A novel cellulose/chitosan composite nanofiltration membrane prepared with piperazine and trimesoyl chloride by interfacial polymerization

A review of valorization of agricultural waste for the synthesis of cellulose membranes: Separation of organic, inorganic, and microbial pollutants

Agricultural waste presents a significant environmental challenge due to improper disposal and management practices, contributing to soil degradation, biodiversity loss, and pollution of water and air resources. To address these issues, there is a growing emphasis on the valorization of agricultural waste. Cellulose, a major component of agricultural waste, offers promising opportunities for resource utilization due to its unique properties, including biodegradability, biocompatibility, and renewability. Thus, this review explored various types of agricultural waste, their chemical composition, and pretreatment methods for cellulose extraction. It also highlights the significance of rice straw, sugarcane bagasse, and other agricultural residues as cellulose-rich resources. Among the various membrane fabrication techniques, phase inversion is highly effective for creating porous membranes with controlled thickness and uniformity, while electrospinning produces nanofibrous membranes with high surface area and exceptional mechanical properties. The review further explores the separation of pollutants including using cellulose membranes, demonstrating their potential in environmental remediation. Hence, by valorizing agricultural residues into functional materials, this approach addresses the challenge of agricultural waste management and contributes to the development of innovative solutions for pollution control and water treatment.

Shell Distribution of Vitamin K3 within Reinforced Electrospun Nanofibers for Improved Photo-Antibacterial Performance

Personal protective equipment (PPE) has attracted more attention since the outbreak of the epidemic in 2019. Advanced nano techniques, such as electrospinning, can provide new routes for developing novel PPE. However, electrospun antibacterial PPE is not easily obtained. Fibers loaded with photosensitizers prepared using single-fluid electrospinning have a relatively low utilization rate due to the influence of embedding and their inadequate mechanical properties. For this study, monolithic nanofibers and core-shell nanofibers were prepared and compared. Monolithic F1 fibers comprising polyethylene oxide (PEO), poly(vinyl alcohol-co-ethylene) (PVA-co-PE), and the photo-antibacterial agent vitamin K3 (VK3) were created using a single-fluid blending process. Core-shell F2 nanofibers were prepared using coaxial electrospinning, in which the extensible material PEO was set as the core section, and a composite consisting of PEO, PVA-co-PE, and VK3 was set as the shell section. Both F1 and F2 fibers with the designed structural properties had an average diameter of approximately 1.0 μm, as determined using scanning electron microscopy and transmission electron microscopy. VK3 was amorphously dispersed within the polymeric matrices of F1 and F2 fibers in a compatible manner, as revealed using X-ray diffraction and Fourier transform infrared spectroscopy. Monolithic F1 fibers had a higher tensile strength of 2.917 ± 0.091 MPa, whereas the core-shell F2 fibers had a longer elongation with a break rate of 194.567 ± 0.091%. Photoreaction tests showed that, with their adjustment, core-shell F2 nanofibers could produce 0.222 μmol/L ·OH upon illumination. F2 fibers had slightly better antibacterial performance than F1 fibers, with inhibition zones of 1.361 ± 0.012 cm and 1.296 ± 0.022 cm for E. coli and S. aureus, respectively, but with less VK3. The intentional tailoring of the components and compositions of the core-shell nanostructures can improve the process-structure-performance relationship of electrospun nanofibers for potential sunlight-activated antibacterial PPE.

Recent progress of bacterial cellulose-based separator platform for lithium-ion and lithium‑sulfur batteries

Bacterial cellulose (BC) has recently attracted a lot of attention as a high-performance, low-cost separator substrate for a variety of lithium-ion (LIBs) and lithium‑sulfur batteries (LISs). BC-base can be used in the design and manufacture of separators, mainly because of its unique properties compared to traditional polyethylene/polypropylene separator materials, such as high mechanical properties, high safety, good ionic conductivity, and suitability for a variety of design and manufacturing needs. In this review, we briefly introduce the sources, production methods, and modification strategies of BC, and further describe the preparation methods and properties of BC battery separators for various LIBs and LISs.

The Performance of Cellulose Composite Membranes and Their Application in Drinking Water Treatment

Water scarcity and water pollution have become increasingly severe, and therefore, the purification of water resources has recently garnered increasing attention. Given its position as a major water resource, the efficient purification of drinking water is of crucial importance. In this study, we adopted a phase transition method to prepare ZrO2/BCM (bamboo cellulose membranes), after which we developed IP-ZrO2/BC-NFM (bamboo cellulose nanofiltration membranes) through interfacial polymerization using piperazine (PIP) and tricarbonyl chloride (TMC). Subsequently, we integrated these two membranes to create a combined "ultrafiltration + nanofiltration" membrane process for the treatment of drinking water. The membrane combination process was conducted at 25 °C, with ultrafiltration at 0.1 MPa and nanofiltration at 0.5 MPa. This membrane combination, featuring "ultrafiltration + nanofiltration," had a significant impact on reducing turbidity, consistently maintaining the post-filtration turbidity of drinking water at or below 0.1 NTU. Furthermore, the removal rates for CODMN and ammonia nitrogen reached 75% and 88.6%, respectively, aligning with the standards for high-quality drinking water. In a continuous 3 h experiment, the nanofiltration unit exhibited consistent retention rates for Na2SO4 and bovine serum protein (BSA), with variations of less than 5%, indicating exceptional separation performance. After 9 h of operation, the water flux of the nanofiltration unit began to stabilize, with a decrease rate of approximately 25%, demonstrating that the "ultrafiltration + nanofiltration" membrane combination can maintain consistent performance during extended use. In conclusion, the "ultrafiltration + nanofiltration" membrane combination exhibited remarkable performance in the treatment of drinking water, offering a viable solution to address issues related to water scarcity and water pollution.

Ag/AgBr/AgVO3 Photocatalyst-Embedded Polyacrylonitrile/Polyamide/Chitosan Nanofiltration Membrane for Integrated Filtration and Degradation of RhB

A nanofiltration (NF) membrane containing a NaOH-treated electrospun polyacrylonitrile (HPAN) substrate, an interfacial polymerization (IP) polyamide (PA) layer, a chitosan (CS) coating layer, and an Ag/AgBr/AgVO₃ photocatalyst loading layer was prepared. The structural evolution of the membranes was investigated, and their performance was estimated in accordance with the water flux and rejection rate. A probable mechanism for the photocatalytic activity of Ag/AgBr/AgVO₃ was proposed. The loading of the Ag/AgBr/AgVO₃ heterojunction on the HPAN/PA/CS NF membrane endowed the membrane with excellent self-cleaning properties owing to the photolytic degradation of the dye. The filtration and degradation processes of the Ag/AgBr/AgVO₃-loaded membrane constantly promoted each other, and the treatment efficiency achieved with the integrated (filtration + degradation) process was superior to those obtained with the filtration and degradation processes alone. The Ag/AgBr/AgVO₃-NF membrane exhibited excellent recyclability and stability when subjected to five integrated filtration-degradation processes. In addition, the Ag/AgBr/AgVO₃-NF membrane exhibited an elastic modulus of 65.75 MPa and a toughness of 38.9 kJ/m³ along with a good disinfection effect on Escherichia coli in visible light. The as-prepared photocatalyst-loaded NF membrane with excellent antifouling performance, antimicrobial activity, high strength, and recyclability showed potential for continuous water purification operation.

Removal of chloride from water and wastewater: Removal mechanisms and recent trends

Increased chloride concentration can cause salinization, which has become a serious and widespread environmental problem nowadays. This review aims at providing comprehensive and state-of-the-art knowledge and insights of technologies for chloride removal. Mechanisms for chloride removal mainly include chemical precipitation, adsorption, oxidation and membrane separation. In chemical precipitation, chloride removal by forming CuCl, AgCl, BiOCl and Friedel's salt. Adsorbents used in chloride removal mainly include ion exchangers, bimetal oxides and carbon-based electrodes. Oxidation for chloride removal contains ozone-based, electrochemical and sulfate radical-based oxidation. Membrane separation for chloride removal consists of diffusion dialysis, nanofiltration, reverse osmosis and electrodialysis. In this review, we specifically proposed the factors that affect chloride removal process and the corresponding strategies for improving removal efficiency. In the last section, the remaining challenges of method explorations and material developments were stated to provide guidelines for future development of chloride removal technologies.

Modification of Orange Bagasse with Reactive Extrusion to Obtain Cellulose-Based Materials

Orange bagasse (OB) could be considered a sustainable, renewable, and low-cost biomass for the extraction of cellulose. In this context, reactive extrusion can be considered an excellent, eco-friendly, alternative process for the extraction of cellulose from lignocellulosic materials. Thus, the present study aimed to obtain cellulose-based materials with a reactive extrusion process and also to investigate the impact of pectin on the delignification process. Two groups of samples (OB and depectinizated OB) were submitted to extrusion with sulfuric acid or sodium hydroxide in one-step processes. The cellulose content of extruded materials was highly affected by pectin content in the raw material; the thermal profile (TGA curves) and crystallinity also changed. The cellulose content of modified materials ranged from 18.8% to 58.4%, with a process yield of 30.6% to 79.2%. The alkaline reagent provided the highest cellulose content among all extrusion treatments tested, mainly for OB without pectin. The extrusion process was considered an efficient and promising process for extracting cellulose from citrus residue. Materials produced in this study can be used as sources of cellulose fiber for various products and processes, such as in the food industry, fermentation substrates, or refined applications after subsequent treatments.

A review on super-wettable porous membranes and materials based on bio-polymeric chitosan for oil-water separation

Appropriate surface wettability of membranes and materials are of an extreme importance for targeting separation of mixtures/emulsions such as oil from water or conversely water from oil. The development of super-wettable membranes and materials surfaces have shown remarkable potential for recovering water from oil-water emulsion while offering maximum resistance to fouling. The availability of clean and potable water has been regarded as an important global challenge for coming human generations. Oil and gas industry is continuously producing immense quantities of waste stream regarded as produced water which contains oil dispersed in water along with other several components. Treating such immense quantities of oily wastewater is of utmost need for recovering precious water for possible reuse or safe disposal. Various technologies have been developed for targeting the separation of oil-water emulsions or mixtures to harness useful potable water and oil as products. Membrane-based separations or use of porous materials such as mesh have been explored in literature for separation of oil-water mixtures/emulsions. Given the unique features of special hydrophilicity, ease of tunability, control of molecular weight, abundant availability, and potential for commercial scale up, chitosan has been extensively used for modifying membranes/meshes or preparing composites with other materials for oil-water separations. This review has described in detail the synthesis, methods of modification and application of chitosan-based super-wettable membranes/meshes and porous materials for oil-water separation. The special wettability features including super-hydrophobicity/superoleophilicity, super-oleophobicity/super-hydrophilicity and super-hydrophilicity/underwater super-oleophobicity of various chitosan-based membranes and materials have been discussed in detail in the review. The strategies for enhancing or developing special wettability for target specific applications have also been discussed. Finally, the challenges, their respective importance have been identified along with a discussion on possible solutions to these challenges.

Fabrication of Poly(amide-co-ester) Solvent Resistant Nanofiltration Membrane from P-nitrophenol and Trimethyl Chloride via Interfacial Polymerization

P-nitrophenol (PNP), a refractory hazardous substance, has not been efficiently utilized so far. In this paper, PNP is used as a membrane modification material for preparing poly(amide-co-ester) composite nanofiltration membrane. An organic solvent nanofiltration (OSN) membrane was prepared via interfacial polymerization reactionby using PNP and trimethyl chloride (TMC) on a ethylenediamine (EDA) crosslinked polyetherimide substrate. The results of ATR-FTIR and XPS show that interfacial polymerization occurs among with PNP and TMC and the terminal amine groups on the ethylenediamine crosslinked -PEI support forming a poly(amide-co-ester) toplayer. The NF-1PNP membrane maintained stable DMF performance permeance of 2.2 L m−2 h−1 bar−1 and rejection of 98% for Rose Bengal red (RB 1017.64 g mol−1) in 36 h continuous separation process. Furthermore, the average pore diameter of the two membranes including NF-1PNP and NF-1.25PNP, which is 0.40 and 0.36nm, respectively. This study not only provides a good way for the preparation of OSN membrane, but also provides a good demonstration for the comprehensive utilization of PNP and other toxic and harmful pollutants.

Preparation and Characterization of Regenerated Cellulose Membrane Blended with ZrO2 Nanoparticles

It is of great significance to search for efficient, renewable, biodegradable and economical membrane materials. Herein, we developed an organic-inorganic hybrid regenerated cellulose membrane (ZrO2/BCM) with excellent hydrophilic and anti-fouling properties. The membrane was prepared by introducing ZrO2 particles into an N-Methylmorpholine-N-oxide(NMMO)/bamboo cellulose(BC) solution system by the phase inversion method. The physi-chemical structure of the membranes were characterized based on thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (ATR-FTIR), field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD). The modified regenerated cellulose membrane has the excellent rejection of bovine serum albumin (BSA) and anti-fouling performance. The membrane flux of ZrO2/BCM is 321.49 (L/m2·h), and the rejection rate of BSA is 91.2%. Moreover, the membrane flux recovery rate after cleaning with deionized water was 90.6%. This new type of separation membrane prepared with green materials holds broad application potential in water purification and wastewater treatment.

Biopolymer-Based Membrane Adsorber for Removing Contaminants from Aqueous Solution: Progress and Prospects

The demand for energy-efficient water treatment as well as the limitation in adsorption of existing membranes has motivated the pursuit of membranes that can break the selectivity-permeability trade-off and provide high selective adsorption for chemicals of interest. The membrane adsorbers have received a lot of attention for removing contaminants from aqueous solution due to combine both advantages of adsorption and membrane separation. Membrane adsorbers constructed by biopolymer with many functional groups are widely used in water purification, because the biopolymers are easily available from biomass materials in nature, degradable, and low-cost. This paper summarizes the characteristics and important development direction of these types of biomass-based membrane adsorption materials to adsorb organic/inorganic contaminants of water and analyzes the preparation methods of natural biomacromolecule cellulose, chitosan, sodium alginate, and protein to construct the membrane adsorption materials, as well as the application of pollutant removal from aqueous solutions. According to the current problems and shortcomings in the research of biopolymer-based membrane adsorbers, it is proposed to improve the understanding of the adsorption mechanism of biopolymer-based membrane adsorbers and accelerate the development of practical applications as the focus of future research.

Multi-ionic electrolytes and E.coli removal from wastewater using chitosan-based in-situ mediated thin film composite nanofiltration membrane

This work presents the experimental investigation of flat sheet composite nanofiltration membrane synthesized with chitosan nanoparticles through interfacial polymerization of piperazine with trimesoyl chloride on polyethersulfone/sulfonated polysulfone substrates. The synthesized membrane was tested in wastewater treatment containing inorganic salts and E.Coli. Single binary electrolyte solution of KCl, MgCl₂, MgSO_4, and Na₂SO₄, ternary electrolyte solution, containing a combination of MgCl₂ and MgSO₄, KCl and MgCl₂ and quaternary electrolyte solution of KCl, MgCl_2, and MgSO₄ as feed were treated in crossflow membrane cell for the water flux and species rejection in the permeate under operating pressure up to 0.5 MPa. The rejection of Na¹⁺, K¹⁺, Mg²⁺, Cl^1-, and SO₄^2- was observed to be 81, 28, 87, 96, and 98%, respectively with an average water flux up to 214 ± 10 L m⁻².hr⁻¹ in the permeate for the binary electrolyte solution. Similarly, the rejection for K¹⁺, Mg²⁺, Cl^1- and SO₄^2- was noted to be 33, 94, 97, and 99%, respectively, for ternary electrolyte solution with an average water flux up to 211 ± 10 L m^-2.hr^-1. The quaternary ion system in the feed resulted in an average water flux up to 198 ± 12 L m⁻².hr⁻¹ with the rejection of K⁺, Mg⁺², Cl^- and SO₄^-2 as 35, 87, 96, and 99%, respectively. The model feed solution of E. coli after passing through the membrane achieved an E. coli rejection (99%) with water flux up to 220 L m^-2.hr^-1.

Cellulose-based special wetting materials for oil/water separation: A review

Oil spill accidents and oily wastewater discharged by petrochemical industries have severely wasted water resources and damaged the environment. The use of special wetting materials to separate oil and water is efficient and environment-friendly. Cellulose is the most abundant renewable resource and has natural advantages in removing pollutants from oily wastewater. The application and modification of cellulose as special wetting materials have attracted considerable research attention. Therefore, we summarized cellulose-based superlipophilic/superhydrophobic and superhydrophilic/superoleophobic materials exhibiting special wetting properties for oil/water separation. The treatment mechanism, preparation technology, treatment effect, and representative projects of oil-bearing wastewater are discussed. Moreover, cellulose-based intelligent-responsive materials for application to oil/water separation and the removal of other pollutants from oily wastewater have also been summarized. The prospects and potential challenges of all the materials have been highlighted.

Valorization of orange bagasse through one-step physical and chemical combined processes to obtain a cellulose-rich material

BACKGROUND

Orange bagasse (OB) is an agroindustrial residue of great economic importance that has been little explored for the extraction of cellulose. The present study aimed to investigate different combinations of chemical (sodium hydroxide, peracetic acid and alkaline peroxide) and physical (autoclaving and ultrasonication) treatments performed in one-step processes for cellulose extraction from OB and to characterize the materials obtained according to their composition, morphology, crystallinity and thermal stability.

RESULTS

The processing yields ranged from 140 to 820 g kg^-1 , with a recovery of 720-1000 g kg^-1 of the original cellulose. Treatments promoted morphological changes in the fiber structure, resulting in materials with higher porosity, indicating partial removal of the noncellulosic fractions. The use of combined chemical treatments (NaOH and peracetic acid) with autoclaving was more efficient for obtaining samples with the highest cellulose contents.

CONCLUSION

Therefore, AC_SH (processed by autoclaving with NaOH) was the most effective one-step treatment, resulting in 71.1% cellulose, 0% hemicellulose and 19.0% lignin, with a crystallinity index of 42%. The one-step treatments were able to obtain materials with higher cellulose contents and yields, reducing reaction times and the quantity of chemical reagents employed in the overall processes compared to multistep conventional processes. © 2020 Society of Chemical Industry.

Toughened chitosan-based composite membranes with antibiofouling and antibacterial properties via incorporation of benzalkonium chloride

Biofouling due to biofilm formation is a major problem in ultrafiltration membrane applications. In this work, a potential approach to solve this issue has been developed by functionalization of chitosan-based membranes with benzalkonium chloride (BKC). The chitosan composite membranes consisting of poly(ethylene glycol) (PEG), multiwalled carbon nanotubes (MWCNT), and BKC were synthesized by mixing the membrane precursors and the antibacterial solution, and casting via an inversed phase technique. The effects of the BKC content on the morphology and performance of the membranes are investigated by varying the BKC feed compositions. The composite membranes demonstrate better antibacterial efficacy against Staphylococcus aureus than Escherichia coli. The permeability and selectivity performances of the composites as filter membranes are examined by employing a dead-end filtration system. Interestingly, enhanced toughness of the membranes is observed as a function of the BKC content. Mechanisms of the structural formation are investigated. The results from SEM, XRD, and FTIR spectroscopy revealed that MWCNT/BKC are located as nanoclusters with π–π stacking interactions, and are covered by PEG chains. The shape of the dispersed domains is spherical at low BKC contents, but becomes elongated at high BKC contents. These act as soft domains with an anisotropic shape with toughening of the brittle chitosan matrix, leading to enhanced durability of the membranes, especially in ultrafiltration applications. The composite membranes also demonstrate improved rejection in dead-end ultrafiltration systems due to high porosity, high hydrophilicity, and the positive charges of the membrane surface.

Chitosan/PEG/MWCNT/BKC membranes exhibit enhanced antibiofouling properties against S. aureus and E. coli. MWCNT/BKC are located as dispersed nano-clusters with π–π stacking interactions in the chitosan matrix, and are coved by PEG chains.

Ultra-low pressure cellulose-based nanofiltration membrane fabricated on layer-by-layer assembly for efficient sodium chloride removal

Cellulose is a renewable, biodegradable, biocompatible, and sustainable material. A bamboo cellulose-based nanofiltration membrane (LBL-NF-CS/BCM) was prepared with a combination of layer-by-layer assembly and spraying methods. The chemical structure, morphology, and surface charge of the resultant LBL-NF-CS/BCM composite membranes were characterized based on Thermo Gravimetric Analysis (TGA), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and X-ray Photoelectron Spectroscopy Scanning (XPS). The nanofiltration performance of the LBL-NF-CS/BCM composite membranes was evaluated using 500 ppm NaCl solutions under 0.3 MPa pressure. It was found that the LBL-NF-CS/BCM composite membranes had a rejection rate of about 36.11 % against a 500 ppm NaCl solution under the conditions tested, and membrane flux of about 12.08 L/(m² h) was reached. The combined layer-by-layer assembly and spraying provides a scalable and convenient process concept for nanofiltration membrane fabrication.