accumulation.

Paper-based food packaging materials offer the advantages of renewability and biodegradability. However, their inherent porous structure and the hydrophilic nature of cellulose limit their resistance to water, water vapor, gas, and grease. This study presents a novel solution: a bio-based bilayer coating using whey protein isolate (WPI) and carnauba wax (CW), successfully applied to standard paper substrates using a rod coater. We investigated the effects of WPI and CW to determine their impact on the barrier and mechanical properties of the coated paper. Results demonstrated a significant improvement in grease/oil resistance, as measured by a 99.7

Porous hydrogels have been developed by chemical modification of chitosan, followed by electrostatic extrusion of the polymer solutions and stabilization of the gels by CaCl2 and genipin. The characterization of the polymers and hydrogels was completed by carrying out FT -IR spectroscopy, 1H NMR, BET, SEM and EDX spectroscopy. The Zeta potential and swelling were also studied. The residual FLX concentration was determined by HPLC analysis. The diffusion mechanism of distilled water at pH 8.5 in the structure of the gels corresponds to a Fickian diffusion mechanism and controls the swelling of the beads. The effect of the parameters (temperature, pH, initial concentration and contact time) was investigated during the FLX batch adsorption tests. The pseudo -first -order kinetic model best fitted the experimental data, while study of the sectional intraparticle diffusion model showed that the time intervals 0 <= t <= 60 min and 60 min <= t <= 180 min had the best statistical parameters. The Langmuir isotherm provided the best fit with R-2 > 0.99 compared to the Freundlich model. qmax and KL decreased with increasing temperature suggesting physisorption of Fluoxetine on the active sites. The maximum adsorption capacity was between 90 and 113 mg.g(- 1) for all adsorbents tested. The separation factor RL < 1 and Gibbs energy revealed a favorable adsorption process. The thermodynamic study suggested that the adsorption was exothermic and FLX molecules could be randomly laid at the solution/adsorbent interface. Samples PHB4 and PHB5 showed better FLX removal capacity even after five adsorption/desorption cycles.

This study focuses on the development of macroporous monoliths using cryopolymerization of sodium acrylate/carboxymethyl chitosan solutions for the adsorption of the antidepressant fluoxetine in aqueous environments. The cryogels were characterized using various analytical techniques, and the effects of pH, temperature, initial concentration, and contact time on the adsorption capacity were investigated. The surface charge of the cryogel was negative when pH(solution) > pH(PZC), and pH 8.5 was optimal for swelling rates and fluoxetine removal efficiency. The NaPA(4)-CMCs cryogel (0.5 mg.mL(-1)) showed the best adsorption performance, with the pseudo-first-order model best describing the experimental kinetics data. The intraparticle diffusion model revealed rapid diffusion through macropores and mesopores. The Langmuir model fitted well to the experimental adsorption equilibrium data, with q(max) = 80.6 +/- 3.4 mg.g(-1). The adsorption process was favorable, exothermic, and governed by physisorption, involving electrostatic, hydrogen bonding, pi-pi, and hydrophobic interactions. The binary solvent HCl (0.1 M)/methanol 1:1 v/v was effective for regenerating the adsorbent, with adsorption efficiency greater than 60 % after three cycles of reuse. The study highlights the potential of these macroporous monoliths for the effective removal of antidepressants from aqueous environments.

Water based polylactic acid (PLA)-surface modified montmorillonite (MMt) nanocomposites as biobased formulations for paper coating were successfully developed using emulsification solvent evaporation method. Electrostatic and steric stabilization mechanisms have contributed to the production of stable emulsions up to 5 months at 23 +/- 1 degrees C, revealing strong repulsive forces generated between the nanoparticles as confirmed by zeta potential (zeta) and dynamic light scattering (DLS) analysis. MMt particles were fully encapsulated by PLA as demonstrated by transmission electron microscopy (TEM) micrographs. Meanwhile the film formation process highlighted the importance of emulsifier's type and solubility in the polymer matrix, as no films were obtained when sodium oleate was used alone compared with continuous, homogeneous, and free-standing films obtained when the combination Tween 80 (80 wt%)-sodium oleate (20 wt%) was used. Scanning electron microscopy (SEM) micrographs of the cross-section's surfaces showed homogeneous dispersion of the MMt particles with no clusters or agglomerates formed. Thermal analyses using differential scanning calorimetry and thermogravimetric analysis (DSC-TGA) showed an overall reduction in the glass transition temperature (Tg) and the thermal stability of neat PLA, whoever this reduction was recovered when MMt was added due to the confinement effect. Thickened PLA and PLA/MMt emulsions using 1 wt% xanthan gum showed a non-Newtonian behavior and shear thinning flow with suitable viscosity values for paper coating applications.Highlights Development of stable PLA/organoclay nanocomposite aqueous dispersions. Steric and electrostatic mechanisms provided excellent stability. Full encapsulation of organoclay platelets in nanometric PLA particles. Formation of free-standing films from PLA/organoclay emulsions. Thickened PLA/organoclay emulsions using Xanthan gum for paper coatings. The preparation of water-based PLA/MMt nanocomposies. image

New stable water-based polylactic acid (PLA) emulsions with high water content were successfully prepared using two food-grade surfactants combined with high-shear mechanical mixing and ultrasonic treatment. PLA particle size distribution (PSD) was varied from micrometric to nanometric depending on the preparation con-ditions, as confirmed by digital microscopies and dynamic light scattering (DLS) analysis. The charged state of the PLA particle surface was evaluated using & zeta;-potential measurements as a significant factor affecting the sta-bility of PLA emulsions. An unstable PLA emulsion with a large particle size has a low negative charge distri-bution on the surface (-26 mV) compared to the stable emulsion with a high negative charge (-39 mV). This repulsion force was sufficient to prevent flocculation and subsequent aggregation. Thickened PLA emulsions with different amounts of xanthan gum (XG) display a shear-thinning behavior in the investigated concentrations up to 2 wt% under controlled shear conditions, with apparent viscosity values dependent on XG concentrations. PLA's minimal film formation temperature (MFFT) was determined by applying a linear temperature gradient from 23 degrees C to 120 degrees C. The drying above the Tg of PLA (58 degrees C) resulted in clear and continuous films. Finally, the barrier properties of PLA-coated paper revealed that increasing the thickness of the PLA coating enhanced the barrier properties of the base paper considerably. The results of air and water vapor permeability tests revealed that our PLA coating in weights ranging from 10 to 15 g/m2 is suitable for achieving superior overall barrier properties combined with smooth surfaces, which are extremely important for fabricating coated paper products in the paper industry.

Cellulose is the most abundant bio-inspired polymer derived from biomass with tremendous promises to expedite the sustainability and green transition. The interesting, fascinating, and applicable properties of nanocellulose-based structures including biocompatibility, low cost, high intrinsic strength, and extraordinary mechanical properties have opened new horizons for their advanced and emerging applications. This comprehensive review aimed to highlight different aspects of cellulose nanomaterials, ranging from preparation, classification, surface modification, nanocomposite fabrication, characterization, and their potential applications in various multifunctional, and high-performance products. This work also reviews the recent approaches applied to modify the surface chemistry of nanocellulose through functionalizing its surface hydroxyl groups to impart advanced desirable properties. Also, emerging applications of CNMs including biosensors, electromagnetic shielding, eco-friendly and sustainable packaging, and bio-medical fields are well demonstrated in this review.

Bacterial contamination of drinking water is becoming a major issue for increasing populations around the world. Current water treatment technologies based on chlorination are effective but generate toxic disinfection by-products. In this study, antibacterial electrospun chitosan-PEO/TEMPO-oxidized cellulose composite was tested for the first time for the deactivation of Gram-positive Bacillus subtilis and Gram-negative Escherichia coli bacteria and their removal by filtration from aqueous solution. Results of the disk diffusion method, confocal microscopy and scanning electron microscopy show that both bactericidal and bacteriostatic behavior against both bacteria depend on the content and mobility of protonated amino groups. It was also found that these properties are enhanced when the biocomposite is doped with copper ions. Filtration tests in a dead-end stainless-steel cell show that both bacteria are completely removed from aqueous solutions (> 95% during the first filtration and 100% after subsequent filtrations). Finally, the composites tested can be used up to three times without significant loss of permeability. However, it was CS-PEO/TOC Cu2+ bio-based composite which displayed the slightest reduction in permeability (2.20%) after three filtrations.

Metal-organic frameworks (MOFs) of different water-stable classes were prepared hydrothermally and studied for fluoride (F-) capture in aqueous medium. In the screening test, the (F-) removal for MIL-53 (Fe), UIO-66, AP -UIO-66, and MOF-235 were 95.6%, 92.3%, 74.1% and 61.5%, respectively. MIL-53 (Fe) further explored by Box-Behnken design (BBD) approach to develop a mathematical model for the prediction of F- removal under determined environmental conditions. The model demonstrated that the mixing time was the most significant operational variable in the process. To maximize the F- capture, model optimization carried out and the best operational condition obtained as pH 4, mixing time of 60 min, and MIL-53 (Fe) dosage 0.25 g/L. Monolayer adsorption onto energetically equivalent sorption sites described the F- capture by MIL-53 (Fe). The qmax obtained by non-linear Langmuir model was 3.82 mmol F- per g MIL-53 (Fe). The sorption was favorable at the different F- concentrations in the range of 10-30 mg/L, based on the separation factor. Moreover, the kinetic models revealed that the rate of adsorption controlled by the migration of F- ions through the boundary layer.

Slow pyrolysis is widely used to convert biomass into useable form of energy. Ultrasound pre-treatment assisted pyrolysis is a recently emerging methodology to improve the physicochemical properties of products derived. Biochar, the solid residues obtained from pyrolysis, is getting considerable attention because of its good physicochemical properties. Various modification techniques have been implemented on biochars to enhance their properties. Ultrasonic pre-treated wood biochar has showcased efficient surface and adsorption properties. Iron impregnated biochar is interesting as it has potentially proved the efficiency as an efficient low-cost catalyst. In this study, by combining the advantages of ultrasonic pre-treatment and iron impregnation, we have synthesized a series of Fe-impregnated biochar from softwood chips. Pre- and post-pyrolysis methods using a lab-scale pyrolyser had been implemented to compare the pyrolysis product yields and degree of impregnation. Biochars derived from ultrasound pre-treated woodchips by post pyrolysis demonstrated better impregnation of Fe ions on surface with better distribution of pyrolysis products such as biochar and biogas. The surface functionality of all ultrasound pre-treated biochars remained the same. However, post-pyrolysed samples at high frequency ultrasound pre-treatment showed better thermal stability. The chemical characteristics of these modified biochars are interesting and can indeed be used as a cost-effective replacement for various catalytic applications.

Physical and chemical modification on biochar is an interesting approach to enhance the properties and make them potential candidates in adsorption of heavy metals from water. Studies have shown that ultrasound treatments as well as alkali activations on biochar has positive impact on adsorption behaviour of the material. Base activation on biochar derived from ultrasound pre-treated woodchips were studied to understand the influence of ultrasound pre-treatment on chemical modification of biochar and the adsorption properties emerged from it. 40 and 170 kHz ultrasound pre-treated softwood woodchips were subjected to laboratory scale pyrolysis and the resulted biochars were treated with NaOH. The physicochemical properties were examined, and the adsorption experiments revealed that ultrasound pre-treatment assisted biochars have better adsorption capacity as compared to untreated biochar samples after activation. 170 kHz pre-treated sample exhibited an equilibrium adsorption capacity of 19.99 mg/g which is almost 22 times higher than that of corresponding non-activated sample. The ultrasound pre-treated samples showed improved competitive adsorption behaviour towards copper ions in comparison with nickel or lead. The overall study suggests that ultrasound pre-treated biochars combined with alkali activation enhances the heavy metal removal efficiency and these engineered biochars can be used as an effective adsorbent in the field of wastewater treatment.

Contamination of water resources by toxic heavy metals has significant impacts on environmental and human health. Their removal from aqueous media is essential to ensure water sustainability and to provide safe freshwater availability to population. Electrospun chitosan (CS) nonwoven mats are efficient at removing heavy metals from aqueous media. However, they suffer from low permeability and low-mechanical strength. They are also unable to remove contaminants in a nonselective way. A bilayer sorbent media made of a porous phosphorylated cellulose substrate covered by electrospun CS nanofibers was developed to overcome those weaknesses. The hydrophilic composite shows good water permeability and mechanical strength with appropriate thermal and chemical characteristics. Adsorption tests with Cd(II) indicate that pseudo-second order and Langmuir models best fitted experimental data, with a maximum adsorption capacity of 591 mg/g at 25 degrees C. Adsorption with multielement samples containing Cr(VI), Cu(II), Cd(II), and Pb(II) also reveal their capability to remove them in a selective way. This mechanically resistant, hydrophilic, and permeable adsorbent media was able to capture both cationic and anionic metallic contaminants.