Molecular simulations of the tunable pore structure models elucidate the adsorption of sulfamethoxazole on biochar.

Construction of bilayer asymmetric humidity-regulating packaging using 2-hydroxypropyl trimethyl ammonium chloride chitosan for enhanced strawberry preservation.

Food-grade abalone muscle hydrolysates as affected by high-pressure homogenization: An in-depth investigation into air-water interfacial behavior of their proteins.

Glucuronoxylan-based quince seed mucilage for efficient Ni(II) removal: Isotherm, kinetic, and thermodynamic insights.

Cationic chitosan/silsesquioxane hybrid cryogel with antibacterial activity for efficient removal of Cr (VI).

ABSTRACT In this study, methylene blue (MB) adsorption onto tomato stem (TS) was comprehensively investigated, and the potential of TS as an effective biosorbent in wastewater treatment was examined. Additionally, the predictive power of the Artificial Neural Networks (ANN) model on the adsorption isotherms, kinetics, and thermodynamics was evaluated and compared with experimental calculations. The adsorption experiments were carried out in the batch system with MB solutions at various initial concentrations (20, 40, 60, 80, and 100 mg/L), temperatures (298, 308, and 318 K), and contact times (up to equilibrium). The adsorption kinetics were examined using nine different initial concentrations predicted by the ANN, and detailed kinetic analyses were performed at minute-level resolution. The ANN model successfully predicted the experimental results for untested concentrations and contact times. However, more experimental data were needed to conduct a rigorous thermodynamic analysis with the ANN model using an appropriate evaluation metric. The Langmuir isotherm provided good agreement at 298 and 308 K, while the ANN model showed a stronger correlation with the Temkin isotherm. The novelty of this study is the first comprehensive assessment of MB adsorption by the TS biosorbent by integrating the ANN model with both the adsorption equilibrium and kinetic analysis.

This study evaluated the sustainability of removing phenolic compounds from olive mill effluents using a nanobiochar synthesized from olive pomace. Catechol, tyrosol, hydroxytyrosol, and homovanillic alcohol were chosen as model pollutants due to their presence in agro-industrial wastewater. The surface morphology, elemental composition, crystallographic structure, functional groups, porosity, and thermal stability of the nanobiochar were investigated by SEM, EDX, XRD, FTIR, BET analysis, and TGA/DTA. The developed nanobiochar exhibited a predominantly amorphous carbon structure, enriched in carbon (85.6%), with localized graphitic domains. Its mesoporous architecture (SBET = 15.478 m2 g−1; Dp = 2.14 nm) promotes accessibility to active sites, while its thermal stability confirmed its suitability for adsorption applications. In this batch adsorption study, the technological aspect considered is the influence of operating parameters on adsorption efficiency, using kinetic and equilibrium models. Pseudo-first-order and pseudo-second-order kinetic models, as well as Freundlich and Langmuir isotherms, were used to analyze the experimental data. The pseudo-second-order model proved to be the most suitable for describing adsorption, suggesting that the process is primarily dominated by chemisorption. Similarly, the Langmuir model gave the least satisfactory results regarding equilibrium data, indicating monolayer adsorption on homogeneous active sites. The adsorption capacity of phenolic compounds was variable. The highest adsorption capacities were observed for catechol (250 mg g−1), tyrosol (19.23 mg g−1), homovanillic alcohol (15.38 mg g−1), and hydroxytyrosol (13.16 mg g−1). The results of this research indicate that adsorption affinity depends on molecular structure and electronic properties. Furthermore, computer modeling based on molecular simulations and electronic descriptors was performed to explain the adsorption mechanism. Linear regression, principal component analysis, and elastic regression revealed strong correlations between adsorption parameters and molecular descriptors. These results demonstrate that olive pomace-based nanobiochar is an environmentally friendly adsorbent for the treatment of phenolic effluents, with adsorption primarily controlled by surface interactions.

ABSTRACT A robust metal–organic framework (MOF) material, UIO67‐PS, was synthesized by grafting sulfonic acid groups onto the UIO67‐NH 2 framework. This modification significantly enhances the electronegativity and coordination‐site density on the MOF surface, enabling threefold higher Au (III) adsorption capacity (536.4 mg/g at pH 2.0 temperature 25°C and agitation speed 120 rpm) compared to pristine UIO67‐NH 2 (168.4 mg/g). The material exhibits exceptional acid resistance and recyclability (91% capacity retention after three cycles). Density functional theory (DFT) calculations and X‐ray photoelectron spectroscopy (XPS) analyses reveal that the adsorption mechanism is governed by synergistic electrostatic interactions and chelation, wherein electron‐rich oxygen/nitrogen‐containing functional groups on the adsorbent surface coordinate with metal ions via covalent bonds to form stable five‐membered ring complexes. Kinetic studies confirm rapid adsorption equilibrium (< 240 min), while thermodynamic analysis indicates an endothermic, entropy‐driven process. Notably, UIO67‐PS demonstrates superior selectivity for Au (III) over competing ions (e.g., Zn 2+ and Cu 2+ ) in simulated e‐waste leachates. Achieving removal rates as high as 80% in real metallurgical wastewater highlights its potential for practical application. This work reveals key coordination interactions, including complexation and electrostatic attraction, within a simulated e‐waste leachate system containing competing ions such as copper and nickel. These insights advance the design strategies of MOFs for sustainable Au (III) recovery and provide a scalable platform for industrial wastewater treatment, contributing to environmental protection and the sustainable utilization of critical material resources.

Uranium contamination in groundwater is a major environmental concern due to its long half-life and chemical toxicity. We had previously developed the phosphorylated cellulose-nanocrystal-ferrihydrite (PCNCFH), a low-cost and sustainable nanomaterial, exhibiting a uranium adsorption capacity of 100 mg/g, and comprehensively characterized the adsorbent's performance and stability. In this study, we specifically focus on elucidating how environmentally relevant uranyl species such as UO2(CO3)34-, UO2(CO3)22-, and (UO2)3(OH)5+ interact with PCNCFH across the typical groundwater pH range of 5-9. Raman spectroscopy confirmed the speciation of uranyl complexes in solution, and time-dependent Raman measurements enabled us to quantify the adsorption kinetics and equilibrium adsorption capacities (qe) of each species under controlled pH conditions. We find that UO2(CO3)34- exhibits significantly slower adsorption kinetics than the other complexes at all pH values. These results were also supported by IR spectroscopy and DFT modeling, revealing fundamental differences in interaction pathways that govern uranyl binding. Raman adsorption data were found to fit a pseudo-second-order model. The findings provide mechanistic insight essential for the rational design of species-specific and pH-optimized uranium remediation strategies for water utilities.

A copper ion concentration sensor based on a chitosan/polyacrylic acid (CS/PAA)-functionalized single-mode fiber (SMF)-no-core fiber (NCF)-multimode fiber (MMF)-NCF-MMF-SMF (SNMNMS) interferometer was fabricated and demonstrated. The wavelength shift of the interference dip was used as an optical indicator of copper ion adsorption in the CS/PAA functional coating. The relationship between wavelength shift and adsorption time was well described by a pseudo-first-order (PFO) kinetic model, allowing the adsorption rate constant and equilibrium behavior to be accurately extracted under different copper ion concentrations. A quantitative correlation between wavelength shift and copper ion concentration was thereby established. The proposed sensor exhibited a sensitivity of 0.00132nm/(mg/L) and a linearity of 0.998 for copper ion concentrations ranging from 100 to 1000mg/L, with a response time of 16min. The standard deviation of the wavelength shift in repeated measurements was below 0.021nm. The wavelength shift induced by copper ion adsorption was significantly larger than that caused by other heavy metal ions, indicating excellent selectivity. Owing to the strong chelating ability of ethylenediaminetetraacetic acid (EDTA), efficient desorption and sensor regeneration were achieved, ensuring stable performance and measurement accuracy in complex environments.

Activated carbon was successfully synthesized from musk melon seeds and tested for its effectiveness as an adsorbent and photocatalyst in removing methylene blue (MB) from water. Compared to other adsorbents, it demonstrated superior removal efficiency. Maximum MB removal (94%) was observed at pH 6.0 using 0.1 g of adsorbent with initial dye concentration of 350 mg/L at room temperature (25 °C). It exhibited significant photocatalytic degradation of methylene blue, highlighting it as an efficient and sustainable dye removing agent. It was characterized using SEM, EDX, XRD, porosimetry, and FTIR techniques. FTIR showed the presence of active functional groups for binding the dye molecules, SEM, and porosimetry revealed porous structure with high surface area (800 m2g−1). XRD showed amorphous carbon structure with crystallinity, favorable for efficient methylene blue removal. Furthermore, fluorescence spectra showed strong interaction with methylene blue. The concentration of dye was analyzed by UV-visible spectrophotometry. The adsorption equilibrium data was analyzed using Langmuir and Freundlich models. Langmuir model showing better fit with maximum adsorption capacity of 193.050 mg/g. Kinetic data was evaluated using pseudo-first and second-order models, with the later providing a better correlation for the adsorption of MB. Furthermore, it exhibited significant photocatalytic activity under visible light, achieving 90% degradation of MB within 20 min. These results highlight musk melon seed-derived activated carbon as an efficient, sustainable, and multi-functional agent for wastewater treatment.

The coastal zone is a critical interface between terrestrial and marine systems, providing ecosystem services and economic value while serving as a major sink for land-derived contaminants. The identification and quantification of new pollutants (NPs), particularly antibiotics, even as trace residues, in coastal environments are necessary owing to their potential ecological and human-health risks. Given the complex, high-salinity matrices of samples from coastal zones and their low analyte concentrations, efficient sample pretreatments for cleanup and enrichment are required. Metal-organic framework-based molecularly imprinted polymers (MOF-MIPs), integrating the high porosity and surface area of MOFs with the molecular recognition ability of MIPs, have become promising sorbents for solid-phase extraction (SPE). Herein, a core-shell ZIF-8@MIP composite was facilely synthesized via surface imprinting and one-pot precipitation polymerization using ciprofloxacin (CIP) as the template and the ZIF-8 MOF as the core. The morphology, structure and composition of the composite were well characterized, and the adsorption equilibrium could be reached within 30 min, with a high maximum adsorption capacity of 151.96 mg g-1. Then, the ZIF-8@MIPs-based dispersive SPE (DSPE) coupled with HPLC-UV was developed for the simultaneous enrichment and determination of six fluoroquinolone antibiotics (FQs) in coastal zone water and biological samples. Under optimized conditions, low limits of detection of 0.060-1.440 μg L-1 and limits of quantification of 0.201-4.799 μg L-1 were achieved. Spiked recoveries in beach seawater, aquaculture wastewater, river water, and biological samples (pomfret and prawn) ranged from 92.6% to 118.9%, with relative standard deviations (RSDs) within 0.2%-6.1%. The present DSPE-HPLC study offers a simple and alternative method for NP analysis in coastal samples and could enrich the research scope of MOF-MIP-based sample pretreatment.

The efficient removal of refractory organosulfur compounds, such as dibenzothiophene, remains a critical bottleneck in achieving ultra-low sulfur diesel standards. While oxidative-adsorptive desulfurization is promising, there is a significant research gap in rationally designing adsorbents that utilize synergistic multi-metal active sites to enhance the capture of sterically hindered species. To address this, we synthesized a novel multi-metal ion-exchanged zeolite (AgNiCeY) via a sequential ion-exchange process, aiming to strategically incorporate Lewis acid sites (Ag+, Ni2+, Ce3+) within the NaY framework. BET surface area for NaY and AgNiCeY was 623 and 540 [Formula: see text] respectively .The desulfurization performance and underlying adsorption mechanisms were rigorously evaluated. Using response surface methodology (RSM) on a model fuel system (DBT in n-octane)), the optimal capacity was determined at a contact time of 55min and an oil/adsorbent ratio of 18.2ml/g. The resulting AgNiCeY adsorbent demonstrated a remarkable increase in equilibrium adsorption capacity from 12.61mg/g (NaY) to 33.26mg/g, marking a 164% enhancement. Mechanistic analysis, supported by FT-IR and electronic structure visualization, confirms that the synergy between the exchanged cations acts as Lewis acids, facilitating superior σ\sigmaσ-bond formation with the sulfur atom. Crucially, when tested under realistic conditions using real diesel fuel containing 2544 ppm sulfur, the modified AgNiCeY maintained high efficiency, achieving a 61.3% sulfur removal, significantly outperforming the parent NaY (57.8%). This study validates a novel design principle for heterogeneous catalysts, demonstrating that precise, sequential multi-metal exchange in zeolites offers a robust and scalable strategy for improving the selective adsorption of refractory sulfur compounds. Regeneration experiments were also conducted to assess the recyclability of the catalysts over multiple cycles.

The corrosion inhibition performance of expired citalopram (Cp) for carbon steel in 1.0M HCl solution was systematically evaluated using chemical and electrochemical techniques. The corrosion rate decreased significantly with increasing Cp concentration, accompanied by a corresponding improvement in inhibition efficiency, which exceeded 92% at a Cp concentration of 0.005M and a temperature of 25°C. The inhibition mechanism was attributed to the adsorption of Cp molecules onto the carbon steel surface, following the Langmuir adsorption isotherm. The adsorption equilibrium constant (Kads) decreased with increasing temperature, indicating partial desorption of Cp molecules from the steel surface. The negative values of the standard free energy of adsorption (ΔG°ads) confirm the spontaneous nature of the adsorption process. Depending on the solution temperature, ΔG°ads values ranged from - 36.16 to - 33.72kJ mol-1, suggesting that the adsorption mechanism involves a mixed physisorption-chemisorption process. The relatively high adsorption energy values further demonstrate the strong interaction between Cp molecules and the steel surface, accounting for the effective corrosion protection provided by Cp.

Kaolinite (K)-based matrices modified with manganese ferrite nanoparticles (MnFe₂O₄) were synthesized via a microwave-assisted route and evaluated as magnetically recoverable adsorbents for methylene blue (MB) removal from aqueous solutions. Structural, morphological, and compositional characteristics were investigated using X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) surface area analysis. XRD confirmed the presence of inverse spinel MnFe₂O₄, while XRF revealed a significant increase in iron oxide content, indicating successful incorporation of manganese ferrite into the kaolinite matrix. FTIR and SEM analyses supported surface modification through changes in functional groups and morphology. Batch adsorption studies demonstrated that MB removal efficiency was influenced by solution pH, adsorbent dosage, initial dye concentration, contact time, and temperature. Optimal adsorption performance was achieved at pH 5, an initial MB concentration of 40 mg/L, and an adsorbent dosage of 0.6 g/L, attaining approximately 91% removal efficiency. Adsorption equilibrium was best described by the Langmuir isotherm, indicating monolayer adsorption on a homogeneous surface. Kinetic data followed the pseudo-second-order model, suggesting that the adsorption rate was governed by surface interaction mechanisms rather than diffusion control. Thermodynamic analysis revealed that the adsorption process was spontaneous and weakly exothermic, with enhanced adsorption at elevated temperatures attributed to improved mass transfer rather than thermodynamic favorability. The MnFe₂O₄-modified kaolinite exhibited superior adsorption capacity and magnetic separability compared with natural kaolinite, along with good regeneration performance over multiple cycles. These findings demonstrate that MnFe₂O₄-embedded kaolinite matrices are promising, low-cost, and reusable adsorbents for dye-contaminated wastewater treatment.

The synthesis and application of a novel nanocomposite material for dye removal from aqueous solutions is described in this work. The nanocomposite consisted of sulfonated poly(vinylpyrrolidonium) triflate [SPVP]TfO reinforced with graphene nanosheets (G). Various concentrations of graphene (0.2-10 wt%) were incorporated into the [SPVP]TfO matrix via in situ polymerization. The resulting nanocomposites were extensively characterized using multiple analytical techniques, including FT-IR, Raman spectroscopy, XRD, SEM, TEM, and thermal analysis, confirming the successful integration of graphene and the formation of well-defined nanocomposite structures. The adsorption performance of the [SPVP]TfO-G nanocomposites for Acid Red 1 (AR) dye removal was thoroughly investigated under various experimental conditions. Optimal adsorption was achieved at pH 2 with an adsorbent dosage of 20 mg and contact time of 90 min. Kinetic studies revealed that the adsorption process followed pseudo-second-order kinetics, while thermodynamic analysis indicated the endothermic and spontaneous nature of adsorption. The Langmuir isotherm model best described the adsorption equilibrium, with a maximum adsorption capacity of 21.96 mg g-1 for AR dye. The nanocomposites demonstrated excellent performance in removing AR dye from real water samples, including seawater, wastewater, and tap water, with removal efficiencies above 93%. In addition, the nanocomposites exhibited good reusability over four adsorption cycles, highlighting their potential as efficient and sustainable adsorbents for the removal of dye pollutants from aqueous environments.

Biomass chitosan-derivative-based hypercrosslinked polymers as high-efficiency iodine adsorbents.

Co-pyrolysis tailored biochar from biowaste: Synergistic sites for ammonia adsorption.

Polyethylene and polylactic acid microplastics affect the migration of Cr(VI) and Cr(III) in acidic clay soil via distinct mechanisms.

Synergistic design of ionic liquid monomers and MOF-cellulose scaffolds for selective protein recognition in molecularly imprinted materials.