Adsorbent Material Research Articles

Template Quality Dependent Conversion Synthesis of Boron Nitride Coated Graphene Hybrid Aerogels for Ultrasensitive and Selective Ammonia Sensing

AbstractRecently, hexagonal boron nitride (h‐BN) nanomaterials, e.g., nanosheets and nanotubes, have been predicted to be effective materials for reversible gas adsorption with high selectivity once charged. However, despite the encouraging theoretical predictions, sensing with h‐BN is difficult to realize experimentally due to its electrically insulating nature stemming from its large band gap. In this research, the controlled synthesis of high surface area hybrid h‐BN/graphene aerogel is reported, using high‐quality graphene as a template, and its application for selective gas sensing. It is discovered for the first time in this system that the difficulty of conversion in template synthesis of h‐BN is positively correlated with the quality of the carbon template, an observation that is verified on both graphene nanosheets and carbon nanotubes. The application of this hybrid material for gas sensing yields ppb level of detection limit and high selectivity for NH3. Through density functional theory calculations, the adsorption energy and charge transfer between NH3 molecules and aerogel are greatly enhanced. Therefore, this innovative approach promises new possibilities for the application of h‐BN in gas sensing, with the potential to play a significant role in gas capture, environmental monitoring, and other related fields.

Waste Bauxite Residue Valorization as Trace Metal Sorbent: Application to Acid Mine Drainage Remediation

With an output of more than two million tons of alumina per year, Venezuela is an important producer. As observed, this mining extraction activity generates a large number of by-products poorly valorized for many reasons (economic, technical, and due to environmental standards and regulations) Venezuela production generates wastes (more than 15 million of m3) called red muds, which are dumped in old lagoons near the Orinoco river or stored. This sludge has a high alkalinity (pH between 10 and 13) and a chemical composition containing some heavy metals (40 ppm Cr, 107 ppm La, 178 ppm Ce) that means it is considered environmentally problematic waste. However, their mineralogical, textural and structural characteristics make them adsorption materials. So, the aim of the study presented here was to investigate the sorption properties of these residues in the case of treatment of water from acid mine drainage. In fact, with an important reactive surface, their capacities to trap by adsorption trace elements such as cadmium, lead or zinc has been studied. Batch sorption tests revealed significant retention of contaminants such as Pb, Zn and As. These retention processes were interpreted using the Langmuir isotherm model. The promising first results indicate that the red mud named Venezuelan bauxite residue (VBR) reveals its great potential as a sorbent of inorganic pollutants. The sorption process is chemically dependent and efficient for certain pH and IS ranges. In addition, the material showed a strong affinity for the adsorption of arsenate (As5+). This was observed during post adsorption chemical speciation experiments, through the very high affinity of this element for the least mobile fractions, including oxyhydroxides mobile fractions, including Fe oxyhydroxides (amorphous). Nevertheless, these mining by-products could be considered as valuable absorbent materials. Despite this promising results, further studies are required to evaluate their potential in different conditions (dynamic tests, pH, IS, inorganic and organic contaminants, concentration and time effect).

Biomass-Based Sorbent with Superoleophilic from Ulva Prolifera for Oil Spill Cleanup

In this study, we demonstrate a new all bio-based adsorbent material by treating Enteromorpho prolifera (EP) fibers with tannic acid-ferric chloride complex and then grafting hydrophobic group octadecylamine. All raw materials are easily available, low-cost, and safe. The modified EP fibers have approximately 63.4 g g−1 of oil absorption and 1.4 g g−1 of water absorption, which is an 62.8% increase in oil absorption and an 82% increase in hydrophobicity over that of untreated EP fibers, respectively, exhibiting high hydrophobicity and oleophilicity. The affinity discrimination to water and oil enables hydrophobic algae candidate materials to separate oils and water efficiently, both in an oil–water mixture and a water-in-oil emulsion. In summary, the as-synthesized modified EP demonstrates a broad application prospect in the treatment of oil spill accidents and oily wastewater.

Unripe Plantain Peel Biohydrogel for Methylene Blue Removal from Aqueous Solution

Dye contamination is a serious environmental issue, particularly affecting water bodies, driving efforts to synthesize adsorbent materials with high dye-removal capacities. In this context, eco-friendly and cost-effective materials derived from bioresidues are being explored to recycle and valorize waste. This study investigates the synthesis, characterization, and application of a biohydrogel made from unripe plantain peel (PP), modified with carboxymethyl groups and crosslinked using varying concentrations of citric acid (CA), an eco-friendly and economical organic acid. The materials were characterized by ATR-FTIR, TGA, and SEM, confirming the successful synthesis of hydrogels, which exhibited rough, irregular surfaces with micropores. Additionally, the materials were analyzed for their pH point of zero charge, swelling capacity, and methylene blue (MB) dye removal efficiency. The results indicate that the biohydrogel formed with 1% CA exhibited the most favorable characteristics for MB removal. Kinetic studies revealed that the adsorption mechanism is pH-dependent, with equilibrium being reached in 720 min. The Freundlich isotherm model provided the best fit for the adsorption data, suggesting a heterogeneous surface and a multilayer adsorption process, with a maximum retention capacity of 600.8 ± 2.1 mg/g at pH 4. These findings contribute to the development of cost-effective and efficient materials for dye removal, particularly from water bodies.

Synthesis of bagasse-derived magnetic biochar for the removal of fluoride from water solution

ABSTRACT Fluoride levels in drinking water pose a significant environmental threat, and adsorption is a common technique. However, many adsorbent materials have drawbacks such as poor adsorption capabilities, extended contact times, high pH levels, and large dosages. A biochar-based magnetic composite adsorbent has been developed for water defluoridation using a chemical co-precipitation process to immobilize iron particles on the biochar surface. X-ray diffraction analysis, Fourier transformed infrared spectroscopy, Brunauer–Emmett–Teller, and scanning electron microscopy were used to analyse the composite. The central composite design was used to design laboratory tests, which included four input variables: solution pH, dosage, contact time, and initial concentration. The adsorbent dosage was 5.92 g/L, the aqueous pH was 5.79, the contact time was 66.48 min, and the initial fluoride concentration was 12.38 mg/L. The removal efficiency was predicted to be 98.61%, with a 98.55% removal efficiency at optimum conditions. The study concluded that the composite adsorbent can be a reliable and sustainable solution for fluoride removal from water.

Defluoridation of Groundwater Using Low-cost Adsorbents

Excessive fluoride in groundwater poses significant health risks to millions of people worldwide, necessitating effective and accessible defluoridation methods. This study investigates the use of column filtration for removing fluoride from groundwater. The study employs a systematic approach to evaluate the performance of different adsorbent materials in a fixed-bed column setup. Various materials were tested as adsorbents in column, including Brick powder, Neem leaf powder, Lime, Sawdust, and Vetiver. The research examines the effects of key operational parameters such as bed depth, flow rate, and initial fluoride concentration on the overall removal efficiency. Experiments were conducted using groundwater to assess the method's effectiveness. Results indicated that column filtration can effectively reduce fluoride concentrations to below the World Health Organization's recommended limit of 1.5 mg/L. This report contributes to the development of efficient, cost-effective, and sustainable solutions for groundwater defluoridation. All adsorbents used were inexpensive materials, available easily in nature and locally at village or rural level. Some of the adsorbents were very effective in removal of fluoride ion and can be used as defluoridating agents but they impart color and turbidity to the groundwater. Among all the adsorbents used, Vetiver demonstrated higher removal efficiency of 78% followed up by limestone 77% removal but hindered by its precipitation. Sawdust and brick powder were also efficient up to a certain extent of 72% and 69% respectively in adsorbing fluoride ions. Neem leaves powder was found to be least effective in adsorbing showing about 50% removal efficiency.

Utilizing Waste Biomass from Agricultural and Forestry Sustainable Resources: Biomass Conversion to Functional Adsorbent Material for Efficient Removal of Total Phosphate in Practical Water.

The promotion of the utilization of waste agricultural and forestry resources (AFRs) as a means of combating environmental pollution represents an advanced and necessary development approach with the potential to achieve sustainable development. In this work, an advanced adsorbent with a functional Mg-Al bimetallic layer was prepared using waste sawdust biomass (WSD) as a raw material. The layer serves as the primary active component for adsorbing total phosphate from both simulated and real wastewater. The hierarchical structure of the Mg-Al bimetallic hydroxide-modified waste sawdust biomass (MA@WSD) has an abundance of nanosheets on its surface, providing ample binding sites and an enhanced specific surface area of 175.99 m2/g. Under the optimal conditions, the maximum removal efficiency toward phosphate can reach 99.99%. The adsorption of phosphate by MA@WSD follows the pseudo-second order kinetic (PSOK) model, indicating that chemisorption is the rate-determining step. Moreover, the thermodynamic data demonstrate the spontaneous nature of the adsorption process, indicating the favorable characteristics of the developed material. The adsorption mechanism can be summarized as the collaboration of physical adsorption, electrostatic interaction, and chemical adsorption. The results of the regeneration process indicate that MA@WSD exhibits a retention of 50.3% of its initial adsorption performance following the fifth testing cycle, thereby suggesting its potential for comparable reusability. The MA@WSD performs well in adsorbing total phosphate in real river water, and the removal efficiency of MA@WSD is evidently superior to commercial activated carbon, which is at least 70% higher than that of the commercial activated carbon. Besides, the 5-time average removal efficiency toward total phosphate by MA@WSD is 62.9%, evidently higher than the 29.1% of commercially available activated carbon, indicating its potential as an alternative for treating phosphorus-containing wastewater. The research provides theoretical support for harmless treatment, resource utilization, carbon sequestration, and emission reduction of waste biomass.

Zirconium hydroxide-activated carbon hybrid material for chemical warfare agents detoxification: Implication of water and temperature

In light of the recent threat from chemical warfare agents (CWAs), the scientific community has focused extensively on developing effective and safe decontamination methodology for CWAs based on environmentally benign technology and the avoidance of corrosive and toxic chemicals. Herein, we report the decomposition of CWAs sarin and sulphur mustard on the hybrid material Zirconium hydroxide-granular activated carbon i.e. Zr(OH)4@GAC which is synthesized by utilizing the reactive zirconium hydroxide and high surface area carbon. In-situ zirconium hydroxide was generated in the pores of GAC by varying the precursor concentration i.e. zirconium oxychloride followed by hydrolysis. The morphology, structural, and textural properties of the reactive hybrid material Zr(OH)4@GAC were examined using several analytical techniques including powder x-ray diffraction, TGA, FT-IR, BET, SEM, EDX, and TEM. Furthermore, the degradation capability of Zr(OH)4@GAC was evaluated in the hydrolytic abatement of CWAs sarin and sulphur mustard. Under pristine laboratory conditions, the effectiveness of reactive hybrid material Zr(OH)4@GAC has been attributed due to a combination of defects and diverse surface hydroxyl species of Zr(OH)4, as well as a high surface area carbon matrix. The impact of water content and temperature on CWAs degradation was also investigated by altering the water percentage from 2 to 8 % and the temperature 25 °C to 45 °C. The GC–MS/GC technique was used to observe the kinetics of in-situ degradation of CWAs over Zr(OH)4@GAC The results indicated that the degradation process follows a first-order reaction kinetics. It is observed that higher water content along with elevated temperature enhance CWA decomposition on Zr(OH)4@GAC; conversely, at lower temperature, it slowed down the degradation of CWAs. This significant enhancement in the decontamination capability of hybrid materials Zr(OH)4@GAC towards CWAs was attributed to the synergistic effects of GAC (adsorption capacity) coupled with the reactive functional group of Zr(OH)4.This strategy will pave the way for the development of self-detoxifying adsorbent material for environmental and defence purposes.

Effective decontamination of DR-81 dye from aqueous solutions using eco-friendly graphene oxide nanoparticles.

Effective management of industrial and agricultural wastes requires a multifaceted approach that considers environmental, economic, and social factors. Our ability to recover resources and create a circular bioeconomy from agricultural waste can be enhanced by implementing sustainable methods such as reducing, reusing, and recycling it. Active graphene oxide (GO) was prepared through the gasification of agricultural waste and further mixed with FeAlOx catalyst for three hours at 800°C as an efficient adsorbent. The synthesized material was comprehensively characterized using Fourier-transform infrared spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller surface area analysis, and thermal gravimetrical analysis. In order to remove direct red 81 (DR-81) dye from wastewater, the synthesized nanomaterial was implemented as an effective adsorbent. Several processing variables, including pH, contact time, and dosage, were studied to examine the optimum conditions that directly influence the DR-81 decontamination of onto the fabricated GO. The optimal dosage from the synthesized GO for DR-81 decontamination was 0.5g/L at pH = 7 after 30min. At pH 7.0 and 25°C, the produced GO had the highest sorption capacity of 132.14mg/g towards the DR-81. In addition, equilibrium and kinetic studies were capably fitted via the Freundlich and pseudo-second-order models, respectively. As a result of its particular properties, which include a high surface area, adsorption capacity, structural robustness, variation tolerance, and thermal stability. These promising findings supported the usage of synthesized GO as a superior adsorbent material for DR-81 decontamination from wastewater.

Magnetic CuFe2O4 Nanoparticles Immobilized on Modified Rice Husk-Derived Zeolite for Chlorogenic Acid Adsorption

Adsorption has emerged as a promising method for removing polyphenols in water remediation. This work explores chlorogenic acid (CGA) adsorption on zeolite-based magnetic nanocomposites synthesized from rice husk waste. In particular, enhanced adsorbing materials were attained using a hydrothermal zeolite precursor (Z18) synthesized from rice husk and possessing a remarkable specific surface area (217.69 m2 g−1). A composite material was prepared by immobilizing magnetic copper ferrite on Z18 (Z18:CuFe2O4) to recover the zeolite adsorbent. In addition, Z18 was modified (Z18 M) with a mixture of 3-aminopropyltriethoxysilane (APTES) and trimethylchlorosilane (TMCS) to improve the affinity towards organic compounds in the final nanocomposite system (Z18 M:CuFe2O4). While the unmodified composite demonstrated inconsequential CGA removal rates, Z18 M:CuFe2O4 could adsorb 89.35% of CGA within the first hour of operation. Z18 M:CuFe2O4 showed no toxicity for seed germination and achieved a mass recovery of 85% (due to a saturation magnetization of 4.1 emu g−1) when an external magnetic field was applied. These results suggest that adsorbing magnetic nanocomposites are amenable to CGA polyphenol removal from wastewater. Furthermore, the reuse, revalorization, and conversion into value-added materials of agro-industrial waste may allow the opportunity to implement sustainability and work towards a circular economy.

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.

Modified gum ghatti based hybrid hydrogel nanocomposite as adsorbent material for dye removal from wastewater

A hybrid hydrogel nanocomposite based on the polysaccharide-gum ghatti, has been made and evaluated as an adsorbent material for wastewater treatment. The nanocomposite is composed of a network of gum ghatti-graft-poly(2-acrylamido-2-methylpropane sulfonic acid) with magnetite nanoparticles embedded within. This functional material Ggh-g-PAMPS/Fe3O4 has been characterized by FTIR, TGA, SEM, EDS, XRD, BET and VSM techniques. The presence of magnetite nanoparticles imparted superparamagnetic property to the adsorbent material enabling its easy separation after use with an external magnet. The characterization data indicated mesoporous nature of the nanocomposite adsorbent with mean pore diameter of 4.9 nm. The nanoparticles imparted high surface area to the adsorbent material the value being 4.7 m2g−1 based on nitrogen adsorption experiments. The suitability of the material as an adsorbent for removal of cationic dyes from water was checked with two cationic dyes namely, rhodamine 6G and methylene blue. The maximum adsorption capacity of the nanocomposite Ggh-g-PAMPS/Fe3O4 towards rhodamine 6G and methylene blue were observed to be 403.2 and 427.8 mg g−1 respectively from their individual solutions of concentration 500 mg L−1. The pH dependence on swelling and surface charge indicated medium of pH of 7.0 as the ideal condition for effective adsorption. Freundlich isotherm model and pseudo second order kinetic model are observed to be the most befitting models to describe adsorption. Further, the thermodynamic studies revealed the adsorption to be a spontaneous and endothermic process. The desorption study portrayed the reusability of the adsorbent material. The excellent adsorption performance and magnetic nature of the developed nanocomposite suggests its potential application as an adsorbent material in wastewater treatment.

Constructing SDBS-intercalated MoS2 nanosheets confined and near-vertically grown on network biochar adsorbent: Insights into highly efficient co-adsorption of ciprofloxacin and lead ions

To overcome the problems of the weak adsorption ability of biochar to heavy metal ions (HMIs) and competitive adsorption between HMIs and antibiotics during co-adsorption, the adsorbent material in which 2D sodium dodecylbenzenesulfonate-intercalated molybdenum disulfide nanosheets confined and growing near-vertically on 3D network biochar (SDBS-MoS2/BC) was synthesized. The SDBS-MoS2/BC demonstrated good adsorption ability for ciprofloxacin (CIP) and lead ions (Pb2+). Notably, the adsorption capacity of SDBS-MoS2/BC for the target in the binary system remains higher than in the single system, even at elevated concentrations of the competing target (Qmax,CIP = 393.701 mg g−1, Pb2+: 100 mg/L; Qmax,Pb = 264.550 mg g−1, CIP: 100 mg/L). This may be due to the improvement in the utilization of edge/interlayer adsorption sites by the near-vertical SDBS interlayer expansion of MoS2 as a heavy metal ion anchor. Furthermore, the spatial difference between the upper edge site of near-vertical SDBS-MoS2 and the BC plane, that is, the “longitudinal steric effect”, can separate the CIP and Pb2+ adsorptions in a different horizontal plane to avoid competitive adsorption. The underlying adsorption mechanism was elucidated through a series of experiments and the analysis of characterization results. Furthermore, the load of the SDBS-MoS2/BC sponge-packed column can continuously remove contaminants from water. The rapid, anti-interference, multifunctional and reusable properties make SDBS-MoS2/BC promising for excellent environmental treatment.

Supervised machine learning-based categorization and prediction of uranium adsorption capacity on various process parameters

Existing uranium poses significant dangers to the environment and the general population's health. Within the scope of this study, machine learning techniques were utilized to assess the characteristics that influence uranium adsorption. The adsorbent material, pH, temperature, solid-liquid ratio (SLR), and initial concentration (Ci) values were imported as the feature to evaluate using ML models in this study. The finding concluded that the Convolutional Neural Network (CNN) model performed excellently by attaining an accuracy of 98%, which is very high in classifying low and high levels of adsorption predictions. The Random Forest model was also the best performer for Qe prediction, with the lowest MSE value of 334.45 and the highest Squared-R score of 0.92 for the uranium adsorption process. Permutation Importance analysis indicated that initial concentration had the strongest impact on Qe. Knowing that a good interaction between uranyl ions and adsorbent surface would result in more active sites for trapping radioactive metal, optimizing this parameter can be quite helpful for designing new materials capable of capturing uranium species strongly from solutions. ML model excels at predicting Qe in uranium adsorption and can directly accommodate large datasets and non-linear input parameter-Qe interactions. As noted, the innovation poised to drive ML research has been made possible by recent technological developments in machine learning and can improve while offering new ways of addressing difficult environmental problems.

An eco-friendly strategy for emerging contaminants removal in water: Study of the adsorption properties and kinetics of self-polymerized PHEMA in green solvents

Water contaminants severely affect human health and aquatic ecosystems, and adsorption poses an economic, available, and feasible technology for remediation that needs to be accompanied by eco-friendly and sustainable materials. This study proposes an eco-friendly strategy for removing emerging contaminants using polyhydroxyethyl methacrylate polymers synthesized by self-polymerization with hydrophilic first-generation deep eutectic solvents. The polymers were characterized using structural and physical characterization techniques and their adsorption capacity against four emerging contaminants: a non-steroidal anti-inflammatory drug, an antibiotic, a pesticide, and a non-ionic surfactant. The experimental results showed high adsorption capacity for the urea: choline chloride-derived polymer with 6.21, 7.19, 6.01, and 6.99 mg⋅g-1 for paracetamol, ciprofloxacin, glyphosate, and triton X-100, respectively; these values are comparable to those obtained for similar systems. Kinetic, isothermal, and thermodynamics were also studied using various mathematical models to understand the adsorption mechanism, further complemented by DFT analysis. Chemisorption was found to be the primary mechanism by exothermic and ordered processes, which is thermodynamically favored. The study demonstrated for the first-time the effectiveness of self-polymerized PHEMA without chemical modification as a reusable adsorbent material and its ability to remove different types of emerging contaminants, thereby offering a promising solution for water treatment in environmental science.

Mitigation of phosphorus contamination from livestock farms with La-containing hydrochar adsorbent

Phosphorus releases from livestock and poultry farms cause environmental contamination that must be mitigated through robust and effective recycle technologies. Lanthanum-modified hydrochars (La-HCN) prepared via mechanochemical modification had 96.8 mg g−1 phosphorus adsorption capacities and unprecedented fast uptake rates (half-maximum absorption capacity in 1.5 min). Presence of nitrogen in the hydrochars enhanced ion electrostatic interactions between lanthanum and carbon and accelerated phosphorus adsorption, which was confirmed theoretically with density functional theory calculations. Life cycle assessment (LCA) on a one-animal one-year basis revealed that production of La-containing hydrochar required fewer resources, had lower greenhouse gas emissions (171 kg CO2) and lower environmental impact than comparable adsorbent materials. Phosphorus removal levels achieved using the La-HCN adsorbent on actual wastewater from livestock and poultry breeding farms reached an adsorption rate of 93.6 %, exceeded sewage effluent standards of China, US EPA and EU, thus, demonstrate the practicality and scope of the developed technology.

Recent development on neem (azadirachta indica) biomass absorbent: surface modifications and its applications in water remediation

This review paper discusses the latest advances in transfiguring Azadirachta indica (neem) biomass into an adsorbent and how it can be used to clean the environment. As an economical and environmentally favorable adsorbent material, neem biomass has become increasingly popular due to its bioactive properties and abundance. The review breaks down modification techniques into chemical and physical processes. Important physical changes covered include preactivation, carbonization, and using fluidized bed technologies and rotary kilns. It has been shown that these methods greatly improve the surface properties of neem biomass, which makes it better at absorbing things and holding more. The changes that were made also have an effect on the adsorption kinetics and isotherms, which helps us understand the adsorption rates and equilibrium behaviors of the changed adsorbents better. Neem biomass adsorbents are illustrated through their versatility and efficacy in the removal of organic pollutants, dyes, and heavy metals from effluent. This is illustrated through specific applications. Additionally, computational studies and artificial intelligence are looked into to see if they can help us understand how adsorption works at the molecular level, improve the efficiency of modification processes, and guess how adsorption will behave. The review also talks about the research gaps and suggests areas for future research. The review emphasizes the crucial importance of integrating experimental and computational methods to enhance the performance of the modified neem biomass and increase its environmental cleaning potential.

Mixed Matrix PVDF Microfiltration Membranes with In-situ Synthesized Polyethyleneimine Particles as a Platform for Flow Through, High Capacity, Weak Base and Salt Tolerant Anion Exchange Membrane Adsorbers for Downstream Bioprocessing

The rapid growth of the monoclonal antibody (mAb) therapeutic market has led to a need for improved downstream bioprocessing, including mAb capture and release from bioreactor harvests followed by product purification and polishing. Membrane chromatography (MC) is poised to displace resin-based column chromatography in mAb product polishing. To remove negatively charged product impurities (e.g., host cell proteins, DNA, viruses, and endotoxins), anion exchange (AEX) membrane adsorbers offer higher process rates and eliminate the risks of cross contamination as they can be deployed as single use separation devices, which are increasingly being utilized in downstream bioprocessing to increase manufacturing speed and decrease production cost. Here, we describe a one-pot and single step phase inversion casting process for the preparation of a family of mixed matrix polyvinylidene fluoride (PVDF) microfiltration (MF) membranes with in-situ synthesized polyethyleneimine (PEI) microparticles that can serve as flow through, high capacity, and salt tolerant weak base AEX membrane adsorbers. These new membranes have a high content of weak base (WB) groups (primary and secondary amines) by virtue of the utilization of bis(2-chloroethyl)amine hydrochloride (BCAH) as crosslinker in the in-situ synthesis of PEI microparticles in the dope dispersions prior to membrane casting. By varying the concentration of PEI and BCAH in the casting dispersions, we successfully utilized nonsolvent induced phase separation (NIPS) with isopropyl alcohol as the nonsolvent in the membrane coagulation bath to prepare a mixed matrix PVDF-PEI MF membrane with (i) a relatively uniform and open microstructure in which the PEI particles completely cover the PVDF spherulites present at the membrane surface and cross section, (ii) high water flux (>1000 liters/m2/hr. at 2 bar) and (iii) a high loading of BCAH crosslinked PEI microparticles (51.0 wt.%) containing weak base primary, secondary, and tertiary amine groups. The protein binding measurements show that this new mixed matrix PVDF-PEI MF membrane can serve as a flow through, high capacity, and salt tolerant WB AEX membrane adsorber with a bovine serum albumin (BSA) dynamic binding capacity of ∼60 mg BSA per mL of membrane in a 50 mM TRIS buffer containing 100 mM of NaCl (15 mS/cm) at 10% breakthrough and flow rate of 10 MV/min. The overall results of this study indicate that our mixed matrix PVDF-PEI MF membranes with in-situ synthesized and BCAH crosslinked PEI microparticles have a promising potential to serve as a platform for the design, preparation, and scale up of a new generation of flow through, high capacity, salt tolerant, WB AEX membrane adsorber materials for downstream bioprocessing.

Amino acid functionalized carboxymethyl cellulose-based crosslinked aerogels for efficient removal of dye and metal ion from aqueous solution

In order to protect water resources and maintain sustainable development of society, it is crucial to design the adsorption materials with high adsorption capacity and environmental friendliness to effectively remove the pollutants in wastewater. In this study, amino acid functionalized carboxymethyl cellulose-based aerogels were successfully prepared by combining grafting, blending, freeze-drying and crosslinking technologies. The aerogels exhibited outstanding adsorption properties for methylene blue (MB) and lead ions (Pb (II)) with adsorption capacities of 461.68 and 304.60 mg/g, respectively. The adsorption experiment showed that the adsorption process of aerogels for MB conformed to Freundlich adsorption isotherm model and quasi-second-order kinetics model, and the adsorption process for Pb (II) conformed to Langmuir model and quasi-second-order kinetics model. Furthermore, the aerogels displayed excellent recyclability, with the removal efficiency of over 90.0 % for MB and only 14.0 % reduction for Pb (II) after 6 cycles. It is evident that the aerogels hold great potential for application in wastewater treatment, which has important practical significance for environmental protection and high-value utilization of natural polymers.

PVA-enhanced green synthesis of CMC-based lithium adsorption films

The titanium-based lithium ion sieve (HTO), renowned for its exceptional adsorption performance and cyclic stability, was utilized in addressing the global shortage of lithium resources. However, the recovery and reuse efficiency of HTO in powder form is relatively low, which limits its application in industrial fields. To address this issue, this study utilized carboxymethyl cellulose (CMC) as the principal matrix material, while polyvinyl alcohol (PVA) played a dual function as both matrix and crosslinker, negating the necessity for supplementary crosslinking materials. Employing water as the only solvent, HTO was embedded into the CMC-PVA blended film matrix. It was observed that augmenting the CMC content substantially elevates the adsorptive capability of the film. However, this enhancement comes at the cost of reduced mechanical robustness and diminished stability in solution. Consequently, by balancing the influence of adsorptive capacity and stability through fine-tuning the CMC-to-PVA ratio. Even when HTO powder is encapsulated within the film, the adsorption film retains the excellent adsorption properties of HTO, achieving an adsorption capacity for lithium of 29.21 mg g−1 within 12 h. This study provides an innovative pathway and ideas for the large-scale, low-cost production of sustainable lithium-ion adsorption materials.