This study investigates the regeneration performance of iron- and aluminum-pillared montmorillonite (Fe-Mt and Al-Mt) adsorbents synthesized from purified Algerian bentonite. Pillaring was achieved using preformed iron and aluminum hydroxyl polycations to enhance the clay's structural and adsorption properties. Comprehensive characterization was conducted via x-ray, Fourier-transform infrared spectroscopy, scanning electron microscopy (SEM), surface charge analysis, and textural measurements. Adsorption behavior toward orange methyl (OM) was assessed under varying conditions of pH, contact time, initial concentration, and adsorbent dose. Regeneration of OM-saturated clays was evaluated using NaOH and HNO3 solutions at different concentrations. Optimal regeneration was achieved with 0.001 M NaOH for 30 min, yielding high desorption efficiency. Despite slight decreases in adsorption capacity over successive cycles, the pillared clays retained considerable reusability. Statistical physics models provided mechanistic insight into the adsorption process and confirmed enhanced dye uptake associated with structural modifications. These findings support the application of these pillared clays as cost-effective, regenerable adsorbents for organic contaminant removal from aqueous systems, contributing to sustainable wastewater treatment technologies.

A series of macroporous hydrogel pillared-clay (MPHPC) solids was developed using iron-pillared clay (Fe-PC). These solids were encapsulated in sodium alginate hydrogel either with or without polyvinyl alcohol (PVA) and calcium carbonate. The macroporous network of the MPHPC materials was created through an acidification step using an HCl solution. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), and X-ray fluorescence (XRF) were employed to characterize the encapsulated MPHPC composites. In addition, a series of experiments using Malachite Green (MG) was conducted to assess their sorption performance. XRD results confirmed that the two polymer molecules did not intercalate into the interlamellar spaces of the clay. FTIR results confirmed the presence of alginate (-OH and-COO-groups) and the silicate chain (-Si-O bond) in the solid. SEM images revealed that the MPHPC sorbents exhibited a highly porous structure. Comparisons based on the EDS and XRF results before and after the sorption of MG onto beads (S2 and S3 samples) show that both analyses established the presence of chlorine on the surface of the samples after MG sorption. A comparative study of kinetic models, including the Elovich model, the Weber-Morris (W-M) intraparticle diffusion model, the pseudo-first-order (PFO) model, and the pseudo-second-order (PSO) model, was performed. The kinetic results indicated that the MG sorption on the MPHPC sorbent was well described by the PSO model with sorption occurring through both surface sorption and intraparticle diffusion. Fitting the experimental MG sorption data to the Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin isotherm models revealed that the Langmuir and Temkin models provided the best fit for the MPHPC matrix prepared with PVA. At the optimal pH of 8, the Langmuir isotherm results indicated maximum MG sorption capacities of approximately 130 and 182 mg g-1 for samples corresponding to MPHPC prepared with and without PVA, respectively. Studies on the reusability of MPHPC sorbents using 90% ethanol as a desorbing agent showed that they can be used for three cycles with an insignificant drop in removal efficiency.

This study investigates the preparation of a novel type of hydrogel beads derived from chemically activated Algerian thyme, a plant traditionally consumed as an herbal infusion and recognized for its digestive and anti-influenza properties. These hydrogel materials were developed for the adsorption and removal of excess diclofenac (DF) from aqueous media. The prepared activated thyme particles that were immobilized by encapsulation in sodium alginate gel were characterized by scanning electron microscopy (SEM), X-ray scattering (XRD), nitrogen physisorption (BET), thermal study (ATG/ATD), Fourier Transform Infrared Spectroscopy (FTIR), and pH point of zero charge (pHpzc). In batch mode, the adsorption process showed pseudo-first-order reaction kinetics while the adsorption isotherms showed a strong correlation with the Langmuir and Temkin adsorption isotherms, thus indicating the presence of a heterogeneous surface on the prepared hydrogel beads, which contained sites with different affinities for DF. An optimal diclofenac uptake capacity of 280 mg. g-1 was obtained under pH 6, using an initial diclofenac concentration of 10 mg. L-1, a beads dosage of 100 mg, an agitation speed of 200 rpm, and a contact time of 5 h. In continuous system on column, breakthrough profiles were obtained for a range of adsorption parameters and then exploited with the fixed bed models of Adams-Bohart, Yoon-Nelson and Thomas that provided an appropriate fit. Experimental data examining the influence of pH, DF initial concentration, and beads dosage were statistically evaluated using ANOVA.

The objective of the study was to synthesize new adsorbent materials in uniform films, based on two synthetic iron (oxy)hydroxides with polyvinyl chloride. A sol–gel process was employed using two deposition techniques: spin coating and dip coating. These films were characterized using a combination of analytical techniques to confirm the successful incorporation and homogeneous distribution of iron (oxy)hydroxides within the PVC matrix. X‐ray fluorescence analysis revealed a significant reduction in Fe 2 O 3 content from ∼98.2% in pure goethite and ∼97.7% in HFO to 54.2% and 47.6%, respectively, in their composite films. Textural analysis showed reductions in specific surface areas from 151.3 to 14.76 m 2 g⁻¹ for (HFO/PVC) composites and from 135.3 to 13.11 m 2 g⁻¹ for (goethite/PVC) matrices. Adsorption studies of 4‐nitrophenol and methyl orange were performed in batch mode, both in single‐component systems and binary mixtures. Kinetic studies showed that the pseudo‐first‐order model provided the best fit ( R 2 ≥ 0.92). Adsorption isotherms revealed that the Freundlich model best described single‐component systems, indicating heterogeneous surface adsorption. In binary systems, three adsorption weight ratios (r = (4‐nitrophenol/ methyl orange) = 1/3, 1 and 3 w/w) showed that the Sheindorf–Rebhun–Sheintuch (SRS) model, accurately described simultaneous adsorption, suggesting a cooperative adsorption mechanism.

This study focused on the adsorption of malachite green onto clays in aqueous solutions. The results were simulated using an artificial neural network (ANN). Materials were characterized using X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, X-ray diffraction, and nitrogen adsorption at 77 K. Sorption experiments were carried out in the discontinuous mode, examining the influences of contact time, adsorbent dose, solution pH, initial concentration, and temperature. The neural network topology was 4–10-1. The results predicted by this model show a good agreement with experimental data. The mathematical modelling of the obtained isotherms revealed that the Freundlich isotherm model is perfectly consistent with the experimental data. The thermodynamic parameters, such as the changes in Gibbs free energy, enthalpy, and entropy, are determined. The MG adsorption is physical, spontaneous, and exothermic for both adsorbents. This method, therefore, appears as an effective means to achieve the objectives of sustainable development of the United Nations.

In this study, a new Cellulose- Nano-Crystals (CNC) was developed from industrial cotton waste that was first treated by hydrolysis acid, then encapsulated in the form of gelled beads in an alginate gel containing Eggshells powders (CNC/Eg-A). The objective is to remove Brilliant Cresyl Blue (BCB) and/or Titanium Yellow (TY) dyes, first in simple monosolute systems then in (BCB/TY) binary mixtures. XRD analysis showed that the CNC and CNC/Eg-A samples have crystallinity indices (XC) of about 73.18 and 33.96

In a recent article in this journal, Mohery et al. [WASP (2025) 236:484] synthesized a new aminophosphonate with a symmetrical structure. They tested it as a sorbent for Cu(II) and examined its microbiological properties. Here, we discuss the interpretation of the original article's experimental results. First of all, we demonstrate that the speciation of Cu(II) under the chosen experimental conditions (pH = 3.5) is erroneous. Regarding the modeling of sorption experiments, the use of kinetic or isotherm equations in linear form is not recommended, as it can lead to errors in parameter determination. Unfortunately, the original authors relied on secondary sources with erroneous equations, casting doubt on the validity of the fitted parameters. Furthermore, the two-step nature of their isotherm curve should have been analyzed using a more appropriate model rather than classical equations. We determined the lipophilicity parameter LogP = 4.75 for the aminophosphonate, which allows us to discuss its behavior. However, the microbiological techniques (anti-oxidant, anti-bacterial assays) described in the original article lack sufficient methodological detail, as the results are presented mainly as images of the inhibition zones. Further experimental validation is needed to reach solid conclusions given the low activities detected. These errors and inaccuracies require the authors of the original article to publish a correction. We acknowledge the originality and interest of the article and offer this comment as constructive criticism. Our aim is to contribute to the scientific dialogue and enhance the clarity and applicability of the authors’ findings.

This paper reports the preparation of a new class of eco- friendly sorbents as well as the study of the continuous dynamic sorption of diclofenac (DF) chosen as a model representative of pharmaceutical pollutants. Biomass based on palm waste was used as base material in the presence of 27% commercial polymer carbopol as granular support, 10% tween 80 as surfactant and NaOH in the preparation of hydrophobic and organophilic effective sorbent grains. Multiple experiments were conducted to investigate the impact of initial diclofenac concentration (20–50 mg/L), flow rate (1.11–1.82 L/h), and column height (10–15 cm) on the breakthrough curve. The maximum adsorption capacity was found to be 137 mg/g under a flow rate of 1.11 L/h, column height 15 cm and inlet concentration of diclofenac of 20 mg/L. The experimental data obtained data were fitted using the empirical models of Thomas, Yoon - Nelson and Adam-Bohart. The reusability assessment demonstrated the potential for reusing this active biomass for a minimum of three adsorption –desorption cycles. The breakthrough curves indicated a positive correlation between breakthrough time and column height, while initial diclofenac concentration and flow rate exhibited negative correlations. The utilization of the Thomas model effectively described the sorption process, supported by a highly satisfactory correlation coefficient (R² > 0.98). However, a marginal decrease in the sorption capacity of diclofenac was observed with the number of sorption-desorption cycles, with reductions of 24%, 10%, and 5%, respectively.

This study evaluates the performance of a new geomaterial (GEOM) based on sodium montmorillonite clay (Na-Mt), local activated carbon (CAC) and fine powder local cement (Chlef plant western Algeria) to remove ammonia from fish farming in a recirculating aquaculture system. The aqueous ammonium (NH4 +/NH3) adsorption efficiency of GEOM was compared with its two principals` constituents (Na-Mt and CAC) and another commercial activated carbon (CAG). The results of X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were used to assess the chemical and physicochemical properties of studied adsorbents. The maximum adsorption capacity of NH4 + on GEOM of about 15.57 mg. g-1 seems to be similar to that of Na-Mt 16.82 mg. g-1. The study of solution pH showed that the best NH4 +/NH3 removal efficiency was at pH=6 for both GEOM and Na-Mt. The efficiency of GEOM for ammoniacal nitrogen (NH4 +/NH3) removal was 79.3% in ultrapure water, 94.05% in seawater and 97.5% in real aquaculture wastewater. Thus, the proposed material, GEOM, can be used as a filter material in a bio-filtration process to treat aquaculture wastewater in a real-world context.

Photocatalysis is an eco-friendly technique used to oxidize various organic contaminants in polluted waters. Previous research has shown that the photocatalytic process effectively degrades persistent organic pollutants such as dyes and pharmaceuticals. However, partial photocatalytic degradation always generates various intermediate products that are sometimes more toxic than the original molecules. These intermediates are highly toxic to aquatic life and must be treated and disposed of before being released into the environment. This study aims to evaluate the toxicity of tetracycline (TC) and its intermediate compounds using the Brine Shrimp (Artemia salina) model system. Toxicity was assessed using the “Lethality Assay” on Brine Shrimp samples. The number of dead nauplii was counted after 24 and 48 h of exposure to TC samples before and after photocatalytic treatment. The first part of the experiment concerned the determination of the 50

The rapidly expanding world of nanotechnology is captivating researchers in fields as diverse as health, nutrition, agriculture and the environment. Many works have been carried out over the last ten years on nanoparticles in the field of water treatment due to their unique properties. They can potentially improve adsorption, catalysis, magnetic separation and promising processes.

Modeling and simulation of fluid flow are considered essential for engineers and scientists to better understand, develop, optimize, and control a process. In the fields of the microfluidics and porous media, researchers are constantly trying to develop innovative geometry microchannel to achieve optimum effectiveness. The difficulty in fabricating microchannel also leads to increases in manufacturing costs. Therefore, it becomes difficult or even impossible to use such structures in tests. However, programs for numerical simulation show their advantages in terms of functionality, pricing, and usability. This investigation was focused on a numerical analysis of fluid flows using cider vinegar residues as the porous medium and employing COMSOL Multiphysics Software. The porous medium was modeled from scanning electron microscopy images of the residues, which showed that the surface was irregular and porous. These images were converted to a binary file using ImageJ software and then saved as DXF file utilizing Inkscape software to make them geometry readable in COMSOL. The fluid flow was simulated for different cases. The inflow of a Newtonian fluid into a porous medium was mathematically described by the Navier-Stokes equation and the continuity equation. The results demonstrated the application of boundary conditions, thus making it possible to trace the streamlines, velocity, and pressure.

Two classes of hybrid reinforced porous gelled beads were fabricated based on sodium alginate (SA), polyvinyl alcohol (PVA), aluminum-pillared montmorillonite (Al-Mt) and calcium carbonate (CaCO3). F1 (SA, PVA and CaCO3) and F2 (SA, PVA, Al-Mt and CaCO3) were generated and used for the removal of Cd2+ ions from aqueous solutions. A secondary aim was to enhance the mechanical stability of the alginate gels beads and increase the specific surface area of the adsorbate. The beads were characterized by Fourier-transform infrared spectroscopy and by physico-chemical measurements. Results showed that the application of F1 and F2 beads by discontinuous adsorption had high adsorption efficiency with Cd2+ elimination rates of the order of 77% and 96% in 1 h, respectively. The study indicated that the effect of pH in the range (3 to 9) seemed negligible with the F1 matrix unlike the F2 matrix, which showed an increase of Cd2+ removal of 74% to 96%. The kinetic studies as well as those of the Cd2+ adsorption isotherms on these new hybrid reinforced porous beads F1 and F2 agreed well with the pseudo-second-order model and Freundlich model, respectively.

The main purpose of this investigation is to model the results related to biosorption using COMSOL (Multiphysics 4.3a), and to solve the advection-dispersion equation by using both linear and Langmuir models. A bidimensional model was then proposed to study the mass transfer in the process of copper ions sorption in a dynamic mode on cider vinegar residues. Sorption tests were realized by evaluating the influence of flow rate (0.75, 1, and 2.65 ml min-1 ), bed height (3.5, 7 and 8.5 cm), and copper initial concentration (169 and 300 mg L-1 ). For all cases, the mathematical formulation was solved by assuming that the column is homogeneous and the sorption is instantaneous. The corresponding results were exploited through breakthrough curve profiles, where it was shown that the solutions obtained by the "Langmuir COMSOL" model coincide with the experimental values. In contrast, the linear model has been unable to fit them. The optimal results were analyzed by Thomas, Adam-Bohart Yoon Nelson, and Ogata-Bank models, which proves that the Thomas method is well adapted with a satisfactory correlation coefficient (0.93). Further, the model validation was performed by determining the residual root mean square error, which was found less than 0.3, thereby indicating a reasonable concordance between the estimated and experimental points. The high sorption capacity obtained was around of 41.37 mg g-1 , which suggests that the cider vinegar residues can be exploited as a low-cost, available, and effective sorbent biomass in the field of the treatment of industrial effluents. PRACTITIONER POINTS: Cider vinegar residues (CVR) as low cost biosorbent were studied for continuous biosorption. A successful COMSOL model was proposed and validated. CVR is an effective biosorbent for copper fixed bed biosorption. High sorption capacity was around of 41.37 mg g-1 under optimal conditions.

The main objective of the proposed work was to optimize an adsorbent gel from biological material with the substitution of PVA by biopolymer extracted from cactus while maintaining the mechanical and sorption properties. The porous composite was based on cactus extract (CE) and sodium alginate (SA) and the mechanical properties and adsorption capacities of these beads were then compared with those modified using polyvinyl alcohol (PVA) and calcium carbonate (CC), respectively. Twenty formulations, based on CE, SA, PVA and CC, have made it possible to prepare, in accordance with an experimental design conducted in Mode 6, four major classes of beads. The three responses used to assess the evolution in bead performance were: the breaking point of the beads, bead rigidity based on a rheological study and the adsorption capacity of pentachlorophenol (PCP). The analysis of these responses showed that CE exerted a positive effect on both the mechanical strength (400-2200 Pa) and rigidity (5%-11%) of the beads, similar to that of PVA with the conservation of bead adsorption capacity (80-120 mg g(-1) of dry matter). The beads, based on CE and SA, revealed their regular shape with a porous structure and good chemical and physical stability. The FTIR spectral analysis suggested that the interactions between SA and CE take place via hydrogen interactions and/or covalent bonds between the hydroxyl and carboxyl groups.

This study reports the preparation of catalyst grains based on oxyhydroxides of iron and zirconium via the coprecipitation method and their application in the degradation of 4-nitrophenol. The morphology, microstructure, and surface composition of these catalysts were characterized by scanning electron microscopy, X-ray diffraction, nitrogen physisorption, and Fourier transform infrared spectroscopy. The catalytic activity of the grains was assessed in the degradation of 4-nitrophenol in a heterogeneous system at different operating conditions. Degradation rates up to 93% were obtained after 4 h of contact time where the catalytic activity of tested materials was higher at pH 7 than in acidic and basic conditions. Amorphous iron hydroxide with a ratio of 75% Zr+25%Fe showed the best catalytic properties. These novel materials are an interesting alternative for facing the water pollution caused by organic compounds.

In many industrial sites, a series of various organic and inorganic co-contaminant species are simultaneously present in their aqueous discharges. This therefore justifies the recent interest and the choice of binary and ternary adsorption of three co-contaminant species to understand their competitive effects. Here we introduced two types of theoretical adsorption models, recently developed by us: multi-logistic distribution and statistical physics. These modeling approaches were applied in order to understand the adsorption of two cationic dyes (Rhodamine B, RB and Malachite Green, MG) and one metal cation (Cadmium Cd(II)) on granulated activated carbon (GAC). New experimental batch adsorption data were obtained with these mono-component, binary and ternary systems. The adsorption capacities of all these pollutants decreased from single to binary and ternary systems. Moreover, although Cd(II) did not lead to any notable competitive effect, when the two dyes were simultaneously present (binary and ternary systems) there was an increase in the adsorption capacity for RB and a decrease for MG, thus indicating a complex removal process due to different adsorption effects. Both models were used to calculate affinities, dissociation constants, steric and energetic parameters to characterize the single, binary, and ternary adsorption of tested pollutants. Modeling results indicated that the number of captured adsorbates per active receptor site of GAC decreased from single to binary and ternary systems, signaling a competitive effect for the same adsorption site. Based on this parameter, the adsorption orientation of these three pollutants was described. Interestingly, the models provided adsorption energies which allowed the characterization of the interactions between the adsorbates and the adsorbent surface. Calculated adsorption energies showed that the adsorption in single, binary, and ternary systems was associated to physisorption.

Composite granules (named Fe-PILMG) based on both an Algerian montmorillonite with iron and gluten as an inert binder are prepared and used in the elimination of cadmium by dynamic adsorption in fixed bed columns. This study is essentially focused on the adsorption of Cd (II) in dynamic mode on a fixed bed based on Fe-PILMG sorbent granules followed by a study on the chemical regeneration of these new saturated adsorbents. The various regeneration tests are carried out with NaOH solution. The experimental data on the elimination of Cd (II) (pH = 7, T = 20 +/- 2 degrees C) in dynamic mode reveal that this adsorption is considerably influenced by the flow rate (2 to 5 mL min-1), Cd (II) initial concentration (20 to 50 mg L-1), and bed height (5 and 15 cm) and that a modification of each of these parameters can strongly influence the efficiency of this process. The assessment of the experimental data is carried out using the Thomas, Yoon & Nelson and Bohart-Adams models. The fit of the experimental and modeled breakthrough curves indicates excellent applicability of the mathematical models studied which is confirmed by high values of the correlation coefficient for the Bohart-Adams model (R-2 = 0.99, model constants N0 = 634.87 mg L-1, kBA = 0.079 (L (mg min)-1 ), from Yoon and Nelson model (R-2 = 0.97, zeta = 413.03 min, KYN = 0.0049 min-1), Thomas (R-2 = 0.98, q0 = 49.03 mg g-1, KTH = 5.21 mL (mg. min)-1).

A new generations of hydrophobic and organophilic grains is prepared by granulation and compacting using mixtures based on a surfactant-modified iron-pillared montmorillonite and wheat proteins. The prepared grains were used in the removal of organic pollutants (humic acids, Malachite green MG and Rhodamine B RB) and heavy metals (copper and cadmium). The study was performed using batch tests by statistical analysis with PAST program. Obtained results have shown the high efficiency of these new composite sorbents towards organic pollutants compared to inorganic ones.

This work aims to investigate the malachite green photodegradation by CuO-modified and unmodified silicon nanowires (SiNWs) as photocatalysts in the presence of peroxymonosulfate (PMS) under UV or Visible light irradiations. SiNWs were synthesized by one-step metal assisted-chemical etching of silicon substrate in aqueous (HF/AgNO3) solution and modified with CuO nanoparticles using an electroless deposition technique. The as-prepared samples were characterized by scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. Obtained results revealed that the Cu-modified SiNWs exhibit higher photocatalytic activity under both UV and visible irradiations compared to unmodified ones. The addition of PMS to the mixture (photocatalyst/MG) leads to an increase in this activity resulting in almost total discoloration of the order of 98% for an irradiation period of 100 min.