Waste Paper Research Articles

Comparing the short-term leaching behaviour of cements containing supplementary cementitious materials in different leachants for low-level waste encapsulation

Pulverized fly ash (PFA) is commonly used as a supplementary cementitious material (SCM) in cement and is permitted for use in cements and grouts used for the encapsulation of low-level nuclear waste. However, with a global decrease in availability of PFA predicted in the near future, alternative SCMs are required. In nuclear encapsulation, a key parameter for a new SCM is that it does not change the leaching behaviour of the grout. We present promising initial leaching data from two SCMs: metakaolin and waste paper fly ash. These were tested for 24 h in two leachants, deionized water and an artificial groundwater, tracking the pH and leachability of a range of elements as the samples equilibrated with the leachants. The study suggests that for many elements, both metakaolin and waste paper fly ash show a very similar leaching behaviour to PFA grout formulations despite differences in the pH equilibration. In general, the tests suggest that the composition of the elute is dominated by leaching from the cementitious phases, and not the SCM. This suggests that further longer-term leaching studies are required as part of testing for SCM suitability for nuclear grouts in order to understand the connections between leaching and grout microstructure.

Effects of hydrodynamic shear during formation of paper sheets with the addition of nanofibrillated cellulose, cationic starch, and cationic retention aid

Laboratory tests were conducted to evaluate effects of hydrodynamic shear levels on papermaking process variables and paper handsheet properties. The furnish was from 100% recycled copy paper, to which was added nanofibrillated cellulose (NFC) at the 5% level following its optional pretreatment with cationic starch. A cationic copolymer of acrylamide (cPAM) was used as the retention aid. Different levels of hydrodynamic shear were applied both after mixing the NFC with the cationic starch (pre-shearing) or after all the furnish components had been combined (final shearing). The presence or absence of pre-shearing was found to have little effect on the measured outcomes. By contrast, increasing final shear hurt filler retention and made the resulting paper more uniform. However, the final shear level did not have a significant effect on the tensile strength of the resulting handsheets. Medium-charge density cationic starch, used in pretreating the NFC, consistently gave greater strength in comparison to a high-charge cationic starch. The significance of these findings is that though the relatively high hydrodynamic shear levels associated with modern paper machines can have some beneficial effects, they do not necessarily overcome all challenges associated with wet-end addition of nanocellulose in combination with other additives.

Colloid chemical aspects of paper formation in the presence of nanofibrillated cellulose and cationic starch

A series of experimental tests were carried out to examine colloidal-scale consequences of optional-ly treating nanofibrillated cellulose (NFC) with cationic starches of different charge density and dosage (0.5% or 2.0% by weight), adding that material to a furnish prepared from 100% recycled copy paper, and then subjecting the mixture to very different levels of hydrodynamic shear. Tests included optical microscopy, sediment volume tests, sediment velocity tests, and “percent fines” assessment by means of a fiber quality analyzer (FQA). In addition, the zeta potential and charge demand of the studied materials were evaluated. Optical imaging revealed that cationic starch treatment of the NFC tended to agglomerate it into multiparticle clusters, which sometimes could be mostly redispersed by hydrodynamic shear. Subsequent addition of the starch-treated NFC to the default furnish resulted in much of the colloidal material becoming attached to fibers. Subsequent shearing of the mixtures was at least partly effective in separating the clusters of NFC from the fiber surface, resulting in essentially a two-component mixture. Multiparticle NFC clusters coexisted with the fiber suspension, sometimes attached and sometimes not, depending on the details of treatments. Sediment volume tests showed that systems containing cationic starch-treated NFC tended to have a higher density after settling in comparison to untreated NFC; these findings are consistent with the cationic starch acting as a stabilizer on the solid surfaces, allowing them to slide past each other during the settling process. Application of intense hydrodynamic shear tended to result in denser sediment. Results of tests with the sediment velocity measurement and the FQA percent fines assessment did not correlate well with changes in test conditions considered in this study.

Prediction of Flotation Deinking Performance: A Comparative Analysis of Machine Learning Techniques

Flotation deinking is one of the most widely used techniques for the separation of ink particles from cellulose fibers during the process of paper recycling. It is a complex process influenced by a variety of factors, and is difficult to represent and usually results in models that are inconvenient to implement and/or interpret. In this paper, a comprehensive study of several machine learning methods for the prediction of flotation deinking performance is carried out, including support vector regression, regression tree ensembles (random forests and boosting) and Gaussian process regression. The prediction relies on the development of a limited dataset that assumes representative data samples obtained under a variety of laboratory conditions, including different reagents, pH values and flotation residence times. The results obtained in this paper confirm that the machine learning methods enable the accurate prediction of flotation deinking performance even when the dataset used for training the model is limited, thus enabling the determination of optimal conditions for the paper recycling process, with only minimal costs and effort. Considering the low complexity of the Gaussian process regression compared to the aforementioned ensemble models, it should be emphasized that the Gaussian process regression gave the best performance in estimating fiber recovery (R2 = 97.77%) and a reasonable performance in estimating the toner recovery (R2 = 86.31%).

Converting large-scale waste paper fibers into lanthanum-modified cellulose carbon aerogel adsorbents for efficient phosphorus removal

This study presents the synthesis of a novel lanthanum-modified cellulose-based carbon aerogel (La-CCA) from waste printing paper, aimed at addressing the issue of phosphate pollution in aquatic environments. The objective was to develop an effective and sustainable adsorbent to mitigate eutrophication caused by excess phosphates in water bodies. La-CCA exhibited a remarkable phosphate adsorption capacity, peaking at 44.32 mg/g under optimal conditions, demonstrating its efficiency as an adsorbent. The novelty of this work lies in the use of waste paper as a raw material, coupled with lanthanum modification, which enhanced adsorption performance through multiple mechanisms, including electrostatic interactions, ligand exchange, and inner-sphere complexation. The study also discussed the retention of the microfibrous structure of cellulose, contributing to the material’s stability and functionality. Comprehensive analyses including zeta potential, FTIR, and XPS elucidate the underlying adsorption mechanisms. La-CCA was demonstrated to be easily separable from solutions with minimal lanthanum leaching, particularly under conditions above pH 3.0, underscoring its potential for practical applications in phosphate removal from nutrient-enriched waters.

Energy dataset of Frontier supercomputer for waste heat recovery

The Hewlett Packard Enterprise–Cray EX Frontier is the world’s first and fastest exascale supercomputer, hosted at the Oak Ridge Leadership Computing Facility in Tennessee, United States. Frontier is a significant electricity consumer, drawing 8–30 MW; this massive energy demand produces significant waste heat, requiring extensive cooling measures. Although harnessing this waste heat for campus heating is a sustainability goal at Oak Ridge National Laboratory (ORNL), the 30 °C–38 °C waste heat temperature poses compatibility issues with standard HVAC systems. Heat pump systems, prevalent in residential settings and some industries, can efficiently upgrade low-quality heat to usable energy for buildings. Thus, heat pump technology powered by renewable electricity offers an efficient, cost-effective solution for substantial waste heat recovery. However, a major challenge is the absence of benchmark data on high-performance computing (HPC) heat generation and waste heat profiles. This paper reports power demand and waste heat measurements from an ORNL HPC data centre, aiming to guide future research on optimizing waste heat recovery in large-scale data centres, especially those of HPC calibre.

Investigation the Use of Waste Glass and Waste Paper as an Alternative Construction Binding Material: An Approach Towards Sustainable Environment

The idea of repurposing garbage as a resource within the building industry has drawn much attention in light of growing worldwide concerns about sustainable development and waste management. This thesis explores the intriguing idea of using waste materials as a practical and ecological replacement for construction materials and also carefully evaluates the technical, environmental and financial viability of incorporating various waste products, like household waste paper and waste glass into different construction applications. The results of this research project are incredibly insightful. Regarding waste paper as a cement replacement, the experiment demonstrated that substituting 10%, 20% or 30% of cement with waste paper is not a recommended practice. In all instances, the resulting concrete blocks exhibited a significant reduction in strength when compared to traditional concrete formulations. This outcome underscores the limitations of waste paper as a viable substitute for maintaining concrete strength. Conversely, findings regarding glass waste replacement in cement are particularly exciting. At just 7 days of curing, concrete blocks incorporating 10% and 20% glass waste replacements displayed higher strength than their conventional counterparts, showcasing an early strength advantage. By the 14-day mark, the strength of these glass waste-reinforced blocks closely approached that of standard concrete, highlighting their potential for use in sustainable construction practices. Even more impressively, at 21 days of curing, when conventional concrete reached its peak strength at 28.33 KN per square meter, the blocks with 10%, 20% and 30% glass waste replacement-maintained robustness, with strengths of 26.4, 25.26 and 19.44 KN per square meter respectively. This prolonged strength retention suggests that glass waste-reinforced concrete can serve as a sustainable alternative without compromising structural integrity, even in the long term.

Experimentation on Sargassum wightii as a flash powder igniter for attaining eco-friendly combustion on pyrotechnics

Firecrackers are a vital element of cultural festivities that happen worldwide. However, the hazardous by-products they emit have a significant impact on environmental pollution, leading to the greenhouse effect and climate change. Aluminium powder serves as the fuel in the traditional flash powder mixture, nitrate of potassium serves as an oxidizing agent, and sulphur acts as the igniter at exact concentrations. The presence of sulfur in the flash powder mixture is critical as it acts as an igniter, contributing to the formation of sulfur dioxide, which can cause environmental harm. We carried out an experiment employing Sargassum wightii brown seaweed powder as a replacement for sulphur at specific amounts to lessen the effects of sulphur in flash powder. We discovered that Sargassum wightii brown seaweed powder may replace up to 50% of the sulphur significance in the flash powder mixture without impairing the flash powder's traditional performance. Our experiments included impact and friction sensitivity, SEM, and FTIR analyses to evaluate the improved flash powder composition. The results revealed that the modified flash powder mixture SP5 and SP10 emits less emission by 12% and 21%, and produces similar noise performance of 108 and 107 dB(A) to the normal flash powder composition (SP), affirming that the SP10 flash powder is a viable alternative. Moreover, in our relentless pursuit to mitigate the detrimental effects on our environment, we have ingeniously introduced a novel product—the Chinese cracker made from vegetable waste paper. Not only does this innovative solution address concerns regarding land pollution, but it also presents a sustainable approach to consumer goods.

Waste paper sludge ash as a pozzolanic material: Enhancing concrete performance and sustainability

Waste paper sludge ash as a pozzolanic material: Enhancing concrete performance and sustainability

Wastewater treatment in the pulp and paper industry: A review

The pulp and paper industry plays a large role in global manufacturing, which creates significant water consumption and generation of wastewater that is filled with organic compounds and other chemicals. This paper will explore many different aspects of the pulp and paper industry such as raw material sourcing, manufacturing processes, environmental concerns, technological advancements, and the various wastewater treatment approaches. While there are many different methods to approach this wastewater issue, in this paper we will focus on anaerobic digestion, the application of biological aerated filters, and the use of constructed wetlands. The main material utilized in this industry is wood pulp, which undergoes multiple different procedures and processes to create the typical paper products we use every day. These processes, such as pulping and bleaching, create a large number of environmental concerns despite efforts to encourage better manufacturing practices and paper recycling.

A facile and sustainable strategy to construct recyclable paper with enhanced water and oil resistance for eco-friendly food packaging

As a potential substitute for petroleum-based plastics as food packaging material, application of paper is hampered by weak resistance to water and oil. In light of this, paper barrier coating was prepared based on sodium alginate and alkyl ketene dimer. The properties of the obtained SAKD emulsion were investigated and stabilizing mechanism was proposed. Furthermore, SAKD emulsion was applied on paper surface for enhancing barrier properties against both water and oil. After coated, oil resistance KIT was increased from 0 to 8, sizing degree increased by 3977 % and Cobb30 decreased by 66.08 % probably because a more closed structure formed with lower surface energy. Barrier properties to air, water vapor and organic solvents were also strengthened. Additionally, the coating exhibited good stability after folded repeatedly. Furthermore, SAKD coating layer did not negatively affected degradability of paper and the coated paper could be efficiently recycled via a facile treatment, confirming its eco-friendliness. This work demonstrates a sustainable and simple route to prepare paper with good barrier properties and provides the feasibility of developing eco-friendly paper packaging for food based on bio-based materials.

To Print or Not to Print - Sustainable Practice in Geriatric Integrated Care Clinics

Abstract Background The Comprehensive Geriatric Assessment (CGA) is a cornerstone of geriatric medicine and is frequently carried out in integrated care clinics using a paper document (1). The expansion of integrated care services occurs alongside climate change, an increasingly challenging public health crisis at a local and national level (2). Paper waste is a contributor to deforestation and carbon emissions. We aimed to assess the environmental impact of paper use within our geriatric integrated care service. Methods 12 months of Geriatric Integrated Care attendances were included between 1st January 2023 to 1st January 2024. We measured the number of CGAs performed and A4 pages used in documentation. Environmental impact was evaluated based on carbon emissions per A4 page (3). Results A CGA was completed on 780 patients in a 12-month period which included in-hospital, frailty at the front door and 2 community specialist teams' assessments. This resulted in 11,700 pages of A4 paper in documentation. Estimated carbon emissions are 70.2kg CO2 emissions for the 12-month period. Extrapolating this solely to the 32 ICPOP teams in geriatric medicine in Ireland it would result in the equivalent of 22 trees per year, emitting 1,123.2 Kg of CO2 emissions per year from these assessments alone or equivalent to driving 8028.6km (4). Conclusion The benefits for patients and staff of integrated digital healthcare records are well established. The environmental impact of how we provide healthcare is not. Paperless solutions are required for both patient safety, seamless record keeping and environmental sustainability in keeping with UN sustainable development goals.

Composition of New York State (United States) Disposed Waste and Recyclables in 2021: An Advanced Analysis of Waste Sort Data

Understanding the composition of disposed municipal solid waste (MSW) and recyclables can lead to better waste management. New York State (United States) has never had a state-wide waste characterization sorting program. In 2021, sampling was conducted at 11 locations, representing 25% of the state population outside of New York City. Twenty-three tonnes from 173 discrete samples were sorted into 41 categories. The resulting data were analyzed by single constituent approaches and more novel multivariate distance techniques. The analyses found that disposed MSW was 22.8% paper, 20.5% food, and 16.8% plastics. Recyclable paper and glass–metal–plastic containers were 18.2% (11.7% paper, 6.5% containers) and yard waste was 6.5%, meaning about 25% of the disposed MSW could have been recovered. Multivariate analysis determined that the disposed MSW was similar to that from other United States jurisdictions such as Wisconsin, Pennsylvania, New York City, and Syracuse (NY), and different from California and United States Environmental Protection Agency model data. Recyclables composition was different from disposed MSW composition. Dual-stream recyclables were sorted better than single-stream recyclables. Corrugated cardboard was the most common paper recyclable and plastics were the most common container recyclable. The data are being used to help guide planning for an expected packaging extended producer responsibility law for the State.

Sustainable three-dimensional printing of waste paper-based functional materials and constructs

Three-dimensional (3D) printing is a prominent technology across various industrial sectors, and its increasing popularity urgently calls for sustainable 3D printing materials. However, the availability of such materials remains under exploit. Here, we present a low-cost strategy to harnesses waste papers as a feedstock to develop sustainable 3D printing inks. This approach offers a remarkable printability and circular utilisation of biodegradable paper wastes to produce 3D printed constructs, with desired mechanical properties and shape stability for high temperature applications. Our constructs can be efficiently recycled into inks for reprinting, and our method can be applied to various types of waste papers. By employing multi-material printing, our approach can be extended to produce multi-coloured constructs, security information printings, and mechanically appealing designs. This strategy offers an innovative and sustainable solution that addresses the need for repurposing paper wastes, which would otherwise end up in landfills, while concurrently reducing the reliance on virgin plastics for 3D printing.

Energy saving potential in steam systems: A techno-economic analysis of a recycling pulp and paper mill industry in Morocco

The industrial sector represents nearly 40 % of global energy consumption, with steam systems accounting for 30 % of energy use in manufacturing. As the need for cleaner processes intensifies within African and global energy transitions, adopting energy efficiency practices becomes imperative. Governments are focusing on reducing energy losses in fossil fuel-dominated manufacturing industries, which are major producers of greenhouse gas emissions. Despite their significant energy consumption, industrial heat processes are often overlooked in efforts to reduce costs and emissions. To address this, the study examines thermal energy processes and identifies energy-saving opportunities within steam systems through a techno-economic analysis of a recycling pulp and paper mill in Morocco. This is the first study focusing specifically on steam systems within a particular industry in the country. The research uses a system approach covering steam generation, distribution, end-use, and recovery. The current system is benchmarked through a rating questionnaire, and proposed energy-saving actions include leak repair, pipe insulation, blowdown management, and improved boiler combustion efficiency. An economic study evaluates the cost-effectiveness of these opportunities. Findings reveal a 6 % reduction in thermal energy consumption, annual savings of $417 899 and nearly 482 TJ, a 6 % decrease in GHG emissions (2158.5 tons of CO2 per year), and water savings of approximately 5300 m³ per year (13 %). The total investment of $8750 has negligible payback periods. Despite diverse industrial activities, this work is useful for other industries since the fundamental components of the steam system are widely shared. Moreover, it supports the African Union's Agenda 2063 and United Nations Sustainable Development Goals by providing practical insights and recommendations for enhancing industrial energy efficiency.

Controllable preparation and morphology regulation of nanocelluloses from waste paper by a green hydrolysis method

This study focused on the morphology regulation of nanocelluloses (NCs) aiming at preparing NCs with the controllable properties. NCs with rod-shaped, spherical, and rod-shaped and spherical composite structures were prepared from waste paper by a green enzymatic hydrolysis. The critical enzyme concentration for the transition of NCs from one morphology to another was explored. Several analytical methods, including TGA, XRD, SEM, TEM, DSC and WCA, were employed to characterize the prepared NCs. The results showed that with the cellulase enzyme concentration lower than 6 μ/ml or higher than 30 μ/ml, the prepared NCs had a single rod-shaped or spherical structure. When the cellulase concentration was between 6 and 30 μ/ml, the prepared NCs had a composite morphology of rods and spheres. Besides, NCs with a composite morphology dominated by rod-like or spherical structures had a higher thermal stability. Moreover, NCs prepared with cellulase enzyme concentration of 6 and 35 μ/ml had the highest and lowest crystallinity of 81.7 % and 59.3 %, respectively. Hence, this work achieved the morphology and property regulation of NCs by a green method which expanded the application scope of NCs and realized the high value utilization of waste paper.

Applicability of Paper and Pulp Industry Waste for Manufacturing Mycelium-Based Materials for Thermoacoustic Insulation

Applicability of Paper and Pulp Industry Waste for Manufacturing Mycelium-Based Materials for Thermoacoustic Insulation

Advancing sustainable molded packaging: Integrating silica aerogel into recycled paper pulp for the fabrication of thermally and mechanically stable superhydrophobic composites

In recent years, the growing demand for sustainable packaging has significantly fueled the quest to explore novel approaches that enhance the applicability of renewable alternatives. This study leverages the unique properties of silica aerogel (SA) to address the limitations of traditional molded pulp products. By integrating SA into recycled paper pulp (RP), we aimed to improve water resistance, thermal stability, and mechanical properties. Composites were prepared with varying SA concentrations (1–10 %). Contact angle measurements showed enhanced hydrophobicity, with RP/SA3 % achieving a contact angle of 152.09°, compared to 122.39° for neat RP. The tensile index (TI) of RP/SA composites with 3 % SA increased by 21.09 % compared to neat RP, indicating better mechanical strength. Thermal conductivity significantly decreased, with RP/SA10 % reducing from 0.155 W m−1·K−1 in neat RP to 0.088 W m−1·K−1, a 43.2 % improvement in thermal insulation. Additionally, composites with 1 % and 3 % SA maintained high biodegradability, showing over 50 % degradation after six weeks in soil. These results suggest that incorporating SA into RP composites enhances their functionality without compromising biodegradability, offering a promising solution for sustainable packaging. As regulatory bodies emphasize resource management and waste reduction, the potential of these innovative and environmentally friendly packaging solutions becomes increasingly significant.

Optimal 4E design and innovative R-curve approach for a gas-solar- biological waste polygeneration system for power, freshwater, and methanol production

BackgroundCogeneration power plants traditionally rely on fossil fuels to produce stable power and heat. However, increasing energy demand and population growth have intensified the emission of biological pollutants due to fossil fuel use. The Global Alliance on Health and Pollution advocates for integrating renewable energy sources to mitigate these issues. ObjectivesThis study aims to evaluate the integration of a solar-biomass polygeneration system with a hybrid solar-waste-fossil fuel cogeneration system. The goal is to analyze the system from technical, economic, and environmental perspectives, focusing on optimizing energy demand and minimizing environmental impact. MethodsTo assess energy demand and supply, the R-curve methodology was applied to the hybrid cogeneration system, with a specific focus on solar and biomass renewable energies. Various scenarios were analyzed, including total annual costs, pollutant emissions, water footprint, and overall environmental impact based on life cycle assessment. The study examined and compared the performance of three types of biomass waste (Municipal solid waste, mixed paper waste, and date palm waste). Multi-objective optimization was performed using artificial intelligence and machine learning techniques, employing four meta-heuristic algorithms. The conditions generated by each algorithm were analyzed and compared. ResultsMunicipal solid waste, being the most readily available fuel, provided the most favorable economic conditions for the system. Environmentally, municipal solid waste ranked in the middle compared to other fuels. Among the optimization algorithms, the Salps swarm algorithm proved to be the most efficient in terms of calculation time and system efficiency improvements. The optimization improved net power generation by 5.25 %, overall energy efficiency by 16.27 %, total cost rate by 10.19 %, and total environmental impact rate by 14.02 %. ConclusionThe integrated system's performance was analyzed across different climatic change throughout the year. The multi-objective Salps swarm algorithm optimization demonstrated significant benefits in enhancing system efficiency and reducing costs and environmental impacts.

Physical and mechanical characterization of solid waste collected from rural areas of China: Experimental study

To support the landfill design and waste management in rural areas of China, solid waste covering eight provisional regions was collected and tested in the laboratory to characterize its physical properties (composition, moisture content, specific gravity, dry unit weight) and mechanical properties (compressibility and shear strength). The results show that, compared with solid wastes from urban areas (MSW), solid waste from rural areas (RSW) comprised a much lower content of soil-like, gravel, and inert waste and a significantly higher content of combustible waste, thereby yielding a much lower specific gravity and dry unit weight. Similar to MSW, the compression index of RSW correlated well with its physical properties. However, its strength properties displayed divergence. Notably, the friction angle φ' of RSW remained relatively consistent, ranging from 28.4° to 30.9°. This narrow range is attributed to RSW's higher combustible-to-inert (CI) ratio compared to MSW. The cohesion intercept c' of RSW ranged from 13.5 to 24.9 kPa, showing a positive correlation with the fiber content without considering contribution from paper waste. This finding combined with data from the literature further revealed that the trend of increasing cohesion intercept with increasing fiber content became weakened over time. Relationships between φ' and c' versus C/I for RSW observed in this study will serve as an extension to the existing finding reported for MSW in the literature, i.e., for predominately combustible waste with C/I exceeding 10, constant values of strength parameters (i.e., moderate values φ' = 30°, c' = 20 kPa) are recommended. The results of this study are useful for the capacity design and slope stability analysis of landfills as well as waste recycle and reuse, ensuring a sustainable development of environment in China.