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Waste paper is a major contributor to municipal and industrial waste, and its recycle and reuse are a current challenge. The aim of this research is to convert waste paper into value-added cellulose films through rapid dissolution in pre-cooled H 2 SO 4 aqueous solution. Two types of waste paper, office paper and cardboard, could be dissolved within 210 s. The regenerated office paper films were transparent, and exhibited excellent mechanical properties (tensile strength: 77.55 ± 6.52 MPa, elongation at break: 2.67 ± 0.30 %, and Young's modulus: 5451.67 ± 705.23 MPa), which were comparable to those of cellulose films prepared from spruce pulp in the same solvent. The mixed paper films showed a dramatically reduced UV transmittance due to the existence of lignin. Moreover, the regenerated films were a promising matrix to load antimicrobial compounds, and thus inhibited the growth of pathogenic bacteria. Therefore, this work provides a convenient way to directly convert waste paper into biodegradable antimicrobial packaging materials., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

China, a big paper-making country, produced hundreds of millions of tons of waste paper which contain a lot of fiber every year. Cellulose nanocrystals were extracted from recycled waste paper which can be a high value utilization of secondary fiber. In this paper, cellulose nanocrystals were successfully extracted from waste paper fibers via two different systems, sulfuric acid hydrolysis (SCNCs) and one-step ammonium persulfate (APS) oxidation (OCNCs). This not only broadened the methods of extracting CNCs from waste paper, but also improved the dispersion and reactivity of CNCs. The CNCs products were investigated by FT-IR spectroscopy for functional group structure, X-ray diffraction for crystal structure, TG-DTG for thermal stability and scanning electron microscope, transmission electron microscope for morphology. The results showed that both OCNCs and SCNCs were a rod-like structure. The crystallinity of OCNCs and SCNCs increased to 72.45 and 77.56, but with a low yield of 22.42% and 41.22%, respectively. The result also suggested H 2 O 2 formed by decomposition of APS, selectively oxidized the hydroxyl on the C 6 in cellulose to carboxyl, introduced 0.57 mmol/g carboxyl. Successful preparation of CNCs extracted from waste paper can effectively utilize the fiber resources in waste paper, thus transforming into higher economic benefits., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Nanocellulose has achieved an inimitable place and value in nano-materials research sector. Promising and exclusive physical, chemical and biological properties of nanocellulose make it an attractive and ideal material for various high end-user applications. Conventionally, the base material for nanocellulose i.e. cellulose is being extracted from various lignocellulosic raw materials (like wood, agro-industrial-residues, etc.) using pulping followed by bleaching sequences. As an alternate to lignocellulosic raw materials, waste paper also showed potential as a competent raw material due to its abundant availability and high cellulosic content (60-70%) with comparatively less hemicelluloses (10-20%) and lignin (5-10%) without any harsh treatments. The production yields of nanocellulose were reported to vary from 1.5% to 64% depending upon the waste papers and treatments given. The diameters of these nanocelluloses were reported in the range of 2-100 nm and crystallinity range around 54-95%. Thermal degradation of waste paper nanocellulose was varied from 187 °C to 371 °C. Although these properties are comparable with the nanocellulose obtained from lignocellulosic raw materials, yet waste paper is an underutilized source for nanocellulose preparation due to its ordinary fate of recycling, dumping and incineration. In the sight of necessity and possibility of waste paper utilization, this article reviews the outcomes of research carried out for preparation of nanocellulose using waste paper as a source of cellulose. There is a need of sincere investigation to convert this valuable waste to wealth i.e. waste papers to nanocellulose, which will be helpful in solid waste management to protect environment in economical way., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

To maintain personal thermal comfort in cold weather, indoor heating consumes large amount of energy and is a primary source of greenhouse gas emission. Traditional clothes are too thick for thermal comfort in cold outdoor environment, resulting the lower wearing comfort. In this work, a multifunctional Ag nanoparticles/cellulose fibers thermal insulation membrane starting from waste paper cellulose fibers was prepared via simple silver mirror reaction and subsequent vacuum filtration process to improve the infrared reflection properties of membranes for human thermal insulation. The sphere-like Ag nanoparticles were tightly anchored on surface of waste paper cellulose fibers, forming an Ag nanoparticles infrared radiation reflection coating with high infrared reflectance, resulting in high thermal insulation capacity of the thermal insulation membrane. In addition, Ag nanoparticles endow the thermo insulation membrane with excellent antibacterial activity, and the thermo insulation membranes can effectively inhibit the growth of both Staphylococcus aureus and Escherichia coli. In this thermal insulation system, the thermo insulation membranes show superhydrophilicity and porosity, which allow the membranes to be breathable for comfortable wearing feeling. These promising results including high infrared reflection for high thermal insolating, high breathability for wearing comfort, and excellent antibacterial activity make the Ag/cellulose thermo insulation membranes promising candidates for applications in human thermal management, energy regulation and other facilities., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Waste paper samples with different cellulose supramolecular structure were treated in hot compressed water (HCW) at 375°C and 22.5MPa within 200s to evaluate the specific effect mechanism of cellulose supramolecular structure on the conversion of waste paper to reusable resource. Although the distribution of liquid products and the oligosaccharides were related to reaction time, depolymerization and decrystallization of the cellulose, the characteristics absorption peak of cellulose from FTIR analysis and crystal structure of the cellulose detected in the residues with hydrolysis rate up 96.5% indicated crystal structure was the dominant factor that affect conversion behavior of waste paper. The conversion of cellulose Iβ to cellulose Iα or cellulose I(α+β) in HCW demonstrated that the recrystallization occurred during the decrystallization of cellulose through the rearrangement of hydrogen bonds., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Metagenomics has revolutionized access to genomic information of microorganisms inhabiting the gut of herbivorous animals, circumventing the need for their isolation and cultivation. Exploring these microorganisms for novel hydrolytic enzymes becomes unattainable without utilizing metagenome sequencing. In this study, we harnessed a suite of bioinformatic analyses to discover a novel cellulase-degrading enzyme from the camel rumen metagenome. Among the protein-coding sequences containing cellulase-encoding domains, we identified and subsequently cloned and purified a promising candidate cellulase enzyme, Celcm05-2, to a state of homogeneity. The enzyme belonged to GH5 subfamily 4 and exhibited robust enzymatic activity under acidic pH conditions. It maintained hydrolytic activity under various environmental conditions, including the presence of metal ions, non-ionic surfactant Triton X-100, organic solvents, and varying temperatures. With an optimal temperature of 40 °C, Celcm05-2 showcased remarkable efficiency when deployed on crystalline cellulose (> 3.6 IU/mL), specifically Avicel, thereby positioning it as an attractive candidate for a myriad of biotechnological applications spanning biofuel production, paper and pulp processing, and textile manufacturing. Efficient biodegradation of waste paper pulp residues and the evidence of biopolishing suggested that Celcm05-2 can be used in the bioprocessing of cellulosic craft fabrics in the textile industry. Our findings suggest that the camel rumen microbiome can be mined for novel cellulase enzymes that can find potential applications across diverse biotechnological processes. [ABSTRACT FROM AUTHOR]

This paper reports an innovative study that aims to address key issues in the efficient recycling of wastepaper cellulose. The research team utilized the temperature-responsive upper critical solution temperature (UCST) polymer P(NAGA-b-DMA) in combination with the LytA label's affinity for choline analogs. This innovative approach enabled them to successfully develop a novel soluble immobilized enzyme, P(NAGA-b-DMA)-cellulase. This new enzyme has proven highly effective, significantly enhancing the degradation of wastepaper cellulose while demonstrating exceptional stability. Compared with the traditional insoluble immobilized cellulase, the enzyme showed a significant improvement in the pH, temperature stability, recycling ability, and storage stability. A kinetic parameter calculation showed that the enzymatic effectiveness of the soluble immobilized enzyme was much better than that of the traditional insoluble immobilized cellulase. After the immobilization reaction, the Michaelis constant of the immobilized enzyme was only increased by 11.5%. In the actual wastepaper degradation experiment, the immobilized enzyme was effectively used, and it was found that the degradation efficiency of wastepaper cellulose reached 80% of that observed in laboratory conditions. This novel, thermosensitive soluble immobilized cellulase can efficiently catalyze the conversion of wastepaper cellulose into glucose under suitable conditions, so as to further ferment into environmentally friendly biofuel ethanol, which provides a solution to solve the shortage of raw materials and environmental protection problems in the paper products industry. [ABSTRACT FROM AUTHOR]

This study focuses on the increased risk of high heat release and asphyxiation (toxic gas poisoning) in the event of a fire involving polyurethane (PU)- and MDF-based building materials, which are commonly used in buildings. Among them, polyurethane (PU) building materials are very commonly used in buildings, except in Europe and some other countries, due to their excellent thermal insulation performance. Still, problems of short-term heat release and the spread of toxic gases in the event of a fire continue to occur. To overcome these problems, researchers are actively working on introducing various flame retardants into building materials. Therefore, in this study, we produced a laboratory-sized (500 mm × 500 mm) plate-like flame-retardant board that can be utilized as a building material with a lower heat release rate and a lower toxicity index. The material was made by mixing expanded graphite and ceramic binder as flame retardants in a material that is formulated based on the cellulose of waste paper, replacing the existing building materials with a hot-press method. According to the ISO-5660-1 test on the heat release rate of the plate-like flame-retardant board, the Total Heat Release (THR) value was 2.9 (MJ/m2) for 10 min, showing an effect of reducing the THR value by 36.3 (MJ/m2) compared to the THR value of 39.2 (MJ/m2) of the specimen made using only paper. In addition, the toxicity index of the flame-retardant board was checked through the NES (Naval Engineering Standards)-713 test. As a result, the test specimen showed a toxicity index of 0.7, which is 2.4 lower than the toxicity index of 3.1 of MDF, which is utilized as a conventional building material. Based on the results of this study, the cellulose fire-retardant board showed the effect of reducing the heat release rate and toxicity index of building materials in a building fire, which reduces the risk of rapid heat spread and smoke toxicity. This has the potential to improve the evacuation time (A-SET) of evacuees in fires. It is also important to show that recycling waste paper and utilizing it as the main material for building materials can be an alternative in terms of sustainable development. [ABSTRACT FROM AUTHOR]

A comparative study of the supramolecular structure, physicochemical properties, and morphology of the powder celluloses (PCs) obtained from the waste paper of newsprint and cardboard, plant celluloses, and nonconventional raw materials was conducted using the methods of FT-IR spectroscopy, high-resolution solid-state 13C NMR spectroscopy, wide-angle X-ray scattering, and scanning electron microscopy (SEM). According to the FT-IR and 13C NMR spectroscopy results, the functional composition of the PCs is similar to that of the wood PCs and matches highly purified cellulose samples. The crystallographic structure of the powder samples corresponds to the structure of cellulose I. The crystallinity and the transverse dimensions of the crystallites are 39.4 and 40.2%, and 45 Å [110] and 54 Å [110], for the PCs from newsprint paper and cardboard, respectively. These values considerably exceed those for the initial waste paper samples. A comparative analysis of the SEM results showed a significant similarity among the PC fibers of different origin. The results of the study of the physicochemical properties of the PCs isolated from the waste paper allow predicting their competitive application in comparison with plant PCs. [ABSTRACT FROM AUTHOR]

Cellulose was successfully extracted from wastepaper with a pre-treatment using sodium hydroxide (NaOH) and hydrochloric acid (HCl). The cellulose was then used to fabricate two types of hydrogels: cellulose/carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) and cellulose/CMC/glycerol. Epichlorohydrin, an ECH solution was used as a cross-linker for the fabrication of both types of hydrogels. NaOH/urea/ultrapure water (NU) solutions were used to dissolve all the materials needed for the formation of hydrogels. The attenuated total reflectance-Fourier transform infrared (ATR-FTIR) showed the presence of hydroxyl group (O-H), hydrocarbon group (C-H) and carbonyl group (C=O) stretching. Scanning electron microscope (SEM) showed different porosities for both types of hydrogels, while the equilibrium swelling, swellingeq of cellulose/CMC/PVA hydrogels were better compared to the cellulose/CMC/glycerol hydrogels. The highest swellingeq was found for the cellulose/CMC/PVA hydrogel (3/3/4 ratio), CCP334 with 6.33 g/g, while the lowest swellingeq (g/g) was obtained from the cellulose/CMC/glycerol hydrogel (3/2/5 ratio), CCG325 with 1.49 g/g. [ABSTRACT FROM AUTHOR]

This study investigates the sulfuric acid hydrolysis process to improve the efficiency of paper waste sludge (PWS) hydrolysis in a paper recycling plant. The Response Surface Methodology (RSM) was used to evaluate the influence of factors, including liquid-to-solid ratio, acid concentration, temperature, and time on the hydrolysis process. The optimal conditions for hydrolysis were determined to be a solid-to-liquid ratio of 1/30.15, an acid concentration of 8.17 wt%, at a temperature of 91.31 °C, and a reaction time of 6.15 h, which yielded the highest sugar content of 11.12 g.L-1 (with the hydrolysis efficiency of 61.4 %). The resulting sugar solution was then fermented by Acetobacter xylinum bacteria to produce bacterial cellulose (BC) layers. This study addresses the environmental organic pollution caused by PWS and transforms it into a more valuable form with high carbon content and purity, such as BC. [ABSTRACT FROM AUTHOR]

In recent years, polymer-supported magnetic iron oxide nanoparticles (MIO-NPs) have gained a lot of attention in biomedical and healthcare applications due to their unique magnetic properties, low toxicity, cost-effectiveness, biocompatibility, and biodegradability. In this study, waste tissue papers (WTP) and sugarcane bagasse (SCB) were utilized to prepare magnetic iron oxide (MIO)-incorporated WTP/MIO and SCB/MIO nanocomposite particles (NCPs) based on in situ co-precipitation methods, and they were characterized using advanced spectroscopic techniques. In addition, their anti-oxidant and drug-delivery properties were investigated. Field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analyses revealed that the shapes of the MIO-NPs, SCB/MIO-NCPs, and WTP/MIO-NCPs were agglomerated and irregularly spherical with a crystallite size of 12.38 nm, 10.85 nm, and 11.47 nm, respectively. Vibrational sample magnetometry (VSM) analysis showed that both the NPs and the NCPs were paramagnetic. The free radical scavenging assay ascertained that the WTP/MIO-NCPs, SCB/MIO-NCPs, and MIO-NPs exhibited almost negligible antioxidant activity in comparison to ascorbic acid. The swelling capacities of the SCB/MIO-NCPs and WTP/MIO-NCPs were 155.0% and 159.5%, respectively, which were much higher than the swelling efficiencies of cellulose-SCB (58.3%) and cellulose-WTP (61.6%). The order of metronidazole drug loading after 3 days was: cellulose-SCB < cellulose-WTP < MIO-NPs < SCB/MIO-NCPs < WTP/MIO-NCPs, whereas the sequence of the drug-releasing rate after 240 min was: WTP/MIO-NCPs < SCB/MIO-NCPs < MIO-NPs < cellulose-WTP < cellulose-SCB. Overall, the results of this study showed that the incorporation of MIO-NPs in the cellulose matrix increased the swelling capacity, drug-loading capacity, and drug-releasing time. Therefore, cellulose/MIO-NCPs obtained from waste materials such as SCB and WTP can be used as a potential vehicle for medical applications, especially in a metronidazole drug delivery system. [ABSTRACT FROM AUTHOR]

One sustainable method of removing oil spills is the use of sorbents. In this study, aerogels made from paper waste and crosslinking starch are investigated as sorbents. Aerogels have a high porosity and, thus, achieve a high sorption capacity. The paper waste aerogels are compared with aerogel samples that also contain hemp fibres as a composite. After hydrophobisation with methyltrimethoxysilane, the maximum sorption capacity of crude oil, marine diesel oil and lubricating oil is investigated. Aerogels made of cellulose from paper waste with starch show the highest sorption capacity of about 50 gg−1 for all studied oils. Unfortunately, hemp fibres offer no advantage in sorption capacity, but they do mitigate a decrease in sorption capacity with an increase in cellulose fibre content. This could be an advantage in a possible commercial product, so that the properties do not vary as much. [ABSTRACT FROM AUTHOR]

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This review presents the research conducted to date in the field of cement-based composites reinforced with waste paper-based cellulose fibres, focusing on their composition, mechanical properties, and durability characteristics. The literature demonstrates that the properties of raw material (depending on their own chemical composition) significantly influence the formation of the cement composite binders. When considering fresh properties, the presence of silica and magnesium compounds generally lead to favourable effects on the setting of the cement composite when combined with waste paper cellulose fibre. Reduction in density values, i.e., approximately 25%, was observed with the inclusion of waste paper fibres from 20 to 80% in cement composites. The homogeneous dispersion of fibres in the matrix is one of the crucial factors to achieve in order to develop composites with well-balanced mechanical properties incorporating waste paper cellulose fibres. Hence, dispersion of fibres can be improved by increasing water quantity corresponding to the optimal value, which was a water/cement ratio of 0.64 leading to optimum strength properties of the composite. Even though the effect of fibre dispersion in the matrix improves with the addition of water, higher porosity and voids govern the strength properties beyond an optimum water-to-cement ratio. Higher porosity leads to an increase in the water absorption and a lowering of the thermal conductivity properties with the addition of paper fibre in cement binders. Paper fibre absorbs a high amount of water leading to higher water absorption. This phenomenon is related to the hydrophilic nature of cellulosic fibres absorbing some volume of water due to their microporous structure. [ABSTRACT FROM AUTHOR]

As an alternative raw material for various cellulose derivatives, the current research studied the processing of old corrugated container (OCC) in the subsequent stages of homogenization (soda cooking) and purification (bleaching with hypochlorite). The properties were characterized in four different categories including chemical composition or purity, accessibility, reactivity, and structural features. Alkali delignification and a bleaching sequence of HEHEHEA were selected for homogenization and purification of pulp followed by characterization of the pulp properties. The dissolving pulp exhibited the following properties: yield, 78%; cellulose, hemicellulose, and lignin content, 90.5%, 7.76%, and 0.3%, respectively; alpha cellulose, 70%. Pulp reactivity measured with two experiments showed Fock reactivity value of 85.67% as well as iodine sorption value (ISV) of 94.95 g/g; accessibility represented by two tests of water retention (WRV) and alkali retention capacity (ARC) with 6.87 for the first and 6.1% for the latter, degree of polymerization (DP), 913.4; crystallinity index, 76.95%; and brightness, 72.87%. FTIR spectroscopy and Brunauer-Emmet-Teller (BET) isotherms were utilized to examine the modifications of OCC to dissolving pulp. The results indicated that the dissolving pulp produced from OCC as a raw material is suitable for DP applications of cellulose derivatives. [ABSTRACT FROM AUTHOR]

An efficient process for recycling paper and cardboard wastes via dissolution in N,N-dimethylacetamide/lithium chloride (DMAc/LiCl) system and regeneration from solutions to obtain hydrogels has been developed. Pretreatment of waste paper has been carried out by thermal defibrillation of waste paper in water and homogenization to obtain fibrous samples. The dissolution of fiber materials was performed in two ways by varying the process temperature and the way the reagents were added. Regeneration from solutions was carried out by spontaneous gelation without the use of antisolvents, at room temperature and atmospheric pressure. As a result, hydrogels were obtained which differed in color and transparency depending on feedstock. The physicochemical properties of the hydrogels were characterized. It was shown that they were steady in an aqueous medium, capable of retaining a significant amount of water (over 4000 wt %), and they were porous systems which was confirmed by scanning electron microscopy. According to a wide-angle X-ray scattering, the crystallographic structure of the pristine waste paper samples corresponded to a structural modification of cellulose I. Regenerated samples as freeze-dried hydrogels had the structure of cellulose II. A functional and an elemental composition studied with FTIR spectroscopy and an energy-dispersive X-ray microanalysis characterized these hydrogels as the cellulose samples containing small amount of inorganic impurities. The resulting hydrogels had a system of open pores of different sizes, and this predetermined their use as adsorbents and active matrices. [ABSTRACT FROM AUTHOR]

Metallogels are a class of materials produced by the complexation of polymer gels with metal ions that can form coordination bonds with the functional groups of the gel. Hydrogels with metal phases attract special attention due to the numerous possibilities for functionalization. Cellulose is preferable for the production of hydrogels from economic, ecological, physical, chemical, and biological points of view since it is inexpensive, renewable, versatile, non-toxic, reveals high mechanical and thermal stability, has a porous structure, an imposing number of reactive OH groups, and good biocompatibility. Due to the poor solubility of natural cellulose, the hydrogels are commonly produced from cellulose derivatives that require multiple chemical manipulations. However, there is a number of techniques of hydrogel preparation via dissolution and regeneration of non-derivatized cellulose of various origins. Thus, hydrogels can be produced from plant-derived cellulose, lignocellulose and cellulose wastes, including agricultural, food and paper wastes. The advantages and limitations of using solvents are discussed in this review with regard to the possibility of industrial scaling up. Metallogels are often formed on the basis of ready-made hydrogels, which is why the choice of an adequate solvent is important for obtaining desirable results. The methods of the preparation of cellulose metallogels with d-transition metals in the present state of the art are reviewed. [ABSTRACT FROM AUTHOR]

It is crucial and significant to boost the utilization of renewable resources and exploitation of biodegradable materials alternative to petrochemical plastics. Waste paper, mainly composed of cellulose (82–95 wt%) and derived from the lignocellulose, is a type of abundant, renewable, and biodegradable resource, whose recycling use and conversion to high value‐added products can reduce the pressure on the environment and exert immense economic benefits. Herein, four kinds of common waste paper (e.g., printing paper, newspaper, straw paper and roll paper) were converted into cellulose‐based bioplastic membranes by using ionic liquid 1‐butyl‐3‐methyl‐imidazolium chloride as solvent. The cellulose‐based membranes are smooth and compact, and their mechanical strength is prominently improved about 3–100 times comparison with the original paper. The maximum tensile strength of the film (F4) is over 127 Mpa and its optical transmittance reaches 80% at 450–800 nm wavelength. Besides, this kind of cellulose‐based films have excellent biodegradability. Thus, the results demonstrated that the cellulose‐based bioplastic membranes stemmed from waste paper possess a magnificent application prospect. [ABSTRACT FROM AUTHOR]

The cellulose and paper industry accounts for a large part of the circular economy. The need for activated carbons is gradually increasing, especially in the environmental and energy fields. In this study, the production of activated carbon from waste papers was carried out with the help of the chemical activation method and activation agents (phosphoric acid and zinc chloride). The parameters used in the experiments and analyzed were kept constant for all activated carbons. The density values of activated carbon were analyzed more than once in each sample with a helium-gas pycnometer device. Fourier transform infrared spectroscopy (FT-IR) was used to detect functional groups in the structure of activated carbon, and a field emission scanning electron microscope (FE-SEM) was used to study surface properties and porosity development. The distributions of activated carbons and their elemental analysis were examined by energy dispersive spectrometry (EDS) and Mapping analyses. When the results obtained from the activated carbons produced from waste paper in the study were compared with commercial activated carbon, it was observed that the waste paper had a better surface and pore structure than commercial activated carbon for the production of activated carbon, and the activation process was successfully performed. [ABSTRACT FROM AUTHOR]

The release of soils and impurities from cellulosic surfaces plays a critical role in such processes as the laundering of clothes and the deinking of wastepaper pulps. This article reviews publications that provide evidence about factors that affect such release and the mechanisms by which such factors operate. In general, cellulosic substrates provide advantages for the release of contaminants due to their hydrophilic nature and due to their permeability, allowing the transport of surfactants to contact interfaces with dirt. However, the same permeability of cellulosic material also provides opportunities for contaminants to work themselves into internal crevices and pores, from which they are difficult to remove. The article also reviews aspects of theory related to detergency and how those theories relate to the laundering, deinking, and purifying of substrates based on cellulose and related plant materials. Cellulose and some of its derivatives also can play a role in detergent formulation, especially as builders or as finishes placed on textile surfaces, which sometimes aid in the release of dirt. [ABSTRACT FROM AUTHOR]

In this study eco-friendly cellulose/graphene oxide scaffold has been formulated in the presence of different ratios of ethylenediamine (EDA) as a crosslinker via a lyophilization instrument. Cellulose was extracted from paper wastes and companied with graphene oxide (GO). Chemical structure and surface morphology of the extracted cellulose and cellulose/GO foam were investigated by infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and the scanning electron microscope (SEM) techniques. The prepared cellulose/GO foam was used as a gas sensing material, including the sensitivity and response/recovery times toward NH3 vapor. The cellulose/GO cryogel which was prepared with the addition of 1.5 mmol of EDA showed the highest sensitivity at room temperature with the response and recovery times at 490 and 620 s, respectively, compared to the cryogel prepared with 2.25 mmol EDA and the pristine cellulose cryogel. [ABSTRACT FROM AUTHOR]

A physical coagulator of fines was employed to separate suspensions comprising refined sulphate cellulose and waste paper, where no reagents were required. The physical coagulator was a porous cylinder with a rotating disk placed in its cavity. Using the MorFi Neo fibre analyser and the Hitachi SU 3500 digital microscope, a dispersed size distribution of well-developed fines in a suspension derived from softwood and hardwood pulp was obtained. The kinetics of fine sedimentation in the suspension was studied. The sedimentation rate of both individual agglomerates and a mass of them, as well as the magnitude of mass concentration in a cleared liquid, was determined. A relationship between the concentration of fines in the suspension and the structure of the pulp during their sedimentation was established. To intensify the fines sedimentation process, it was proposed to return a part of the sediment to the suspension passing into the physical coagulator. Process parameters for the sedimentation process and the construction of the sedimentation tank were obtained. The unit designed for collecting fines from the suspension is shown schematically. Use of this unit reduced the fibre sedimentation time, decreased the loads in wastewaters, and retained the consumer value of the pulp fibres. [ABSTRACT FROM AUTHOR]

Background: Cellulose extraction from gloss art paper (GAP) waste is a recycling strategy for the abundance of gloss art paper waste. Here, a study was conducted on the impact of ultrasonic homogenization for cellulose extraction from GAP waste to improve the particle size, crystallinity, and thermal stability. Results: At treatment temperature of 75.8 °C, ultrasonic power level of 70.3% and 1.4 h duration, cellulose with properties of 516.4 nm particle size, 71.5% crystallinity, and thermal stability of 355.2 °C were extracted. Surface modification of cellulose GAP waste with H3PO4 hydrolysis and 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidation was done followed by starch reinforcement. Surface hydrophobicity and mechanical strength were increased for H3PO4 hydrolysis and TEMPO oxidation starch–cellulose. No reduction of thermal properties observed during the treatment, while increment of crystallinity index up to 47.65–59.6% was shown. Neat starch film was more transparent, followed by starch–TEMPO film and starch–H3PO4 film, due to better homogeneity. Conclusions: The cellulose GAP reinforced starch film shows potential in developing packaging materials and simultaneously provide an alternative solution of GAP waste recycling. [ABSTRACT FROM AUTHOR]

Industrialization and urbanization have led to water pollution. Pollutants such as metals, oils, and organic dyes can cause serious harm to the environment and human health. Adsorption has been proposed as a suitable method for removing contaminants thank to its efficiency, low cost, and simple operation. In this study, the aerogel from banana-derived biomass, paper waste, and polyvinyl alcohol has been successfully fabricated using a freeze-drying process for water treatment. The physico-chemical properties including morphology and chemical structures of the obtained aerogel were characterized by scanning electron microscope, Fouriertransform infrared spectroscopy, and thermogravimetric analysis. The fabricated aerogels have low density of 0.0235-0.0297 g/cm3 and extremely high porosity of 97.87-98.37 %. These aerogels exhibit great capability in oil absorption (27.27-32.86 g/g), in methylene blue adsorption (4.23-6.69 mg/g), and in Cu2+ adsorption (61.68-85.45 mg/g). Hence, this type of aerogel is a promising candidate that can be applied for water treatment. [ABSTRACT FROM AUTHOR]

This study sustainably developed natural fiber composites from extracted nano-cellulose (ENC) from waste paper egg trays and incorporated them into vinyl ester/kenaf fiber (ENCVK) composites using a vacuum-assisted resin transfer molding (VARTM) process. Overhead stirring, three-roll milling, and ultrasonication were used to uniformly mix the ENC into the resin. The surface morphology exhibited a homogeneous distribution of ENC in the composites, and change in the % of transmittance of spectral peaks refers to the chemical interaction of ENC with the VK composites. ENC significantly improved tensile (32 MPa), flexural (77 MPa) and impact (0.0197 J/mm2) properties of the VK composites (18 MPa, 61 MPa and 0.009 J/mm2) by approximately 73%, 25% and 110%, respectively. Further, ENC inclusion enhanced the storage modulus of VK composites owing to the addition of rigid ENC particles, which enhances the bearing capacity of the composite and is reflected in its high performance. The loss modulus indicates that the interfacial interaction of ENCVK is more vital than VK. The tan Δ value indicates that the filler has strong adhesion, and the polymer cohesion damping is reduced, thus reflecting its high performance. [ABSTRACT FROM AUTHOR]

Disposable paper cups are widely used in daily life and most of them are landfilled or incinerated after use, resulting in a serious ecological hazard and significant waste of resources due to the usage of thin polyethylene (PE) as their inner coating. Hence, converting these common solid domestic wastes into high-value added materials is attractive and meaningful. In this study, transparent cellulose-based films were achieved from old bamboo-based disposable paper cups after pretreatment through using the room ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as solvent. The cellulose-based film with a dense texture demonstrated a relatively nice mechanical and UV-shielding performances, and its tensile strength was as high as 48 MPa, much higher than that of commercial polyethylene (PE, 12 MPa) film. Thus, the resultant cellulose-based film showed a great potential in the packaging field. Besides, the flexible paper plastic composites (PPC) were also fabricated from the rest thin PE coating with the stuck fibers, and it was found that PPC showed excellent mechanical property and hydrophobicity. Consequently, a feasible and eco-friendly process of recycling and reusing waste disposable paper cups was developed to achieve a complete utilization and valorization of waste disposable paper cups. [ABSTRACT FROM AUTHOR]

In this study, cellulose was extracted from waste paper using alkaline and bleaching treatments. The flocculation performance of six quaternized cellulose (QC) samples (QC-1, QC-5, QC-10, QC-15, QC-20, and QC-30) was evaluated through kaolin suspension using the standard jar test method at varying flocculant dosages, kaolin concentrations, pH values, and settling times. The cellulose content of the waste paper and extracted celluloses were 68.6% and 78.1%, respectively. Fourier-transform infrared spectroscopy, x-ray diffraction, thermogravimetric analysis, and scanning electron microscopy showed that the waste paper properties changed after chemical treatment, confirming that the extracted product was cellulose. The QC derivatives were homogeneously synthesized by reacting the extracted cellulose with 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHPTAC) in the aqueous medium of sodium hydroxide/urea. QC-15 exhibited a highly effective flocculation capability (99.67%) compared to alum (83.91%), with good performance in a wide pH range. The flocculation kinetics (kNo: 5.9 × 10−1 s-1) supported this finding. QC-15 removed 99.67% of turbidity compared to alum (83.9%). Besides, filtration of the conditioned sludge with QC-15 was relatively easy, with low specific resistance compared to the commercial alum. Overall, Q-15 was an effective and environmentally friendly flocculant with potential application for treating drinking water. [ABSTRACT FROM AUTHOR]

Cellulose nanofibers were produced with waste from the paper industry, in a stone grinder and were used as filler in elastomeric composites in the acrylonitrile-butadiene copolymer (NBR). Two different cellulose mass concentrations (0.5 and 2.0 wt%) were ground in water and incorporated in concentrations of 0, 10 and 20 phr by the coagulation of the NBR, followed by drying. The other components of the formulation were incorporated and vulcanized in an open mixer and molded by compression. Due to the proposed grinding it was possible to obtain nanocellulose, in the range of 20.5 nm to 83.6 nm at an average diameter of 42.8 nm for the solution produced with 2.0 wt% and 18.3 nm at 90.5 nm at an average diameter of 44.3 for the solution with 0.5 wt%. The composites with a 20 phr of nanofiber presented lower vulcanization times and better mechanical properties before and after accelerated aging for 7 days, as well as a superior resistance to gasoline and diesel than the NBR and the samples with 10 phr. A tear strength of 61 N.mm−2 was obtained at the concentration of 20 phr and 0.5 wt% of incorporated nanofibers in line with a shorter vulcanization time. [ABSTRACT FROM AUTHOR]

The method for production of amorphous cellulose (AC) by the treatment of initial cellulose material (MCC and mixed waste paper) with a cold solvent containing 7% NaOH and 12% urea has been studied at different solvent to cellulose ratios (R, mL/g). Using X-ray diffraction, it was shown that the MCC treatment at R = 3 resulted in a transformation of the crystalline modification (CM) CI of the initial cellulose into CM CII characterized by a low crystallinity degree. In the case of R ≥ 5, the treatment process resulted in a formation of completely amorphous cellulose (AC). Due to its high hydrolyzability, the AC substrate with a concentration of 50 g/L is almost completely converted into glucose within 48 h under the action of the CTec-3 enzyme preparation with a dose of 30 mg/g of dry substrate. The obtained AC sample can be used as an amorphous standard for the study of the crystallinity and enzymatic hydrolysis of various types of cellulose and lignocellulose. The enzymatic saccharification of AC was found to be the most beneficial with the substrate concentration raised to 150 g/L. Due to a high cost of MCC, a low-cost raw material, such as mixed waste paper, is preferable for use in the industrial production of ACC and glucose. [ABSTRACT FROM AUTHOR]

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In the present society, the recycling and reuse of valuable substances are of utmost importance for economic and environmental purposes. At the same time, there is a pressing need to develop new methods to protect the ecosystem from many human activities, including those that have contributed to an ever-increasing presence of pharmaceutical pollutants. In this study, a straightforward approach that applies a magnetic carbon composite for the effective removal of NSAIDs from biological fluids is reported. The composite was produced by recycling wasted handkerchiefs, to provide cellulose to the reactive system and then transformed into carbon via calcination at high temperature. The morphological and structural features of the prepared "Fe3O4@-activated carbon" samples were investigated via thermal analysis, X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. Magnetic solid-state extraction was carried out to reveal the adsorption capabilities of the magnetic carbon composite and then combined with UHPLC–PDA for the determination and quantification of five NSAIDs (furprofen, indoprofen, ketoprofen, flurbiprofen, and indomethacin). The method developed herein proved to be fast and accurate. The adsorbent could be reused for up to 10 cycles, without any decrease in performance; thus, it contributes to an intelligent and sustainable economic strategy projected toward minimal waste generation. [ABSTRACT FROM AUTHOR]

Cellulose-fibre lifecycle is severely limited within today's recycling methodology. Feedstock cellulose and filler abound in products considered uneconomic, unsuitable for standard deinking or too weak for original product re-use. Regeneration of cellulose from ionic liquid (IL) solution offers a novel valorisation route with potential to replace oil-based plastics, simultaneously bringing filler-containing cellulose waste into circular economy. To exemplify, composite cellulose-CaCO3 filaments were produced from cellulose pulp and waste office paper (already containing 27 w/w% precipitated CaCO3filler), without any pretreatment, using diazabicyclo[4.3.0]non-5-enium-acetate ([DHBN][OAc]) as IL solvent to form a dope. The dope suspension was extruded via dry-jet wet spinning. Surface morphology and elemental analysis were investigated using scanning electron microscopy with energy dispersive X-ray spectroscopy. X-ray diffraction was used to measure the degree of cellulose crystallinity. Static and dynamic mechanical properties were determined. Thermal stability was evaluated by thermogravimetric analysis. Filaments obtained from waste office paper showed that high filler levels and the presence of print toner enhanced both mechanical and thermal stability, while decreasing, as expected, ultimate breaking strength in comparison to filaments containing virgin cellulose alone. For comparison, 2 w/w% ground CaCO3 introduced into pure cellulose dope led to significant increase in cellulose crystallinity and resulting stiffness, while thermal properties remained unchanged at the low level filler addition. Such addition of CaCO3 during cellulose regeneration, or usage of already filled paper, could be an effective way to obtain high strength cellulose-CaCO3 composite materials, thus valorising in a circular economy renewable cellulosic wastes rejected from the current recycling stream. [ABSTRACT FROM AUTHOR]

Colorimetric sensor was successfully prepared from office waste paper-based composite. Chitosan film was coated onto surface in order to ensure the dimensional stability and reduce the water adsorption. 0.1%w/v of methyl red was employed as a sensing element. Fourier transform infrared confirmed that chitosan and methyl red were attached on the surface of cellulose. No significant change of crystallinity was observed. Morphological properties of cellulose-based composite were randomly oriented. Chitosan and methyl red were integrated in porous network. The existence of nitrogen atom was reported by Energy dispersive analysis. This element can be used to determine the position of chitosan and methyl red. Paper based composite was thermally stable up to 300 ºC. The roughness of surface was estimated to be 10–12 micron. Intensity of color was slightly enhanced when composite was attached to vapor of biogenic amine. It can be observed for 8 h. It was remarkable to note that office waste paper can be employed as a substrate in colorimetric sensor for food spoilage detection. [ABSTRACT FROM AUTHOR]

In this study, all‐cellulose composite materials are prepared through the dissolution and regeneration process using waste kraft papers as raw material in the sodium hydroxide/thiourea/urea solvent system. The degree of conversion is controlled by adjusting the microenvironment of the cellulose solvents, and the composite membrane is prepared by mixing the regenerated cellulose with the insoluble cellulose, which aims at adjusting the morphology and mechanical properties of the composite material. The shape of the regenerated cellulose after the dissolution and regeneration change from the original fiber into a sphere as shown by SEM images. The composite films show different phenomena, the insoluble part, and the matrix phase form a dense and strong network structure. The presence of this insoluble part increases the strength of the matrix phase and fundamentally changes the brittleness of the regenerated cellulose. This work provides a green and promising method to prepare high‐performance, environmentally friendly all‐cellulose composite materials. [ABSTRACT FROM AUTHOR]

Digital printing waste paper fiber/nanocrystalline cellulose/poly(lactic acid) composites, modified through γ‐methacryloxy propyl trimethoxy silane (KH570), isopropyl tri(dioctylpyrophosphate) titanate, sodium hydroxide, polyethylene glycol 6000 (PEG6000), and a composite silane coupling agent (KH570/PEG6000), were fabricated by melt blending and injection molding, and the effects of different modifiers on the properties of composites were studied. The results show that the mechanical properties of the modified composites were improved, and the best flexural strength, tensile strength, and impact strength were obtained by PEG6000, KH570/PEG6000, and KH570, respectively. Thermogravimetric analysis showed that the thermal decomposition performance of the composites treated by KH570 was relatively superior. Differential scanning calorimetry analysis demonstrated that the melting enthalpy and crystallinity of the modified material increased, while the cold crystallization temperature decreased. After modification, both water absorption and degradation showed a decreasing trend, especially KH570/PEG6000. Under the action of several modifiers, the diffusion coefficient, thermodynamic solubility, and permeability of composites were reduced to varying degrees. Furthermore, scanning electron microscopy demonstrated that interfacial adhesion and composite compatibility were improved with significantly fewer and smaller pores, as well as a fuzzy boundary among the three phases. [ABSTRACT FROM AUTHOR]

This study aims to improve the utilization rate of abandoned corn bracts, while decreasing the production cost of the bag of fruit cultivating in sustainable agriculture. Five representative bags of fruit cultivating were collected in the market as the controlled samples, including the plastic film bag A, special bag B for grape, one-, two- and three-layered bag C, D, and E. The basic structural characteristics of controlled samples were firstly analyzed. Then, alkali cooking was used to degum the corn bracts for the extraction of fibers. Subsequently, the corn bract fibers were cut into (5±0.5) mm long, thereby mixing evenly with the waste paper scraps in a ratio of 1.5:1. The wet mesh forming was adopted to prepare the fruit-cultivating bag material F. The mechanical properties of material F were tested after fabrication. The experimental results showed that the prepared material F behaved a strong tensile resistance, where the tensile loads for the dry and wet material F were up to 20.02 N and 13.79 N, respectively. Moreover, the retention rate reached 68.9% for the tensile load of wet material F. Furthermore, an excellent extension performance was achieved for the high requirements of mechanical properties in the fruit bagging. A scanning electronic microscopy (SEM) was adopted to observe the microstructure of the prepared materials F and the controlled samples in the market, further to analyze the distribution of holes in the matrix. The bagging properties were also measured, including air permeability, heat-insulating property, shading property, and water management ability. The experimental data demonstrated that the fruit-cultivating bag material F presented an excellent air permeability. Specifically, the air-flow rate and permeability of material were 73.5 mm/s and 173.7 L/m2 •s, respectively. In contrast to the controlled samples, the maximum air-flow rate and permeability were only 2.5 mm/s and 0.3 L/m2 •s, respectively. In addition, the heat loss of boiling water was about 265 kJ, when the prepared material was used to keep the boiling water for 60 min. The transmittance of the material F was about 0.4 % in the visible light range, and 0.09 % in the ultraviolet light range. The shielding properties showed that the prepared material ensured the photosynthesis of fruits during the growth process. Meanwhile, material F was expected to protect the fruit from ultraviolet light burning. Excellent ability of water conductivity was also achieved, where the core suction height reached 31 mm within 30 min. As such, the water in the fruit-cultivating bag during rainy days discharged quickly to enhance the quality of fruit products. Low wet evaporation indicated that the water retention performance was obviously better than that of the special bag B for the grape in the market. Most significantly, the thermal insulation performance of the new fabricated material was better than that of the controlled samples in the market. [ABSTRACT FROM AUTHOR]

The pulp and paper industry is a major source of lignocellulose-containing streams. The components of lignocellulose material are lignin, hemicellulose, and cellulose that may be hydrolyzed into their smaller components and used as feedstocks for valorization efforts. Much of this material is contained in underutilized streams and waste products, such as black liquor, pulp and paper sludge, and wastewater. Bacterial fermentation strategies have suitable potential to upgrade lignocellulosic biomass contained in these streams to value-added chemicals. Bacterial conversion allows for a sustainable and economically feasible approach to valorizing these streams, which can bolster and expand applications of the pulp and paper industry. This review discusses the composition of pulp and paper streams, bacterial isolates from process streams that can be used for lignocellulose biotransformations, and technological approaches for improving valorization efforts. Key points: • Reviews the conversion of pulp and paper industry waste by bacterial isolates. • Metabolic pathways for the breakdown of lignocellulose components. • Methods for isolating bacteria, determining value-added products, and increasing product yields. [ABSTRACT FROM AUTHOR]

Paper wastes form the major biodegradable fraction of the municipal solid waste. One of the best ways to treat paper wastes is using them as a feedstock for biomethane production through anaerobic digestion (AD). However, the AD characteristics, kinetics, and energy potential of different types of paper wastes are not clear. In this study, four kinds of typical paper wastes including corrugated board (CB), office paper (OP), tissue paper (TP), and magazine paper (MP) were used as feedstocks to produce biomethane at different volatile solids (VS) organic loading (OL). TP had a high cellulose content and showed high biomethane potential, while the lowest was obtained by CB, possibly due to its high lignin content. Kinetic analysis showed that Cone and modified Gompertz model could fit the biomethane production process well. Energy potential analysis revealed that biomethane yield, electric generating efficiency, and electricity price were the principal factors accounting for the profitability of biomethane production project treating paper wastes. Overall, paper wastes could be a promising feedstock for biomethane production, because paper wastes not only had high biomethane yield and biodegradability that exceeded many kinds of organic wastes but also could be continuously supplied for AD plants without the influence of seasonal changes. • Anaerobic digestion characteristics of typical paper wastes were investigated. • High cellulose content in tissue paper might account for its high biomethane yield. • Corrugated board with high lignin content showed the lowest biomethane yield. • Energy potential of the anaerobic digestion of paper wastes was evaluated. [ABSTRACT FROM AUTHOR]

The purpose of this study was to develop a biotechnological process to produce citric acid using paper residues from Urban Solid Waste (USW), like raw material. The selected microorganism to transform degraded cellulose from paper to produce citric acid was Aspergillus niger. The aerobic bioreaction was carried out in a heterogeneous bioreactor. The efficiency of the biotransformation in this study was measured under different operating conditions: 2 and 3 pH levels, 30 and 40 °C temperatures, and high and low concentrations of trace elements: Copper (Cu), Manganese (Mn) and Zinc (Zn). In optimized operation conditions from 20 g of waste paper the maximum citric acid amount obtained was 5.73 g l−1. [ABSTRACT FROM AUTHOR]

Background: With every oil tanker comes the risk of an accident and oil spill. Sorbents are the most suitable means to remove oil spills. Aerogels as sorbents have high porosity and can be made from cellulose from paper waste. The literature does not distinguish between paper and cardboard as sources of cellulose aerogels and little is known about composites of cellulose aerogels consisting of cellulose fibres and chemically untreated, unprocessed fibres or particles of straw, wool, macroalgae or cellulose acetate from cigarette butts. In this study, the sorption properties for marine diesel oil and biodiesel of such aerogels and their regenerative capacity with bioethanol were investigated. Methods: Cellulose aerogels were prepared from office paper and cardboard waste without and with chemically untreated algae, straw, wool and cellulose acetate as a composite by freeze drying. All samples were hydrophobised with methylsilane. The density to calculate the porosity and the contact angle were determined. Then the sorption capacity was determined over five cycles of sorption of oil and regeneration with bioethanol. Results: The average contact angle of all samples was 125°, indicating hydrophobicity. Paper-based aerogels were found to consistently have higher sorption capacities for biodiesel, marine diesel oil and bioethanol than cardboard-based aerogels. In particular, the wool/cellulose aerogel composite was found to have better sorption capacity for biodiesel, marine diesel oil and bioethanol than all other samples. The cellulose acetate/cellulose aerogel composite showed significantly higher sorption capacities than the paper and cardboard control samples (highest value is 32.25 g g−1) only when first used as a sorbent for biodiesel, but with a rapid decrease in the following cycles. [ABSTRACT FROM AUTHOR]

Nanocrystalline cellulose (NCC) was prepared from office waste paper (OWP) by sulfuric acid hydrolysis method in this paper and it was used to prepare a series of poly (lactic acid) PLA/NCC composites by using a dissolution method in solvent N, N‐dimethylformamide solution. The results indicated that with the addition of only 3 wt% NCC, the composites exhibited outstanding mechanical property. The tensile, bending and impact properties of the PLA/3NCC composite were improved by 8.2%, 13.1%, and 35.9% than those of pure PLA, respectively. On this basis, office waste paper fibers (OWF) were also used as a physical blended filler to enhance PLA/NCC composites to reduce the preparation cost of PLA composites and the perfect PLA/NCC/OWF sample was easily manufactured by melting–blending and injection molding. According to the crystallization and melting performance table, both NCC and OWF can act as nucleating agent to promote the crystallization properties on composites, while the blends did not have positive effect on thermal stability. Furthermore, the water absorption and degradation properties of PLA composites were also studied. This work not only provided a novel idea for the utilization of office waste paper but also successfully produced environment friendly composites with favorable mechanical properties and crystallization performance. [ABSTRACT FROM AUTHOR]

Combining recycling of paper wastes (WPs) with extrusion‐based additive manufacturing represents a sustainable route to cellular cellulose composites tailored for lightweight construction. Particularly, shear mixing of shredded WPs with an aqueous solution of a polymer binder like polyvinyl alcohol (PVA) yields aqueous pastes suitable for 3D printing. As a shear thinning additive, both WP and microfibrillated cellulose account for enhanced shear thinning and dimensional stability. Opposite to the formation of dense WP/PVA composites by melt extrusion, 3D printing of aqueous pastes produces cellular cellulose/PVA composites exhibiting hierarchical pore architectures. In spite of low densities around 0.8 g cm−3, high Young's modulus (2.0 GPa) and tensile strength (53 MPa) are achieved. Mechanical stability, water resistance, and even flame retardancy simultaneously improve by crosslinking with glyoxal and especially by mineralization. Multimaterial 3D printing combines the 3D dispensing of cellulose/PVA pastes with the simultaneous, staged, or subsequent spraying of aqueous water glass to enable mineralization of composite surface, bulk, and interlayers. Furthermore, the glyoxal‐mediated crosslinking affords thermo‐ and moisture‐responsive cellulose/PVA composites with programmable shape change induced either by heating at 100 °C or by exposure to moisture at 37 °C. [ABSTRACT FROM AUTHOR]

This study is the first, to the best of our knowledge, where waste napkin paper was successfully valorized to low-density (27.2 mg cm-3) cellulose aerogels for oil sorption material. Two simple methods with different gel coagulators, ethanol and sulfuric acid, were used for preparation of the aerogel. Conditions for the alkaline treatment of the raw material and the pre-freezing temperature in the lyophilization process were optimized. It was found that the water and oil sorption capacities of the aerogels were not significantly affected by alkaline treatment, while they could be adjusted by changing the pre-freezing temperature. Although the produced aerogels were initially amphiphilic, hydrophobic surfaces were obtained by vapor deposition of methyltrimethoxysilane (MTMS) and these materials possessed high sorption capacities, up to 32.24 cm³ g-1 (28.56 g g-1) for pump oil and 26.77 cm³ g-1 (39.59 g g-1) for chloroform. This was comparable to aerogels prepared from fresh cellulosic materials via the sol-gel method, as their sorption capacities varied in the range of 14-45 g g-1.

Waste paper, a promising renewable source of cellulose, was successfully prepared into a magnetic carbonaceous solid acid (SMWP) via a facile and integrated impregnation-pyrolysis–sulfonation process. The resultant catalyst was confirmed to possess a porous structure with a high surface area, various oxygen-containing functional groups and contain Fe 3 O 4 components. The SMWP catalyst also exhibited a high catalytic activity in the alcoholysis of furfuryl alcohol with n-butanol, up to 90.6% yield of n-butyl levulinate and 100% conversion of furfuryl alcohol was achieved by optimizing the reaction conditions. In comparison with other solid acids such as HZSM-5 zeolite and Nafion-212 resin, the better performance of SMWP could be explained by its strong acidity and good affinity to furfuryl alcohol, which results from the synergistic effect of SO 3 H, COOH and phenolic OH groups on the carbon surface. Moreover, the catalyst could be easily recycled with an external magnet and reused 7 times without a distinct loss of activity. The findings in this work provided an environmentally friendly manner for waste paper utilization and fuel additive production. Image 1 • A novel magnetic carbon catalyst derived from waste paper (SMWP) was fabricated. • SMWP possessed high surface area, strong acidity and good magnetic separability. • Up to 90.6% yield of n-butyl levulinate was obtained over SMWP via alcoholysis. • 90% of its original activity could be preserved after seven times recycles. [ABSTRACT FROM AUTHOR]

The demand for fresh water will increase in the coming decades as the world population grows. While large-scale water purification plants will serve highly populated areas, the demand of fresh water will continue to grow even in remote and potentially under-developed locations. In this work, it has been shown that fresh water can be produced from seawater or polluted water using waste paper and direct solar exposure, without the need of electricity during water purification. The highly efficient solar evaporation system proposed here, which is based on graphene/cellulose aerogels, can be fabricated quickly without highly technical skills, requiring only a microwave oven, graphene oxide samples, and cellulose fibers obtained from packaging (i.e., waste paper and polyethylene foams). The produced aerogels show high photo-thermal conversion, excellent hydrophilicity and low thermal conductivity, properties that are conducive to evaporation rates as high as 1.83 kg m−2 h−1, photo-thermal efficiency of 92%, and stability for more than 40 operation cycles. Despite using waste materials, these performance metrics are superior to those reported for most materials to date, and are a consequence of the manufacturing process described here. Field tests confirmed that 1 m2 of the as-prepared aerogels can produce between 6.44 and 11.27 kg of fresh water from seawater or polluted water in a 12-hour period, which is the daily amount of drinking water required for three adults based on World Health Organization projections. [Display omitted] • An efficient graphene/cellulose arogel (GCA) is developed for waste water treatment. • GCA achieves evaporation rates of 1.83 kg m−2 h−1 and poho-thermal efficiency of 92%. • GCA demonstrates stability for > 40 cycles when purifying different waste water. • A decentralized solar evaporation system is developed from domestic solid wastes. • The system produces ∼11.3 kg/day of fresh water in field tests. [ABSTRACT FROM AUTHOR]