Search Results (27)

The possibility of using the secondary cellulose-containing raw material resource of the cereal production of buckwheat, namely, its husk, as sorbents for the collection of oil and oil products is shown. In order to increase the yield of the finished product, develop porosity, and improve the sorption characteristics of the buckwheat husk, methods for its physical and chemical modification are proposed. The effect of the modification modes on the parameters of the porous structure, as well as the sorption capacity of the developed materials for various types of oil products, was studied. The selection of the optimal parameters of the buckwheat husk modification was carried out, ensuring the production of effective unsinkable sorbents based on the buckwheat husk with a reserve buoyancy of more than 20 days and a high sorption capacity of sorbents for oil of up to 6.1 g/g and waste motor oil of up to 4.9 g/g. The use of the buckwheat husk as a sorbent allows not only the elimination of oil pollution on both water and surfaces but also solving the problem of the disposal of agricultural waste. Full article

Cellulose-based sorbents are promising materials for wastewater treatment due to their environmental friendliness, biodegradability, and high sorption capacity. This paper presents an overview of cellulose modification methods, including carboxylation, amination, oxidation, graphene, and plasma treatments, as well as combined approaches. Their effect on key physicochemical properties, such as porosity, morphology, and chemical stability, is considered. Examples from the literature confirm the effectiveness of modified cellulose sorbents in removing heavy metal ions and organic pollutants from wastewater. The analysis shows that combined methods allow for creating materials with improved characteristics that are resistant to extreme operating conditions. The main advantages and disadvantages of cellulose sorbents, as well as challenges associated with their scalability and cost-effectiveness, are discussed. The paper emphasizes the importance of further research to advance these materials as a key element of sustainable water treatment technologies. Full article

The need for sustainable, biodegradable materials to address environmental challenges, such as oil-water separation, is growing. Cellulose-based absorbents offer an eco-friendly alternative to synthetic materials. However, their hydrophobicity must be enhanced for efficient application. In this study, cellulose-based sorbents derived from Kraft and half-bleached chemo-thermomechanical pulp (BCTMP) were hydrophobized using silanization and alkyl ketene dimer (AKD) techniques. Hydrophobic properties were successfully imparted using methyltrimethoxysilane (MTMOS), n-octyltriethoxysilane (NTES), and N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane (AATMS), with water contact angles ranging from 120° to 140°. The water sorption capacity was significantly reduced to below 1 g/g, whereas the oil sorption capacity remained high (19–28 g/g). The most substantial reduction in water vapor absorption (3–6%) was observed for the MTMOS- and AATMS-silanized samples. These results demonstrate the potential of hydrophobized cellulose-based sorbents as sustainable alternatives for oil-water separation, contributing to environmentally friendly water treatment solutions. Full article

Plant food production generates a lot of by-products (BPs). These BPs are majorly discarded into the environment, polluting it, or into landfills where they just decompose, providing no benefit and taking up storage space, causing financial costs. These plant BPs are biodegradable, but reusing them may provide a better outcome and profit. The vast majority of plant-based food BPs are polysaccharide polymers like gums, lignin, cellulose, and their derivatives. It is possible to utilize plant food production waste, like banana peels, leaves, pseudostems, and inflorescences, to produce bioethanol, single-cell protein, cellulase, citric acid, lactic acid, amylase, cosmetics, fodder additives, fertilizers, biodegradable fibers, sanitary pads, bio-films, pulp and paper, natural fiber-based composites, bio-sorbents, bio-plastic, and bio-electricity in the agro-industry, pharmaceutical, bio-medical, and bio-engineering fields. Moreover, the use of banana BPs seems to be a way of dealing with many issues in underdeveloped countries, providing a clean and ecological solution. The suggested idea might not only reduce the use of plastic but also mitigate waste pollution. Full article

Contaminated sediments may induce long-term risks to humans and ecosystems due to the accumulation of priority and emerging inorganic and organic pollutants having toxic and bio-accumulation properties that could become a secondary pollution source. This study focused on the screening of novel bio-based materials to be used in the decontamination of marine sediments considering technical and environmental criteria. It aimed to compare the environmental impacts of cellulose-based adsorbents produced at lab scale by using different syntheses protocols that involved cellulose functionalization by oxidation and branching, followed by structuring of an aerogel-like material via Soxhlet extraction and freeze-drying or their combination. As model pollutants, we used 4-nitrobenzaldehyde, 4-nitrophenol, methylene blue, and two heavy metals, i.e., cadmium and chromium. When comparing the three materials obtained by only employing the Soxhlet extractor with different solvents (without freeze-dying), it was observed that the material obtained with methanol did not have a good structure and was rigid and more compact than the others. A Life Cycle Assessment (LCA) was conducted to evaluate the environmental performance of the novel materials. Apart from the hierarchical categorization of the materials based on their technical and environmental performance in eliminating organic pollutants and heavy metal ions, it was demonstrated that the cellulose-based material obtained via Soxhlet extraction with ethanol was a better choice, since it had lower environmental impacts and highest adsorption capacity for the model pollutants. LCA is a useful tool to optimize the sustainability of sorbent materials alongside lab-scale experiments and confirms that the right direction to produce new performant and sustainable adsorbent materials involves not only choosing wastes as starting materials, but also optimizing the consumption of electricity used for the production processes. The main results also highlight the need for precise data in LCA studies based on lab-scale processes and the potential for small-scale optimization to reduce the environmental impacts. Full article

Removal of contaminants from discharge water is vital and demands urgent assistance with the goal to keep clean water. Adsorption is one of the most common, efficient, and low-priced methods used in water treatment. Various polysaccharide-based gels have been used as efficient dye adsorbents from wastewater. This review summarizes cutting-edge research of the last decade of different hydrogels based on natural polysaccharides (chitin, chitosan, cellulose, starch, pullulan, and dextran) concerning their dye adsorption efficiency. Beyond their natural abundance, attributes of polysaccharides such as biocompatibility, biodegradability, and low cost make them not only efficient, but also environmentally sustainable candidates for water purification. The synthesis and dye removal performance together with the effect of diverse factors on gels retaining ability, kinetic, and isotherm models encountered in adsorption studies, are introduced. Thermodynamic parameters, sorbent recycling capacity along with conclusions and future prospects are also presented. Full article

Aerogels are an excellent alternative to traditional oil absorbents and are designed to remove oil or organic solvents from water. Cellulose-based aerogels can be distinguished as polymers that are non-toxic, environmentally friendly, and biodegradable. The compression measurement properties of aerogels are often evaluated using dry samples. Here, oil-soaked, hydrophobized cellulose aerogel samples were examined in comparison to dry samples with and without additional hemp fibers and various levels of starch for crosslinking. The samples were characterized by compression measurement properties and filmed to evaluate the regeneration of the sorbent with repeated use. Overall, the measurements of the mechanical properties for the dry samples showed good reproducibility. The Young’s modulus of samples with additional hemp fibers is significantly increased and also shows higher strength than samples without hemp fibers. However, samples without hemp fibers showed slightly better relaxation after compression. Oil acts as a weak plasticizer for all aerogel samples. However, it is important to note that the oil does not cause the samples to decompose in the way unmodified cellulose aerogels do in water. Therefore, using hydrophobized cellulose aerogels as sorbents for oil in a sea or harbor with swell means that they can be collected in their entirety even after use. Full article

Rapid extraction and concentration systems based on green materials such as cellulose or lignin are promising. However, there is still a need to optimize the material properties and production processes. Unlike conventional cellulose or lignin sorbent materials, aquatic reed root cells can concentrate external organic pollutants in the water and accumulate them in the plant. Inspired by this, a new nanocellulose–lignin aerogel (NLAG) was designed, in which nanocellulose was used as a substrate and lignin and polyamide epoxy chloropropane were used to crosslink cellulose in order to enhance the strength of the NLGA, resulting in good mechanical stability and water–oil amphiphilic properties. In practical applications, the organic membrane on the NLAG can transport organic pollutants from water to the NLAG, where they are immobilized. This is evidenced by the fact that the aerogel can remove more than 93% of exogenous phenol within a few minutes, highly enriching it inside. In addition, the aerogel facilitates filtration and shape recovery for reuse. This work establishes a novel biopolymer–aerogel-based extraction system with the advantages of sustainability, high efficiency, stability, and easy detachability, which are hard for the traditional adsorbent materials to attain. Full article

This article concerns the effect of the chemical modification of short flax fiber on its sorption properties for heavy metal ions. The main purpose of the modification was to achieve the oxidation of flax cellulose with sodium metaperiodate to form dialdehyde cellulose. Additionally, the research shows the subsequent interaction of dialdehyde cellulose with 1-amino-8-hydroxynaphthalene-3,6-disulfonic acid and its transformation into a derivative capable of forming chelate complexes with heavy metal ions. Additionally, this article presents the results of equilibrium and kinetics studies of the sorption of Cu(II), Cd(II), and Fe(II) ions from aqueous solutions by primary and modified cellulose sorbents. SEM spectra indicate changes in the surface structure of the modified sorbents compared to the original one. IR spectra show the appearance of amino- and sulfogroups in short flax fibers in the process of their modification. The research revealed the efficiency of the method and the possibility of its use for the purification of aqueous solutions from heavy metal ions in industrial processes. Full article

Cellulose-based aerogels have been seen as a promising sorbent for oil and organic pollutant cleaning; however, their intrinsic hydrophilicity and difficulty of recycling has hindered their practical application. In this work, a superhydrophobic, magnetic cellulose-based aerogel was fabricated as a highly efficient sorbent for the adsorption of oils and organic solvents. The aerogel was prepared via a simple freeze-drying method, followed by chemical vapor deposition (CVD). The incorporation of Fe₃O₄ nanoparticles into the aerogel not only makes it responsive to external magnetic field, but also contributes to the better hydrophobicity of the aerogel, in which the water contact angle (WCA) was about 20° higher than the aerogel without loading with Fe₃O₄ nanoparticles. The adsorption test showed that the resultant aerogel can selectively adsorb a wide range of oils and organic solvents from oil/water mixtures with a high adsorption capacity (up to 113.49 g/g for silicone oil). It can retain about 50% of its adsorption capacity even after 10 adsorption–squeezing cycles, which indicates its outstanding reusability. Moreover, the aerogels can be easily controlled by an external magnet, which is preferred for the adsorption of oily contaminants in harsh environments and enhanced the recyclability of the aerogel. We believe that this study provides a green and convenient approach for the practical fabrication of cellulose-based oil sorbents. Full article

Adsorption is one of the common stages in the hydrometallurgy of rare metals. Its efficiency is largely determined by the quality of the sorbent used. The purpose of this work was to create an activated sorbent based on rice husk cellulose for the extraction of rhenium from aqueous solutions. Two types of cellulose were obtained by treating rice husk with a 1.5% NaOH solution (alkaline cellulose) and a nitric acid solution in ethyl alcohol (Kürschner and Hoffer cellulose). They were tested by IR, SEM, TA, TPD-MS, and XRD methods. It was found that Kürschner and Hoffer cellulose does not contain lignin and retains structural order to a greater extent. By means of this cellulose carbonization at 600 °C and activation by physical, chemical, and combined methods, a series of sorbents were prepared and studied by different methods. It was determined that the sorbent KHC4-600VA obtained by combined activation of cellulose carbonizate by water vapor at 850 °C, followed by an alkaline treatment, has the best textural characteristics: S—~1200 m²·g⁻¹, V—1.22 cm³·g⁻¹, and R—2.05 nm. KHC4-600VA provides 90% recovery of Re (VII) ions from aqueous solutions. According to the Freundlich model, sorption proceeds favorably on the sorbent’s heterogeneous surface. Full article

In this work, a sorbent was prepared from wastepaper samples enriched with iron oxide particles and graphene oxide and used in the solid phase extraction of antibiotics. The precursor underwent a carbothermal reduction to promote the formation of paramagnetic phases useful for the recovery of the sorbent during the analysis, and to disperse and fix graphene and the iron oxide in a durable way throughout the cellulose structure. Characterizations were carried out to evaluate the composition (Raman, XRD and EDX) and the morphological structure (SEM) of the material. A UHPLC-PDA method was developed for the simultaneous determination of antibiotics from different drug families (carbapenems, fluoroquinolones, β-lactams) using a 120 SB-C 18 poroshell column (50 × 2.1 mm I.D., 2.7 um particle size) and a mobile phase consisting of 10 mM acetate buffer at pH 5 (Line A) and acetonitrile (Line B) both containing 0.1% of triethylamine. A gradient elution was used for the separation of the analytes, while for the quantitative analysis each analyte was determined at its maximum wavelength. Several experiments were carried out to evaluate the influence of different parameters involving the dispersive magnetic solid phase extraction of these analytes. Samples were extracted using 25 mg of sorbent at pH 5 and desorbed in 5 min using methanol. We report herein on some of the outstanding advantages of using carbon-based sorbent, such as lower toxicity, scalability, improved absorption capacity, target selectivity and stability in acidic medium. Moreover, from the results obtained it is evident that, despite the use of some recycled materials, the performances obtained were comparable or even superior to the methods reported in the literature. Full article

Nowadays, pollution has become the main bottleneck towards sustainable technological development due to its detrimental implications in human and ecosystem health. Removal of pollutants from the surrounding environment is a hot research area worldwide; diverse technologies and materials are being continuously developed. To this end, bio-based composite hydrogels as sorbents have received extensive attention in recent years because of advantages such as high adsorptive capacity, controllable mechanical properties, cost effectiveness, and potential for upscaling in continuous flow installations. In this review, we aim to provide an up-to-date analysis of the literature on recent accomplishments in the design of polysaccharide-based composite hydrogels for removal of heavy metal ions, dyes, and oxyanions from wastewater. The correlation between the constituent polysaccharides (chitosan, cellulose, alginate, starch, pectin, pullulan, xanthan, salecan, etc.), engineered composition (presence of other organic and/or inorganic components), and sorption conditions on the removal performance of addressed pollutants will be carefully scrutinized. Particular attention will be paid to the sustainability aspects in the selected studies, particularly to composite selectivity and reusability, as well as to their use in fixed-bed columns and real wastewater applications. Full article

The present work was undertaken to elucidate the potential contribution of biosynthetically produced ferulic acid (FA) via enzymatic hydrolysis (EH) of rye bran (RB) to the formation of silver nanoparticles (AgNPs) during green synthesis. An analytical approach accomplished by multiple reaction monitoring (MRM) using triple quadrupole mass selective detection (HPLC-ESI-TQ-MS/MS) of the obtained hydrolysate revealed a relative abundance of two isomeric forms of FA, i.e., trans-FA (t-FA) and trans-iso-FA (t-iso-FA). Further analysis utilizing high-performance liquid chromatography with refractive index (HPLC-RID) detection confirmed the effectiveness of RB EH, indicating the presence of cellulose and hemicellulose degradation products in the hydrolysate, i.e., xylose, arabinose, and glucose. The purification process by solid-phase extraction with styrene-divinylbenzene-based reversed-phase sorbent ensured up to 116.02 and 126.21 mg g⁻¹ of t-FA and t-iso-FA in the final eluate fraction, respectively. In the green synthesis of AgNPs using synthetic t-FA, the formation of NPs with an average size of 56.8 nm was confirmed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques. The inclusion of polyvinylpyrrolidone (PVP-40) in the composition of NPs during synthesis favorably affected the morphological features, i.e., the size and shape of AgNPs, in which as big as 22.4 nm NPs were engineered. Meanwhile, nearly homogeneous round-shaped AgNPs with an average size of 16.5 nm were engineered using biosynthetically produced a mixture of t-FA and t-iso-FA and PVP-40 as a capping agent. The antimicrobial activity of AgNPs against Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa, E. coli, Enterococcus faecalis, Bacillus subtilis, and Staphylococcus aureus was confirmed by the disk diffusion method and additionally supported by values of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Given the need to reduce problems of environmental pollution with cereal processing by-products, this study demonstrated a technological solution of RB rational use in the sustainable production of AgNPs during green synthesis. The AgNPs can be considered as active pharmaceutical ingredients (APIs) to be used for developing new antimicrobial agents and modifying therapies in treating multi-drug resistant (MDR) pathogens. Full article

Eutrophication, a process in which algae grow inordinately, adversely affects aqueous fauna. Phosphorous at levels above 0.1 mg/L is adequate to cause eutrophication. In this study, we aimed to reduce the amount of PO₄³⁻ in water using biodegradable and ecofriendly sorbents. Lanthanum oxide nanoparticles were doped in agar and cellulose sponge to produce two new sorbents, agar–La and sponge–La, respectively. Both sorbents showed high efficacy in remediating up to 10 mg/L PO₄³⁻ in water. Sponge–La was found to be more proficient in terms of adsorption than agar–La because it required just 1 h to achieve 80% adsorption when the initial concentration of PO₄³⁻ was 10 mg/L. Sponge–La was effective at pH levels ranging from 4 to 8, with a removal rate of 80–100%. Although agar–La displayed a slow sorption process, it presented a high adsorption capacity (156 mg/g); moreover, the cake-shaped agar–La could be easily manufactured and separated from an aqueous matrix or any water-based solutions. These two sorbents could effectively remove high concentrations of PO₄³⁻, and their preparation requires a simple step. Agar–La was easier to manufacture, whereas the adsorption process using sponge–La was more rapid. In addition, both sorbents can be easily separated from the matrix after sorption. Full article