Adsorption Properties Research Articles

Mechanochemical “Cage‐on‐MOF” Strategy for Enhancing Gas Adsorption and Separation through Aperture Matching

AbstractPost‐modification of porous materials with molecular modulators has emerged as a well‐established strategy for improving gas adsorption and separation. However, a notable challenge lies in maintaining porosity and the limited applicability of the current method. In this study, we employed the mechanochemical “Cage‐on‐MOF” strategy, utilizing porous coordination cages (PCCs) with intrinsic pores and apertures as surface modulators to improve the gas adsorption and separation properties of the parent MOFs. We demonstrated the fast and facile preparation of 28 distinct MOF@PCC composites by combining 7 MOFs with 4 PCCs with varying aperture sizes and exposed functional groups through a mechanochemical reaction in 5 mins. Only the combinations of PCCs and MOFs with closely matched aperture sizes exhibited enhanced gas adsorption and separation performance. Specifically, MOF‐808@PCC‐4 exhibited a significantly increased C2H2 uptake (+64 %) and a longer CO2/C2H2 separation retention time (+40 %). MIL‐101@PCC‐4 achieved a substantial C2H2 adsorption capacity of 6.11 mmol/g. This work not only highlights the broad applicability of the mechanochemical “Cage‐on‐MOF” strategy for the functionalization of a wide range of MOFs but also establishes potential design principles for the development of hybrid porous materials with enhanced gas adsorption and separation capabilities, along with promising applications in catalysis and intracellular delivery.

Study on the Adsorption Mechanism of Cu2+ by ZnAl-LDH-Containing Exchangeable Interlayer Chloride Ions.

Different Zn/Al ratios of Cl- intercalated ZnAl-layered double hydroxide (ZnAl-LDH) were prepared using the coprecipitation method, and their adsorption performance for Cu2+ in aqueous solution was evaluated. The factors affecting adsorption properties, such as dosage, reaction time, and pH, were determined by adsorption experiments. Then, the adsorption kinetics and isotherm models were fitted to evaluate the adsorption mechanism. The results show that the Zn/Al ratio has a great influence on the adsorption effect, the best adsorption effect is obtained when the Zn/Al ratio is 4:1, and the maximum adsorption capacity of Cu2+ is 213 mg/g. The mechanism study shows that the adsorption of Cu2+ by ZnAl-LDH is mainly an isomorphic substitution. Additionally, during the adsorption of CuSO4, the presence of SO42- undergoes interlayer anion exchange with Cl-, and the process of SO42- entering the interlayer facilitates the isomorphic substitution of Cu2+ and Zn2+. X-ray diffraction (XRD) analysis shows that as the Zn/Al ratio increases, the interlayer spacing of ZnAl-LDH increases, and the crystallinity decreases. The adsorption process conforms to the pseudo-second-order kinetic process and the Langmuir isotherm adsorption model. Therefore, the adsorption type of ZnAl-LDH for Cu2+ is monolayer chemical adsorption. The adsorption thermodynamic results indicate that the adsorption of Cu2+ is a spontaneous endothermic process. The research results revealed the mechanism of ZnAl-LDH adsorbing Cu2+, providing ideas for removing and recovering copper-containing electroplating wastewater.

Preparation of Loess‐Clay Based Eco‐Friendly Geopolymer for Efficient Removal of Pollutants in Water

AbstractHeavy metals and dyes cause serious harm for water environment, geopolymer materials with the large pores and specific surface area, and easy modification of pore surface have received extensive attention in wastewater treatment. Herein, using loess‐clay (LC) as natural mineral materials, we developed an eco‐friendly geopolymer of loess‐clay (GpLC) with excellent adsorption properties and promotion plant growth was prepared by alkali excitement. Its morphology and structure were exhibited by scanning electron microscopy, Fourier transform infrared spectroscopy, XRD, and Brunauer–Emmett–Teller. Moreover, its adsorption property for removing metal ions and different dyes was measured, and the adsorption kinetics and thermodynamics were investigated. GpLC presented excellent adsorption ability for Pb2+, which the removal rate got to 98.7 %. It had the universality of removing organic pollutants, and the removal rate reached to 98.0 %. It was dominated chemisorption and single‐layer adsorption, which GpLC conformed to quasi‐second‐order adsorption kinetics, and being more consistent with Langmuir isothermal model. Furthermore, it was found that GpLC could promote growth of crops as it contain P and K element with essential element of plants. In summary, it provides insights and strategy for developing a kind of eco‐friendly functional materials with strong adsorption capacity and promoting plant growth, and it is an effective method for reusing loess resources.

Role of Clay Minerals in Natural Media Self-Regeneration from Organic Pollution-Prospects for Nature-Inspired Water Treatments

Pollution from organic molecules is a major environmental issue that needs to be addressed because of the negative impacts of both the harmfulness of the molecule structures and the toxicity that can spread through natural media. This is mainly due to their unavoidable partial oxidation under exposure to air and solar radiation into diverse derivatives. Even when insoluble, the latter can be dispersed in aqueous media through solvatation and/or complexation with soluble species. Coagulation–flocculation, biological water treatments or adsorption on solids cannot result in a total elimination of organic pollutants. Chemical degradation by chlorine and/or oxygen-based oxidizing agents is not a viable approach due to incomplete mineralization into carbon dioxide and other oxides. A more judicious strategy resides in mimicking natural oxidation under ambient conditions. Soils and aqueous clay suspensions are known to display adsorptive and catalytic properties, and slow and complete self-regeneration can be achieved in an optimum time frame with a much slower pollution throughput. A deep knowledge of the behavior of aluminosilicates and of oxidizing species in soils and aquatic media allows us to gain an understanding of their roles in natural oxidative processes. Their individual and combined contributions will be discussed in the present critical analysis of the reported literature.

SERS Sensor for Acetylcholine Detection Based on Covalent Organic Framework Hybridized Gold Nanoparticles As Nanozymes.

An innovative and potent nanozyme with reductase-like activity was developed by integrating the in situ synthesis of gold nanoparticles (Au NPs) onto the surface of a covalent organic framework (COF). Based on the reductase-like activity of the COF-hybridized Au NPs, this nanozyme could efficiently catalyze the reduction of 4-nitrophenol (4-NPH). Moreover, the prepared nanohybrid was utilized as an excellent surface-enhanced Raman scattering (SERS) substrate for highly sensitive SERS detection by combining the excellent adsorption properties of COFs and the large number of Raman hotspots between the high-density Au NPs. For the first time, 4-NPH was used as an SERS marker to detect the electron receptor acetylcholine (Ach), with high sensitivity; Ach acted as an inhibitor in this catalytic reaction. The linear range of Ach was 1.0 pM to 10 nM, the correlation coefficient was 0.993, the detection limit was approximately 0.3 pM with a signal-to-noise ratio (s/n) of 3, and the acceptable recovery in the serum was 97.2% to 104.5%. The results from this study show that the nanozyme-SERS system has great potential for chemical and bioassay applications.

Lateral Flow Immunoassay for the Rapid Detection of Thiamethoxam in Tea Based on a SERS Tag Constructed by Phenolic-Mediated Coating Engineering.

Sensitive and accurate detection of thiamethoxam in tea is significant to ensuring consumer health. In this study, surface-enhanced Raman scattering (SERS) tags were prepared by using a polyphenol-mediated coating engineering strategy. This approach involved the self-assembly of tannic acid (TA) and self-polymerization of benzene-1,4-dithiol (BDT) on the surface of gold nanoparticles, resulting in the formation of Au@pBDT-TA. The SERS tags possess high Raman signals and antibody adsorption properties, avoiding the complex decoration or label steps of SERS reporters. We discovered that Au@pBDT-TA, composed of gold nanoparticles at 40 nm and a pBDT-TA thickness of 10 nm, was optimal for the development of the SERS lateral flow immunoassay (LFIA). In comparison to the gold nanoparticle-based LFIA, the SERS-LFIA demonstrated 4-fold and 720-fold enhancements in visual and quantitative limits of detection in buffer solution. The SERS-LFIA demonstrated quantitative limits of detection of 0.06 and 0.1 ng/g for black and green tea, respectively, with a broader linear range spanning over 2 orders of magnitude and a short detection time of 20 min. The proposed SERS-LFIA not only offers a sensitive and reliable method for monitoring thiamethoxam in tea but also possesses a versatile potential that can be easily adapted for the trace detection of various other targets.

Preparation of CYCU‐3/MCM‐41 Composites and Adsorption Properties for n‐Hexane

AbstractAdsorption method is one of the effective technologies for treating VOCs. Compared with activated carbon, silicon‐based materials have well‐ordered pore structure, good thermal stability and non‐flammability. In this paper, CYCU‐3/MCM‐41 composites were prepared by hydrothermal method through mixing MCM‐41 powder in situ. The nitrogen adsorption isotherms, saturation adsorption and cyclic adsorption/desorption curves of n‐hexane on CYCU‐3/MCM‐41 composites were experimentally measured. The results displayed that the CYCU‐3/MCM‐41 (3) exhibited the largest BET specific surface area (1631 m2/g). And its n‐hexane adsorption capacity was 776 mg/g, which was 19.4 % higher than that of MCM‐41, 1.42 times that of activated carbon, and 2.64 times that of molecular sieve. The kinetic fitting results showed that the pseudo‐first order kinetic model can more precisely embody the n‐hexane adsorption process on CYCU‐3/MCM‐41 composites, and the W‐M intraparticle diffusion model confirmed that intraparticle diffusion was not the only control step for the adsorption rate of n‐hexane on CYCU‐3/MCM‐41 composites. In addition, the regenerative rate of CYCU‐3/MCM‐41 (3) was over 98.9 % after ten adsorption and desorption cycles of n‐hexane, showing good desorption performance and excellent structural stability, and proving its broad application prospect in the field of VOCs treatment.

Ajuga orientalis L. Extract as a Green Corrosion Inhibitor of Aluminum in an Acidic Solution: An Experimental and DFT Study

The inhibitory effect of A. orientalis L. extract (AO) on aluminum corrosion in a 1.0 M HCl solution was investigated utilizing weight loss, electrochemical polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The results show that AO is a potent inhibitor in an acidic environment, and that the inhibition potency increases with concentration. Temperature investigations showed that, in an acidic medium, the efficiency decreased, increased, and then decreased as the temperature rose. Adsorption isotherms from Freundlich, Temkin, El Awady, and Redlich–Peterson (R-P) approximated the inhibitor’s adsorption properties. For the inhibitory behavior, a physical and chemical adsorption mechanism is proposed. The adsorption process’s thermodynamic parameters (Ea, ΔH*, and ΔS*) were determined and explained. The inhibitor, AO, was identified as a mixed-type (anodic and cathodic) inhibitor based on polarization studies. According to the SEM findings, the inhibitor partially covers the metal surface, providing it with a respectable level of protection. The weight loss, electrochemical polarization, EIS, scanning electron microscopy (SEM), and quantum chemical calculations show a strong agreement, indicating that the AO extract is a highly effective inhibitor of aluminum in an acidic solution.

Large Adsorption Capacity for Space Molecular Pollutants Realized by a Metal-Organic Framework.

The rapid development of capable spacecraft coatings for removing volatile organic compounds (VOCs) demands materials with a large adsorption capacity to ensure a long-duration exploration mission in a low Earth orbit (LEO). MIL-53(Al) with abundant sites exhibits resistance to the space environment in the LEO and shows great potential for VOC removal. This study combined an adsorption experiment and first-principles simulations to investigate the adsorption performance of MIL-53(Al). MIL-53(Al) demonstrated an excellent adsorption capacity for various VOCs, reaching 606.04 mg/g for m-xylene and 22.69 cm3/g for methane, which is 6 times higher than traditional adsorption methods. First-principles simulations revealed that the adsorption capacity is significantly influenced by micropores through the pore effect and breath effect, which restrict diffusion and enhance adsorption, respectively. Additionally, we predicted the adsorption properties of VOCs that are difficult to characterize through ground-based simulated experiments, further validating the potential application of MIL-53(Al) for VOC removal in the LEO. This work expands the application range of MIL-53(Al), optimizes VOC removal strategies, and offers a novel approach to protecting spacecraft in the LEO. Our findings contribute to the development of advanced materials for space exploration and provide valuable insights into the design of efficient VOC removal systems for spacecraft in the LEO.

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.

Harnessing Novel Reduced Graphene Oxide-Based Aerogel for Efficient Organic Contaminant and Heavy Metal Removal in Aqueous Environments

Ensuring clean water sources is pivotal for sustainable development and the well-being of communities worldwide. This study represents a pioneering effort in water purification, exploring an innovative approach utilizing modified reduced graphene oxide (rGO) aerogels. These advanced materials promise to revolutionize environmental remediation efforts, specifically removing organic contaminants from aqueous solutions. The study investigates the exceptional adsorption properties of rGO-aerogel, enhanced with cysteamine, to understand its efficacy in addressing water pollution challenges. The characterization methods utilized encompass various analytical techniques, including FE-SEM, BET, FTIR, TGA, DSC, XPS, NMR, and elemental analysis. These analyses provide valuable insights into the material’s structural modifications and surface chemistry. The research comprehensively explores the intricacies of adsorption kinetics, equilibrium, and isothermal study to unravel the underlying mechanisms governing contaminant removal. MO and Ni2+ exhibited adsorption of 542.6 and 150.6 mg g−1, respectively, at 25 °C. Ni2+ has unveiled the highest removal at pH 5, and MO has shown high removal in a wide pH range (pH 4–7). Both contaminants have shown fast adsorption kinetic performance on an rGO-aerogel surface. This study aims to identify the synergistic effect of cysteamine and rGO in aerogel formation to remove heavy metals and organic contaminants. These findings mark a significant stride in advancing sustainable water-treatment methods and pioneering in synthesizing innovative materials with versatile applications in environmental contexts, offering a potential solution to the global water pollution crisis.

Regulation of Adsorption Properties of Whey Protein Isolate Fibril-Calcium Alginate Aerogels by Controlling Protein Fibrillation Time.

Amyloid-like fibrils have a relatively high specific surface area, which makes them suitable as absorbents. In this study, we prepared absorbent composite aerogels from whey protein isolate fibril (WPIF) and calcium alginate (CA). The impact of protein fibrillation time (4-24 h) on the adsorption properties of these aerogels was assessed, as this influences the nature of the WPIFs formed. Fourier transform infrared spectroscopy analysis indicated that hydrogen bonding, hydrophobic interactions, and electrostatic interactions were the main molecular interactions in the composite aerogels. Then, the adsorption properties of the aerogels were investigated using crystal violet as a model compound. The adsorption properties of all composite aerogels were significantly improved compared to CA aerogels, which was mainly attributed to the numerous functional groups of the surfaces of the WPIFs, as well as the rougher surface topology of the composite aerogels. The adsorption capacity of the composite aerogels first increased and then decreased with increasing fibrillation time, with 8 h fibrillation leading to the largest adsorption capacity (1886.11 mg/g). Thioflavin T fluorescence, atomic force microscopy, light extinction, average particle size, and zeta potential analysis indicated that the high fibril content, mature fibril morphology, large number of available functional groups on the surface, and relatively low zeta potential of WPIF8 might be the main reasons. Adsorption kinetics and isothermal adsorption profile analysis suggested that monolayer adsorption occurred through chemical adsorption processes. The edible aerogel with high adsorption properties developed in this work has potential application in food and biomedical fields.

Facile synthesis of ZnO/RGO/Fe2O3 using macroalgae Caulerpa taxifolia as green reductor and its application as malachite green removal

This study presents the synthesis of a novel ZnO/rGO/Fe₂O₃ composite using Caulerpa taxifolia as a green reductant for the effective removal of Malachite Green from aqueous solutions. Characterization techniques, including FTIR, SEM, and XRD, confirmed the successful incorporation of ZnO and Fe₂O₃ onto the rGO matrix, enhancing its adsorption properties. The composite achieved an exceptional maximum adsorption capacity of 454.5 mg/g at pH 9, significantly outperforming rGO alone and other adsorbents. The adsorption kinetics followed a pseudo-second-order model, indicating chemisorption as the dominant mechanism, with a high correlation coefficient (R² = 0.999). The adsorption isotherms were best described by the Langmuir model, suggesting monolayer adsorption. Thermodynamic parameters revealed that the process was spontaneous and exothermic, with a Gibbs free energy (ΔGo) of -10.93 kJ/mol at 25 °C. The composite's high adsorption capacity, rapid kinetics, and favorable thermodynamics highlight its potential as an efficient and sustainable adsorbent for dye removal. This research offers a promising approach to water treatment, aligning with environmentally friendly practices and providing a viable solution for mitigating water pollution caused by organic dyes. KEY WORDS: Reduced graphene oxide, Water treatment, Caulerpa taxifolia, Isothermal and kinetic studies, Malachite Green Bull. Chem. Soc. Ethiop. 2025, 39(1), 29-47. DOI: https://dx.doi.org/10.4314/bcse.v39i1.3

N-doping strategy for enhancing the adsorption performance of Ti2CT2 MXene for Sr ion

Radionuclides, such as strontium (Sr), are hazardous radioactive isotopes commonly found in nuclear waste, posing serious environmental and health risks due to their long half-lives and ability to bioaccumulate. Inspired by the electronic modification effect, this study theoretically predicts that doping can significantly enhance the adsorptive performance of MXenes for radionuclides. Specifically, we employed comprehensive first-principles simulations to investigate the impact of nitrogen (N) doping on the adsorption behavior of Ti2CT2 (T = O, F, OH) MXenes for Sr ions, focusing on surface N doping and C-site N doping as effective strategies to improve adsorption. The results confirmed that both types of N doping are beneficial for the adsorption performance of Ti2CT2, and the adsorption strengths of Ti2CT2 with surface N doping are significantly enhanced. This was analyzed and attributed to the ability of N doping to enhance the charge transfer between the Ti2CT2 surface and Sr ions, thus enhancing the adsorption properties. By elucidating the N doping mechanisms, this study is expected to provide theoretical guidance for the design of high-performance MXene materials in radionuclides remediation applications.

Experimental study on enrichment of heavy metals by modified mullite during co-combustion of lignite with eucalyptus wood

ABSTRACT Modifying the content of oxygen vacancies (OVs) has emerged as a crucial approach to tailoring silicate's adsorption properties, microstructure, conductivity, and catalytic performance. Some studies have reported the formation of OVs during ammonia treatment. However, there are limited studies on the production of OV-enriched mullite by treating it with N-containing compounds at low temperatures. In this work, formamide, urea, and ammonium acetate were used as ammonia-assisted reduction modifiers to induce oxygen vacancies in mullite at 30 ℃, 60 ℃, and 90 °C. The aim was to enhance the enrichment effect of heavy metals (Cr, Cu, Mn, Ni, Pb, Zn) during the co-combustion of coal and biomass. The modified mullite was analyzed by using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The results indicated that the particle size of mullite decreased, and the concentration of internal Al3+ ions and oxygen vacancies was enhanced. Coal-biomass-mullite combustion experiments were conducted in a tubular furnace at 900 °C, revealing a significant enhancement in the enrichment of heavy metals during the combustion process, particularly when the modification temperature was 60 °C using ammonium acetate as the modifier. This work holds significant importance for developing novel heavy metal adsorbents and the reduction of pollutant emissions from coal-biomass co-combustion in industrial applications.

Novel magnetic adsorbents based on oyster and clam shells for the removal of cadmium in soil

Magnetic adsorbents can effectively remove heavy metals from soil. However, the magnetization process may reduce availability of adsorption sites, making it challenging to balance magnetic and adsorption properties. In this study, oyster shell (OS) and clam shell (CS) material was magnetized by an improved chemical co-precipitation method. The organic matter in the shells was destroyed by calcination modification to expose new active sites, and calcinated ferro-magnetic adsorbent was produced with either ferrosodium EDTA (giving CEOS and CECS) or with iron citrate (for CCOS and CCCS). All four modified adsorbents reached adsorption equilibrium for Cd2+ in solution within 120 min, with maximum adsorption capacities ranging from 115.5 to 266.5 mg/g, giving high removal efficiencies for Cd2+. Adsorption by precipitation and cation exchange mechanisms was dominant, together contributing >60 % of all adsorption capacity, followed by complexation. When used for remediation of Cd-contaminated soil, CEOS demonstrated the best Cd removal efficiency, achieving removal rates of 46 % and 58 % for total and available Cd, respectively. This was mainly because CEOS had the highest magnetic recovery rate, of 98 %. CEOS maintained removal rates of 34 % for total Cd after regeneration and reuse three cycles, with recovery rates remaining above 90 %. Contaminated soil was treated with the novel adsorbents and in pot experiments with water spinach cultivation it was shown that both CEOS and CECS treatment significantly reduced Cd content (by up to 56 %). The magnetic adsorbents presented here demonstrate excellent performance to remove Cd from water and soil, and have promising application prospects.

Improved gel properties of Nemipterus virgatus myofibrillar protein emulsion gel by Konjac glucomannan incorporation: Insight into the modification of protein conformation

This study aimed to improve the gel properties of emulsion gels prepared by physical complex of fish protein and polysaccharide. The effects of Konjac glucomannan (KGM) on the structure, emulsibility of Nemipterus virgatus myofibrillar protein (MP), and the gel properties of heat-induced MP emulsion gel were investigated. The results indicated KGM modification facilitated the unfolding of MP, exposing more tryptophan and hydrophobic groups, thereby improving the wettability and emulsifying activity of MP/KGM mixtures. The interactions between MP and KGM molecules were mainly non-covalent hydrogen bonding and hydrophobic interaction. The MP/KGM mixtures exhibited superior adsorption properties at the oil-water interface, particularly with 0.5 % KGM addition, thus forming small and evenly distributed oil droplets. Besides, the curves of viscosity, G' and G" of MP/KGM emulsions climbed continuously with the increased KGM concentration. The presence of KGM, especially the medium amount (0.5 %), was conducive to the translation of α-helix into β-sheet and the formation of more dense and ordered gel network structure, thereby enhancing the gel properties of MP/KGM emulsion gels.

Effective remediation of toxic metal ions (Cd(II), Pb(II), Hg(II), and Ba(II)) using mesoporous glauconite-based iron silicate nanorods: Experimental and theoretical studies

Glauconite minerals underwent an advanced exfoliation and scrolling process, yielding novel iron silicate nanorods (GRs) with increased surface area, reactivity, and improved physicochemical properties. These structures were introduced as superior adsorbents for the highly efficient adsorption of various toxic metal ions, such as Cd(II), Pb(II), Hg(II), and Ba(II). The GRs exhibited maximum adsorption capacities of 283 mg/g for Cd(II), 247 mg/g for Pb(II), 132.3 mg/g for Hg(II), and 165.2 mg/g for Ba(II). The adsorption properties of the GRs during the adsorption of these four metal ions were elucidated through traditional (Langmuir model) and advanced (monolayer model of single energy site) isotherm analyses. Advanced isotherm modeling revealed that the GR surface was saturated with numerous effective adsorption sites, with densities of 125 mg/g for Cd(II), 68.8 mg/g for Pb(II), 40.9 mg/g for Hg(II), and 57.9 mg/g for Ba(II). Moreover, each site could accommodate approximately four ions of the studied metals, which are vertically oriented and participate in multi-ionic adsorption reactions. Energetic analyses, whether based on classical models (Gaussian energy <8 kJ/mol) or advanced models (adsorption energy <40 kJ/mol), indicated that the adsorption processes are governed by physical mechanisms, including electrostatic attractions, van der Waals forces, and hydrogen bonding. Furthermore, thermodynamic assessments confirmed that the adsorption of these ions occurs through exothermic and spontaneous reactions.

Mycelium-Doped Straw Biochars for Antibiotic Control

Straw, a predominant agricultural residue, represents a significant waste product. Harnessing its potential is of paramount importance both in terms of research and economic value. In this study, chemically pretreated corn straw was infused with distinct microbial fungal mycelium variants and subsequently transformed into a series of biochars through a process involving carbonization and activation. The findings revealed enhancements in the specific surface area and total pore volume of mycelium-doped straw biochars compared to the original corn straw biochar (BCS). Additionally, discernible disparities were observed in their physical and chemical attributes, encompassing functional groups, surface chemistry, and micro-morphology. Notably, in water-based antibiotic removal experiments focusing on tetracycline hydrochloride (TH) and chloramphenicol (CP), the mycelium-doped straw biochars outperformed BCS. Their maximum adsorption capacities for TH and CP surpassed those of alternative adsorbents, including other biochars. Impressively, even after five cycles, the biochar exhibited a removal rate exceeding 80%, attesting to its robust stability. This study successfully emphasized the efficacy of incorporating fungal mycelium to enhance the adsorption properties of straw-based biochar, introducing a new theoretical basis for the development of lignocellulosic materials.

The Impact of Adsorption Property Modification by Crosslinkers on Graphene Oxide Membrane Separation Performance

The health risks associated with the presence of heavy metals in drinking water can be severe. To address this issue, membrane separation technology is one of the consolidated alternatives. Inorganic, porous membranes were found in applications where low energy consumption is highly desirable. The selectivity of these membranes is attained by functionalisation. Graphene oxide functionalised membrane technology is promising for removing heavy metal ions. This work summarises, discusses and presents the relationship between adsorption and overall membrane separation process performance for heavy metal ions removal from wastewater when a graphene oxide-functionalised membrane is used. The separation performance depends on the hydrophobic interactions of the membrane and the solute. The electrostatic interaction between the negatively charged membrane surface and positively charged metal ions facilitates the adsorption, leading to the rejection of these metal ions. The influences of the chemical nature of the modifiers of graphene oxide layers are highlighted.