High Adsorption Performance Research Articles

Preparation of ortho-hydroxyl/carboxyl dual-functionalized hypercrosslinked polymers for highly efficient enrichment of nitrosamines with broad polarity prior to gas chromatography-mass spectrometry analysis

N-nitrosamines (NAs) are highly carcinogenic substances commonly detected in food. They demonstrate a broad spectrum of polarity, posing a challenge in finding a suitable adsorbent capable of simultaneously adsorbing and enriching both polar and nonpolar NAs with high extraction recoveries. The present study involves the synthesis of a series of carboxyl functionalized hypercrosslinked polymers, followed by a comparative evaluation of their adsorption performance towards NAs. The results demonstrated that the ortho-hydroxyl/carboxyl dual-functionalized hypercrosslinked polymer (SA-FDA-HCP), synthesized using salicylic acid as the monomer and formaldehyde dimethyl acetal as the crosslinking agent, exhibited significantly enhanced adsorption performance on NAs. The maximum adsorption capacities of SA-FDA-HCP for N-nitrosodimethylamine, N-nitrosodiethylamine, N-nitrosopyrrolidine, and N-nitrosodiphenylamine were determined to be 1.40, 4.18, 2.84, and 52.4 mg g−1, respectively. These values surpass those reported in the literature for other adsorbents. Furthermore, the polymer exhibited extraction recoveries exceeding 80 % for all four NAs, and it exhibits exceptional selectivity towards NAs. The high adsorption performance can be attributed to the synergistic effects of multiple interactions, including electrostatic, hydrogen bonding and hydrophobic interactions. Based on the synthesized hypercrosslinked polymers, a method for analyzing these NAs was developed using dispersed solid-phase extraction combined with gas chromatography-mass spectrometry. The method demonstrates good accuracy and precision within the linear range of 1 - 80 ng mL−1, while providing relative recoveries for the four NAs range from 91.1 % to 111.5 %. The intra-day and inter-day relative standard deviations are between 4.4 % and 9.8 %, as well as 5.6 % and 10.9 %, respectively. Moreover, the limits of detection fall within a range of 0.11 to 0.73 ng mL−1. These results indicate that the developed material holds great potential for the separation, enrichment and analysis of N-nitrosamines across diverse applications.

Hydrophobicity and Pore Structure: Unraveling the Critical Factors of Alcohol and Acid Adsorption in Zeolites

Adsorbing and recycling alcohols and acids from industrial wastewater is of great significance in wastewater treatment; establishing the possible quantitative relationship of alcohol–acid adsorption capacity with the struct0ures of adsorbents and exploring the key factors determining their adsorption performance is very important and challenging in environment science. To solve this difficult problem, the adsorption of C1-5 alcohols, C2-4 acids, and Fischer–Tropsch synthesis (FTS) wastewater on zeolites with similar hydrophobicity and pore structures (β and MFI), similar hydrophilicity but different pore structures (Y and MOR), and similar pore structures but significant differences in hydrophobicity (MOR vs. β and MFI) was systematically investigated. It was found that: (1) For materials with similar pore structures, increased hydrophobicity correlates with enhanced adsorption capacities for alcohols and acids. (2) For materials with similar hydrophobicity, a higher content of ultramicropores leads to increased adsorption of alcohols and acids. (3) Between pore structure and hydrophobicity, it is hydrophobicity that ultimately plays a decisive role in adsorption capacities. The adsorption behavior of zeolites in FTS wastewater exhibits a consistent trend, with β-zeolite demonstrating the highest hydrophobicity (contact angle of 105°) and the greatest adsorption capacity in FTS wastewater, achieving 103 mg/g. Following five adsorption–desorption cycles, the zeolites retained their adsorption capacity without significant degradation, indicating their excellent stability and reusability. The findings identify the critical factors determining adsorption performance and provide a solid foundation for the design and development of high-performance adsorbents for alcohol–acid adsorption.

Modulating structure of Ce-UiO-66 by introducing fluorinated terephthalic acid for enhanced removal efficiency of antibiotics: Insights into degradation kinetics and pathways

In this work, the 2-fluoroterephthalic acid with asymmetric structure and high electronegative F species was introduced in the assembly of Ce-UiO-66 catalysts to increase the defect density and enlarge pore structure for enhancement in removal efficiency of sulfamethoxazole. Owing to the strong coordination ability from high electronegative F species of 2-fluoroterephthalic acid with Ce-oxo nodes, the designed CUF exhibited improved interfacial properties (accelerated electron transfer rate, available active sites and enhanced interaction with PMS), which was favorable for the exploration and accessibility of active sites with sulfamethoxazole and PMS to decrease the adsorption barrier and accelerate PMS activation. As a result, the CUF catalysts exhibited higher adsorption capacity (173.4 mg/g) than that of CUH (117.8 mg/g), the enhanced degradation efficiency of sulfamethoxazole with a rate constant higher than 2.3 times CUH, good elimination (>95 %) of methylene blue, tetracycline and ibuprofen. In addition, the CUF/PMS system possessed satisfactory stability in wide solution pH, recycling and real water and good potential application in continuous wastewater treatment based on the designed dynamic catalytic reactor. This work provided deep insight into the design of catalysts with high adsorption performance and degradation efficiency based on the structure–activity relationship.

Synthesis and enhanced adsorption for F− by three novel high entropy LDHs using TEA-assisted hydrothermal technology

Nowadays the design, preparation and application of high entropy LDHs (HE-LDHs) has already become research hotspots. In this paper, three types of high entropy ZnCoCrMgZr-LDHs (HE-LDHs-1, 2 and 3) were successfully prepared for the first time using TEA as alkali source by simple hydrothermal synthesis, and characterized by XRD, TG, SEM, X-ray photoelectron spectroscopy, BET and zeta potential. The effect of triethanolamine (TEA) on the formation of high entropy LDHs and their adsorption behaviour for F− were investigated. Research showed that high content of TEA can maintain and provide more hydroxyl groups required for the formation of LDHs, while the introduction of high valence Zr4+ breaks the regular arrangement of LDHs themselves. Three types of high entropy LDHs have excellent adsorption performance for F− with the maximum adsorption capacities of 113.78 mg/g, 142.12 mg/g and 128.24 mg/g, respectively. They also have strong resistance to anionic interference. The adsorption process is the transition from physical adsorption to chemical adsorption in the F− adsorption process from HE-LDHs-1 to 3. The adsorption isotherm models of LDHs-1 exhibit high R2 values which shown that their F− adsorption behaviour is the result of the combined effect of physical and chemical adsorption. The adsorption behaviour of LDHs-2 and 3 is more in line with the quasi second-order kinetic model and Langmuir model, indicating that the F− adsorption process is a single-layer adsorption based on chemical reaction-controlled kinetics. The lower temperatures are more conducive to the process for all three adsorbents adsorption process generates heat. FLDHs can still re-adsorb the dye CR after four cycles of adsorbing fluoride ions. HE-LDHs exhibit high adsorption, selectivity, and good reuse performance for fluoride ions, making them promising for wastewater treatment applications.

Highly efficient adsorption of ethyl mercaptan on hierarchical porous carbon derived from rice husk

In this work, rice husk-derived hierarchical porous carbon (HPC) was developed as a high-performance adsorbent for ethyl mercaptan removal. Various characterization methods were used to comprehensively characterize the HPC adsorbent. HPC-2 exhibited an adsorption capacity of 118.1 mg/g for ethyl mercaptan at 500 ppm and a space velocity of 12000 h−1, outperforming similar materials reported previously. The high adsorption capacity was attributed to the material’s well-developed microporosity and the abundance of hydroxyl groups (–OH) on its surface, facilitating the chemisorption of ethyl mercaptan. Given the chemically adsorbed nature of sulfur compounds, N2 thermal regeneration was insufficient to fully recover the adsorbent’s performance. However, oxidative regeneration using O2/N2 (3/97 v/v) at 250 °C successfully removed these compounds and restored desulfurization efficiency, likely due to oxygen-assisted reactions on the adsorbent surface. This study provides valuable insights for effectively treating sulfur-containing odorous gases in the air.

Controlled fabrication of hierarchical porous carbon nanospheres with high doped nitrogen content for high-performance adsorbent of biomacromolecule

Constructing nitrogen-doped porous carbons with high specific surface area, rapid mass transfer channels, and positive charge is a crucial requirement for high-performance adsorbents. Herein, by the kinetic self-assembly synthesis strategy, we prepared nitrogen-doped hierarchical porous carbon spheres (N-HPCS) with adjustable pore structure, high specific surface area, and high nitrogen doping content (8.88 %). By using ethylenediamine as an assisted polymerization and assembly agent, the hydrolysis and condensation rate of tetraethyl orthosilicate (TEOS) as the silica source and the condensation rate of 3-aminophenol and formaldehyde as the phenolic resin precursor were controlled by adjusting ammonia volume as the alkaline catalyst to tune kinetic self-assembly of silica and phenolic resin components, thus achieving their simultaneous or sequential nucleus and growth. After carbonization and selective silica etching, three types of carbon nanospheres with center-radial pores, hollow center-radial pores and hollow structure were obtained. High nitrogen doping content endowed the nanospheres with positive charge. Through adsorption experiments on the bovine serum albumin (BSA) and Hemoglobin (Hb) as typical biological macromolecules, hollow carbon nanospheres with center-radial pores exhibited excellent adsorption performance for BSA(622.34 mg g−1) and Hb(759.96 mg g−1). Our fabricated N-HPCS may become a potential candidate for high-performance adsorption materials.

Role of Charge Density and Surface Area of Tailored Ionic Porous Organic Polymers for Adsorption and Antibacterial Actions.

The development of high-performance adsorbents for environmental remediation is a current need, and ionic porous organic polymers (iPOPs), due to their high physicochemical stability, high surface area, added electrostatic interaction, and easy reusability, have already established themselves as a better adsorbent. However, research on the structural design of high-performance iPOP-based adsorbents is still nascent. This study explored the building blocks' role in optimizing the polymers' charge density and surface area to develop better polymeric adsorbents. Among the three synthesized polymers, iPOP-ZN1, owing to its high surface area and high charge density in its active sites, proved to be the best adsorbent for adsorbing inorganic and organic pollutants in an aqueous medium. The polymers were efficient enough to capture and store iodine vapor in the solid state. Further, this study tried to address using iodine-loaded polymers in antibacterial action. Iodine-loaded iPOPs show impressive antibacterial behavior against E. coli, B. subtilis, and H. pylori.

Mg and Fe co-loaded biochar prepared by microwave-synergized K2FeO4 of marine biomass for efficient CO2 capture: Performance assessment and mechanism exploration

To overcome the limitations of complex preparation and suboptimal performance of CO2 adsorbents, the present work synthesized a polymetallic oxide-loaded biochar (MgO·FeOx@biochar) with good performance in one step using a green and simple method of microwave-synergized K2FeO4. MgO·FeOx@biochar-700–10-0.1 with a hierarchical porous structure, abundant adsorption sites and well-distributed basic sites was obtained by optimizing the preparation parameters, which had a good CO2 trapping performance of 4.92 mol/kg with a retention rate of 83.01 % over 20 cycles, and exhibited good selectivity for O2 and N2. CO2 capture by MgO·FeOx@biochar was predominantly driven by chemical interaction between surface adsorption sites and CO2, supplemented by microporous filling. The adsorption kinetics revealed that the CO2 adsorption rate of MgO·FeOx@biochar was influenced by the combined effect of membrane diffusion resistance and intraparticle diffusion resistance. This study established a theoretical basis and technical insight for the environmentally friendly and efficient preparation of high-performance biochar-based CO2 adsorbents.

Mitigation of Fluoride Contamination in Drinking Water Supply Sources by Adsorption Using Bone Char: Effects of Mineral and Organic Matrix

This study focused on fluoride (F−) contamination of water sources in Bahimi village, Cameroon. After the first investigation, results revealed that all water samples collected had elevated concentrations of fluoride ions (2.3 ± 0.1) mg/L to (4.5 ± 0.2) mg/L above the WHO guidelines (less than 1.5 mg/L). To mitigate the F− levels, the use of bone char (BC) as an adsorbent material was proposed and its performance was tested. BC was prepared from bovine bones at different calcination temperatures (350 °C, 450 °C, 550 °C and 650 °C) and residence times (1 h and 2 h). The prepared materials were characterized in detail by SEM/EDS, BET, FTIR, and XRD. The BET findings indicated that the surface area of BC samples decreased with increasing calcination temperature and residence time. At a lower heating temperature and holding time (350 °C, 1 h), the prepared BC exhibited a higher specific surface area (112.3 ± 0.3) m2/g and adsorption capacity for F− in the sampled water. Also, the batch adsorption experiments showed that the optimized adsorbent dose of 8 g/L facilitates the reduction in the F− level of the sampled water below the acceptable limit level (1.5 mg/L) within 5 min of treatment. The presence of Ca2+ and Mg2+ in natural water has a positive effect on the removal of F− in BC resulting in a high adsorption performance range of (72.5 ± 1.4)% to (80.3 ± 0.6)%. It was found that the adsorption of Ca2+ on the BC surface occurs via cation exchange with Na+. However, an increase in dissolved organic carbon (DOC) in the treated water limited the application of BC. Overall, the study presented a cost-effective adsorbent for the removal of this recalcitrant ion in the water source.

Energy-Efficient Separation of Xylene Isomers through Stacked 1-Aminopyrene Polymer Composite.

Developing high-performance adsorbents for energy-efficient separation of xylene isomers has important research and application value. Identification and separation of xylene isomers (PX, MX, and OX) at room temperature based on the different relative positions of two methyl groups on the benzene ring is an unprecedented attempt. Herein, 1-aminopyrene polymer (PAP) is designed and electro-synthesized composited with a supporting electrolyte as an adsorbent for the separation of xylene isomers using a multi-stage dispersed liquid-solid adsorption process at room temperature. Each -NH-pyrene-NH- unit can form a force field to identify and discriminate xylene isomer through π-π interaction combined with -CH3···-NH- interactions of different strength, thereby achieving separation of PX, MX, and OX isomers by amplifying the slight differences in the adsorption capacity and diffusion rates. The density functional theory (DFT) simulations provide a more quantitative analysis of the adsorbate-adsorbent interactions to illustrate PX > MX > OX order of adsorption selectivity. This study may offer an alternative strategy for the precise designing of energy-efficient and adsorption-based separation materials.

In-situ growth of Fe-MOF on magnetic materials by self-template method to enhance practicality and removal of tetracycline antibiotics from aqueous solution

In this work, core–shell structured Fe3O4@PCN-333 (Fe) composite was constructed using a self-template method, in which Fe3O4 microspheres not only serve as magnetic centers but also provide Fe (III) for the preparation of PCN-333 (Fe). PCN-333 (Fe) uniformly grew as a shell on the surfaces of the microspheres, and the shell thickness was approximately 38 nm. The composite exhibited high adsorption performance, with maximum adsorption capacities of 471.7, 303.3 and 314.5 mg/g for chlortetracycline, tetracycline and oxytetracycline, respectively. The adsorption of tetracycline antibiotics (TCs) was based on the Langmuir and pseudo-second-order model, and external diffusion and pore diffusion were the rate-limiting steps in adsorption. The strong adsorption capacity was attributed to the mechanism of π–π interaction, coordination bonds, electrostatic interaction, hydrogen bonding, and van der Waals force. Fe3O4@PCN-333 (Fe) composite displayed good stability in the aqueous solution, strong TCs adsorption capacity, high selectivity, anti-interference performance for adsorbing TCs, fast recovery with external magnetic field, reusability, thus effectively reducing the cost for removing water pollutants. These features make the composite a potential material for removing TCs in the environment.

The high adsorption performance of banana (Musa ABB Cv. Kluai ‘Namwa’) beaded materials modified with zinc and magnesium oxides for cadmium removal

Wastewater contaminated with cadmium is a concern because of its toxicity, persistence, and bioaccumulation to the environment, ecosystem, and human health, so it is required to remove cadmium(II) ions before releasing them to receiving water. Banana powder beads (BPB), banana powder doped ZnO beads (BPZB), banana powder doped MgO beads (BPMB), and banana powder doped ZnO + MgO beads (BPZMB) were synthesized as the novel cadmium adsorbents, and their characterizations, cadmium adsorption performances, cadmium adsorption patterns and mechanisms, thermodynamic study, and reusability were investigated. BPMB had the highest specific surface area of 16.60 m2/g and the smallest pore size of 1.69 nm than other materials. BPB was an amorphous structure, whereas BPZB, BPMB, and BPZMB were crystalline structures presenting their specific metal oxide peaks of ZnO or MgO. They were coarse surfaces and had a spherical shape consisting of C, O, Ca, Cl, and Na. Their main functional groups were O–H, C–H, C=O, C–O, and N–H. The points of zero charge of BPB, BPZB, BPMB, and BPZMB were 5.37, 6.75, 9.87, and 9.43. The cadmium removal efficiencies of BPB, BPZB, BPMB, and BPZMB were 89.18%, 96.62%, 99.59%, and 97.85%, and their qm values were 90.09, 232.56, 454.55, and 303.03 mg/g, respectively. Thus, the metal oxide helped to improve material efficiency, especially MgO. The Freundlich and pseudo-second-order kinetic models were good fit models for describing their adsorption patterns and mechanisms. The increasing temperature affected to decrease their cadmium adsorptions. They could be reused in more than 3 cycles of more than 73% of cadmium adsorption. The electrostatic interaction played an important role in describing their cadmium adsorptions. Therefore, BPBM was a good cadmium adsorbent for application in industrial wastewater treatment since it had a higher performance of cadmium adsorption than other materials.

A green strategy to realize the high value utilization of lignin for hydrogel formation

Grafting lignin extracted from pulping black liquor onto hydrogel not only endows hydrogel with strong adsorption capacity, but also realizes the high value utilization of lignin, thereby alleviating the environmental pressure caused by the exhaust gas generated by direct combustion of black liquor. However, those lignin fragments have lost generous active functional groups as the high temperature polycondensation during industrial production, restricting the improvement of lignin-based hydrogel adsorption capacity. Herein, we propose a strategy combining amination and oxidation to prepare lignin derivatives with low molecular weight and high activity groups. The introduced amino groups promote the Cα-Cβ cleavage of β-O-4 unit and the oxidation treatment converts S-unit hydroxyl to carboxyl. The hydrogel obtained by grafting aminated-oxidized-lignin shows satisfactory adsorption performance with a methylene blue adsorption capacity of 697.47 mg/g (vs. 195.12 mg/g for pristine hydrogel). The retention ability has also been greatly improved that only 0.43 % of the adsorbed methylene blue is released even after 96 h (vs. 5 % within just 12 h for pristine hydrogel). This work not only provides a new strategy for the high-value utilization of biomass resources, but also offers a new idea for the preparation of hydrogels with high adsorption performance.

Structural design and performance correlation of porous Poly(ionic liquid)S for 2-bromophenol adsorption

The demand for bromophenol is on the rise, driven by its extensive applications in industries, including human medicine. This surge in demand has spurred the development of eco-friendly methods for bromophenol recovery and the synthesis of new, low-toxicity compounds. In our study, we prepared a novel poly(ionic liquid) (PIL) featuring a benzene ring. The synthesis of this PIL involved using benzyl alcohol as the primary crosslinking agent, dimethoxymethane as an auxiliary crosslinking agent, and an imidazolium-based ionic liquid monomer, [Dimbb]Cl₂, for the adsorption of 2-bromophenol from aqueous solutions. We designed the PIL to be a high-performance and sustainable adsorbent by optimizing its specific surface area and pore structure. Structural analysis revealed that the PILs have a highly rich micro-mesoporous structure. The adsorption kinetics conformed to pseudo-second-order kinetics, reaching equilibrium in just 6 min. According to the Langmuir model, PIL-1 demonstrated a remarkable maximum adsorption capacity of 434.71 mg/g for 2-bromophenol. Quantum chemical calculations suggested that the adsorption mechanism involves processes such as pore filling, hydrogen bonding, electrostatic interactions, and π-π interactions. Furthermore, the adsorbent can be effectively recovered at least five times using anhydrous ethanol as the desorption agent, while maintaining an adsorption efficiency exceeding 90 %.

Anthill clay activated Ocimum gratissimum extract for effective adsorption of methylene blue and chromium (VI) ion from wastewater: Insights into the adsorption isotherms, kinetics, thermodynamics, and mechanisms

The removal of methylene blue (MB) dye and hexavalent chromium (Cr(Vl)) ions from water bodies have necessitated the search for a promising adsorbent material with high adsorptive performance, facile operation, and economical. Here, a novel adsorbent was prepared by activating anthill clay (AC) with Ocimum gratissimum leaf extract (OG@AC) by ultrasonic strategy method to eliminate MB and Cr(Vl) from the aqueous environment; however, the activation strategy serves as an important factor that influenced the adsorptive performance towards MB and Cr(Vl). Furthermore, a high BET surface area of 120.48 m2/g was measured for OG@AC which is attributed majorly to the green activation strategy. The SEM micrograph of OG@AC was seen to have displayed a leaf-like plate formed by quartz and kaolin. In the batch experimental study, the MB and Cr(Vl) adsorption capacities towards OG@AC were determined to be 227.52 and 143.45 mg/g, respectively. Also, the adsorption kinetics and isotherms models results revealed that the adsorption process of OG@AC towards MB and Cr(Vl) was best described by pseudo-first-order and Freundlich models, suggesting that the adsorption process involves a multilayer physisorption. Moreso, thermodynamic results revealed the adsorption process is feasible, spontaneous, and endothermic in nature. The OG@AC exhibited an outstanding regeneration ability and stability towards MB and Cr(Vl) by maintaining a removal efficiency of 79.11 % and 81.20 % even at the tenth successive adsorption-desorption cycles. Overall, this research sheds more insight on how anthill clay is activated using a feasible design and green chemical (Ocimum gratissimum leaf extract) to enhance its adsorptive performance towards MB and Cr(Vl), which can broaden its wide application in the real world.

Amine-impregnated elastic carbon nanofiber aerogel templated by bacterial cellulose for CO2 adsorption and separation

Carbon aerogel has become a promising electrode material for CO2 capture and capacitor due to its large specific surface area, well-developed pore structure, adjustable porosity and ultra-high specific power. However, most of the carbon-based materials suffer from poor mechanical properties, low recycling efficiency, and low adsorption capacity, making it difficult to be put into industrial applications on a large scale. Bacterial cellulose (BC) has an ultra-fine reticular structure, a modulus of elasticity that is several to more than ten times that of typical plant fibers, and high tensile strength. In this paper, BC was treated by unidirectional freeze-drying method, and the aerogels with ordered honeycomb pore structure were constructed by unidirectional growth of ice crystals, and the pyrolytic chemical properties of BC were adjusted by using (NH4)2SO4, which effectively prevented the shrinkage and deformation of materials during carbonization, and successfully prepared elastic nanocarbon fiber aerogels. At the same time, the introduction of (NH4)2SO4 made the material realize N doping in the carbonization process, providing more adsorption sites, which was conducive to the adsorption of CO2. Finally, the carbon fiber nanoaerogel was modified by TEPA to further improve its adsorption selectivity for CO2. The prepared elastic carbon nanofiber aerogel (CBCNT) has high CO2 adsorption performance and high selectivity, and its CO2 capture capacity is up to 4.88 mmol/g. At the same time, its capacitance also reached 246F/g.

Preparation of highly graphitized porous carbon and its ethane/ethylene separation performance

The efficient separation of ethane (C2H6) and ethylene (C2H4) is crucial for the preparation of polymer-grade C2H4, necessitating the development of highly selective and stable C2H6/C2H4 adsorbents. Highly graphitized porous carbon, denoted GC-800, was synthesized by polymerization at room temperature followed by carbonization at 800 °C using phenolic resin as the precursor and FeCl3 as the iron source. Vienna Ab-initio Simulation Package (VASP) calculations confirmed a higher binding energy between C2H6 molecules and graphitized porous carbon surfaces, so that a high degree of graphitization increased the adsorption capacity of porous carbon for C2H6. However, catalytic graphitization using Fe at high temperatures disrupted the microporous structure of the carbon, thereby reducing its ability to separate C2H6/C2H4. By controlling the carbonization temperature, the degree of graphitization and pore structure of the porous carbon could be changed. Raman spectra and XPS spectra showed that the GC-800 had a high degree of graphitization, with a sp2 C content as high as 73%. Low-temperature N2 physical adsorption measurements estimated the specific surface area of GC-800 to be as high as 574 m2·g−1. At 298 K and 1 bar, it had an equilibrium adsorption capacity of 2.16 mmol·g−1 for C2H6, with the C2H6/C2H4 (1:1 and 1:9, v/v) ideal adsorbed solution theory selectivity respectively reaching 2.4 and 3.8, significantly higher than the values of most reported high-performance C2H6 selective adsorbents. Dynamic breakthrough experiments showed that GC-800 could produce high-purity C2H4 in a single step from a mixture of C2H6 and C2H4. Dynamic cycling tests confirmed its good cyclic stability, and that it could efficiently separate C2H6/C2H4 even under humid conditions.

Zeolite-based absorbent: Polyacrylic acid loading for enhanced ferric(III) removal from aqueous solution

The process of adsorption shows promise as an effective method for water purification due to its cost-effectiveness, reusability, and adaptability in treating various metal ions. However, it has been noted that this method has limited Fe(III) removal capacity and is susceptible to interference from co-existing ions. To address this, a new adsorbent material (ZEO-PAA) was developed by loading polyacrylic acid (PAA) onto NaOH-treated zeolite using γ-Glycidoxypropyltrimethoxysilane (GPTMS) as a linker. In comparison to natural zeolite, ZEO-PAA demonstrates a strong affinity for Fe(III), exhibiting remarkable Fe(III) removal performance even in the presence of other common cations, such as Na(I), Ca(II), and Mg(II). Furthermore, ZEO-PAA maintains high adsorption performance for heavy metal ions such as Pb(II), Cu(II), Ni(II), Cd(II), and Cr(III). After 7 cycles of adsorption/regeneration, the Fe(III) removal rate of ZEO-PAA remains over 85 %. The adsorption process of ZEO-PAA for Fe(III) aligns with the Langmuir isotherm model and PSO Kinetics model, with a maximum adsorption capacity (qm) of 37.53 mg/g. This study provides valuable insights into the development of a reusable adsorbent material, demonstrating great potential for practical water treatment.

2‐Oxazoline‐Based Polymer for Pharmaceutical Products Adsorption in Aqueous Media

ABSTRACTWe present the synthesis and comprehensive evaluation of a novel 2‐oxazoline‐based polymer (polyPhOx) functionalized with phenyl groups, designed for the efficient adsorption of pharmaceutical contaminants from aqueous solutions. Employing living polymerization techniques (CROP) with two distinct initiators, we optimize reaction parameters including time, temperature, and initiator concentration. The rigorous characterization of the obtained polymer is depicted as well as the demonstration of its significant binding capacity for various pharmaceuticals, exploiting π–π and electrostatic interactions to achieve superior adsorption efficiency. Adsorption experiments are performed using high concentrations of model pharmaceuticals, including aspirin, ibuprofen, metoclopramide, pyramidone, oestradiol, and indomethacin, in hydroalcoholic solutions. Initial investigations confirm polyPhOx's exceptional efficacy, particularly with hydrophobic compounds such as oestradiol, achieving adsorption capacities of up to 56.67 mg g−1. Further validation in real environmental samples highlights the polymer's practical applicability, showing substantial removal rates even under complex matrix conditions and bringing hope for effective water purification solutions. Remarkably, polyPhOx retains high adsorption performance after 10 cycles, underscoring its potential for sustainable and cost‐effective water purification. This study not only introduces a promising material for environmental remediation but also demonstrates its robustness and reusability, paving the way for advanced wastewater treatment solutions targeting persistent pharmaceutical pollutants.

Facile Synthesis of Core-Shell Magnetic Iron Oxide@SiO2-NH2 Nanoparticles and Their Application in Rapid Boron Removal from Aqueous Solutions

In this study, amino-functionalized magnetic particles (iron oxide@SiO2-NH2) with core-shell structures were synthesized and evaluated for rapid boron removal from aqueous solutions. The results showed that the specific surface area of the iron oxide@SiO2-NH2 (131.24 m2⋅g−1) increased greatly compared to pure iron oxide (30.98 m2⋅g−1). The adsorption equilibrium was less than 2 h, with an adsorption capacity of 29.76 mg⋅g−1 at pH = 6 at 15 °C. The quasi-second-order kinetic model described the boron adsorption process well, and both the Langmuir and Freundlich models were suitable for characterizing the adsorption isotherms. The zeta potential and XPS analysis before and after adsorption revealed that the main adsorption mechanism was the hydrogen bonding formation between the terminal -NH2 groups of the adsorbent and the boric acid. In addition, the adsorbent still maintained a high adsorption performance after five adsorption–desorption cycles, which illustrated that the iron oxide@SiO2-NH2 may be a potential adsorbent for environmental boron removal treatment.