Excellent Adsorption Performance Research Articles

Adsorption studies of methylene blue using mangosteen shell porous biochar as adsorbent

The biomass of mangosteen shells was utilized as a raw material to prepare activated carbon based on mangosteen shells through a two-step process of mixed alkali carbonization and activation. This study aimed to investigate the efficacy of the activated carbon in removing methylene blue. The optimum preparation conditions for the study are KOH : NaOH : MSC = 1 : 1 : 1 with a particle size of 80 mesh. The activated carbon exhibits a BET specific surface area of 1432.699 m2/g and a Langmuir maximum specific surface area of 2066.130 m2/g. It demonstrates excellent adsorption performance for methylene blue, with a maximum adsorption amount of 985.5 mg/g. Characterization of the activated carbon is conducted using various techniques including Scanning Electron Microscope, X-ray Diffraction Instrument (XRD), Raman Spectrometry (RMS), Fourier IR Spectrometry (FT-IR), XPS, and BET theory. The adsorption results were consistent with the Freundlich model and the pseudo-first-order kinetic model, indicating that the carbon material exhibits multilayer physical adsorption characteristics for methylene blue. The prepared material offers a large specific surface area, good environmental economics, and excellent adsorption performance, making it a promising choice for adsorption material preparation compared to other biomass activated carbons.

Introduction of mesopores effectively enhances the accessibility of volatile organic compounds within the micropores of covalent triazine frameworks

Porous organic polymers (POPs) with abundant pores have great potential for the treatment of volatile organic compounds (VOCs). However, narrow micropores increase gas diffusion resistance and limit the accessibility of VOCs within the micropores. Here, we have synthesized microporous covalent triazine frameworks (mpCTFs) with abundant mesopores using nano-silica. And the effects of the introduced mesopore structure on the sorption performances of CTF were further investigated by 1,2-dichloroethane adsorption. The results indicate that mpCTF12.5 has the most suitable mesopore volume, and its specific surface area and total pore volume are 2.40 and 2.17 times that of CTF, respectively. Meanwhile, the mpCTF12.5 exhibited excellent adsorption performance for methanol, ethanol, acetone, benzene, ethyl acetate, 1,2-dichloroethane and toluene due to the multiple C-H…O, C-H…Cl, O-H…N and C-H…π interactions between VOCs and mpCTFX framework, demonstrated via DFT calculations. Additionally, the two-component gas-competitive adsorption behavior and the impact of water vapor on the adsorption performance of mpCTFX were investigated, with the adsorption mechanism thoroughly analyzed using the GCMC model. The introduction of abundant mesopores undoubtedly shortened the diffusion paths within the micropores of CTFs, significantly enhancing their accessibility for VOC adsorption. This study presents a viable strategy to improve the performance of porous materials in VOC adsorption applications.

Efficient treatment of Coking Wastewater by Coal-based Activated Carbon Prepared through Coal Blending Method

In this study, the adsorption performance of coal-based activated carbon produced from Shandong gas-fertilized coal, Taixi anthracite coal, and Datong weakly viscous coal, was investigated for coking wastewater treatment. All prepared activated carbons demonstrated excellent adsorption performance, boasting an iodine number surpassing 1000mg/g and achieving a chemical oxygen demand determined by the dichromate method (CODcr) removal rate of over 85% under static coking wastewater adsorption. A positive correlation exists between the total pore volume of activated carbon and its iodine number, methylene blue value, and caramel decolorization rate. Furthermore, dynamic adsorption experiments were conducted and there was an evident increase in the CODcr removal rate as the flow rate decreased. However, increasing the bed height beyond 400mm only marginally enhanced the CODcr removal rate. The burn-off rate of activated carbon and the ratio of raw materials significantly influenced the pore structure. Notably, with a high anthracite ratio (40%), elevating the burn-off rate (up to 70%) did not enhance the effective porosity of activated carbon. The mesopore volume, particularly within 1.2–2.8nm range, exerted a substantial influence on the coking wastewater adsorption efficiency. Overall, coal-based activated carbon demonstrated significant promise as a cost-effective adsorbent for coking wastewater treatment.

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.

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.

Efficient microplastics adsorption in aqueous environments via bidirectional ordered graphene oxide/nanocellulose aerogels

Microplastics not only accumulate various harmful substances but also are ingested by marine organisms and humans, causing immeasurable impacts. Therefore, the removal of microplastics has become a crucial proposition for addressing the issue of microplastic pollution. This study investigated a bidirectional ordered graphene oxide (GO)/nanocellulose aerogels (D-DPGG) to remove microplastics from water bodies. The concentration of microplastics before and after adsorption was measured using a fluorescence spectrophotometer. D-DPGG aerogel exhibited excellent adsorption performance for microplastics (241.56 mg/g) and maintained high adsorption efficiency (>80 %) over 20 cycles of adsorption testing. Additionally, the link between GO and dual-directional treatment significantly improved the aerogel microstructure. It had an apparent layered structure in the transverse direction and improves the mechanical properties. D-DPGG aerogel not only served as an effective solution in adsorption but also held promise as a novel material in directional structural design.

A novel hollow flower shaped Cu9S8 antibacterial agent for removing sulfonamide in water environment: effects of composite with magnetic biochar, differential adsorption, and mechanism study.

In this study, hollow nanoflower spherical Cu9S8 and Cu9S8/Fe3O4@BC with adsorption and antibacterial properties was prepared by coprecipitation and solvothermal method, respectively. The adsorption results showed that the Cu9S8 exhibited excellent adsorption performance on sulfonamide antibiotics (SAs), especially for sulfamethoxazole (SMZ). The optimal addition amount of Cu9S8 is 0.2 g, which results in a maximum adsorption capacity of 33.4 mg/g for SMZ within 120 min. The fitting results of adsorption and desorption kinetics and thermodynamics, as well as the conditions such as pH value and ionic strength were compared. It was found that different interactions led to the differential adsorption of SAs by Cu9S8. The desorption experiment further elucidated its adsorption mechanism. The large desorption capacity indicates that SAs on Cu9S8 can be further recovered and treated. The auto-deposition characteristics of Cu9S8 and the hysteresis loop of Cu9S8/Fe3O4@BC were studied to effectively recover Cu9S8 from aquatic environments. Additionally, more than 99% of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were exterminated by Cu9S8 and Cu9S8/Fe3O4@BC within 20 min. The above results suggested that the hollow nanoflower spherical Cu9S8 and Cu9S8/Fe3O4@BC composite materials can provide a new strategy for solving pollution problems and waste treatment.

Room-Temperature Synthesis of a Fluorine-Functionalized Nanoporous Organic Polymer for Highly Efficient SF6 Adsorption and Separation.

Sulfur hexafluoride (SF6) is widely used in the power industry and significantly contributes to the greenhouse effect, necessitating the development of efficient materials for SF6 capture, particularly fluorine-containing materials. However, existing fluorine-containing materials often require complex monomers and high synthesis temperatures. Herein, we report the synthesis of a fluorine-functionalized carbazole-based nanoporous organic polymer (CNOP-7) at room temperature, using commercially available 4,4'-bis(9H-carbazole-9-yl)-1,1'-biphenyl and 1,1,1-trifluoroacetone. CNOP-7 contains 14.7% fluorine atoms and exhibits a high specific surface area of 1270 m2·g-1, demonstrating excellent SF6 adsorption and separation performance. The SF6/N2 selectivity of CNOP-7 reaches 107 at 273 K and 73 at 298 K. Furthermore, dynamic breakthrough experiments confirm that CNOP-7 can efficiently and repeatedly separate SF6 from SF6/N2 mixtures. Molecular simulations reveal the mechanism behind its efficient separation. This work offers fresh perspectives on the development and fabrication of adsorbents for efficient SF6 sequestration.

Evaluation of the excellent adsorption performance for lead ions of (sodium alginate/ waste para-aramid)-based polymer composite functionalized by ethylene diamine tetra (methylene phosphonic acid)

Evaluation of the excellent adsorption performance for lead ions of (sodium alginate/ waste para-aramid)-based polymer composite functionalized by ethylene diamine tetra (methylene phosphonic acid)

Recovery of Low-Concentration Tungsten from Acidic Solution Using D318 Macroporous Resin.

Tungsten is a crucial strategic metal that plays a significant role in various fields, such as the defense industry, fine chemicals, and the preparation of new materials. During the practice of numerous tungsten smelting processes, a large amount of acidic wastewater containing low concentrations of WO3 is generated. The adsorption method, known for its simplicity, effectiveness, and ease of operation, represents the most promising approach for tungsten recovery and is vital for the sustainable development of the tungsten industry. In this study, D318 macroporous resin was used as an adsorbent to investigate its effectiveness in adsorbing WO3 from acidic solutions. Static adsorption experiments revealed that the adsorption capacity of D318 resin for WO3 was 683 mg·g-1. Kinetic analysis indicated that the controlling step for the adsorption of WO3 from acidic solutions by D318 resin was intraparticle diffusion. Thermodynamic analysis demonstrated that the adsorption process was endothermic and could occur spontaneously. By fitting the isothermal adsorption equation, it was found that the Langmuir model was more suitable for describing the adsorption process of WO3 on D318 resin in acidic solutions. The results of dynamic adsorption experiments showed that under optimized conditions, the dynamic adsorption capacity for WO3 was 529 mg·g-1; when using NaOH as the desorbent for cyclic desorption, the desorption rate for WO3 was 98.21%. XPS and SEM-EDS testing and analysis confirmed that D318 macroporous resin exhibited excellent adsorption performance for tungsten in acidic solutions.

Low-temperature hydrothermal self-assembly synthesis of ZnIn2S4/chitosan-graphene aerogels for enhanced aqueous pollutants removal

A novel visible-light-responsive ZnIn2S4/chitosan graphene aerogel (ZCGA) was prepared using a low-temperature hydrothermal self-assembly method for the adsorption and degradation of tetracycline. Infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) indicated interactions between ZnIn2S4 and chitosan graphene aerogel (CGA). Under the irradiation of a 500 W xenon lamp, ZCGA exhibited excellent adsorption and photocatalytic degradation performance for tetracycline, with a removal rate exceeding 90 % within 180 min. This significant performance improvement is attributed to the high carrier transport properties of CGA, which greatly enhanced the activity of the photocatalytic reaction and also showed high efficiency in removing other types of organic pollutants. Radical trapping experiments further confirmed that the superoxide anion (·O2−) is the main active species in the photocatalytic process. In addition, the monolithic aerogel has good recyclability and mechanical stability. This study not only demonstrates the great potential of ZCGA in the field of photocatalysis but also provides new ideas for designing efficient, recyclable, and visible light-responsive photocatalysts.

Flexible MOF@fabrics composites: The in-situ growth of metal-organic frameworks on cotton and selectively adsorption of gold(III) from aqueous solution

Metal-organic frameworks (MOFs) show great potential applications in dealing with heavy metal pollution due to their unique large specific surface area, tunable pore size, and diverse active groups. However, the powder form of MOFs has suffered from the disadvantages of difficult recycling and secondary contamination after adsorption of heavy metals, which seriously limits their practical application. Therefore, in this work, we prepared a series of bifunctional zirconium-based MOFs cotton fabric composites (MCFC) via in situ growth of MOFs on carboxylated cotton fabric, exhibiting large specific surface area, adjustable pore size, and effective adsorption ability. The prepared CF-UiO-66-(OH)2-FA shows an excellent adsorption efficiency of Au(III) more than 99.990 %, and the saturated adsorption amount is up to 190.98 mg·g−1 at 25 °C. Meanwhile, the kinetic experiment analysis demonstrated that the Au(III) adsorption behavior of MCFC follows pseudo-second-order (PSO) kinetic model. More importantly, it also exhibits great selectivity in adsorbing Au(III) from the mixture of multiple metal ions coexisted solution. The results of adsorption thermodynamics and adsorption isotherms indicate that adsorption is monolayer and a spontaneous, exothermic process. And the ideal adsorption and separation process could be finished by quickly filtrating with a single or multi-layer MCFC. Excellent adsorption performance even after four cycles of adsorption. Therefore, the fabricated MCFC shows great processability, flexibility, collectability and reusability in adsorbing and recycling precious metal ion from wastewater.

Garlic Peel-Based Biochar Prepared under Weak Carbonation Conditions for Efficient Removal of Methylene Blue from Wastewater

Background: Due to it containing cellulose, hemicellulose, and lignin with abundant specific functional groups which could interact with organic dyes, garlic peel (GP) might be used as an efficient biosorbent. The aim of this study is to evaluate the adsorption performances of GP-based bio-adsorbents and obtain optimum preparation conditions. Methods: GP-based bio-adsorbents were prepared by thermal pyrolysis under different temperatures (150–400 °C). The morphologies, chemical states, and surface functional groups of the adsorbents were analyzed by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Batch experiments were conducted to investigate the adsorption of methylene blue (MB) under various conditions, including contact time, contact temperature, initial dye concentration, and initial pH value. The equilibrium adsorption data were fitted to different kinetic and isothermal models, and the adsorption thermodynamics were also calculated. Significant Findings: The physicochemical properties of the GP-based bio-adsorbents were primarily dominated by the pyrolysis temperature, because their morphologies and surface functional groups of GP-based bio-adsorbents significantly varied with the changes in pyrolysis temperature. The adsorption capacity of GP materials for MB decreased as the pyrolysis temperature increased. At an initial concentration of 50.00 mg L−1, GP150 possessed a higher adsorption capacity of 167.74 mg g−1 toward MB. The possible adsorbate–adsorbent interactions, including electrostatic attraction, hydrogen bonding, and π-π stacking, were recognized. After 10 consecutive adsorption–desorption cycles, GP150 maintained a high removal rate (88%) for MB, demonstrating its excellent adsorption performance, good reusability, and potential application in the treatment of MB-contaminated water.

Enhancement of visible light adsorption and photocatalytic degradation activity of organic dye by coating semiconducting TiO2 shell on plasmonic Au particles

The plasmonic effect enhances light absorption in semiconductor photocatalysts, while the noble metal-semiconductor interface promotes charge carrier transfer and separation, boosting photocatalytic activity. However, current methods for synthesizing metal-core TiO2-shell nanoparticles face challenges, such as keeping stable and preventing aggregation. This study presents a simple and moderate synthesis method for Au@TiO2 core-shell nanoparticles, enabling precise control over the TiO2 shell thickness and stable photocatalytic performance. Various characterization techniques were employed to assess the optical and structural properties of the synthesized Au@TiO2 core-shell nanostructures. The results demonstrated that increasing the Au core concentration led to a gradual decrease in TiO2 shell thickness. The adsorption properties and photocatalytic degradation efficiency of the synthesized Au@TiO2 core-shell nanostructured catalysts were thoroughly examined, particularly focusing on their performance with methyl orange (MO) and methylene blue (MB). Au@TiO2 achieved excellent adsorption performance for MO, with a maximum capacity of 231±6 mg/g. Furthermore, Au@TiO2 exhibited higher photocatalytic degradation activity of both MO and MB than pure TiO2. The mechanism study indicated that it attributed to enhanced visible light absorption, reduced bandgap, and higher valence band energy. Additionally, the Au@TiO2 catalysts showed good cyclic stability, making them promising for future applications. This research offers insights into designing efficient photocatalysts, addressing existing synthesis challenges, and contributing valuable references for future advancements.

Facile synthesis and characterization of magnetic iron oxide (Fe3O4)-loaded cationic amino-modified passion fruit shell nanocomposite and their application in removal of anionic Alizarin Red S dye from aqueous medium

A newly synthesized magnetic nanocomposite, iron oxide-loaded cationic amino-modified passion fruit shell (Fe3O4@CMPFS), was utilized as a sorbent to eliminate anionic Alizarin Red S (ARS) dye from the wastewater. The Fe3O4@CMPFS was characterized to confirm the properties by physicochemical methods such as VSM, XRD, pHPZC, BET, FTIR, and FE-SEM with EDX. Batch tests were conducted to study the adsorption process, focusing on factors like the solution pH (from 2.0 to 11), amount of Fe3O4@CMPFS (from 10 to 80 mg/30 mL), contact duration (from 0 to 240 min), agitation speed (from 0 to 400 rpm) and temperature (from 298 to 328 K). The optimal conditions for attaining a 92.3 % removal efficiency were found to be a pH of 2.0, 60 mg of Fe3O4@CMPFS, a contact time of 60 min, agitation at 250 rpm, and a temperature of 298 K. The Fe3O4@CMPFS was determined to have a pHPZC value of approximately 6.2. The kinetic data indicated that the adsorption of ARS onto Fe3O4@CMPFS followed the pseudo-second-order model (high R2 = 0.9919; low SSE = 1.5) and was governed by film and intraparticle diffusion mechanisms. Furthermore, the isotherm data fit well with the Langmuir model (high R2 = 0.9983; low χ2 = 12.69), suggesting monolayer adsorption behaviour. The maximal sorption uptake of ARS on the Fe3O4@CMPFS was determined to be 233.4 ± 3.174 mg/g at 298 K through the Langmuir model. The estimated ΔH° (18.3 kJ/mol) and ΔS° (82 J/mol K) indicate the endothermic and enhanced randomness at the adsorbent/solute interface. The negative ΔG° values (−6.2298 to −8.7283 kJ/mol at 298–328 K) confirm spontaneous sorption dominated by physisorption. The Fe3O4@CMPFS composite had good recyclability and was easy to separate from water, which maintained excellent adsorption performance after eight regeneration cycles. The superb adsorption efficiency and recycling performance of Fe3O4@CMPFS provide a prospect way to remove ARS dye from industrial effluents.

S-Cu Doubly Doped NiFe LDH@Diatomite with Adjustable Surface Characteristics for the Efficient Removal of Tetracycline.

Overuse of antibiotics can lead to increased bacterial resistance; therefore, there is a need to develop efficient nanomaterials for removing antibiotics from water. NiFe bimetallic hydroxide nanosheets doped with S-Cu were prepared on diatomite (S-CuNiFe LDH@diatomite) by using a two-step hydrothermal method. The surface of CuNiFe LDH@DE has a layered structure with an increased specific surface area and pore volume. The average pore size of S-CuNiFe LDH@De increases from 13.3 to 24.7 nm, and a more stereoscopic channel structure is obtained. Tetracycline removal experiments were performed on CuNiFe LDH@De and S-CuNiFe LDH@De. It was found that CuNiFe LDH@De had excellent photocatalytic performance and S-CuNiFe LDH@De had excellent adsorption performance. After CuNiFe LDH@De had been in contact with tetracycline (TC) for 2 h, the TC removal rate reached 95.6%. After S-CuNiFe LDH@De had been in contact with TC for 1 h, the adsorption capacity of TC was 145.5 mg/g. The pseudo-first-order kinetics and Sips isotherm model can be used to describe the adsorption process more accurately. The response surface method was used to optimize the adsorption conditions. According to the optimized conditions, a better adsorption performance of 166.9 mg/g was obtained. The two prepared materials showed good performance in the removal of tetracycline. This study provides a way to synthesize low-cost adsorbents and photocatalysts, which has value in the treatment of TC wastewater.

Enhanced Benzene Adsorption in Chloro-Functionalized Metal-Organic Frameworks.

The functionalization of metal-organic frameworks (MOFs) to enhance the adsorption of benzene at trace levels remains a significant challenge. Here, we report the exceptional adsorption of trace benzene in a series of zirconium-based MOFs functionalized with chloro groups. Notably, MFM-68-Cl2, constructed from an anthracene linker incorporating chloro groups, exhibits a remarkable benzene uptake of 4.62 mmol g-1 at 298 K and 0.12 mbar, superior to benchmark materials. In situ synchrotron X-ray diffraction, Fourier transform infrared microspectroscopy, and inelastic neutron scattering, coupled with density functional theory modeling, reveal the mechanism of binding of benzene in these materials. Overall, the excellent adsorption performance is promoted by an unprecedented cooperation between chloro-groups, the optimized pore size, aromatic functionality, and the flexibility of the linkers in response to benzene uptake in MFM-68-Cl2. This study represents the first example of enhanced adsorption of trace benzene promoted by -CH···Cl and Cl···π interactions in porous materials.

Polyacrylonitrile nanofibrous mat modified with cysteamine and ionic liquid as a recyclable and efficient adsorbent for selective removal of sulfonamides and Cu(II) from aqueous solution: Roles of multi-function adsorption

The combined contamination of heavy metals and antibiotics is a prevalent occurrence, yet the distinct chemical characteristics of these substances pose a significant obstacle to their simultaneous elimination. In this work, novel polyacrylonitrile nanofibrous mat (NFsM) modified with cysteamine and ionic liquid (IL@Cys@PAN NFsM) was developed using a cascade thiol-ene click reaction. The IL@Cys@PAN NFsM exhibits a rich array of functional groups and demonstrates strong binding affinity, fast mass transfer, and exceptional selectivity for sulfonamides (SAs) and Cu(II). The maximum adsorption capacities for SAs and Cu(II) in single-component systems were 122.3 and 97.4 mg/g respectively, according to the Langmuir isotherm model. The time dependent adsorption capacities followed a pseudo-second-order kinetic model, demonstrating a chemisorption-dominant process for each analyte. In binary pollutant systems, the co-occurrence of SAs and Cu(II) in water produced a competitive effect; however, the decrease in adsorption capacity was minimal. Through experimental analysis, FTIR characterization and density functional theory (DFT) studies, reasonable interactions of hydrogen-bond, electrostatic interactions, π-π stacking for SAs, and chelation effect for Cu(II) were proposed. Additionally, the reusability and recyclability of IL@Cys@PAN NFsM enhance its practicality for real-world applications. This paper presents the first systematic study on the simultaneous adsorption of heavy metals and antibiotics using NFsM, offering a novel perspective on the design of custom adsorbents capable of efficiently removing multiple contaminants with diverse characteristics while balancing eco-friendliness, excellent adsorption performance, and impressive recyclability for wastewater remediation.

Efficient and Regenerative Phosphate Removal from Wastewater Using Stable Magnetite/Magnesium Iron Oxide Nanocomposites

Using magnetite-based nanocomposite adsorbents to remove and recycle phosphate from wastewater is crucial for controlling eutrophication and ensuring the sustainable use of phosphorus resources. However, the weak structural stability between magnetite and adsorptive nanoparticles often reduces phosphate removal efficiency in real-world applications. This instability primarily results from the loss of adsorptive nanoparticles from the magnetite surfaces, particularly when metal oxide nanoparticles are used for phosphate removal and recycling. In this study, we present a top-down approach that involves lattice locking magnesium iron oxide nanoparticles to the magnetite core, preventing magnesium loss from the magnetite surfaces. These nanocomposites exhibit exceptional performance in both phosphate recycling and removal, with a maximum adsorption capacity of 101.8 mg P·g−1. Excellent adsorption performance is also observed even in the presence of competing anions at phosphate-to-competing ion molar ratios of 1:5, 1:25, and 1:100, as well as dissolved organic matter, across a broad pH range of 4 to 10. The adsorbent also demonstrated minimal magnesium release during regeneration and in acidic conditions. Microscopic and spectroscopic analyses reveal that surface deposition is the primary mechanism of phosphate removal in the magnesium-containing shells. The findings of this study address the current limitations of magnetite nanocomposites in phosphate removal, paving the way for the development of highly stable and sustainable nanocomposites for various chemical removal and recycling applications in wastewater treatment.

One-step green synthesis of melamine-modified cellulose nanofiber composite aerogels for efficient removal of Pb(II) and Cu(II): Experiments and DFT calculations

A composite aerogel (CGMA) with high porosity (98.32 %) and multiple active sites was prepared for the adsorption of Pb(II) and Cu(II) by sol-gel combined with freeze-drying process using melamine and (3-Glycidyloxypropyl)trimethoxysilane as cellulose nanofiber modifying materials. Characterized by SEM-EDS, XPS, FTIR, BET, MIP and TG, CGMA has a hierarchical pore structure and abundant adsorption sites. At pH = 6, the adsorption reached equilibrium within 120 min, following the Pseudo second-order kinetic model and the Langmuir model, with maximum capacities of 268.1 mg/g for Pb(II) and 152.6 mg/g for Cu(II). The process was primarily governed by homogeneous chemisorption. The coexisting ion, organic matter, and water quality experiments confirmed the excellent anti-interference properties of CGMA. Competitive adsorption experiments showed that CGMA has excellent selective adsorption performance for Pb(II). After 5 cycles, Pb(II) and Cu(II) adsorption performance decreased to 79.21 % and 83.40 %, respectively. FTIR, XPS, DFT and RDG analysis showed that amino groups and oxygen-containing groups were the main sites of adsorption. CGMA forms coordination bonds and complexes with Pb(II) and Cu(II) via amine and oxygen groups and adsorbs via electron transfer, hydrogen bonding, and van der Waals forces, with Pb(II) being more selective. CGMA has good prospects for application in heavy metal ion treatment.