Static Adsorption Experiments Research Articles

Transforming waste into valuables: Preparation and evaluation of dual-ligand hydrophobic charge-induction chromatography using two poor performing ligands

In conventional chromatographic ligand screening, underperforming ligands are often dismissed. However, this practice may inadvertently overlook potential opportunities. This study aims to investigate whether these underperforming ligands can be repurposed as valuable assets. Hydrophobic charge-induction chromatography (HCIC) is chosen as the validation target for its potential as an innovative chromatographic mode. A novel dual-ligand approach is employed, combining two suboptimal ligands (5-Aminobenzimidazole and Tryptamine) to explore enhanced performance and optimization prospects. Various dual-ligand HCIC resins with different ligand densities were synthesized by adjusting the ligand ratio and concentration. The resins were characterized to assess appearance, functional groups, and pore features using SEM, FTIR, and ISEC techniques. Performance assessments were conducted using single-ligand mode resins as controls, evaluating the selectivity against human immunoglobulin G and human serum albumin. Static adsorption experiments were performed to understand pH and salt influence on adsorption. Breakthrough experiments were conducted to assess dynamic adsorption capacity of the novel resin. Finally, chromatographic separation using human serum was performed to evaluate the purity and yield of the resin. Results indicated that the dual-ligand HCIC resin designed for human antibodies demonstrates exceptional selectivity, surpassing not only single ligand states but also outperforming certain high-performing ligand types, particularly under specific salt and pH conditions. Ultimately, a high yield of 83.9 % and purity of 96.7 % were achieved in the separation of hIgG from human serum with the dual-ligand HCIC, significantly superior to the single-ligand resins. In conclusion, through rational design and proper operational conditions, the dual-ligand mode can revitalize underutilized ligands, potentially introducing novel and promising chromatographic modes.

Effects of soil colloids on adsorption and migration of benzo(a)pyrene on contaminated sites under runoff infiltration processes

In the environment, soil colloids are widespread and possess a significant adsorption capacity. This makes them capable of transporting different pollutants, presenting a potential risk to human and ecological well-being. This study aimed to examine the adsorption and co-migration characteristics of benzo(a)pyrene (BaP) and soil colloids in areas contaminated with organic substances, utilizing both static and dynamic batch experiments. In the static adsorption experiments, it was observed that the adsorption of BaP onto soil colloids followed the pseudo-second-order kinetic model (R2=0.966), and the adsorption isotherm conformed to the Langmuir model (R2=0.995). The BaP and soil colloids primarily formed bonds through π-π interactions and hydrogen bonds. The dynamic experimental outcomes revealed that elevating colloids concentration contributed to increased BaP mobility. When the concentration of soil colloids in influent was 500 mg L-1, the mobility of BaP was 23.2 % compared to that without colloids of 13.4 %. Meanwhile, the lowering influent pH value contributed to increased BaP mobility. When the influent pH value was 4.0, the mobility of BaP was 30.1 %. The BaP’s mobility gradually declined as the initial concentration of BaP in polluted soil increased. When the initial concentration of BaP in polluted soil was 5.27 mg kg-1, the mobility of BaP was 39.1 %. This study provides a support for controlling BaP pollution in soil and groundwater.

One-Step Synthesis of Polyethyleneimine-Grafted Styrene-Maleic Anhydride Copolymer Adsorbents for Effective Adsorption of Anionic Dyes.

Wastewater containing organic dyes has become one of the important challenges in water treatment due to its high salt content and resistance to natural degradation. In this work, a novelty adsorbent, PEI-SMA, was prepared by grafting polyethyleneimine (PEI) onto styrene-maleic anhydride copolymer (SMA) through an amidation reaction. The various factors, such as pH, adsorbent dosage, contact time, dye concentration, and temperature, which may affect the adsorption of PEI-SMA for Reactive Black 5 (RB5), were systematically investigated by static adsorption experiments. The adsorption process of PEI-SMA for RB5 was more consistent with the Langmuir isotherm model and the pseudo-second-order model, suggesting a single-layer chemisorption. PEI-SMA exhibits excellent adsorption performance for RB5 dye, with a maximum adsorption capacity of 1749.19 mg g-1 at pH = 2. Additionally, PEI-SMA exhibited highly efficient RB5 competitive adsorption against coexisting Cl- and SO42- ions and cationic dyes. The adsorption mechanism was explored, and it can be explained as the synergistic effect of electrostatic interaction, hydrogen bonding and π-π interaction. This study demonstrates that PEI-SMA could act as a high performance and promising candidate for the effective adsorption of anionic dyes from aqueous solutions.

Selective adsorption of zearalenone by a novel magnetic molecularly imprinted carbon nanomaterial.

In this paper, the objective is to immobilize molecularly imprinted polymers (MIPs) onto the surface of magnetic carbon nanoparticles (Fe3O4@SiO2@C) to develop an effective method for the adsorption of zearalenone (ZEN). The prepared products were characterized by FT-IR, SEM, TEM, XRD, VSM, TGA, and BET. The content of zearalenone in corn samples was monitored by HPLC. The results indicate that the particle size of magnetic molecularly imprinted polymers (MMIPs) is approximately 200nm. The adsorption mechanism of MMIPs was confirmed by static adsorption and dynamic adsorption experiments. The maximum adsorption capacity was 1.56mg/g, and the adsorption equilibrium was reached within 50min. The scatchard model showed that MMIPs had two binding sites, a high-affinity binding site and a low-affinity site. Kinetic second-order fitting indicates that MMIPs are mainly through chemisorption. In the actual sample application, the limit of detection (LOD) and limit of quantitation (LOQ) were 0.3mg/L and 0.9mg/L, respectively. The recovery of corn with the standard addition of ZEN was 73.6-88.1%, and the relative standard deviation (RSD) was 2.86-5.63%. The results demonstrated that MMIPs possess the advantages of straightforward operation, high precision, and cost-effectiveness, rendering them suitable for rapid ZEN detection.

Study of CHF3/CH2F2 Adsorption Separation in TIFSIX-2-Cu-i.

Hydrofluorocarbons (HFCs) have important applications in different industries; however, they are environmentally unfriendly due to their high global warming potential (GWP). Hence, reclamation of used hydrofluorocarbons via energy-efficient adsorption-based separation will greatly contribute to reducing their impact on the environment. In particular, the separation of azeotropic refrigerants remains challenging, such as typical mixtures of CH2F2 (HFC-23) and CHF3 (HFC-32), due to a lack of adsorptive mechanisms. Metal-organic frameworks (MOFs) can provide a promising solution for the separation of CHF3-CH2F2 mixtures. In this study, the adsorption mechanism of CHF3-CH2F2 mixtures in TIFSIX-2-Cu-i was revealed at the microscopic level by combining static pure-component adsorption experiments, molecular simulations, and density-functional theory (DFT) calculations. The adsorption separation selectivity of CH2F2/CHF3 in TIFSIX-2-Cu-i is 3.17 at 3 bar under 308 K. The existence of similar TiF62- binding sites for CH2F2 or CHF3 was revealed in TIFSIX-2-Cu-i. Interactions between the fluorine atom of the framework and the hydrogen atom of the guest molecule were found to be responsible for determining the high adsorption separation selectivity of CH2F2/CHF3. This exploration is important for the design of highly selective adsorbents for the separation of azeotropic refrigerants.

Effect of cement-based composite pellets on phosphorus removal and microbial community structure in eutrophic water

Phosphorus (P) removal still faces challenges in eutrophic water treatment. Combining adsorption and biological reactions can efficiently reduce the P concentrations, achieving long-term function. In this study, five kinds of pellets were produced using cement, bentonite, and organic carbon (rice husk powder) with mass ratios of 100%:0%:0% (M1), 95%:5%:0% (M2), 92.5%:5%:2.5% (M3), 90%:5%:5% (M4), and 85%:5%:10% (M5) for phosphorus removal in eutrophic water. The static adsorption experiment revealed that both Langmuir and Freundlich models were suitable for describing the adsorption characteristics. The P-bonding energy (KL) and adsorption capacity (K) followed the order of M1 < M2 < M3 < M4 < M5. The adsorption processes conformed to the Pseudo-second-order kinetic model. The adsorption capability of pellets decreased with increasing pH levels. The Cl−, NO3−, and SO42− showed negligible effects on adsorption, while CO32− reduced the adsorption amount. In the dynamic experiment, all the pellets have sustained P removal efficiency with the average removal rates of 58.54% (M1), 60.78% (M2), 63.97% (M3), 66.81% (M4), and 72.05% (M5). The presence of CaHPO4·2 H2O in pellets after P removal indicated phosphate precipitation and ion exchange. The attached microbes in pellets exhibited an increase in Proteobacteria abundance contributed to biological phosphorus removal and long-term effectiveness. Hence, this study introduces innovative cement-based pellets for phosphorus removal in eutrophic water, establishing a possibility for practical applications.

A vinyl-pedant triazine-based covalent organic framework for efficient C3H6/C2H4 separation

The separation of propylene (C3H6) and ethylene (C2H4) during the methanol-to-olefin (MTO) process is crucial yet challenging. Herein, we report a covalent organic framework (TzDva) featuring favorable nitrogen adsorption sites and vinyl modification for the capture of C2H4 from C3H6/C2H4 mixtures. TzDva exhibits enhanced crystallinity and porosity as well as reduced pore size compared to its vinyl-free counterpart (TzPA), as revealed through comprehensive characterization. The excellent performance of TzDva for C3H6/C2H4 separation combined with its excellent recyclability was confirmed by both static adsorption and dynamic breakthrough experiments. Particularly, it exhibits a C2H4 productivity of 4.29 mmol·g–1 at 298 K with C3H6/C2H4 (10/90) mixture. With decreasing temperature to 273 K, the performance can be further enhanced. Theoretical calculations and in-situ infrared analysis suggested that the remarkable selectivity of TzDva towards C3H6 stems from its favorable pore environment, which facilitates a greater number of interactions with C3H6 compared to C2H4 guests. These results underpinned the effective separation of gas mixtures relevant to the MTO process.

Adsorption of Pyrene and Arsenite by Micro/Nano Carbon Black and Iron Oxide.

Polycyclic aromatic hydrocarbons (PAHs) and arsenic (As) are common pollutants co-existing in the environment, causing potential hazards to the ecosystem and human health. How their behaviors are affected by micro/nano particles in the environment are still not very clear. Through a series of static adsorption experiments, this study investigated the adsorption of pyrene and arsenite (As (III)) using micro/nano carbon black and iron oxide under different conditions. The objectives were to determine the kinetics and isotherms of the adsorption of pyrene and As (III) using micro/nano carbon black and iron oxide and evaluate the impact of co-existing conditions on the adsorption. The microstructure of micro/nano carbon black (C 94.03%) is spherical-like, with a diameter of 100-200 nm. The micro/nano iron oxide (hematite) has irregular rod-shaped structures, mostly about 1 µm long and 100-200 nm wide. The results show that the micro/nano black carbon easily adsorbed the pyrene, with a pseudo-second-order rate constant of 0.016 mg/(g·h) and an adsorption capacity of 283.23 μg/g at 24 h. The micro/nano iron oxide easily adsorbed As (III), with a pseudo-second-order rate constant of 0.814 mg/(g·h) and an adsorption capacity of 3.45 mg/g at 24 h. The mechanisms of adsorption were mainly chemical reactions. Micro/nano carbon black hardly adsorbed As (III), but its adsorption capability for pyrene was reduced by the presence of As (III), and this effect increased with an increase in the As (III) concentration. The adsorbed pyrene on the micro/nano black carbon could hardly be desorbed. On the other hand, the micro/nano iron oxide could hardly adsorb the pyrene, but its adsorption capability for As (III) was increased by the presence of pyrene, and this effect increased with an increase in the pyrene concentration. The results of this study provide guidance for the risk management and remediation of the environment when there is combined pollution of PAHs and As.

Characterization Analysis of Mudstone and Study of Its Pb (II) Adsorption Characteristics in Polluted Water Bodies

In order to explore a medium material for the efficient treatment of Pb(II) pollutants in groundwater, in this paper, mudstone is selected as the medium material, and the morphological structure of the mudstone is characterizes via X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) analyses to study the feasibility of the mudstone adsorbing Pb(II) ions. Then, static adsorption experiments are carried out to investigate the removal effect of mudstone on Pb(II) in aqueous solutions under different conditions and to determine the optimal adsorption conditions. Finally, the results are fitted and analyzed using a thermodynamic model to explore the adsorption mechanism of the mudstone. The main results of this study are as follows. The main mineral composition of the mudstone used in the experiments includes CaCO3, SiO2, CaAl2O4·10H2O, and CaFe4O7. The specific surface area of the mudstone is as high as 23.027 m2·g−1, the pore size is 9.145 nm, and its surface structure is rough, with pores and fissures developed. The pore space and adsorption capacity of the mudstone were enhanced. When 1 g·L−1 of mudstone was added, the pH value of the solution was 6, the reaction time was 60 min, and the initial concentration of Pb(II) was 30 mg·L−1. The removal efficiency of Pb reached 84.5%, and the adsorption amount was 25.352 mg·g−1. For the removal of Pb(II) from the aqueous solution by the mudstone under different concentrations of Pb(II), the reaction was in accordance with the Langmuir adsorption isotherm model, and the maximum adsorption amount reached 54.975 mg·g−1. The relationship between the removal of Pb(II) and the reaction time was in accordance with the pseudo-second-order rate model. The results of this study suggest that mudstone can be used for the removal of Pb(II) from aqueous media.

Synthesis of stable mesoporous Zr-MOFs using pyrazine-containing ligand for efficient capture of Pb(II) in wastewater

By optimizing the reaction conditions, a zirconium-based adsorbent Zr-PzDC with pyrazine-2,5-dicarboxylic acid as the ligand was synthesized for the treatment of lead ions in an aqueous solution. SEM, EDS-Mapping, XRS and FT-IR characterization confirmed the synthesis of Zr-PzDC. Meanwhile, BET results show that Zr-PzDC is a typical mesoporous material. The analysis of the binding process of Zr-PzDC with Pb(II) in water shows that the adsorption kinetics conform to the pseudo-second-order model; The adsorption isotherm data fits well with the Langmuir model, and the maximum adsorption capacity of Pb(II) is 298.39 mg/g; The thermodynamic parameters show that the adsorption of Pb(II) in water is a spontaneous endothermic process. Combined with the XPS spectral results, physical adsorption is the main binding mode, and single-layer chemisorption is the limiting step in the adsorption process. The results of both static and dynamic column adsorption experiments show that Zr-PzDC can treat lead ions quickly and efficiently, and has excellent reusable performance, which makes Zr-PzDC have good application potential in treating lead-containing wastewater of the battery production process.

Magnetic alginate supported potassium manganese ferrocyanide for the recovery of uranium from acidic wastewater

Abstract With the rapid development of the atomic energy industry, the demand for nuclear fuel has risen, while the limited resources of uranium mines make it difficult to meet the needs of the future development of nuclear energy. Expanding sources of uranium acquisition is necessary, and the enrichment and recovery of precious uranium from uranium-containing wastewater is invaluable. By synthesizing alginate supported potassium manganese ferrocyanide nanocomposites with magnetic response (KMnFC/MA/Fe3O4), the high efficiency adsorption and separation of uranium in acidic uranium-containing wastewater can be realized conveniently and quickly. The magnetic composite was characterized by a variety of technical means, and the adsorption behavior of the magnetic material on uranium was studied by static adsorption experiments under different environmental conditions. The adsorption kinetics and isotherm of uranium by KMnFC/MA/Fe3O4 were studied by using some common linear adsorption models. The results show that the adsorption rate of KMnFC/MA/Fe3O4 on uranium is fast, and the adsorption equilibrium can be reached within 90 min. The adsorption process conforms to a pseudo-secondary kinetic model and is dominated by chemisorption. The adsorption of uranium by KMnFC/MA/Fe3O4 magnetic material is single molecular layer adsorption, and the maximum adsorption capacity is 425.5 mg g−1 at 35 °C. KMnFC/MA/Fe3O4 is a promising adsorbent in the field of acidic low-concentration uranium wastewater treatment because of its good effect on the treatment of low concentration uranium wastewater, the concentration of uranium in the wastewater reaches the emission standard after treatment and it is easy to be separated magnetically after adsorption.

Novel manganese and nitrogen co-doped biochar based on sodium bicarbonate activation for efficient removal of bisphenol A: Mechanism insight and role analysis of manganese and nitrogen by combination of characterizations, experiments and density functional theory calculations

A novel porous manganese and nitrogen co-doped biochar (Mn-N@SBC) was synthesized via one-step pyrolysis, utilizing loofah agricultural waste as the precursor and NaHCO3 as the activator. The behavior of bisphenol A adsorbed on Mn-N@SBC was evaluated using static batch adsorption experiments. Compared to direct manganese-nitrogen co-doping, co-doping based on NaHCO3 activation significantly increased the specific surface area (231 to 1027 m2·g−1) and adsorption capacity (15 to 351 mg·g−1). Wide pH (2–10) and good resistance to cation/anion, humic acid and actual water demonstrated the robust adaptability of Mn-N@SBC to environmental factors. The significantly reduced specific surface area after adsorption, adverse effects of ethanol and phenanthrene on the removal of bisphenol A, and theoretically predicted interaction sites indicated the primary adsorption mechanisms involved pore filling, hydrophobicity, and π-π-electron-donor–acceptor interaction. This work presented an approach to create high-efficiency adsorbents from agricultural waste, offering theoretical and practical guidance for the removal of pollutants.

Selective adsorption and identification of penicillin G sodium in milk by molecularly imprinted polymer doped carbon dot.

A carbon dot (CD) was prepared by o-phenylenediamine and water, which showed bright yellow fluorescence under ultraviolet light irradiation (λ = 580nm), and verified good fluorescence quenching effect on penicillin G sodium (Png-Na). Using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, and Png-Na as a template, a kind of composite microsphere combining CD and molecularly imprinted polymer (MIP) was synthesized by surface-initiated atomic transfer radical polymerization (SI-ATRP). For reasons ofcomparison, we also prepared MIP without CD and non-imprinted polymers (NIPs). Through static and dynamic adsorption experiments, the maximum adsorption capacity was 47.05mgg-1 and the equilibrium time was 30min. High-performance liquid chromatography (HPLC) was utilized to determine the content of Png-Na in the spiked milk samples. A sensitive, rapid, and simple method for determination of Png-Na in food samples was developed. The utilized approach enabled the quantification of Png-Na within theconcentration range 20-1000μg L-1 (with a limit of detection of 5μg L-1). The recoveries achieved were in the range 93.3-98.2%, with a relative standard deviation of 1.2-4.2%. The results demonstrated that CD@MIP possessed the capability of specific adsorption and fluorescence detection of Png-Na, enabling simultaneous detection and enrichment of Png-Na in real samples.

Effective removal of Congo red from aqueous solutions using ethylenediamine-modified wheat straw as adsorbent

In this study, ethylenediamine (EDA)-modified wheat straw (EMWS) was prepared and used as an efficient adsorbent for removing Congo red (CR) from aqueous solutions. Adsorption of CR by EMWS was examined through static adsorption experiments to determine the effect of contact time, initial pH values, particle size of the adsorbent, solution concentration, and temperature. As pH ranged from 4.0 to 10.0, CR adsorption by the EMWS remained considerably elevated. The equilibrium adsorption capacity was determined to be 97.92 mg·g−1 for a CR concentration of 400 mg·L−1, pH of 4.0, temperature of 318 K, and EMWS dose of 2 g·L−1, which was found to be comparable to other materials used for CR adsorption. Following that, optimal conditions were used to conduct isothermal, kinetic, and thermodynamic studies. In the adsorption process of CR, the Freundlich isotherm model and the pseudo-second-order (PSO) kinetics provided the best fit, indicating the presence of both physisorption and chemisorption mechanisms. Electrostatic attraction and hydrogen bonding were primarily responsible for CR adsorption onto the EMWS. Based on thermodynamic investigations, the adsorption of CR on EMWS is determined to be spontaneous (ΔG < 0) and endothermic (ΔH = 60.83 kJ·mol−1), while also exhibiting an increase in disorder (ΔS = 289.9 J·mol−1·K−1). The elution was carried out using 0.20 M HCl, followed by washing the EMWS with water, resulting in no loss of functionality. This study suggests that EMWS possesses the potential to serve as a feasible and efficient adsorbent for CR removal in wastewater.

Synthesis of micro-mesoporous hierarchical structure of coal-based activated carbon and its effect on methane adsorption

This research synthesized a series of porous carbon materials utilizing three different coal-rank samples as raw materials through carbonization and activation processes. The resulting activated carbon has a high specific surface area of up to 2092.83 m2/g, a micro-mesopores volume of 1.08 cm3/g and a hierarchical porous structure, and the surface is enriched with heteroatoms. These properties can be adjusted by adjusting the charging temperature, activation temperature and KOH/Coal mass ratio. Methane adsorption experiments showed that the maximum adsorption capacities of the three activated carbons at 40℃ were 7.97 mmol/g, 9.34 mmol/g, and 11.71 mmol/g (Langmuir parameter a), respectively. It was found that methane adsorption is primarily related to nanopores (0.5 nm −2 nm), with micropores playing a dominant role and mesopores supplying transport channels for gas molecules and contributing to their immobilization on solid surfaces. The results of the dynamic and static adsorption experiments were consistent, demonstrating that better adsorption separations could be attained for samples with stronger molecular affinities. Coal-based activated carbon shows potential as a material for low-concentration methane separation due to its superior affinity for methane molecules, providing theoretical support for the selection of materials for variable pressure adsorption.

Adsorption of Phosphate by Two-Step Synthesis of Ceramsite from Electrolytic Manganese Residue/Dredged Sludge.

Carrying out research on the management of electrolytic manganese residue (EMR) is necessary to maintain the environment and human health. The dredged sludge (DS) and water hyacinth (WH) generated from dredging projects are potential environmental threats, and therefore suitable methods need to be found for their treatment. In this study, ceramsite was prepared by a two-step low-temperature firing method using DS and EMR as raw materials, WH as a pore-forming additive, and aluminate cement as a binder for the adsorption of phosphorus from wastewater. The optimal ratio and process parameters of the ceramsite were determined by mechanical and adsorption properties. The static adsorption experiments were conducted to study the effect of ceramsite dosage and solution pH on the removal of phosphorus. At the same time, dynamic adsorption experiments were designed to consider the influence of flow rate on its actual absorption effect, to explore the actual effect of ceramsite in wastewater treatment, and to derive a dynamic adsorption model that can provide technical support and theoretical guidance for environmental management.

A Hydrothermal Synthesis Process of ZSM-5 Zeolite for VOCs Adsorption Using Desilication Solution

ZSM-5 zeolite is a kind of high-value-added porous aluminosilicate zeolite. The use of the coal gasification slag utilization process by-product desilication liquid as a silicon raw material to replace the current raw materials such as water glass will help reduce production costs and achieve high-value utilization of solid waste. ZSM-5 zeolites for volatile organic compounds (VOCs) adsorption were prepared by a one-step hydrothermal method using the desilication solution prepared from coal gasification slag as the main silicon source and sodium source. The effects of crystallization reaction time, the crystallization temperature, the Na2O/SiO2 molar ratio, and the SiO2/Al2O3 molar ratio on the relative crystallinity and the specific surface area of the ZSM-5 zeolite were investigated and optimized. The optical reaction conditions were as follows: a crystallization time of 12 h, a crystallization temperature of 170 °C, a Na2O/SiO2 molar ratio of 0.2, and a SiO2/Al2O3 molar ratio of 200. The optimal ZSM-5 zeolite synthesized is hexagonal, with regular grains, a relative crystallinity of 101.48%, a specific surface area of 337.48 m2·g−1, and a pore volume of 0.190 cm3·g−1. And the optimal ZSM-5 zeolite was composed of SiO2 content of 97.52 wt%, Al2O3 content of 1.58 wt%, Na2O content of 0.33 wt%, and SiO2/Al2O3 molar ratio of 104.93. Na2O/SiO2 molar ratio is 0.0033. The results of static adsorption experiments show that the static adsorption capacities of ZSM-5 zeolite for p-xylene, benzene, toluene, and butyl acetate were 118.85, 69.98, 68.74, and 95.85 mg·g−1, respectively, which can effectively adsorb VOCs. The synthetic process of the ZSM-5 zeolite is a simple preparation process and short in synthesis time. The results of this study not only help to realize the high-value utilization of silicon components in solid waste, but also provide an economical and effective way to synthesize VOCs adsorption materials.

Activation of hydrochar derived from food waste via hydrothermal carbonization for Cu(II) adsorption

ABSTRACT Currently, heavy metal pollution is a challenge that needs to be solved urgently, and there is a broad prospect for food waste(FW) utilization. In this paper, activated hydrochar (AHC) made from FW according to actual proportion was produced by hydrothermal carbonization (HTC) and activated with K2CO3. The effects of the AHC on Cu(II) adsorption were investigated using static adsorption experiments. The results indicated that the sample fabricated at 160°C (FW-160) for 6 h had the best adsorption performance with the maximum adsorption amount of Cu(II) (36.77 mg/g). The oxygenated functional group on the surface of FW-160 was observed. The pseudo-second-order kinetic model fitted the experimental results better, which proved that chemisorption was the main adsorption mechanism, and the surface complexations, including oxygenated functional groups, were the predominant factors in hydrochar(HC) sorption for Cu(II). The adsorption amount of the sample simulating rotten FW with Aspergillus niger (FW-160A) was 24.82 mg/g. Through the HTC process, the rotten FW can be made into heavy metal absorbents which can be stored for long term, and finally realize the reduction of volume and cost of storage.

Cubic CoSe2@carbon as polysulfides adsorption-catalytic mediator for fast redox kinetics and advanced stability lithium-sulfur batteries

Although lithium-sulfur batteries (LSBs) are an attractive next-generation rechargeable battery with high theoretical energy density (2600 Wh kg−1) and specific capacity (1675 mA h g−1), the shuttle of soluble lithium polysulfides (LiPSs) is still the protruding obstacle to accelerate the redox reaction of LSBs. Here, cubic cobalt diselenide@carbon (CoSe2@C) derived from zeolite imidazole framework-67 (ZIF-67) was employed as the functional coating of polypropylene (PP) separator to efficiently adsorb and catalyze polysulfides, inhibit “shuttle effect” and improve the electrochemical reaction kinetics of LSBs. The CoSe2@C offers larger mesopore proportion of 77.19 % and abundant active sites to ensure space as a secondary reaction region, and infiltration of electrolyte and rapid transport of Li+. The involved adsorption and catalysis effect are discussed by static adsorption experiment, XPS, and Li2S nucleation kinetics analysis. The results show that CoSe2@C exhibits strong adsorption effect and catalytic activity on LiPSs, and CoSe2@C/PP cells display fast Li+ diffusion and improved redox kinetics (high Li2S nucleation peak current of 0.27 mA and deposition capacity of 148.46 mA h g−1). Ascribe to these advantages, the CoSe2@C/PP cell provides an initial discharge specific capacity of 1335.01 mA h g−1 at 0.1 C and a fine reversible capacity at 5.0 C, and achieves stable and durable lifespan with an average capacity decay rate of 0.12 % over 400 cycles at 0.5 C. This work could promote the practical application of metal selenides in the key components and devices for LSBs.

A acylthiourea based ion-imprinted membrane for selective removal of Ag+ from aqueous solution

The efficient removal of Ag+ ions from wastewater not only preserves the environment but also promotes the reutilization of silver metal. Therefore, in this study, we have developed an advanced ion imprinted membrane (IIM) and employed it as an adsorbent for the efficient removal of Ag+ ions from aqueous solution. The dynamic adsorption results demonstrated that the prepared IIM exhibited superior filtration and separation performance when applied to feed solutions with lower concentrations (12 mg/L) and higher pH levels (pH=6). The presence of co-existing metal ions in the feed solution had negligible impact on the separation efficiency of IIM towards Ag+ ions, highlighting its exceptional recognition ability and selective separation capability. The results from static adsorption experiments indicated that the adsorption of Ag+ ions onto the membrane surface conformed to both Langmuir model and the pseudo-second-order model, indicating that the adsorption process was a monolayer chemisorption. Reusability findings revealed a slight decline in uptake capacity and water flux of IIM after five desorption-adsorption cycles, showcasing its potential application value in Ag+ ions removal. The EDS, FTIR and XPS results substantiated that Ag+ ions were adsorbed onto the IIM surface through the chemical reactions between Ag+ ions and CS and CO groups.