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• Waste production from schools changes depending on the level of institutions. • High rate of positive answers but unsuccessful sorting indicate lack of practice. • Recycling capture rates do not differ significantly between school types. • There is a strong positive correlation between capture rates of some recyclables. • The success of recycling is higher if it is is supported with specific programmes. In this study, the waste generation at the educational institutes chosen from four different levels (kindergartens, primary, secondary and high schools) in Istanbul was measured on-site and the contents of the waste thrown into the recycling bins were determined to specify capture rates. Separation and weighing processes were performed at 16 spots in high schools, 12 spots in secondary schools, 7 spots in primary schools and 7 spots in kindergartens. A survey was conducted to determine the students' awareness of recycling in these schools. It was revealed that the wastes produced from educational institutes are organics (36.4 %), paper (24 %), plastics (14.4 %), glass (8.1 %), metals (4.8 %) and miscellaneous (12.3 %). The survey results indicate that 93 % of the participants think recycling is important, 71 % of them throw their waste into suitable waste bins and 59 % of them know the location of the recycling bins. At the primary school level, a very high rate of paper waste (92.3 %) was reported in plastic bins while plastic waste collected in these bins remained only 5.7 %. It was also seen that glass waste captured in glass bins and metal waste in metal bins remain very low rates (20.9 % and 29.2 %, respectively) at the secondary school level. At the high school level, it was determined that the most commonly captured wastes in glass, plastics and paper bins are glass (47.5 %), plastic (43.2 %) and paper (32.5 %), respectively. Correlation analyses indicated a high positive correlation (p < 0.05) between particular types of waste. [ABSTRACT FROM AUTHOR]

Due to a shortage of resources, exploring new biomass fillers has become critical for paper making. In this study, we reported an eco-friendly strategy for fabricating low-cost and efficient recycled paper with high mechanical properties using corrugated cardboard waste paper and harmless municipal sludge (HMS). First, the characteristics of HMS, including the particle size, pH, specific surface area, organic functional groups and organic component content, were analyzed. Then, the influence of the amount of HMS on the properties of the recycled paper was studied. Finally, the strengthening mechanism of biomass filling recycled paper was discussed. The results showed that HMS, a biomass filler for recycled paper preparation, exhibited excellent physical and chemical properties, with a median particle size of 6.395 μm, a surface area of 39.974 m2 g−1 and organic functional groups. The tensile index of the recycled paper with 30 % HMS was 13.10 Nm/g, which was 16.4 % greater than that of the unfilled paper and showed better thermal stability. This excellent performance could be attributed to the uniform distribution of HMS on the fiber surface, which improved the accessibility of hydrogen bond formation between fibers. Thus, this study proved that HMS was an excellent biomass filler for producing recycled paper. [ABSTRACT FROM AUTHOR]

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]

Xylanase finds extensive applications in diverse biotechnological fields such as biofuel production, pulp and paper industry, baking and brewing industry, food and feed industry, and deinking of waste paper. Here, polyethylene glycol (PEG)-phosphate aqueous two-phase system (ATPS) was applied for the purification of an alkaline active and thermotolerant xylanase from a marine source, Cladophora hutchinsiae (C. hutchinsiae). In the purification process, the effects of some experimental factors such as PEG concentration and PEG molar mass, potassium phosphate(K2HP04) concentration, and pH on xylanase distribution were systematically investigated. Relative enzymatic activity and purification factor obtained were 93.21% and 7.18, respectively. A single protein band of 28 kDa was observed on SDS-PAGE. The optimum temperature and pH of xylanase with beechwood xylan were 30 °C and 9.0, respectively. The Lineweaver-Burk graph was utilized to determine the Km (4.5 ± 0.8 mg/mL), Vmax (0.04 ± 0.01 U) and kcat (0.001 s−1) values of the enzyme. It was observed that the purified xylanase maintained 70% of its activity at 4 °C and was found stable at pH 4.0 by retaining almost all of its activity. Enzymatic activity was slightly enhanced with Na+, K+, Ca2+ and acetone. The highest increase in the reducing sugar amount was 53.6 ± 3.8, for orange juice at 50 U/mL enzyme concentration. [ABSTRACT FROM AUTHOR]

The current research focuses on the efficiency of energy recovery from non-hazardous organic wastes. It entails the generation of low-chloride refuse-derived fuel (RDF) from municipal solid waste (MSW) through moderate pyrolysis of combustible components. The moderate pyrolysis settings and composition ratio of biogenic/non-biogenic content from MSW combination (food waste, plastic waste, and paper waste) had a significant impact on the thermochemical characteristics and fuel behavior of RDF. Furthermore, pyrolysis with optimal MSW composition was studied to reduce toxic elements (chlorides, sulphides, and nitrides) and enhance the energy value in RDF by utilizing potassium-rich (waste orange peels (OP); banana peels (BP); and maize cob (MC)) and calcium-rich species (waste animal bone meal (ABM); egg shells (ES); and mussel shells (MS)) as natural additives. The results showed that increasing the pyrolysis temperature maximized the carbon concentration with reduced oxygen moieties (low O/C ratio), indicating a high energy value as the oxygenates were eliminated during moderate pyrolysis. The RDF treated at 400 °C (SF4-400) with MSW composition of 55% non-biogenic carbon and 45% biogenic carbon resulted in HHV of 29.22 MJ kg−1, the lowest ash concentration (0.96%), and a densified microstructural surface. The addition of natural maize cob additive into MSW (SF4-400-MC) yielded the maximum HHV (33.07 MJ kg−1) with considerable reductions in chlorides (71.43%), sulphides (87.50%), and insignificant nitrides content, all of which meet ASTM RDF quality criteria Grade I. [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]

The main part of companies in Bulgaria are built, however in the 70s, and upgraded last decade. The country supplies around 80 % of its supplies of paper, paperboard and pulp with own production. Integrated treatment of wastes is a priority for realizing closed life cycle of materials. The aim of the present work is to investigate the composition and other important characteristics of biomass wood ash wasted from paper industry. The correlations and associations among the chemical characteristics are also studied to find some basic trends and important relationships between two similar wastes from different enterprises. It was proved that all samples taken contained Ba, Cr, Mn, Ni, Co, Al, Fe, Cu and Zn far below the legal limits for such type of products. A product has a certain anti-acidic effect. The other positive result was that the content of iron is between 34 to 60 mg per 1 kg dry waste. The microscopic photos confirmed that the particles are close to the nano-size materials. The content of the elements C, N, H is in good quantities and ratios, which is a prerequisite for their use as a soil improver. By the results of this study, it was confirmed that all samples produced as a result of the thermal treatment and final low water content achieved are free from pathogen microorganisms and different weed seeds, affecting the yield and soil sustainability. That allows determining the optimal ratio between the used components with a view to obtain products with desired thermal stability and physico-chemical properties as soil improvers. [ABSTRACT FROM AUTHOR]

Enzymes derived from microbial sources have gained increasing popularity in industrial applications over the past decades. Despite the high production cost, alkaline proteases have wide applications in industries such as tanneries, food production, and detergents. In recent years, there has been a shift towards utilizing natural carbon sources for cultivating microorganisms and extracting proteases in order to reduce production costs. This study aimed to investigate the biochemical and kinetic properties of protease enzymes obtained from Aspergillus niger cultivated in a paper waste medium and compare with the enzyme produced in a basal medium. Glucose is a more favorable carbon source compared to cellulose, so paper waste was pretreated with cellulose-degrading bacteria to convert cellulose into smaller carbohydrates. After the growth of A. niger in basal and combinational media, the enzymatic properties were compared between the extracted enzymes by using casein as substrate. The results demonstrated that A. niger could produce protease enzymes in the paper waste medium similar to the basal medium with more than 5-fold cost saving. The specific activity of the enzymes isolated from the basal and paper waste media was calculated to be 184.95 ± 10.56 U ml−1 and 169.88 ± 11.05 U ml−1, respectively. Carbon sources did not affect the optimum pH and temperature of the protease enzyme, which were found to be 8 and 37 °C, respectively. This study provides valuable insights into the production of alkaline protease from A. niger using a combinational medium (paper waste pretreated by cellulose-degrading bacteria), offering a cost-effective approach for industrial applications. [ABSTRACT FROM AUTHOR]

Selective enrichment of La(III) by green material as an industrial raw material is of great research interest. In this study, the selective interaction between P and La(III) was utilized, and waste paper (WP) modified with phytic acid (PA) was used to adsorb La(III) from water using a simple one-pot method. The adsorption capacity was 237.23 mg g−1 (30 °C, pH = 5, initial concentration of 200 mg L−1). The equilibrium isotherm fitted the Langmuir isotherm model well. The adsorption equilibrium was reached after 15 min. The adsorption kinetics followed the pseudo-second-order kinetic model, indicating that the adsorption mechanism of the material towards La(III) is single-layer chemisorption. It selectively adsorbed La(III) from four coexisting substances (Pb, Ni, Cu, and Co). After six cycles, the adsorption efficiency of the adsorbent material remained at 60%. [ABSTRACT FROM AUTHOR]

Socio-ecological theories have long been in search of general principles to characterise anthropogenic activity-environmental change dynamics. Besides allowing for more flexible hypothesis testing, stochastic-extended IPAT and ImPACT baselines opened the door to multiple environmental applications in which solid waste generation took a growing stage. This paper surveys Waste Kuznets Curve's original foundations and underlines why the nature and shape of the hypothetical curvilinear income-waste response function tend to compare to a "black-box". It then stresses why diverging conclusions are linked to heterogeneous estimators' choices differing in their statistical assumptions and powers; whereas generic patterns hardly emerge (e.g., income elasticities of waste generation vary even when the mathematical functional form does not; population elasticities are sensitive to time-varying data and income groups). Next, we identify persisting biases of endogeneity which threaten the internal validity of WKC conclusions, if uncontrolled for (e.g., simultaneity, waste measurement errors and garbage policy confounding effect); along with other identification problems including within-panel heterogeneity with systematic slope variations and cross-sectional and spatially dependent income series. Although we propose a set of theoretically justified instrumental variables to exogenously predict income levels and ensure unbiased elasticities, we also detect and underline that additional threats to external invalidity do play out in practice (e.g., asymmetric geographical coverage and bias of case study selection due to environmental data constraints; missing policy-realm; within-waste heterogeneity hidden by widely aggregated indicators; and a non-systematic treatment of the technological effect). All prevent the waste literature from converging and should be considered by future empirical assessments. [ABSTRACT FROM AUTHOR]

The growing demand for environmentally friendly and sustainable materials has led to the invention of innovative solutions aiming to reduce negative impacts on the environment. Mycelium-based green composites (MBCs) have become an alternative to traditional materials due to their biodegradability and various potential uses. Although MBCs are accepted as modern materials, there are concerns related to some of their physical and mechanical properties that might have limitations when they are used. This study investigates the effects of using paper waste to improve MBC properties. In this study, we investigated the physical and mechanical properties of MBCs produced from lignocellulosic materials (corn husk and sawdust) and mushroom mycelia of the genus Lentinus sajor-caju TBRC 6266, with varying amounts of paper waste added. Adding paper waste increases the density of MBCs. Incorporating 20% paper waste into corn husks led to the enhancement of the compression, bending, and impact strength of MBCs by over 20%. Additionally, it was also found that the MBCs produced from corn husk and 10% paper waste could help in reducing the amount of water absorbed into the material. Adding paper waste to sawdust did not improve MBC properties. At the same time, some properties of MBCs, such as low tensile strength and high shrinkage, might need to be further improved in the future to unlock their full potential, for which there are many interesting approaches. Moreover, the research findings presented in this publication provide a wealth of insightful information on the possibility of using paper waste to improve MBC performance and expand their suitability for a range of applications in sustainable packaging materials and various home decorative items. This innovative approach not only promotes the efficient utilization of lignocellulosic biomass but also contributes to the development of environmentally friendly and biodegradable alternatives to traditional materials. [ABSTRACT FROM AUTHOR]

Thiophene sulfide is difficult to be removed by hydrodesulfurization. In this study, ZnCl2-waste paper fiber activated carbon was used as adsorbent to remove thiophene sulfide from simulated oil by hydrothermal modification. Under the optimum condition of ammonia modification, the adsorption capacity of modified adsorbent to BT is 14.8 mg S/g, 2.98 times that of unmodified. BET, FTIR and Boehm analysis showed that the mesopore volume of ammonia modified adsorbent increased by 96.62% and the mesopore ratio increased from 12.58% to 43.40%, which was conducive to improving the adsorption rate. After modification, the basic groups on the surface of the adsorbent increased by 44.3 times, and –NH3+, –OH and –NH2 enhanced the electron attraction and hydrogen bonding force between the adsorbent and BT molecule. Adsorption isotherms, adsorption kinetics and adsorption thermodynamics show that the adsorption process is spontaneous, entropic and exothermic. The pseudo-second-order kinetic rate constant increases with the increase of adsorption temperature, indicating that the increase of temperature is beneficial to accelerate the adsorption rate. The adsorption desulfurization process follows the mechanism of single and multilayer adsorption mixing. The results of this study can help to reveal more clearly that biobased activated carbon can be modified to adsorb thiophene sulfide. Ammonia modified adsorbents enhance the adsorption capacity for benzothiophene [ABSTRACT FROM AUTHOR]

This study evaluated the production of marine biodegradable plastics, specifically polyhydroxyalkanoates (PHAs), using waste paper from food containers as a novel material source. The results showed that adding dilute sulfuric acid as a pretreatment may have a negative impact on enzyme hydrolysis efficiency. Without pretreatment, the highest glucose concentration was observed in the 50-min heating group. In the experimental group with 1% dilute sulfuric acid as a pretreatment, the highest average glucose concentration was observed in the 25-min treatment group. In flask scale experiments, the C/N ratio was controlled at 10, 20, and 30. The results showed that when the C/N ratio was 10, the PHA/CDM ratios were 16.3 and 23.6 at 48 and 72 h, respectively. After 96 h of cultivation using hydrolysis liquid from the waste paper container as the sole carbon source in a 5-L scale experiment, the PHA/CDM ratio was 28.7 and the PHA concentration was 0.95 g/L. The potential bacterial strain in this study was confirmed to be a Bacillus genus bacterium after strain identification. The signal peaks indicated that the PHA obtained from the Bacillus sp. production process was PHB. [ABSTRACT FROM AUTHOR]

Purpose: To assess the extent of paper waste generated per year by instructions for use (IFUs) brochures included in intraocular lens (IOL) packaging in Europe and the U.S. Setting: Rothschild Foundation Hospital, Paris, France; Royal Free London NHS Foundation Trust; Center for Sight, London, United Kingdom. Design: Experimental study. Methods: A sample of IOLs were collected and each IFU was weighed. In addition, the cumulative weight of these brochures used in cataract surgeries performed annually in Europe and the U.S. was estimated, and the potential annual paper conservation that could be achieved if all manufacturers adopted electronic IFUs (e-IFUs) in Europe and the U.S. was determined. Results: The mean and standard deviation of the weight for overall IFUs, classic IFUs, and e-IFUs were 17.6 ± 13.8 g, 23.5 ± 13.2 g, and 2.9 ± 1.9 g, respectively. The estimated cumulative weight of paper generated from the IFUs accompanying implants used in European and U.S. cataract surgeries is 153 tons. If all manufacturers transition to e-IFUs, the cumulative weight saved would be 128 tons (-84%), equivalent to 120 tons of carbon dioxide equivalent and the preservation of more than 2000 trees annually. Conclusions: The classic IFUs in IOL packaging result in a significant amount of paper waste annually. Therefore, there is an urgent need for a rapid transition to e-IFU technology. The adoption of e-IFUs has already been authorized in Europe and the U.S., and it is crucial to expedite this process. [ABSTRACT FROM AUTHOR]

Complex polymers represent a challenge for remediating environmental pollution and an opportunity for microbial‐catalysed conversion to generate valorized chemicals. Members of the genus Streptomyces are of interest because of their potential use in biotechnological applications. Their versatility makes them excellent sources of biocatalysts for environmentally responsible bioconversion, as they have a broad substrate range and are active over a wide range of pH and temperature. Most Streptomyces studies have focused on the isolation of strains, recombinant work and enzyme characterization for evaluating their potential for biotechnological application. This review discusses reports of Streptomyces‐based technologies for use in the textile and pulp‐milling industry and describes the challenges and recent advances aimed at achieving better biodegradation methods featuring these microbial catalysts. The principal points to be discussed are (1) Streptomyces' enzymes for use in dye decolorization and lignocellulosic biodegradation, (2) biotechnological processes for textile and pulp and paper waste treatment and (3) challenges and advances for textile and pulp and paper effluent treatment. [ABSTRACT FROM AUTHOR]

Cellulose hydrogel derived from cellulose fibers extracted from printed paper waste is prepared. The hydrogel derived from 3 wt% of the cellulose concentration exhibits a maximum water absorption capacity of 465.5%. The effects of the cellulose hydrogel on the soil moisture are evaluated using four types of soils namely river sand, clayey soil, loamy soil, and gley soil (the wetland soil). The potential application of cellulose‐based hydrogel as an eco‐friendly seed germination media of the paddy seeds under the soil‐less condition is evaluated. This study shows that paddy seeds exhibit a higher seed germination rate of 53% when cellulose hydrogel is used as a seed germination media as compared to seed germination rate ranging from 14% to 35% when various types of soil are used as the germination media. The prepared cellulose hydrogel could be applied as an eco‐friendly and cost‐effective seed germination media to enhance the paddy seeds' germination rate. [ABSTRACT FROM AUTHOR]

Mathematical modeling is a high-leverage topic; it is critical to students' participation in STEM education and supports civic engagement. Until recently, research on modeling at the elementary level has been underemphasized, particularly research on supports and challenges for teachers who engage in designing authentic modeling tasks. In this study, we employed qualitative case study methods to investigate how elementary teachers designed and implemented authentic mathematical modeling tasks, with an explicit focus on how their tasks evidenced different dimensions of authenticity. We analyzed three cases of teams of elementary teachers as they developed modeling tasks connected to school and community contexts. The three cases were: 1) a student-driven modeling task related to paper and plastic waste in a school cafeteria, 2) a modeling task based on authentic situations at a community-run resource center, and 3) a modeling task focused on designing and monitoring a school community-building art project. Our cases illustrate that elementary teachers can successfully design and implement modeling activities that utilize different entry points and evidence multiple dimensions of authenticity. Furthermore, we found that the specific dimensions of authenticity may vary depending on the design supports and curriculum challenges within each context. [ABSTRACT FROM AUTHOR]

Halochromic azo dyes have versatile applications, including sensing and anti‐counterfeiting, due to their reversible color‐changing properties. In this work we investigated the structure‐dependent halochromism of azo compound (E)‐4‐((2‐hydroxynaphthalen‐1‐yl)diazenyl)benzenesulfonamide (HDBS) and explore its potential applications using experimental and theoretical approaches. Different spectroscopic techniques confirm the structural change in the dye as a consequence of tautomerism reaction upon changing pH (7 to 13). The stable form of hydrazone is isolated and characterized. Based on the spectroscopic characterization, it is concluded that the azo form exists at pH ≤ 9, whereas the hydrazone form at highly alkaline pH. To understand the origin of the absorption peaks, the stability, and tautomerism in water, DFT and TD‐DFT calculations are performed. A reasonable agreement between the theoretical and experimental observations enabled us to unravel the structure‐dependent halochromism. Further, we have shown that HDBS‐coated paper can be a real‐time visual sensor to monitor fish freshness and for anti‐counterfeiting ink. It changes colors with pH shifts, alerts consumers about the status of food. Additionally, erasable paper strip reduces paper waste and chemical pollution. The findings presented in this work provide a promising avenue for the development of halochromic azo compounds with potential applications in sensing and anti‐counterfeiting. [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]

This research explores the challenges and limitations faced at the basic level for the recycling of paper in an academic institute. It focuses on encouraging recycled paper use rather than bringing traditional virgin paper to prevent the rate of deforestation for reducing global warming. Data was collected from the academic institute via questionnaire and on-site observation and found that the institute was producing approximately 16 tons of wastepaper in a year. Besides that, another purpose of this research is to estimate the energy and assess the environmental effect by using the life cycle assessment as a tool. The results of this study revealed that traditional virgin paper derived from wood proves to be costly and less environmentally friendly than recycled paper. It also revealed that Traditional virgin paper has greater global warming, human toxicity, smog, acidification, and eutrophication potential than recycled paper. This study concludes that recycled paper does not only prove economically beneficent for any institution, but also beneficial for environment as well. [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]

Finding sustainable solutions to the increasing waste generation in Ghana has received a lot of attention in recent years. Through several waste-to-energy processes, the energy potential of municipal solid waste has recently witnessed significant technological advancements. The Renewable Energy Master Plan has projected the production of about 122 MWp from waste-to-energy installations by 2030 in Ghana. To help policymakers and engineers achieve national goals, this paper reviews the waste generation in Ghana estimated from 2010 to 2030 and the status of various bioenergy technologies in Ghana. This paper further estimates the energy recovery potential of municipal solid waste in Ghana under incineration, anaerobic digestion, and landfill gas recovery technologies. The review establishes that, by 2030, municipal solid waste generation will increase by 123% of the 2023 quantities and may produce 1484.25 MW of installed electricity capacity and 13,002.03 GWh per year, which would amount to nearly 59% of Ghana's 2030 renewable energy target. Additionally, it was determined that anaerobic digestion, incineration, and landfill gas recovery technologies, when properly developed, will add 105.33 MW, 301.4 MW, and 377.31 MW of installed electrical capacity, respectively, to Ghana's energy mix in 2028. [ABSTRACT FROM AUTHOR]

The rapid increase in solid waste along with urbanisation, especially arising from the industrial and agricultural sectors, sparks concern from the public regarding their adverse impact on human and environmental wellness. Therefore, waste biorefinery is the current interest that aligns with the concept of 'waste-to-wealth'. The conversion of waste into valuable products such as cellulose nanocrystals (CNCs) is an alternative method of circular waste management as CNCs have various applications. Their non-toxicity, biocompatibility, excellent mechanical strength, and load-bearing properties render them a good reinforcement agent for packaging films, sensors, and scaffolds. Nonetheless, the lack of studies on the comparison of waste sources and the complex parameters for the extraction of CNCs hinders the development of CNC extraction from waste products. This review paper compares and organizes the information from previously published scientific papers and reports on waste product sources, methods, parameters, and environmental effects of the derivation of CNCs from waste. Previously, no thorough reviews have been done closely on the sustainability aspect of CNC extraction from waste products. Through this review, it shows that there is a positive trend where novel CNC extraction routes are discovered to improve the yield, environmental friendliness, performance, and cost. However, most of the studies did not specify the environmental impacts of the extraction routes, limiting their feasibility for conventional applications. [ABSTRACT FROM AUTHOR]

Composite materials have been widely used because of their superior properties compared to those of the original material. Separation of the constituent materials is not easy in the recycling process, and such an effort lowers economic viability. As such, this study employed a pyrolysis as a valorizing method for the composite material. Disposable paper cup waste (DPCW) was chosen as the model compound for paper-plastic composites. To offer green/sustainable features, CO2 was employed as a raw and reactive material in the pyrolysis process. It was proved that DPCW primarily composed of cellulose (outer layer) and polyethylene (inner layer). In the single-stage and multistage pyrolysis of DPCW, the CO2 reactivity in the homogeneous reaction of CO2 and DPCW-derived volatiles was not rapid. To accelerate the reaction kinetics governing the reactivity of CO2, the catalytic pyrolysis of DPCW over Ni/SiO2 was performed. The formation of syngas increases significantly, suggesting that CO2 reactivity was catalytically enhanced. The generation of syngas (enhanced by CO2) was inversely related to the DPCW oil generation, indicating that more carbon was assigned from the oil to the gaseous pyrogenic products. The study results would offer a strategic means to valorize paper-plastic composites and CO2 into energy through pyrolysis. [ABSTRACT FROM AUTHOR]

The research on the recovery of low-grade thermal energy carried away by boiler flue gas is significant for sugar mills. This paper designs a waste heat recovery system based on sugar plant flue gas, integrating absorption refrigeration cycle and the organic Rankine cycle, and the effects of nine working fluids on the system are investigated. The aim is to realize the multi-form conversion of energy. The performance of the system is evaluated in terms of energy, exergy, and economic metrics. Multi-objective optimization is performed with the method of the NSGA-II genetic algorithm. The results show that Butane is the most suitable working fluid for ORC. The exergy efficiency of the system is 32.125% before optimisation, with an increased space cooling capacity of 15820.56 MW per year for the sugar mill. The exergy destruction analysis of the system reveals that the generator accounts for the highest proportion of exergy destruction (50.8%). The entire system shows the LCOE is as low as 0.0406$/kWh under the optimized condition. The optimized system can obtain an estimated annual electricity sales revenue of $136,300, and the sugar mill can save $308,600 in cooling costs. In addition, the payback period can be shortened to 5.79years. [ABSTRACT FROM AUTHOR]

The study assessed quality of briquettes produced from bagasse (B), corn husk (CH), and cassava roots (CR) using banana peels (BP), wastepaper (WP), and clay soil (CS) as binders. Mixing ratios were established from carbonized materials, and briquettes physical and combustion properties were determined. Weak shatter resistance appeared in WP, CS briquettes had best tumbling resistances while WP briquettes had better water penetration. CS briquettes (3:1:1) had low (2.7%) moisture content (MC), and 1:3:1 had low (28%) volatile matter (VM) while the highest was 41% for 2:2:1. Ash content (AC) for 2:2:1 was the highest (41%) with highest heating value (HV). BP briquettes for 0:4:1 (CH:CR:BP) had the lowest MC (4.9%), whereas 2:2:1 (B:CH:BP) had the highest VM (41.5%). AC (15.5%) for 1:3:1 was the highest while 2:2:1 (CH:CR) had the highest HV. WP briquettes 1:3:1 (B:CH) had the lowest MC (2%) and 3:1:1 had highest VM (35%), while the highest AC appeared for 4:0:1. The 2:2:1 (B:CR:WP) briquette yielded the highest HV (25.5 MJ/Kg). All materials were suitable for briquetting, although their qualities are sensitive to weather conditions. Together with BP briquettes, WP briquettes 2:2:1 (B:CR:WP) produce the best results, especially when using CR and CH feedstocks. [ABSTRACT FROM AUTHOR]

This article presents the results of the study of the morphological composition of municipal solid waste (MSW) from the landfill of Atyrau city, and the waste's energy characteristics and presence of microorganisms, including bacteria, fungi and viruses. This study was carried out under a government order to determine the feasibility of recycling accumulated and incoming waste into electricity and its hazard to the environment and the workers involved in handling it. At the moment, there is no MSW recycling in Kazakhstan, which has led to the accumulation of more than 125 million tons of waste with an annual increase of 5 million tons. The research included four major cities (Almaty, Shymkent, Atyrau and Astana), which were selected not only on the basis of population, but also because the cities were located in different climatic zones. Samples were collected at the city landfills: 10 samples with an average distance of 100 m from each other were collected to provide a maximum coverage of both recently received waste and long-time stored waste. The research showed that neither climatic conditions nor the population size had a significant impact on MSW density, the values of which ranged from 120.1 kg/m3 to 145.4 kg/m3, as this indicator directly depends on the quality of life. The mass of the combustible fraction ranged from 39.41% to 54.62% and was mainly represented by plastic, textile and paper waste. The average value for the four cities was 50.30%. The higher calorific value fell in the range of 24.22–30.49 MJ/kg, with an average value of 26.71 MJ/kg. Microbiological studies showed little difference in average composition regardless of climatic conditions. Thus, no sharp differences in MSW composition, its energy characteristics and microbiological composition were found. The results of this study may be useful for optimising MSW recycling and disposal processes, as well as for developing measures to reduce their negative impact on the environment and human health. [ABSTRACT FROM AUTHOR]

This article covers the study of the nature of ash content of containerboard from waste paper, as well as fractional composition of ash. With increasing use of waste paper with white top layer and deterioration of conditions of collecting and storing waste paper at the storing fields, there is an increase in mineral impurities in the incoming waste paper. This fact leads to increased load on cleaning equipment and accelerated wear of working parts of sorters and mills. Ash content includes all mineral impurities without any division into fractions or sources of occurrence. Reducing the total ash content of products becomes quite difficult, because suppliers of cleaning equipment guarantee the efficiency of removing only those mineral contaminants, the size of which is greater than the a certain value (70…100 microns). Standard methods for determining ash content of paper and cardboard do not imply the possibility of determining the fractional composition. To solve this problem, the authors applied a method for determining the fractional composition of granular materials in a certified laboratory. The method of sample preparation for analysis was developed by the authors independently. Based on the results of the research, it was possible to identify the volume of the ash fraction that can be separated by means of cleaning equipment. This volume is mainly quartz sand of various degrees of grinding, and the other part of ash content is the filler, calcium carbonate, which cannot be effectively removed from the technical process due to the small particle size. To determine the content of calcium carbonate, qualitative and quantitative research methods were used - treatment with hydrochloric acid followed by washing and weighing of the resulting sludge. This test methodology and the results of the research work can serve as a basis for the need to install additional or upgrade the existing cleaning equipment. Unfortunately, at present there are no studies concerning abrasive ability of the main filler – calcium carbonate, and its influence on service life of the corrugator. Also, at the moment there are no data concerning critical size of ash particles, which lead to accelerated wear of the rolls. At the same time, determination of critical particle size is important from the point of view of setting up and upgrading of cleaning equipment of the stock preparation department of a typical paper mill processing waste paper raw materials. For citation: Zhirnov D.N., Dernova E.V., Gorazdova V.V., Dulkin D.A. Ash Content of Containerboard. Problems and Solutions. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 5, pp. 184–194. (In Russ.). https://doi.org/10.37482/0536-1036-2023-5-184-194

Indonesia has the highest number of active volcanoes in the world due to its geologic location at the confluence of the Eurasian and Australian plates. However, despite this, the knowledge of local communities regarding volcanic eruptions is still very minimal. Therefore, it is important to provide education to the community in this context is the local community. This Community Service Program aims to increase community knowledge related to the process of volcanic eruption by using pulp-based learning media, so that it can become disaster mitigation knowledge. The methods used are observation, coaching or training based on practical simulations, questionnaires and interviews. The subject of this Community Service is the community of Tambun village, Baolan sub-district, Tolitoli district, totaling 21 people in collaboration with students of the elementary school teacher education program in semester III. The results of this program are the increase in community knowledge related to volcanic eruptions and the growth of community awareness related to the use of waste paper, this is in line with SDGs 4 and SDGs 17 relating to quality education and partnerships with the community.

Wastepaper is a potential biomass source that can be processed into solid fuel (briquette). The present work proposes a novel method to improve the storage property of briquettes for large-scale production. Improvement is made by adding a hydrophobic compound (paraffin wax) to form a shape-stabilized paper briquette (SSPB). Three different storage scenarios are performed for 720 hours. The moisture content of the paper briquette increases significantly up to 35.44% with a relaxed index of 1.19. SSPB shows unsubstantial moisture increment (5.1%) with a relaxed index of 1.05. The SSPB has better mechanical durability (97%) than paper briquette (82%). Thus, the shape-stabilized method can be used to maintain the briquette quality during the storage period.

Background. Physico-chemical modification of leather production waste opens up the possibility of their use, which reduces the environmental load on the environment. Purpose. Establishing a relationship between the components and strength of composite paper from modified leather and waste paper. Methodology. Modification of fibrous waste in an alkaline solution, differential thermal analysis, testing of physical and mechanical properties. Originality. An increase in the degree of leather cross-linking during the modification process was established, and the thermal and physical-mechanical properties of the composition were determined. Findings. Alkaline treatment of chrome shavings promotes the appearance of new polar groups and an increase in the degree of cross-linking of the product. The thermal effects of the leather-waste paperacrylic emulsion composite characterize the process of adhesion of the sizing agent to the fibers. [ABSTRACT FROM AUTHOR]

Tetra Pak® paper and PE (polyethylene) wastes were evaluated to obtain a new composite material with awareness of environmental responsibility. Fillers and coupling agents were used for this joining process. Calcite (CaCO3), boric acid (H3BO3), SPT (Sodium Perborate Tetrahydrate / NaBO3.4H2O), titanate, MAPE (maleic anhydride grafted polyethylene, and vinyltriethoxysilane (C8H18O) composites were produced in 30 x 30 cm plates. A total of 30 samples were prepared as 5 mg flour for thermogravimetric analysis (TGA). Samples were observed in a thermal analyzer at 10, 15, or 20 °C/min heating rate in nitrogen atmosphere. Graphs were obtained as a result of TGA, and the activation energies were calculated using these graphs. The activation energy was calculated using the Flynn-Wall-Ozawa method. The determined activation energies of the composites were close to each other for each temperature group. In the samples using calcite and vinyltriethoxysilane, relatively higher activation energies were observed in comparison to the samples with boric acid and MAPE. [ABSTRACT FROM AUTHOR]

Plastic concrete is a kind of flexible concrete cutoff wall material, which is used to solve the problem of poor coordinated deformation ability between ordinary concrete cutoff wall and surrounding soil. It has the characteristics of small elastic modulus and large limit strain, which greatly improves the operation condition of cutoff wall. In order to save bentonite resources and recycle waste automobile tires, this paper crushed waste automobile tires into rubber particles and mixed them into plastic concrete, through the uniaxial compression test and triaxial compression test, obtained the corresponding stress–strain curve, rubberized plastic concrete strength and deformation properties are studied and the rubber particles and the relationship between dosage. The test results show that the compressive strength of rubberized plastic concrete decreases with the increase of rubber particles content, but the deformation capacity increases with the increase of rubber particles content. In this paper, the regression analysis of rubberized plastic concrete constitutive relation and failure criterion including the influence factor of rubber particles are helpful to promote the engineering application of rubberized plastic concrete and reduce the exploitation of natural resources and environmental pollution. [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]

The surface of plant fibers was modified by silane coupling agents to prepare plant fiber/polylactic acid (PLA) composites, which can improve the dispersion, adhesion, and compatibility between the plant fibers and the PLA matrix. In this work, three silane coupling agents (KH550, KH560, and KH570) with different molecular structures were used to modify the surface of waste corrugated paper fibers (WFs), and dichloromethane was used as the solvent to prepare the WF/PLA composites. The effects of different silane coupling agents on the microstructure, mechanical properties, thermal decomposition, and crystallization properties of the composites were studied. The mechanical properties of the composites treated with 4 wt% KH560 were the best. Silane coupling agents can slightly improve the melting temperature of the composites, and WFs can promote the crystallization of PLA. The modification of WFs by silane coupling agents can increase the decomposition temperature of the WF/PLA composites. The content and type of silane coupling agent directly affected the mechanical properties of the WF/PLA composites. The interfacial compatibility between the WFs and PLA can be improved by using a silane coupling agent, which can further enhance the mechanical properties of WF/PLA composites. This provides a research basis for the further improvement of the performance of plant fiber/PLA composites. [ABSTRACT FROM AUTHOR]

Geopolymer concrete has been developed as a means of reducing carbon dioxide (CO2) emissions due to concrete manufacturing, which account for around 5-10% of the total global CO2 emissions. Additionally, this innovative material aims to utilize industrial waste as a sustainable resource. This study concentrates on developing a geopolymer mortar composition comprising 70% fly ash and 30% metakaolin. The mixture also includes 14 molars of sodium hydroxide, sodium silicate, saturated surface dry sand, water at a volume of 10% of the mix, and 1.5% superplasticizer. The solution-to-solid materials ratio was established at 0.55 while the ratio between sodium silicate and sodium hydroxide was established at 2.5:1. The geopolymer mortar was enhanced by rice husk fibers at varying volume percentages of 1%, 1.5%, and 2%. Additionally, waste paper, in the form of paper ash, was introduced as filler at a volume percentage of 5%. Following the demolding process, the specimens were cured in the controlled environment of an oven, with the temperature set at 60 °C for a period of 24 hr. Subsequently, the cured samples were stored for 7 and 28 days and then were tested. When different amounts of rice husk fibers were mixed in with a fixed amount of 5% paper ash, the flexural resistance of the geopolymer mortar increased significantly. After 7 days of curing, it was seen that the flexural strength experienced an increase of 4%, 13%, and 25%, and a further increase of 11%, 18%, and 31% after 28 days of curing. The results of the impact test showed a notable enhancement in impact resistance and energy absorption when incorporating paper ash and rice husk fibers. Specifically, the initial crack results exhibited a 50% rise, while the specimen failure after 28 days of curing showed a 66% improvement. [ABSTRACT FROM AUTHOR]

This study assesses the mechanical properties of mortars incorporating waste paper sludge-derived cellulose fibers. Compression and flexural tests were carried out on specimens prepared with cellulose fibers at different proportions, ranging from 0% to 2% of the total weight of the solid mortar constituents (cement, sand, and lime). In addition, a comparative analysis was carried out to evaluate the influence of the preparation method on the mechanical properties of the mortars. To this end, two series of mortars were studied: one prepared following a rigorous control of the preparation parameters and the other made without systematic parameter control to simulate typical on-site conditions. Finally, the applicability of both traditional and eco-friendly mortars in the construction of small-scale masonry walls was assessed through compression tests. Overall, the mechanical properties of mortars with cellulose fibers were comparable to those with 0% waste material, regardless of the production process. Regarding the compressive behavior of masonry walls, experimental tests showed significant similarities between specimens made with traditional and eco-friendly mortar. In conclusion, incorporating cellulose fibers into cement-based mortar shows considerable potential for building applications, enhancing the environmental benefits without compromising the mechanical behavior. [ABSTRACT FROM AUTHOR]