Fibrous Adsorbent Research Articles

PE/PP fibrous adsorbents with bifunctional groups of tertiary amine and phosphate prepared by electron beam induced co-grafting for heavy metal adsorption of both cationic and anionic forms in acidic conditions.

A novel fabric adsorbent having bifunctional groups of tertiary amine and phosphate was prepared by co-graft polymerization of 2-diethylaminoethyl methacrylate (NMA) and 2-hydroxyethyl methacrylate phosphate (PMA) onto a polyethylene/polypropylene nonwoven fabric (PE/PP NF) under low-energy electron beam acceleration. The process involved pre-irradiating the fabric and immersing it in the comonomer solution for grafting. The kinetics of radiation-induced graft polymerization at a total dose of 100 kGy was investigated. For pre-irradiation at 100 kGy, the optimum condition offering highest degree of grafting was at 12 wt% of NMA, 8 wt% of PMA and 4 h of reaction time. The adsorption of anions using hydrogen chromate (HCrO4−) or Cr(VI) and cations using lead (Pb(II)), cadmium (Cd(II)) and copper (Cu(II)) in aqueous solution was carried out. The results demonstrated that the bifunctional adsorbent was able to adsorb both heavy metal anionic and cationic ions from water. The co-grafted adsorbents with tertiary amine and phosphate were able to adsorb 85% Cr(VI) anion and 29% Pb(II) cations from mixed Cr(VI) and Pb(II) solution at pH 3.0 and 71% Pb(II), 13% Cd(II) and 31 % Cu(II) from mixed Pb(II), Cd(II) and Cu(II) solution at pH 5.0. The unique achievement of this study is its hypothesis that a bifunctional adsorbent can be prepared from radiation-induced graft polymerization of two different monomers onto NF, along with proof that the prepared bifunctional adsorbent can actually absorb both cationic or anionic heavy metals forms. Additionally, the adsorbent's preparation offers a rapid and straightforward one-step grafting technique. Therefore, the new bifunctional adsorbents can remove heavy metal ions in aqueous solution, either in the cation or anion form, thus offering highly promising applications in industrial wastewater treatment.

Versatile Keratin Fibrous Adsorbents with Rapid-Response Shape-Memory Features for Sustainable Water Remediation.

Biodegradable shape-memory polymers derived from protein substrates are attractive alternatives with strong potential for valorization, although their reconstruction remains a challenge due to the poor processability and inherent instability. Herein, based on Maillard reaction and immobilization, a feather keratin fibrous adsorbent featuring dual-response shape-memory is fabricated by co-spinning with pullulan, heating, and air-assisted spraying ZIF-8-NH2. Maillard reaction between the amino group of keratin and the carbonyl group of pullulan improves the mechanics and thermal performance of the adsorbent. ZIF-8-NH2 immobilization endows the adsorbent with outstanding multipollutant removal efficiency (over 90%), water stability, and photocatalytic degradation and sterilization performance. Furthermore, the adsorbent can be folded to 1/12 of its original size to save space for transportation and allow for rapid on-demand unfolding (12 s) upon exposure to water and ultraviolet irradiation to facilitate the adsorption and photocatalytic activity with a larger water contact area. This research provides new insight for further applications of keratin-based materials with rapid shape-memory features.

Microwave assisted synthesis of ion-imprinted polyacrylonitrile fibre via one-step phosphorylation for selective recovery of Dy(III) from wastewater

The selective recovery of Dy(III) from wastewater is highly desirable. Ion imprinted fibers are considered as attractive adsorbents due to their low flow resistance, high selectivity and ease of recovery. Phosphate groups with strong affinity to rare earth ions are widely used to construct ion imprinted polymers. However, current approaches for introducing phosphate groups into fibers suffer from the low grafting percentage and long reaction time because of the complicated procedures. Herein, a simple one-step phosphorylation method was explored to simultaneously introduce highly active primary amine and phosphate groups into polyacrylonitrile fiber (PANF) under microwave assisted conditions. Additionally, an unique Dy(III) ion-imprinted fibrous adsorbent (IIF-3) was fabricated by cross-linking of the aminated and phosphorylated PANF for selective capture of Dy(III) from wastewater. The advantages of this innovative technology in synthesizing fibrous adsorbent include: short reaction time, high phosphonic content and good mechanical property. In addition, batch sorption tests reveal that the uptake of Dy(III) onto IIF-3 is well described by the Langmuir isotherm and pseudo-second order models. Besides, IIF-3 exhibits a high adsorption selectivity for Dy(III) in multi-component system with different types of interfering ions. Importantly, benefiting from the protective effect of surface imprinting layer, the IIF-3 not only achieves enhanced mechanical property, but also shows satisfied reusability in six times application. This work opens a novel path to prepare phosphorylated ion-imprinted fibers and sheds light on their applications for selective capture of Dy(III) from wastewater.

Efficient and selective gold recovery using amine-laden polymeric fibers synthesized by a steric hindrance strategy

Various alkylamines are commonly used for efficient Au recovery; however, their high hydrophilicity can result in dissolution in water, hindering effective Au recovery and potentially causing environmental contamination. Currently, the forms in which alkylamines are immobilized on supports provide unsatisfactory Au recovery capabilities and exhibit low structural stability. This study proposes a pragmatic approach for synthesizing amine-laden polymeric fiber (ALPF) adsorbents with efficient Au recovery capabilities and superior structural stability. Polyacrylonitrile fibers (PANF) were employed as a supportive matrix to immobilize the alkylamine molecules chemically. The densely grafted amine groups on the ALPF adsorbed significant amounts of Au ions and reduced them to Au(0) crystals. This chelation–precipitation hybrid method achieved a Au recovery efficiency of nearly 100 % over a wide pH range of 1–4. In addition, it demonstrated an exceptional Au adsorption capacity of 1463 mg/g, surpassing the values reported for other adsorbents categorized by size and shape. Even in the presence of 14 different coexisting metal ions, the ALPF showed a Au recovery efficiency above 99.9 %. It also exhibited excellent reusability, maintaining a Au recovery rate of ∼91 % after 10 cycles. Furthermore, fibrous adsorbents alleviated the pressure drop in columns filled with adsorbents, thereby enabling energy-efficient and environment-friendly processes.

High mechanical property and hydrophilic electrospun poly amidoxime/poly acrylonitrile composite nanofibrous mats for extraction uranium from seawater

Seawater reserves about 4.5 billion tons of uranium, if properly extracted, could be a sustainable green energy resource for hundreds of years, alternating its limited terrestrial ore and reducing the CO2 emitted from fossil fuels. The current seawater uranium adsorbents suffer neither economically viable nor adsorption efficiency, requiring more development to harvest satisfactorily uranium from seawater. Amidoxime-based fibrous adsorbents are the most promising adsorbents of seawater uranium due to abundant chelating sites. However, they suffer from severe shrinkage and stiffness once they dry, losing porous architecture and mechanical properties. Herein, an economical and scalable two-nozzle electrospinning technology was applied to produce poly amidoxime nanofibers (PAO NFs) supported by Poly acrylonitrile nanofibers (PAN NFs) as composite PAO/PAN nanofibrous mats with high structure stability. These PAO/PAN mats, with rapid wettability and excellent mechanical strength, show promising uranium adsorption capacities of 369.8 mg/g at seawater pH level, much higher than PAO and PAN NFs. The uranium adsorption capacity of the PAO/PAN mat reached 5.16 mg/g after 7 days of circulating (10 ppm uranium) spiked natural seawater. Importantly, the composite mat maintained its fibrous structure after five adsorption-desorption cycles with more than 80 % of its adsorption capacity, confirming its recyclability and stability. Therefore, the composite PAO/PAN mat fulfills the basic requirements for effectively and economically trapping uranium from seawater, which could be a matrix for further development.

Fibrous adsorbents derived from polyphenolic chemistry for remediation of fluoride contamination at low concentrations

Fluoride contamination in drinking water is one of the most concerned environmental issues. Herein, a new type of fibrous adsorbent was prepared by polyphenolic chemistry enabled facile synthesis approach that was dependent on the surface modification of chitosan fibers (CF) with plant polyphenols, followed by the chelation with Zr(IV) (CF-Zr). The presence of plant polyphenols allow for a facile and stable anchoring of Zr(IV) onto the CF, which provided sufficient active sites for the adsorption of fluoride at low concentrations. Notably, at low concentration of 2.0 mg/L, the CF-Zr was capable of removing 97.59 % of fluoride, which was considerably higher than commercial activated carbon (3.58 %). The outstanding adsorption performances of CF-Zr to fluoride was attributed to the Zr(IV), which provided high affinity to fluoride by the formation of Zr-oxyfluoride species. The fibrous morphology of the CF-Zr guaranteed a fast adsorption process, with ∼ 30 min to reach the adsorption equilibrium. The Langmuir model well fitted the adsorption isotherms, and the corresponding equilibrium adsorption capacity was determined to be 74.52 mg g−1, close to the experimentally determined maximum adsorption capacity (77.04 mg g−1). The fluoride adsorbed onto the CF-Zr was desorbed by NaOH solution, with the desorption percentage of 90.22 %.

Study on the uranium adsorption and reusability characteristics of amidoximated polypropylene-acrylonitrile-acrylic acid fibrous adsorbent

Study on the uranium adsorption and reusability characteristics of amidoximated polypropylene-acrylonitrile-acrylic acid fibrous adsorbent

Bionic multifunctional fibrous materials for efficient oil/water separation

AbstractSpecial wettability fibrous materials have received a lot of attention because of their good connectivity, mechanical flexibility, large specific surface area, and ease of shape manipulation. Their outstanding performance paves the way toward efficient oil/water separation in a variety of environments and for separation requirements. This paper discusses the distinct advantages, challenges, and future research directions of various substrates for fibrous materials, such as nonwoven natural biomass fibers, fabrics, electrospinning fibers, metallic fibers, and inorganic nonmetallic fibers. The special wettability fibrous filter materials and fibrous adsorbents are summarized based on the different separation methods. The principles of preparation of various special wettabilities are introduced, and the unique advantages of fibrous adsorbents are emphasized. The preparation strategy of fibrous filter materials is discussed, as well as some representative work and research progress. The benefits, drawbacks, and research directions in terms of various materials are examined. This article emphasizes the pollution resistance of fibrous filter materials and the elasticity of fibrous adsorbents. Finally, the prospects in terms of the problems, challenges, and future development of special wettability fibrous materials used in oil/water separation are discussed.

Improving toxic dye removal and remediation using novel nanocomposite fibrous adsorbent

Materials with regulated nanoscale morphology provide capabilities to remove dangerous pollutants from wastewater, by adsorption. In this study, the chitosan-based composite fibrous adsorbent was fabricated and used as a novel and facile eliminator in the process of removing cationic methyl orange (MO) from the water medium. Different methods were applied to check the properties of the desired composite fibrous adsorbent. The removal value showed that the chitosan-embedded composite fibrous adsorbent has super characteristics and can be removed the organic dye from the water. The influence of pH, time, temperature, eliminator quantity, and MO content was explored. With increasing time and eliminator quantity, the adsorption efficiency increased. The composite fibrous adsorbent with the advantage of its high functionality and combined micro-nanomorphology features, has emerged as a very promising candidate for obtaining versatile and robust adsorbents. This work presents how the tunned synthesis of composite fibrous adsorbent tailored their nanoarchitecture giving rise to adsorption capacities toward cleaning aqueous samples polluted with MO dye. The composite fibrous adsorbent was prepared by the direct immobilization method, with normal aging temperature, in order to study the effect of synthesis conditions on the adsorption properties of MO dye. The solution acidity was exhibited as the key factor, and a suitable pH of 5.50 was selected based on the efficiency. The competing ions were not adversely affected in the dye adsorption as defined by the stable bonding mechanism. The adsorption data were highly fitted with the Langmuir adsorption model with monolayer coverage. The determined maximum adsorption was 175.45 mg/g, which was comparable with the other forms of materials. The adsorbed MO dye elution was evaluated using ethanol and then the composite fibrous adsorbent was ready to use for MO dye adsorption after washing with water without significant loss in its functionality. Therefore, we explored the tunned morphology of composite fibrous adsorbent for obtaining performant adsorbents for the elimination of refractory pollutants in wastewater.

Moving adsorption belt system for continuous bioproduct recovery utilizing composite fibrous adsorbents.

A continuous protein recovery and purification system based on the true moving bed concept is presented. A novel adsorbent material, in the form of an elastic and robust woven fabric, served as a moving belt following the general designs observed in known belt conveyors. The composite fibrous material that forms the said woven fabric showed high protein binding capacity, reaching a static binding capacity equal to 107.3mg/g, as determined via isotherm experiments. Moreover, testing the same cation exchange fibrous material in a packed bed format resulted in excellent dynamic binding capacity values (54.5mg/g) even when operating at high flow rates (480cm/h). In a subsequent step, a benchtop prototype was designed, constructed, and tested. Results indicated that the moving belt system could recover a model protein (hen egg white lysozyme) with a productivity up to 0.5mg/cm2/h. Likewise, a monoclonal antibody was directly recovered from unclarified CHO_K1 cell line culture with high purity, as judged by SDS-PAGE, high purification factor (5.8), and in a single step, confirming the suitability and selectivity of the purification procedure.

Investigation on the adsorption characteristics of pharmaceuticals and personal care products on polyethylenimine-alginate-activated carbon composite fiber

A new fibrous adsorbent, a composite of polyethylenimine, alginate, and activated carbon was developed for the removal of ionic and non-ionic pharmaceutical and personal care products (PPCPs) from aqueous phases. The adsorbent was conceptually designed to strongly adsorb charged and neutral PPCPs and to have a fibrous form for easy recovery after use. Instrumental analysis, isotherms, and modeling studies were used to characterize the adsorbent. The instrumental analysis provided the morphological properties, functional groups, and surface charges, and the isotherm study assisted in determining the adsorption affinity (Kd) of the adsorbent for various PPCPs. The measured ranges of log Kd were 1.22–1.82 for cations, 0.32–1.03 for anions, and 0.85–1.31 for non-ions. In addition, the effects of salts and wastewater on adsorption were examined. The results reveal that overall, the adsorbent has higher adsorption in salt-containing solutions and wastewater than pure water. In the modeling study, the quantitative structure-adsorption relationship was modeled to help rapidly estimate the Kd of any PPCPs. The developed model was highly predictable, i.e., R2 of 0.892–0.894 and a standard error in log units of 0.150–0.151. Notably, the modeling study revealed that ionic and hydrogen-bond interactions were the primary adsorption interactions for the adsorbent.

CO2 adsorption and CO2/CH4 separation using fibrous amine-containing adsorbents: isothermal, kinetic, and thermodynamic behaviours.

A series of fibrous aminated adsorbents for CO2 adsorption were prepared by covalent incorporation of poly (glycidyl methacrylate) (PGMA) by graft copolymerization of GMA onto electron beam (EB) irradiated polyethylenepolypropylene (PE/PP) fibrous sheets and subsequent amination with ethylenediamine (EDA), diethylenetriamine (DETA), or tetraethylenepentamine (TEPA). The physico-chemical properties of the adsorbents were evaluated using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric (TGA), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) analysis. All the adsorbents displayed typic primary and secondary amine features combined with a decrease in both of crystallinity and surface area of PE/PP, and such a decrease was higher in adsorbents with longer aliphatic chain of the amine. Of all adsorbents, TEPA-containing fibres showed the highest CO2 adsorption capacity and thus was further investigated for CO2 capture from CO2/CH4 mixtures of different gas ratios under various pressures and temperatures. The selectivity of CO2 over CH4 and equilibrium isotherms, kinetics, and thermodynamics of the adsorption on the fibrous aminated adsorbent were all investigated. The Sips model was found to best fit the isotherm of CO2 adsorption suggesting the presence of a combination of monolayer and multilayer adsorptions. The adsorption kinetic data was found to best fit Elovich model reflecting chemisorption. The ΔG°, ΔS°, and ΔH° showed positive values suggesting that the adsorption of CO2 on the present fibrous adsorbent was non-spontaneous with an increase in randomness implying that the process was endothermic. Overall, it can be suggested that PE/PP-g-PGMA/TEPA adsorbent has a strong potential for separation of CO2 from NG.

Radiation-induced grafting of glycidyl methacrylate onto natural cotton fibers and trimethylamine modification for p-nitrophenol adsorption

The pre-irradiation grafting procedure was employed to achieve the grafting of natural cotton fibers (Cot) with glycidyl methacrylate (GMA). It was found that the extent of grafting (DG) of GMA was influenced by the dose of radiation that was absorbed; increased doses led to larger DGs. Dose of 10 kGy was chosen for the preparation of the GMA grafted cotton (Cot-g-GMA); this provided a DG of 200%. Subsequently, (Cot-g-GMA) was modified using Trimethylamine (TMA). In order to describe the physiochemical qualities of the fibrous adsorbent, the fibrous adsorbent was characterized with the use of FTIR, FESEM, XRD, TG-DTG, and pHpzc. In addition, the designed TMA(Cot-g-GMA) adsorbent was utilized to examine the adsorption of p-nitrophenol from aqueous solution. An examination was made of the adsorption kinetics and isotherm in order to permit the elucidation of the adsorption of p-nitrophenol behavior. In accordance with the findings emerging from this work, p-nitrophenol adsorption was described with a pseudo-second order. Moreover, the fact that the Langmuir isotherm model was the best fit was determined by the isotherm analysis. In relation to adsorption capacity, the maximum capacity achieved was 180 mg/g at 298 K. The spontaneous and exothermic nature of adsorption was identified by thermodynamic analysis. Specifically, it is evident that adsorbent can be readily reproduced and recycled with no accompanying loss of adsorptive performance in the alkaline medium. These findings indicate the potential of the fibrous bio adsorbent as a means of eliminating p-nitrophenol from wastewater.

Efficient removal of trace uranium from nuclear effluents using irradiation-functionalized fibrous adsorbents with very high salt tolerance

The extraction of uranium from nuclear effluents is both conducive to the recycling of nuclear fuel and reduces environmental pollution. Adsorbents are widely regarded as the most promising materials for trace uranium extraction; however, the adsorption of trace uranium from high-salinity environments is a challenge for adsorbents used to recover uranium from nuclear effluents. In this study, four different irradiation-functionalized adsorbents were fabricated and evaluated to screen suitable adsorbents for the removal of trace uranium from nuclear effluents. We found that the adsorbent with synergistic adsorption groups (NWF-g-PGMA-AO) exhibited the most distinctive trace uranium removal efficiency and robust stability in acidic, alkaline, and high-salinity environments. It was the synergistic involvement of hydroxyls in the coordination of amidoximes with uranium that enhanced the binding energy of uranium to NWF-g-PGMA-AO, thus improving its performance. In addition, the residual uranium concentration decreased to the maximum allowable emission concentration of 50 ppb over a wide pH range, with a minimum concentration of 9.35 ppb. Interestingly, nitrate, sulfate, phosphate, and chloride anions in the effluents did not decrease the uranium removal efficiency, whereas fluoride considerably reduced the efficiency, and the removal ratio was negatively correlated with fluoride concentration. This is attributed to the formation of [UO2Fn]2−n (n = 1, 2, 3, 4) species, which exhibit a decreasing affinity for adsorbents with increasing fluorine atoms as revealed by density functional theory calculations. This work makes a stride in designing superior adsorbents with synergistic adsorption groups for extracting trace uranium from nuclear effluents.

Adsorption of uranium by amidoximated polypropylene–acrylonitrile–acrylic acid fibrous adsorbent

Adsorption of uranium by amidoximated polypropylene–acrylonitrile–acrylic acid fibrous adsorbent

Development of polyethylenimine-functionalized cellulose fibers for recovery of Au(0) from Au(III)-containing acidic solutions through an adsorption–reduction–detachment–aggregation mechanism

The aim of this study was to develop cellulose-based, fibrous adsorbents for the selective recovery of gold (Au) and to reveal the adsorption–reduction–attachment–aggregation mechanism. Polyethylenimine (PEI)-functionalized cellulose fibers (PCFs) were fabricated by extruding a mixture of PEI and cellulose into a sulfuric acid solution. To maximize the performance of the PCFs, the amounts of PEI and ethylene glycol diglycidyl ether, a crosslinking agent, were optimized. The maximum uptake of Au(III) by PCFs was 1108.2 ± 58.8 mg/g obtained based on adsorption isotherm experiments. PCFs characterization and mechanistic investigations were carried out using FT-IR, XPS, XRD, FE-SEM, EDX, and HR-TEM. After 0.5 h of Au(III) adsorption on the PCFs, Au(III) was reduced to Au(I) owing to electron transfer when –NH3+/−NH2+‒, functional groups of PCFs, were oxidized to = NH+‒ and = N‒. After 12 h, –NH3+/−NH2+‒ were oxidized to = N‒, and C–N was oxidized to CO; therefore, Au(I) present on the fibers was reduced to Au(0) owing to the oxidation–reduction reaction. The released nitrogen was detected as NO2− and NO3− in the solution. Subsequently, the Au particles detached from the PCFs, and the aggregated Au particles on the vessel wall were recovered. In addition, the prepared PCFs showed outstanding selectivity for Au(III) in a solution containing the main metals found in electronic waste. PCFs maintain the Au(III) adsorption performance even in the 10 times adsorption-desorption cycles. These results indicated the application potential of PCFs as efficient adsorbents for Au recovery.

Ofloxacin Removal from Aqueous Media by Means of Magnetoactive Electrospun Fibrous Adsorbents.

Functionalized electrospun polymer microfibrous membranes were fabricated by electrospinning and further surface-functionalized with magnetic iron oxide (FexOy) nanoparticles to yield magnetoactive nanocomposite fibrous adsorbents. The latter were characterized in respect to their morphology, mechanical properties and magnetic properties while they were further evaluated as substrates for removing Ofloxacin (OFL) from synthetic aqueous media and secondary urban wastewater (UWW) under varying physicochemical parameters, including the concentration of the pharmaceutical pollutant, the solution pH and the membranes’ magnetic content. The magnetic-functionalized fibrous adsorbents demonstrated significantly enhanced adsorption efficacy in comparison to their non-functionalized fibrous analogues while their magnetic properties enabled their magnetic recovery and regeneration.

Negatively Charged Composite Nanofibrous Hydrogel Membranes for High-Performance Protein Adsorption.

Nanofibrous materials are considered as promising candidates for fabricating high-efficiency chromatography media, which are urgently needed in protein pharmaceuticals purification and biological research, yet still face several bottlenecks. Herein, novel negatively charged composite nanofibrous hydrogel membranes (NHMs) are obtained by a facile combination of electrospinning and surface coating modification. The resulting NHMs exhibit controllable morphologies and chemical structures. Benefitting from the combined effect of the stable framework of silicon dioxide (SiO2) nanofiber and the function layer of negatively charged hydrogel, as well as good pore connectivity among nanofibers, NHMs exhibit a high protein adsorption capacity of around 1000 mg g−1, and are superior to the commercial cellulose fibrous adsorbent (Sartobind®) and the reported nanofibrous membranous adsorbents. Moreover, due to their relatively stable physicochemical and mechanical properties, NHMs possess comprehensive adsorption performance, favorable resistance to acid and solvents, good selectivity, and excellent regenerability. The designed NHMs composite adsorbents are expected to supply a new protein chromatography platform for effective protein purification in biopharmaceuticals and biochemical reagents.

Harvesting and preparation of sludge-based fibrous adsorbent for heavy metals removal: Effects of organic substances molecular weight

The proper recycling of anaerobically digested sludge (ADS) is a great challenge, and the recovering and harvesting of the dissolved organic substances (DOS) in ADS to prepare innovative adsorbents may be an attractive option. This study uses ADS as the raw material to develope the DOS based amyloid-fibrils-like adsorbent (DOS-AFs) for heavy metal removal, and the mechanisms involved in DOS fibrosis and heavy metals adsorption are illustrated. Results indicate that the molecular weight (MW) of the DOS precursors greatly affect the fibrosis extent and the DOS-AFs surface morphology. DOS with low MW tends to form the rigid and smooth rod-like DOS-AFs with long-chain fibrous structure, whereas the macromolecular DOS is more likely to form DOS-AFs with rougher and more complicate branching structure. The formation of β-sheet structured DOS-AFs is largely formed from low-MW DOS rather than high-MW ones. The as-prepared DOS-AFs with different DOS fractions as precursors show different affinities towards heavy metals. The adsorption sites on macromolecular DOS-AFs are more likely to bind silver ion, whereas those small molecule DOS-AFs exhibit stronger affinity towards copper ion and nickel ion. The humic acid fraction in DOS plays two different roles in terms of heavy metals adsorption. The strong ligand of humic acid within DOS-AFs favors heavy metals adsorption, and the fibrosis extent of low-MW fraction is rather weak and the formation of soluble heavy metals complexes adversely inhibits adsorption performance. This study provides an alternative to harvest organic substances in ADS and to prepare valuable adsorbents towards heavy metals, although further studies are necessary to advance it in engineering practice.

Enhancement of carbon dioxide adsorption performances by hydrazinolysis of poly(n-vinylformamide) grafted fibrous adsorbent

Abstract Emission of carbon dioxide (CO2) becomes a main concern in battling issues of global warming. The strategy to reduce the concentration of CO2 could be achieved by implementing carbon capture and storage (CCS) technology such as adsorption by solid adsorbents. In this work, hydrazone containing adsorbent was prepared by radiation induced grafting of N-vinylformamide (NVF) onto polyethylene coated polypropylene (PE/PP) fibrous sheets and subsequent hydrazinolysis for CO2 capture. Hydrazinolysis of the amide group to hydrazone moieties was accelerated by the addition of ammonium salts. These newly prepared adsorbent was characterized by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The adsorption tests of pure CO2 and N2, and their mixture were carried using the gravimetric method. The result revealed that the obtained adsorbent was highly CO2 selective and attained remarkably higher CO2 sorption capacity of 3.1 mmol/g at 30 bar and room temperature compared to 0.3 mmol/g for amide-containing sample. The new adsorbent could be used for few repeated cycles with negligible loss in sorption capacity. Overall, the hydrazone-containing adsorbent has storing potential for CO2 capture, and more studies need to be conducted for further development.