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Plastic-coated paper straws are insufficient to solve the plastic pollution problem because microplastics are formed during their degradation. In this study, upgraded paper straws were prepared by coating with biodegradable sodium alginate/cellulose nanofiber/stearic acid (SA/CNF/STA) on the surface of paper without additional adhesives. The tensile strength of the paper was enhanced synergistically by the coated SA and CNF after cross-linking with Ca2+ ions, reaching a maximum (26.46 MPa) when the mass ratio of SA to CNF was 4:1. The straws were prepared by spirally winding coated paper into tubes. Subsequent STA modification with different concentration (1–40%) improved the water stability of the paper straws. The paper straws exhibited excellent mechanical properties (including 13.45 MPa of flexural strength, 13.30 MPa of compressive strength) and hydrophobicity (103.67° of maximum water contact angle). After 130 days of soil burial, the paper straws were completely degraded. The comprehensive performance of prepared straws exceeds that of commercially available products in the same category, and they are safe and biodegradable. Paper straw in the work is in line with the concept of green and low-carbon development. [Display omitted] • Processing a paper straw based on biomass resource coatings. • SA/CNF hybrid coating synergistically enhanced the tensile strength of the straw. • The STA imparts satisfactory water stability to the straw. • The comprehensive performance of the straw outperforms commercial straw products. [ABSTRACT FROM AUTHOR]

Unprinting of paper can reduce multiple life-cycle stages in the recycling of paper to yield significant environmental impact. Laser-unprinting has been demonstrated for uncoated paper but causes significant damage to coated paper. This work explores a scalable optical (non-laser) process for unprinting coated paper. Printed coated paper is exposed to pulsed broad-spectrum Intense Pulsed Light (IPL) from a xenon lamp and the toner is then removed by dabbing gently with an ethanol wipe. While black toner is easily unprinted, unprinting of colored prints (red, blue, green) is best realized by incorporating an initial overprint of black toner. An unprinting throughput on the order of mm2/s is achieved. Three distinct regimes of unprinting are identified based on the extent of toner removal and damage of the paper. The optical properties of the unprinted paper, characterized via UV–Visible spectrophotometry, are correlated to these regimes to understand the potential for in-situ optical process monitoring. Scanning Electron Micrography and Fourier-Transform Infrared Spectroscopy are performed to understand the underlying mechanisms that govern the occurrence of the different unprinting regimes. Further, the potential impact of the developed approach on recycling of paper is discussed in the context of the capabilities of current optical unprinting approaches and the potential elimination of life-cycle stages in conventional paper recycling. • Intense Pulsed Light can scalably unprint toner from coated paper with minimal chemical usage. • Our overprinting approach enables colored prints to be removed as well. • Unprinting throughput of mm2/s is achieved. • Three distinct unprinting regimes exist, depending on process parameters and toner types. • Thermal weakening of toner-coating bonds and cracking are the primary governing mechanisms. [ABSTRACT FROM AUTHOR]

Allocating environmental impacts within life cycle assessment (LCA) is a recognised methodological problem. Different allocation methods have been developed to fulfil the various goals of LCA studies. At present, there is neither a consensus regarding the method to be used nor a one-fits-all method for dealing with recycling in LCA. The paper discusses some of the main allocation procedures practised in the pulp and paper industry, namely those covered by ISO/TS 14067:2018, GHG Protocol/PAS 2050, and the Product Environmental Footprint (PEF). All in all, the allocation method described in the ISO/TS 14067:2018 standard was considered the most appropriate to account for open-loop recycling of paper products. However, the method neither considers the number of subsequent uses of recycled fibres, nor the recycled fibre age. Yet, both of them are considered especially important in the open-loop recycling of paper products. In order to account for these aspects, the present study proposes an advanced, step-wise approach to handle allocation in LCAs accounting for the open-loop recycling of paper products. The advanced approach is based on the fibre mass flow model used to calculate the mean fibre age and the mean number of uses of paper products within the European context. The approach was validated with the data from the pulp and paper industry, particularly examining the newsprint paper grade with different contents of recycled fibre and fibre age. The paper, however, introduces all the parameters required to perform allocation based on the proposed method for other paper grades. The categpory of global warming potential was considered in the study as an illustrative example. yet the method could be applied to other impact assessment categories. The results calculated using the proposed allocation approach were compared to those obtained with the allocation methods described in the GHG Protocol/PAS 2050 and the PEF. The proposed allocation method can be used to guide further development of available standards and the product category rules, which will contribute to increased harmonisation and consistency of LCA studies in the pulp and paper sector, as well as to the enhanced practical implementation of LCA in industry. • A science based method for open loop recycling in life cycle assessment. • European fiber flow model used for calculation of fiber age and mean number of uses. • For product environmental footprint calculations of paper and board products. [ABSTRACT FROM AUTHOR]

Paper-based electronics offer a simple and cost-effective means to fabricate flexible devices. Here, we report an efficient pen-on-paper approach to construct metasurfaces on paper with silver units. Further, paper-based metasurfaces are employed to shield the electromagnetic interference which create new opportunities in turning waste paper into a solution for eliminating electromagnetic pollution. Experimental measurements and simulations show that waste paper-based metasurface manufactured in this way exhibits remarkable electromagnetic shielding properties with small thickness (thickness reduced more than 90% compared with that of traditional shielding materials), which makes it an ideal candidate for specific frequency electromagnetic filters. In addition, it can be readily extended to other regions of the electromagnetic spectrum, widened the shielding band by simply scaling the silver units' sizes and utilizing appropriate three-dimensional structures. Having taken performance into consideration, production is also taken into account. Paper-based shields offer both economic and energy benefits when considered on electronic printing, in addition, environment friendly nature and pliability of paper as well as simple fabrication procedure make paper-based metasurfaces promising candidates for the future 'green' electronics. • Shielding frequencies band can be readily extended in three-dimensional configuration of paper-based metasurfaces. • Paper-based metasurfaces exhibit remarkable electromagnetic shielding properties at small thickness. • Paper-based metasurfaces not only solve the electromagnetic pollution, but also effectively utilize the waste paper. [ABSTRACT FROM AUTHOR]

The pulp and paper industry (PPI) is one of the main pillars of the global economy, but its high energy consumption, pollution, and emissions necessitate urgent transformation. Various types of enzymes can play a crucial role in improving pulp performance, reducing energy consumption, as well as decreasing pollution, which benefits a lot to clean and sustainable development. Due to the complex and numerous substrates in the papermaking processes, enzyme cocktails are often more effective single enzymes. In addition, the effect of enzyme cocktails is affected to varying degrees by the complex environment, including the different papermaking process, pH, temperature, residence time, chemical additives and auxiliary technologies. In this review, we provide a brief summary of hydrolases and oxidases frequently applyed in PPI, along with a list of auxiliary enzymes and proteins with potential applications in this field. More attention is given to enzyme cocktails for various processes such as pulping, refining/beating, deinking, bleaching, and stickies control. The factors influencing enzyme efficiency are analyzed and progresses in this area are reviewed. Further, cutting-edge biotechnologies are highlighted to improve the robustness of enzymes, which could expand the market share of enzyme preparations. By and large, studying the mechanisms and influencing factors of enzyme cocktails will facilitate the transition of the PPI to a greener, low-carbon, economical and energy-efficient industry. [Display omitted] • Compared with single enzymes, enzyme cocktails are more suitable for pulp and paper industry applications. • Enzyme cocktails require more special consideration of application environment (pH, temperature, chemical additives). • Development of biotechnology can further improve the robustness of PPI related enzymes. [ABSTRACT FROM AUTHOR]

Microbial fuel cell is a promising technology to harvest energy from wastewater, and effective anode catalysts are essential for its applications. In this study, zero-dimension nitrogen-doped carbon dots, as biocompatible efficient modifiers, were synthesized and decorated onto the carbon paper surface to prepare microbial fuel cell anode. The as-fabricated nitrogen-doped carbon dots decorated carbon paper anode was able to enhance electricity generation and efficient wastewater treatment. It was found that the as-fabricated electrode had a high hydrophilicity, which was favorable for the microbial immobilization. Compared with the carbon paper anode, the biofilm on the as-prepared anode was almost twice of thickness. After introducing nitrogen-doped carbon dots, the extracellular electron transfer process from the microorganisms to the anode was enhanced. The microbial fuel cell with the as-developed anode generated a remarkable power output of 0.32 mW, 1.1 times higher than that of the raw carbon paper anode with same measurement area. Moreover, 16 sRNA pyrosequencing analysis shows that the quantity of Pseudomonas on the electrode increased by ∼40%, which also promoted the electron transfer rate by excreting mediators like phenazines or phenazine derivatives. This work developed a new approach to design microbial fuel cell anode material and fabricate a high-efficiency and environmentally friendly anode for electricity generation from wastewater. Image 100697 • Notable power output was obtained from MFC with N-doped CDs@carbon paper electrode. • The carbon paper electrode was highly hydrophilic by decorating with N-doped CDs. • The EET efficiency was enhanced by modifying the electrode with N-doped CDs. • The relative abundance of Pseudomonas was enhanced with N-doped CDs' decoration. [ABSTRACT FROM AUTHOR]

This comprehensive review explores recent advancements in the manufacturing of cellulose nanofiber (CNF)-based cellulose nanopaper (CNP). The analysis delves into customizing CNPs through nanofiber manufacturing, mechanical refining, and chemical treatments. The report underscores the growing interest in CNPs derived from CNF due to their exceptional properties and eco-friendly attributes. CNP strength significantly enhanced through mechanical refining encompassing cellulose nanofibrillation were breaking down of cellulose into nanofibers takes place. Conversely, dense CNF network formed through filtration and casting method. Chemical treatments such as dispersion, functionalization, and coating methods followed by drying and consolidation introduce custom functionalities for diverse applications. These applications span packaging, electronics, energy harvesting, EMI shielding, optoelectronics, nanogenerators, transparent conducting films, water treatment, bioelectronics, and neuromorphic computing. The study conducts an in-depth investigation to assess CNP's effects on promoting sustainability and minimizing environmental waste, making a significant contribution to the circular economy. This investigation underscores the pursuit of innovation and aligns with the principles of progressing toward a more environmentally sustainable future. [Display omitted] • Explores CNF production, refining and chemical treatments for CNP customization. • Remarkable properties of CNP draw academic and industrial interest. • CNP applied in packaging, electronics, energy, and environmental science. • Investigates role of CNP in circular economy. • Emphasizes CNPs as eco-friendly, fostering innovation and sustainability. [ABSTRACT FROM AUTHOR]

This paper presents an overview of pulp and paper mills (PPM) production processes, the resulting release of wastewater effluent loaded with wide range of pollutants and associated environmental impacts. The review highlighted the different types of functional materials and their modified forms employed as coagulants for pulp and paper mills industries effluent (PPME) treatment that have been intensively studied as a promising strategy for PPM to achieve cleaner and sustainable treatments in accordance with sustainable development goals (SDGs) "6-Clean water and sanitation", "9-Industry, innovation, and infrastructure", and "12-Responsible consumption and production". Standalone coagulation treatment processes are inherently ineffective towards meeting the increasingly stringent discharge requirements, coupled with their higher energy demand, and increased operational and maintenance costs. Owing to the recalcitrant nature of PPME contaminants, this review explored the effectiveness of the coagulation processes for decontamination of PPME. Furthermore, the review provides a state-of-the-art coagulation-based hybrid systems employed for enhanced PPME treatment. The process limitations, influencing factors and optimization techniques are highlighted. The review also highlights how sustained research in the subject area impacts on achieving cleaner production. The review also discusses coagulant classifications and the synergistic, antagonistic and shock load toxic effects of hybrid coagulants on toxicant biodegradation and their associated system efficiency. Moreover, it offers a guide for the development and application of sustainable hybrid-based coagulants for PPME treatment. The findings presented herein provide a vital theoretical foundation for sustainable solutions to improve coagulation-based hybrid systems efficiency and their scale-up towards potential commercialization. [Display omitted] • Pulp and paper mills produce effluents containing diverse and emerging contaminants. • Different materials and their modified forms are used as coagulants for PPME treatment. • The synergistic and shock load toxic effects of hybrid-based coagulants could be identified. • Hybrid systems are highly efficient techniques for PPME treatment. • The review highlights process weaknesses, influencing factors and optimization techniques. [ABSTRACT FROM AUTHOR]

The industrial solid waste generation and its stockpile disposal have major environmental consequences. These consequences could be minimized through the solid waste application as a raw material in other industries. The current study focusses on the utilization of lime sludge with boiler ash synthesized nanosilica for production of belite based clinker at relatively lower temperature. Lime sludge was also used in combination with fly ash and boiler ash to check the synthesis of compounds at varying temperatures. Nanosilica was synthesized from pretreated boiler ash through alkali treatment and acid precipitation. The synthesized nanosilica has been characterized for specific surface area, crystallinity, surface functional groups and size. Three different mixtures, containing lime sludge with nanosilica, fly ash, and boiler ash are fired at temperatures ranging from 900 °C to 1200 °C and characterized for the synthesis of belite. Conventionally, belite is synthesized above 1200 °C, whereas the combined application of lime sludge and nanosilica reduces the temperature of belite synthesis to 900 °C without pre calcination or addition of any chemical stabilizer. In the case of lime sludge and boiler ash blend, belite formation takes place at the higher temperature (1100–1200 °C). Anorthite synthesis takes place in case of lime sludge and fly ash blend, due to high percentage of alumina present in fly ash. Lime sludge and nanosilica based belite clinker are used to develop newer cementitious binder. Hydration and strength properties of developed binder proved worthy as building materials. This study will present alternatives for sustainable utilization of lime sludge, fly ash and boiler ash in construction. Image 1079591 • Nano silica is synthesized from boiler ash. • Lime sludge and Nanosilica are utilized for belite based clinker synthesis at low temperature. • Blends of lime sludge with boiler ash and fly ash are also checked for clinker synthesis. • The binder is prepared for the product development from synthesized belite clinker. • This prepared binder is tested for hydration and strength properties and found sustainable. [ABSTRACT FROM AUTHOR]

Abstract Pulp and paper industry is one of the high priority sectors that generates large amount of solid (sludge) and liquid (paper mill effluent) wastes. Making use of this huge quantity of paper mill sludge (PMS) in an environment friendly manner is challenging and cost involving. Similarly the present wastewater treatment strategies based on physical and chemical methods encounter certain serious setbacks including secondary pollution generation with expensive mode of abatement processes. The present study aims at a "waste treats waste" strategy for the bioremediation of paper mill effluent in fluidized bed reactor (FBR) using another waste of the same industry, PMS as immobilizing matrix for Planococcus sp. TRC1, a wastewater bacterial isolate. This study simultaneously explores this isolate for the yellowish orange pigment it produces (2.3 ± 0.2 mg/gm of dry bacterial biomass) and characterizes it as a member of the pharmacologically important carotenoid pigment family via UV-Vis spectrophotometry, TLC, FT-IR and 13C NMR. The antioxidant potential of this pigment was studied by DPPH assay (IC 50 = 33 ± 0.4 μg/ml) and H 2 O 2 assay (IC 50 = 147.4 ± 2.2 μg/ml). In FBR, the PMS immobilized bacteria showed removal of phenol, lignin, colour and COD from the effluent by 96%, 74%, 81% and 85% respectively after 60hr of treatment. The experimental data on immobilization fitted well with pseudo second-order (R2 = 0.955) and Freundlich adsorption isotherm (R2 = 0.996) models. The alterations in PMS before and after bacterial immobilization, as revealed by SEM and FT-IR, depicted the success of PMS as immobilization matrix. Phytotoxicity (90% seed germination) and mutagenicity studies confirmed that the treated effluent was substantially less toxic than its raw state. This study highlights a novel utilization possibility of PMS in an eco-friendly and economic way as immobilization matrix for Planococcus sp.TRC1 for paper pulp mill effluent treatment along with production of carotenoid pigment from this potential bacterial isolate as value added product. Graphical abstract Image 1 Highlights • Carotenoid production and abatement of paper pulp mill effluent by Planococcus sp.TRC1 was studied. • Paper mill sludge (PMS) was characterized for immobilizing the bacteria to be used in fluidized bed reactor. • Reusability of PMS and scale up possibility was described. • Toxicity studies revealed reduced phytotoxicity and mutagenicity of the effluent by this approach. [ABSTRACT FROM AUTHOR]

Abstract Building bricks were produced by utilizing deinking paper mill sludge (DPMS) and alluvial soil by varying percentage of sludge at different firing temperatures. Different mix proportions were prepared with 0%, 5%, 10%, 15%, 20%, 25% and 30% of DPMS incorporation in alluvial soil by weight. Three firing temperatures of 900 °C, 950 °C and 1000 °C were investigated to simulate the typical condition of kiln. The density, firing shrinkage, water absorption, efflorescence, apparent porosity, compressive strength and thermal conductivity of the bricks were determined. The XRD and microstructural analysis of brick specimens were also studied. The optimum firing temperature was 950 °C. The thermal conductivity decreases with increase in percentage of deinking paper mill sludge. It was found that 15% deinking paper mill sludge gives optimum strength at firing temperature of 950 °C. Developed bricks satisfy the requirements of class 10 of Bureau of Indian Standards (BIS), in terms of efflorescence, compressive strength and water absorption. Thermal conductivity results show that the developed brick was thermally more insulated than the conventional bricks and can be used as alternative to conventional bricks. This will address the issue of waste management through cleaner production and show the ways towards sustainable, economical and energy efficient construction. Highlights • Building bricks were developed utilizing deinking paper mill sludge (DPMS) & soil. • Maximum level of DPMS in production brick is 15% at firing temperature of 950 °C. • The developed bricks satisfies the requirement of class 10 bricks of BIS. • Developed bricks are sustainable and thermally insulated. [ABSTRACT FROM AUTHOR]

Research has revealed the existence of an energy-efficiency gap – the difference between optimal and actual energy end-use, suggesting that energy efficiency can be improved. Energy management (EnM) is a means for improving industrial energy efficiency. However, due to various barriers, the full potential of EnM is not realised. Several studies have addressed drivers and barriers to energy efficiency but few to EnM. This study aims to identify EnM practices, the most important perceived drivers and barriers for EnM, and relations among them in the energy-intensive Swedish pulp and paper industry (PPI), which has the longest experience internationally of practising EnM systems, and has worked according to the standards since 2004. Our results show that, altogether, the PPI works regularly and continuously with EnM, with a clear division of responsibilities. The highest maturity for EnM practices was for energy policy, followed by organization, investments, and performance measurement. The study also shows that communication between middle management and operations personnel has potential for improvement. The most important categories of drivers were economic, whereas for barriers they were organizational. Nevertheless, knowledge-related barriers and drivers were amongst the most important, suggesting that the absorptive capacity for energy issues could be improved. Image 1029 • Energy is managed continuously, with clear policies and responsibilities. • The main drivers are economical while main barriers are organizational. • Knowledge related barriers and drivers are amongst the next most important. • Employees' absorptive capacity for energy issues could be improved. • Link between energy policy and performance measurement could be improved. [ABSTRACT FROM AUTHOR]

Abstract The biological deinking method using microbial enzymes is quite promising and rather eco-friendly. In this paper, we discuss about the impact of enzymatic deinking of newspaper pulp using ligno-cellulosic (cellulase, xylanase and laccase) and lipolytic enzymes. The individual treatment of paper pulp with enzymes (cellulase/xylanase) could enhance the paper brightness to about 32.86% whereas combinational effect could enhance only about 28.67%. There was a release of chromophores from phenolic and hydrophobic compounds released during the deinking process. Physico-chemical parameters of effluents were also found to be within the standard limits and the metals like iron, lead and zinc were not detected in the enzyme assisted deinking effluent sample. The heavy metals in the paper pulp was found to be reduced after enzyme treatment. The obtained effluent was found have low phytotoxicity and was safe for agricultural applications. Hence, the present report was found to be a suitable enzymatic deinking process which was eco-friendly that results in non-toxic effluents. The method also provides an avenue in water resource recycling within industries. Graphical abstract Image 1 Highlights • Individual enzyme treatment was effective for increasing brightness upto 10%. • Combinational enzyme treatment improved 8.2% brightness of recycled paper. • Ligno-cellulosic enzyme along with lipase was effective in deinking. • Effluent was non-toxic and had very low heavy metals detected. • The effluent fit for irrigational purposes due to low phytotoxicity. [ABSTRACT FROM AUTHOR]

Abstract To reduce pollution emissions and achieve a cleaner production in paper industry, it is essential to understand the inner links between concentrations of gaseous pollutants, types of final products and production techniques. In this study, the concentrations of four potential gaseous pollutants, total volatile organic compounds (TVOC), formaldehyde (HCHO), hydrogen sulfide (H 2 S), and hydrocarbon compounds (C x H y), in the ambient air on thirty sampling points of five pulp and paper mills were detected and analyzed. The results were summarized with respect to the following aspects: (1) Levels of four gaseous pollutants on all the sampling points in five mills. It was obvious that the situation of gaseous pollution from pulp mill was much more serious than those from paper mills. (2) Gaseous pollutant distinctions due to different production processes. The levels of gaseous pollutants from five mills were greatly influenced by the utilized raw materials and the applied paper chemical agents (flavor, coating materials and additives) in mills. (3) Gaseous pollution comparisons at common points. At the two common points in five mills, i.e. the wet end of paper machine and the wastewater treatment process, TVOC and HCHO, C x H y and H 2 S were the main gaseous pollutants, respectively. In addition, some feasible measures to realize a cleaner production in pulping and papermaking process were also put forward in the article. Highlights • We analyze the levels of 4 gaseous pollutants on 30 sites of 5 pulp & paper mills. • Gaseous pollution distinctions due to different production processes are studied. • Feasible measures to realize the cleaner production in the processes are suggested. • Gaseous pollution are greatly affected by raw materials and added paper chemicals. [ABSTRACT FROM AUTHOR]

Abstract The global demand for bio-plastic particularly polyhydroxyalkanoate (PHA) have been increased in the last few decades as a substitute of petrochemical-based plastic. Utilization of waste paper, the primary constituent of municipal solid waste (MSW), as a carbon source for polyhydroxybutyrate (PHB) production is not only an alternative, environmental friendly route of waste management but also helps to valorize the waste. In this study, hydrogen peroxide pretreated waste paper saccharification has been optimized using central composite design (CCD). The maximum hydrolysis (88.18%) occurred at paper loading 5.0 g/L, agitation 242 rpm, working volume 20%, cellulase 49.82 U/g, β-glucosidase 20.9 U/g and hemicellulase 29.5 U/g. PHB synthesis and biomass accumulation by xylose-utilizing Burkholderia sacchari using waste paper hydrolysate were studied using different nitrogen sources and carbon to nitrogen (C/N) ratios. Maximum PHB and dry cell weight (DCW) occurred with ammonium sulfate and a C/N ratio of 20. The highest biomass (3.63 g/L), the maximum PHB accumulation (44.2%) and the maximum reducing sugar utilization (92.1%) were observed after 48 h of cultivation using diluted hydrolysate. The physicochemical properties of the extracted PHB were compatible with the standard PHB. Hence, the waste paper could be exploited as a renewable feedstock for the sustainable production of PHB. Graphical abstract Image 1 Highlights • The maximum enzymatic hydrolysis 88.18% was achieved by response surface method. • PHB produced from waste paper hydrolysate using xylose utilizing B. sacchari. • Maximum PHB and dry cell weight occurred with (NH 4) 2 SO 4 and C/N ratio of 20. • High thermostability of PHB with a maximum degradation rate around ∼ 300 °C. • PHB production using waste paper is cost effective and ecofriendy approach. [ABSTRACT FROM AUTHOR]

Abstract Black liquor, an industrial waste, also generally called spent liquor is a promising feedstock for production of bio-carbon due to its high lignin and energy contents. Mild processing conditions and sustainable resource utilization can drive commercial utilization of this industrial waste. A novel oxidative procedure using hydrogen peroxide as a green liquid oxidant at room temperature for processing of paper recycling neutral sulphite semi-chemical spent liquor was established and evaluations were carried out for its efficiency. Standard hydrothermal carbonization was carried out for comparing bio-carbon production qualitatively and quantitatively using the same spent liquor. The oxidation procedure was performed at room temperature using 5% of H 2 O 2 followed by washing in diluted sulfuric acid (0.15 N) while hydrothermal carbonization was performed at 250 °C. The bio-carbon produced were similar in terms of ash percentage and ranged from 1.25 ± 0.05 to 1.48 ± 0.05% for oxidation method and from 1.11 ± 0.03 to 1.45 ± 0.04% for hydrothermal carbonization. The carbon contents for the oxidation method ranged from 60.54 to 61.50% and 66.81–67.31% for hydrothermal carbonization while higher heating values ranged from 25.32 to 26.11 MJ/kg and from 28.68 to 29.34 MJ/kg respectively. The mass yield ranged from 29.98 to 31.88% by the oxidation, while it was 15.02–16.08% by hydrothermal carbonization. Highlights • Bio-carbon is generated from byproduct of plant that uses recycled paper feedstock. • Oxidation method is a promising approach to obtain pure bio-carbon from spent liquor. • Hydrothermal carbonization demands energy for pure bio-carbon production. • Bio-carbon from both methods differ quantitatively but are similar qualitatively. • Bio-carbon can be a potential platform for environmental friendly fuel and materials. [ABSTRACT FROM AUTHOR]

Abstract Papermaking enterprises are currently under both environmental pressure and economic pressure for sustainable development in China. Thus, the efficiency, effectiveness, and benefits of resource utilization need to be improved. High-consumption and high-pollution companies should manufacture paper using sustainable methods. This study highlights a resource value flow analysis from the circular economy perspective, developing an extension of material flow cost accounting and modifying it by accounting for environmental damage as well as economic benefits. With reference to the Plan-Do-Check-Act cycle, this specific case study was conducted to verify the comprehensive utility of resource value flow analysis by establishing decision-making prioritization according to the dualistic diagnosis of "internal resource loss–external environmental damage costs." In general, applying a resource value flow analysis can both reduce resource consumption and minimize environmental damage, enhancing the sustainable development of a process industry with limited resources. Highlights • Material flows and value flows form an interactive unit in the resource value flow analysis model. • The resource value flow analysis model extends the environmental dimension of material flow cost accounting. • A dualistic diagnosis of "internal resource loss and external environmental damage costs" can achieve both economic profits and environmental benefits. • The Plan-Do-Check-Act cycle was introduced to strengthen the practical application of the resource value flow analysis. [ABSTRACT FROM AUTHOR]

High pressure laminate has a key role at the protection of wood-based panels. Borax and recycled papers can be used for production of high pressure laminate which may impart the multitude effects. The readily availability of waste papers and borax may be a useful alternative to expensive papers with high quality, and also can compensate the strength losses of recycled papers. The recycled paper and borax are relatively inexpensive and environmentally friendly, and this results the production of not only a cleaner product but also provides an excellent performance against applied load, humidity and high temperature. In this study, three types of waste papers including newsprint, writing and paperboard were first recycled to be used for production of high pressure laminate. Phenol formaldehyde and borax were utilized to improve the strength and fire retardancy of high pressure laminate. Bending resistance, flame resistance and water absorption of high pressure laminate samples were tested. The results of the experiments showed that high pressure laminate made of recycled newspaper and borax had a superior performance when compared to samples that made from writing paper and paperboard. For example, an increase up to 1.4 times was observed in the bending resistance. The mixing of borax with resin increased the strength of high pressure laminate at 95 percent confidence level. The amount of water absorption after 2 h, bending resistance, glowing time and char length of high pressure laminate with recycled newspaper and borax were equal to 14%, 41 mNm, 37 s and 0.7 cm, respectively. The bending strength of coated particleboard with this overlay increased up to 1.5 times. High pressure laminate produced from recycled paper and borax was introduced as an environmentally acceptable product. [ABSTRACT FROM AUTHOR]

Collection, as the first stage of the recycling process, and pre-processing to increase waste stream purity constitute key operations for achieving high recycling rates and a closed loop in the circular economy. For wastepaper recycling in Hong Kong, it is the semi-formal-informal recycling (SFIR) sector that plays a central role in both stages. This study analyses the so far little explored SFIR stakeholder network in Hong Kong and sheds light on value chains, recovered waste paper quantities and the impact of policies on the sector. The findings show that SFIR stakeholders reclaim 55.6 t/recycling station/month of wastepaper and thereby achieve about a 5.7 times higher reclaim rate than the formal-private recycling system. Critical to this achievement is the SFIR transaction network, which enables its stakeholders to develop a value chain and thereby generate an added value of around 1900 HKD (243.9 USD/t) for wastepaper. Given limited circular structures in Hong Kong, financial subsidies are critical to sustain the SFIR's operations over the short-term. However, over the long-term legalization and integration of its stakeholders are necessary to ensure an economically and socially sustainable wastepaper recovery system in Hong Kong. [Display omitted] • Qualitative & quantitative analysis of the semi-formal-informal recycling (SFIR) sector. • The SFIR's wastepaper value chain achieves a cumulative added value of 1900 HKD/t. • The SFIR recovered 5.7 times higher capacities than the formal system in 2021. • Financial support can enhance the SFIR sector's recovery capacities. [ABSTRACT FROM AUTHOR]

Adsorption separation and photocatalytic techniques have emerged as effective methods to eliminate organic dyes from water environment, but the poor recycling of most powdered adsorbents and photocatalysts in aqueous solutions hinders their commercial viability. Herein, we propose an effective and reusable dye-elimination module through the bottom-up self-assembly of photocatalyst (TiO 2 nanoparticles) and adsorbent (Al-fumarate) on a corrugated paper (CP) support. Results show that the hydrophilic and electrostatic interactions between the components ensure the integrity of the whole module in aqueous phase dyes, thereby ensuring its practicality and cyclic stability (10 times). Al-fumarate with a superior specific surface area of (1117.82 m2/g) and porosity (0.47 cm3/g) on the substrate serves to induce and capture the dye molecules, while TiO2 nanoparticles with a wide bandgap trigger a redox reaction to further degrade the organic pollutants. Through the synergistic effect between adsorption and photocatalytic strategies, the resultant functional CP-based composite exhibits superior dye-removal performance than other potential composite materials, reaching 98.93% degradation efficiency of congo red (CR) solution (25 mg/L), and 97.91% elimination capacity of methylene blue (MB) solution (20 mg/L). Therefore, the designed dye-elimination module can serve as a convenient, recyclable, and efficient cleaning module in practical wastewater treatment fields. [Display omitted] • The 3D dye-removing module is designed by a hierarchical self-assembly method. • The designed composite possesses two water purification strategies. • The designed composite shows high dye-removal efficiency. • Different from powdered materials, the recycling of block samples is very convenient. [ABSTRACT FROM AUTHOR]

Vermicomposting of paper mill sludge (PMS) with cowdung (CD) and green manure plants, Tephrosia purpurea (TEP) and Gliricidia sepium (GLS) in different combinations (21 days pre-decomposed) was carried out using Eisenia fetida (60 days). Results revealed that electrical conductivity, total Kjeldahl nitrogen, total phosphorus, total potassium and N NO 3 - levels were higher in vermicomposts generated from PMS + CD with TEP/GLS combination than in composts prepared without earthworms; while total organic carbon, C/N ratio, C/P ratio and organic matter content depicted significant reduction. C/N and C/P of final vermicompost ranged from 13.45 to 22.33 and 15.54 to 28.56 respectively. The total microbial population was significantly higher in CD + TEP/GLS vermicomposts (P < 0.001). Activities of dehydrogenase, urease, acid and alkaline phosphatases during vermicomposting elevated initially and then declined, indicating vermicompost maturity. Also, the seed germination tests with maize and cowpea in vermicomposts of PMS, CD and green manure combination support the maturity and less phytotoxic nature of vermicompost produced. Growth and reproduction of E. fetida explained that the addition of CD along with GLS/TEP significantly created an impact on bioconversion of PMS. The PMS + CD + TEP/GLS (2:1:1 ratio) combination can be used for sustainable PMS utilization through vermicomposting, and enriched vermicompost can also be obtained by the addition of green manure plants. Image 108 • Vermicomposting paper mill sludge + cowdung + green manure (2:1:1) improved nutrients. • Microbial and enzyme activities governed maturation and enrichment of vermicompost. • Cowdung + green manure significantly improved growth and reproduction of earthworms. • Germination studies confirmed that the vermicompost produced is safe to use. • Enriched vermicompost envisages sustainable utilization of paper mill sludge. [ABSTRACT FROM AUTHOR]

Developing separation materials for rapidly oil absorption and emulsions separation is urgently needed and remains a great challenge. Here, a biomass-derived banana peel/waste paper (BPWP) hybrid aerogel with hierarchical porous structure has been successfully fabricated via combination of freezing-cast, freeze-drying and pyrolysis approach, for application in oil adsorption and water-in-oil emulsions separation. In this hybrid system, the microsheets that derived from banana peel immobilize were immobilized on surface of the waste paper fibers, forming a hierarchical structure. The resulting BPWP aerogels exhibit a compression strain of 75%, high-hydrophobicity (WCA of 149.3°)/underair superoleophilicity (OCA of 0°), and high porosity, which can absorb of free oils in water with high oil sorption capacity of 35–115 times its own weight. Moreover, these aerogels effectively separate various surfactant-stabilized water-in-oil emulsions driven solely by gravity, with high separation efficiency above 99.6% and higher fluxes of up to 8550 L m −2 h −1 than traditional filtration membranes with pressure driven, even the sizes of emulsified droplets are smaller than the pore size of the BPWP aerogels. More importantly, the BPWP aerogels exhibit a superior antifouling property and regenerability for emulsion separation, which match well with the requirements for treating the real emulsions. Due to the advantages of banana peel/waste paper aerogels in rich source and high oil separation efficiency, the obtained banana peel/waste paper aerogel can be a potential candidate in industrial applications and environmental protection. This work opens up a new avenue for design new hierarchical biomass-derived aerogels for a variety of applications including energy storage, sensors and pressure-sensitive electronics. [ABSTRACT FROM AUTHOR]

Waste incineration is an effective solid waste disposal method; however, its by-product pollutants hinder its widespread adoption. This research aims to develop novel unglazed ceramic tiles by recycling industrial solid waste incineration fly ash (IWA) from recycled paper mills. Experimental investigations were conducted on ceramic tiles with IWA additions (0–30 wt%) and firing temperatures (1100 °C, 1200 °C, and 1300 °C). Various scientific tests, including XRF, XRD, strength, water absorption, thermal properties, heavy metal leaching, SEM analysis, and micro-CT analysis, were performed. The results suggest that the addition of IWA may deteriorate the technical performance of ceramic tiles; however, satisfactory performance can still be achieved by tailoring the firing temperature due to the existence of iron and calcium in the IWA, which narrows and displaces the densification temperature range. Remarkably, tiles with 30 wt% IWA, which completely replaced the flux materials and fired at 1300 °C, achieved the highest flexural strength (exceeding 30 MPa). These tiles exhibited promising attributes such as water absorption of 5.9%, an estimated energy saving of 33.86%, and compliance with heavy metal leaching limits. This study proposes a sustainable solution for IWA disposal by utilising recycled paper mill fly ash as a substitute for flux material in ceramic tile manufacturing. The findings contribute to minimising environmental impact and conserving non-renewable natural resources, supporting sustainable development. • Industrial waste incineration fly ash (IWA) recycling in unglazed ceramic tiles was investigated. • The effect of substituting potassium feldspar with IWA at different temperatures was assessed. • 30% IWA tiles, with the highest strength of all samples, fully replaced potassium feldspar, achieving 31.85 MPa at 1300 °C. • Predicted energy savings for 30% IWA tiles are up to 33.8% during manufacturing. • Most batches' metal leaching complies with EPA guidelines. [ABSTRACT FROM AUTHOR]

Guiding industries to produce in an effective and environmentally sustainable manner has become a key issue for governments around the world. Over the past 15 years, series of regional and industrial development policies have been introduced by the Chinese government. This has influenced the geographical distribution and energy efficiency performance of China’s industries. This paper quantifies the influence of enterprises geographical distribution on energy efficiency improvement in the paper industry and aims at providing some helpful suggestions on industrial development to policy makers. The main results show that, firstly, the paper industry in eastern China shows obvious characteristic of agglomeration. The average location quotient is 1.2278. However, following the industrial and regional development policies, the characteristic of agglomeration is weakening. Secondly, only when agglomeration reaches a certain level (location quotient is above 0.5447) will industrial agglomeration positively impact on industrial energy efficiency improvement (a 1% increase in agglomeration will increase dynamic energy efficiency by at least 0.23%). Thirdly, the regional development policies carried out by the government slow the pace of energy efficiency improvement in China’s paper industry. The empirical results indicate that the government needs to consider regional characteristics and consciously guide industrial enterprises to concentrate in the dominant area. [ABSTRACT FROM AUTHOR]

The need to view innovation policy through the lens of policy mixes has gained momentum given the growing complexity, the dynamics of real-world policy and the wide array of difficulties to address the current great societal challenges, notably the increasing pressure on the ecosystems that support our society. One of the main challenges concerning the transition towards bioeconomy, is to gain a more in-depth understanding on the policy mix to stimulate innovation in sustainability transitions. Our paper aims at enriching the portfolio of empirical case studies on policy mixes for innovation and sustainable transitions, by investigating the development of the policy mix underpinning the sustainability transition of the pulp and paper industry in Sweden. We apply a case study approach which draws on event history analysis, semi-structured interviews with industry and policy makers, literature reviews, a participative workshop with stakeholders from the pulp and paper industry, as well as on the IEA databases on climate change and energy efficiency policies and measures. Our analysis emphasises coordination, timing and scale in policy mixes as important elements to understand how instruments interact to accelerate sustainability transitions. The mapping of the policy mix shows that destabilising policies were crucial for accelerating the transition process of the industry. Prior to novelty creation policies, destabilising policies (e.g. environmental policies) were needed for 'innovation policy instruments' to be effective. More specific instruments (e.g. carbon tax), targeting particular functions of the innovation systems, require 'on-the-ground' policy intelligence and benefit from close interaction with industry. [ABSTRACT FROM AUTHOR]

Paper products are carbon-intensive and having a huge potential for carbon reduction due to their biomass-oriented characteristics. A uniform standard for total carbon footprint (CF) accounting is vital. However, the existing standards have not yet been unified. Inconsistencies between standards cause difficulties in their use and significantly weaken the credibility and comparability of the carbon footprint of a product (CFP). This work rethought the three most widely used standards (Publicly Available Specification 2050 (PAS2050), Product Life Cycle Accounting and Reporting Standard (GHG Protocol), and Product Life Cycle Accounting and Reporting Standard (ISO14067)) from the life-cycle perspective, and established a more appropriate and comprehensive CF accounting standard for paper products (CFASPP). Sanitary pads were selected as a case study to illustrate the discrepancies between PAS 2050, the GHG Protocol, ISO 14067, and CFASPP, for which the annual production CF results were 1424.60, 1481.08, 1453.57, and 1427.04 tons of carbon dioxide equivalent (CO 2 e) respectively. The main reasons for the different CF results were the cut-off criteria and the inclusion or exclusion of carbon storage, delayed emissions, and energy recovery. Each element increased or decreased 22.57 (carbon storage), 29.96 (cut-off criteria), 10.4 (delayed emissions), and 27.52 (incineration with energy recovery) tons of CO 2 e in the results. With increasing demand, these discrepancies will become increasingly significant and may lead to corporations shouldering more or less carbon emission responsibilities by selecting different standards, which will challenge the fairness of product carbon neutrality management. CFASPP covers all paper product life-cycle stages and places greater emphasis on the aspects of carbon storage, delayed emissions, and energy recovery in incineration, which cannot be ignored for the CF accounting of paper products and other biomass-oriented products. This study aims to provide a more applicable and comprehensive guide for corporations to evaluate the CF of paper products, and to provide a reference for the construction of a carbon-neutral evaluation system. [ABSTRACT FROM AUTHOR]

The aim of this study was the valorization of paper sludge waste from paper industry in designing one-part geopolymer cement using ground granulated blast furnace slag as main precursor. The effects of increasing the amount of paper sludge pretreated with a constant amount of sodium hydroxide (2% of slag) on mechanical strength, heat evolution, setting time and durability were analyzed. The reaction products were characterized using X-ray diffraction and thermogravimetric analysis. The findings showed that paper sludge can successfully be used as a secondary source of calcium carbonate in the one-part (“just add water”) geopolymer. The compressive strength of the cured geopolymer increased with increasing the amount of paper sludge, and the non-reacted sludge acted as a filler. The maximum strength (42 MPa, 28 d) was reached at 18 wt-% paper sludge addition. The main reaction products were calcium aluminate silicate hydrate and hydrotalcite-like cementitious gels. From the perspective of its blast-furnace slag content, strength properties, water absorption and setting time, the one-part geopolymer cement could be classified as a CEM IIIC and Type 32.5N class cement under the European standard EN-197. [ABSTRACT FROM AUTHOR]

China’s paper industry consumes a lot of energy and emits huge amounts of pollutions. The Chinese government over the past decades has done a lot to promote energy efficiency of the industry. This paper studies the impact of industrial polices to improve energy efficiency. The energy efficiency change is firstly studied under a framework of total factor efficiency. On this basis, different econometric models are built to discuss the detailed energy efficiency characteristics of the paper industry. The main results are as follow: (i) ownership structure did influence the energy efficiency, but the influence is different in different conditions; (ii) energy efficiency of the paper industry can be improved by economies of scale; (iii) market competition can to some extent overcome the motivation and supervision problem that often occur in state-owned companies; (iv) energy price cannot play the role of resource allocation well in China. Finally, based on our findings, some suggestions are provided. [ABSTRACT FROM AUTHOR]

The papermaking industry has developed rapidly in recent years in China. Papermaking is a high-energy-consuming process. Consequently, large-scale paper mills usually have cogeneration systems that supply both electricity and steam for the papermaking process. In China, almost all these cogeneration systems in paper mills are powered by coal combustion, which consumes a large amount of energy and emits large amounts of greenhouse gas. The Integrated Gasification Combined Cycle (IGCC) technology is regarded as a clean and efficient method of coal utilization. In this work, an IGCC process for application in paper mills was designed and modeled. An IGCC coupled with a cascade refrigeration process (CRP) was further proposed in order to reuse the waste heat from the dryer section and improve the energy efficiency of the papermaking process. A paper with a conventional cogeneration system, one with an IGCC cogeneration system, and one with an IGCC coupled with a CRP cogeneration system were analyzed and compared in terms of energy efficiency, capital investment, operational cost, and dynamic payback period. The results showed that the integration of IGCC technology allows paper mills to be more competitive than those featuring conventional cogeneration systems in terms of energy efficiency and operational cost. [ABSTRACT FROM AUTHOR]

Over 100 million tons of cotton waste are produced annually, representing 35–40% of global textile waste. However, less than 30% of cotton waste is recycled annually. In particular, the fibers less than 7 mm in length dropped during the opening and carding process of cotton waste fabrics have not found a mature utilization method. This work demonstrates and reveals a strategy to transform short cotton fibers into a renewable cellulose fiber self-reinforcing composite paper (CCP). Recycled cotton staple fibers less than 3 mm were prepared into CNFs by TEMPO oxidation. The use of recycled cotton fiber (3–7 mm) as reinforcement and CNFs as a matrix results in a composite material bonded through hydrogen bonding. The recovered cotton fibers and CNFs soliquoid combine together to form a paper pulp, which is then transformed into CCP using wet-laid webs and hot-pressing techniques. When the CNF content reached 5%, the tensile strength of CCP was 86.68 MPa, which is 1.8 times that of the commercial A4 paper. The tensile strength of the CCP only decreases by 25% from the dry state to the wet state, while that of A4 paper after soaking water is almost zero. This makes CCP a special paper with broad application prospects. Since CNF extracted from cotton waste textiles is used as a strengthening agent and without any chemical adhesives added in the paper-making process, which makes the production process of CCP cleaner and can be recycled in a closed loop. Overall, the promising strategy achieves at least four objectives related to cleaner production: maximum recycling of cotton waste, CNF instead of traditional chemical adhesives used in paper-making, water recovery (internal recycling), and realising closed-loop recycling. This technology can potentially be applied to a wide range of colored papers and intelligent packaging papers in the future. [Display omitted] • Cellulose nanofibers extracted from cotton waste were used as an adhesive in papermaking. • A cellulose fiber self-reinforcing composite paper was prepared from cotton waste. • The cellulose composite paper has excellent mechanical strength and water stability. • The cellulose composite paper can be easily recycled with a prolonged life cycle. [ABSTRACT FROM AUTHOR]

Sunflower stalk was evaluated as a potential fiber source to make fluting paper using neutral sulfite semi-chemical pulping process, in comparison with Mazandaran wood and paper industry mill made hardwood-based neutral sulfite semi-chemical (NSSC) pulp. Sunflower stalk consists of two distinct fractions including inner bulky pith and outer woody wall. The stalk has to be de-pithed for the purpose of papermaking because of lower cellulose, and higher ash content in pith-containing stalk. The results of pulping showed that the rate of delignification in NSSC cooking of de-pithed sunflower stalk with 20% lignin was surprisingly very low, despite of being a non-wood fiber source. However, sunflower stalk NSSC pulp showed very good response to refining and produced denser sheet due to lower digester yield and higher fiber flexibility coefficient, in comparison with Mazandaran wood and paper industry pulp sample. In addition, sunflower stalk pulp has been demonstrated to be an appropriate fiber source for making fluting paper at higher or comparable tensile-loaded strength properties such as tensile and burst, and higher compression-loaded strength properties including corrugated medium test and ring crush test. [ABSTRACT FROM AUTHOR]

Utilization of the quality-upgraded waste paper in the manufacture of paper and board will reduce the wood consumption and pulping energy. While the optical property of the fibers from recycled old newspaper is very poor, in-situ calcium carbonate formation on those fibers by injecting carbon dioxide to the mixed slurry of those pulp and calcium oxide improved their brightness. Upgrading recycled old newspaper to substitute more expensive wood furnish, such as recycled old magazine, was successfully demonstrated in the present study. This study showed that the in-situ calcium carbonate formation process improved the optical quality of the recycled old newspaper by covering colored impurities with newly formed calcium carbonate, and improved calcium carbonate retention in papermaking process by attaching them to fibers. The strength reduction by the presence of newly formed calcium carbonate in the paper was recovered by adding strength agent. High ash retention at high ash content under the strong turbulence in the modern paper mill was achieved by the application of the in-situ calcium carbonate formation method. The quality-upgrade of recycled fibers and cost saving in the manufacture of duplex paperboard were demonstrated in the mill trial. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFASs), a new class of contaminants of emerging concern in different water sources and industrial discharges, have been highlighted, mainly ascribed to the high mobility, persistent, and bioaccumulative behaviors. In this work, the analytical detection of PFASs in the paper mill processing discharge (PMPD), physicochemical parameters, tannin and lignin, and phenolic content were carried out. The phytotoxicity evaluation and bioaccumulative profiles of PMPD-assisted irrigation have been conducted using a soilless cultivation system. The cytotoxicity, genotoxicity and human exposure risk were ascertained via in vitro assay on the human hepatocellular carcinoma (HepG2) cell and the estimation of daily intake, respectively. PFASs were quantitatively detected at the mean concentration of 2712.72 ng/L, consisted of mainly perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkane sulfonic acids (PFSAs), perfluoroalkane sulfonamidoacetic acids (FASAAs), perfluoroalkane sulfonamides (FASAs), and fluorotelomer sulfonic acids (FTSAs). Significant reductions of the physical elongation, dry weight, and chlorophylls up to 33.49%, 31.71%, and 52.17% were recorded. Profound increase in the proline (101.81%), hydrogen peroxide (55.56%), superoxide anion (67.86%), lipid peroxidation (43.91%), and protein oxidation (32.31%), and up-regulation of antioxidant enzymes activities have been quantified. Bioaccumulation and translocation of PFASs revealed a concentration-, chain length- and functional group-dependent trend within different plant compartments. PFASs-contaminated PMPD treatments induced dose-dependent cell viability reduction and DNA damage in the HepG2 cell. The findings have highlighted that PMPD could be an underestimated source of PFASs, which represents a sharp threat to plants and public health via the water-food crop-human continuum. Future studies gearing towards the genomic profiling of PFASs in different plant species are suggested. [Display omitted] • Detection of per- and polyfluoroalkyl substances (PFASs) in the industrial effluent. • Phytotoxicity evaluation using a hydroponic system. • Distortions of physical traits and chlorophylls in the plant model. • PFASs triggered oxidative stress damages and up-regulation of antioxidant enzymes. • PFASs induced profound dose-dependent cytotoxicity and genotoxicity in human cell. [ABSTRACT FROM AUTHOR]

Different heating processes were applied to pretreat the pulp and paper mill sludge to enhance the hydrolysis stage. Hot air oven, autoclave, microwave and water bath were used for comparison. Chemical analyses exposed that all the pretreatment methods have shown improvement in solubilisation of organic matter. Among the pretreatments studied, heat transfer through hot air (80 °C for 90 min) mode had the highest impact on sludge solubilisation. There was an increase in cellulose (P = 0.0096), acid soluble (P = 0.0053) and insoluble lignin (P = 0.0012), but decrease in hemicellulose (P = 0.0009) content after pretreatment. The XRD and FT-IR spectroscopic characterisation shows the development of aliphatic, unsaturated and carbonyl carbon functionalities in the pretreated samples at higher severities. FESEM picture also confirms the change in structure after pretreatment. Thus, pretreatments contribute to disruption of the lignocellulosic structure making the cellulose easily accessible to acidogenic microorganisms. [ABSTRACT FROM AUTHOR]

For the first time the feasibility of using an alkaline wastewater coming from the pulp and paper industry as an activator, partially (50 vol%) replacing commercial sodium hydroxide, in the production of cork-based activated carbons was evaluated. The activated carbons showed the highest value of specific surface area ever reported for cork-based activated carbons (1670 m 2 /g), surpassing several other commercial and waste-based ones. These eco-friendly cork and paper waste-based activated carbons were then evaluated as methylene blue adsorbent materials. The influence of contact time, methylene blue initial concentration and adsorbent amount on the methylene blue removal efficiency by the activated carbons was studied. Extremely fast (>99.9% removal in 5 min) and efficient methylene blue adsorption (uptake of 350 mg/g) by the cork and paper waste-based adsorbents was achieved, which demonstrates the huge potential of these innovative adsorbents. These activated carbons were produced using two unexplored industrial by-products (alkaline wastewater and cork) and, therefore, may be an inexpensive source of activated carbons, which can be used for the effective removal of dyes from wastewaters. Furthermore, despite the very large surface area and high removal efficiency this is not a nano material (being around 30–50 μm in size), its capabilities being due to its unique cork-derived microstructure, and hence it can be handled and removed/filtered much more easily than nanocarbons, and without any associated health or environmental risks. [ABSTRACT FROM AUTHOR]

Characterization of neutral sulphite semi-chemical black liquor (NSSCBL), sampled from paper manufacturing process that uses recycled fibers as primary feedstock, was carried out for potential bioenergy and biomaterial applications. Physico-chemical characteristics including inorganic elements content, thermogravimetric analysis, GC/MS, and FT-IR are presented. The black liquor of the recycled fibers in the manufacturing process revealed unique characteristics in terms of chemical composition profile compared to the black liquor originating from regular pulp and paper industries. The major findings include the presence of chemical compounds, from a non-plant origin, such as derivatives of hexanedioic acid in significant quantities. The favorable biofuel characteristics of this black liquor are: neutral pH, a higher volatile content, and HHV. The recycled paper NSSCBL can be a good candidate for biomaterial and biofuel applications. [ABSTRACT FROM AUTHOR]

In recent years, the pulp and paper industry has changed a lot and products have been constructed in quite different methods using new technologies. It can be due to the emergence of challenges and constraints such as shortage of raw materials, energy consumption (fossil fuels, electric, etc.), management of the resulting pollutants, environmental issues, ongoing legal requirements and cleaner production strategies. In Iran, the pulp and paper industry's technological development is not keeping pace with global growth. Iran's pulp and paper mills supply a small fraction of domestic market. The reasons can be due to old technologies being used in factories, aging machinery, low productivity of production systems and lack of coordination with modern technologies. It leads to low-quality of paper products and willingness to buy local products. The aim of this study is to select the most appropriate technologies in the pulp section, due to high impact of pulp quality on the quality of final paper. Using a 2-filterd fuzzy decision-making, hierarchical structure of research is designed to assess technological alternatives according to the selected criteria. Findings show that after passing through two filters, Kraft method was chosen as the most appropriate method. The Kraft process has still many advantages like the high quality of the produced pulp and self-sufficiency in energy supply. This framework offers an appropriate procedure for identifying and selecting technologies that has not been used in past researches. Using this framework facilitates using a clear procedure for evaluating and selecting technology and prevents future losses for organizations. [ABSTRACT FROM AUTHOR]

China's paper industry accounts for a larger proportion of the global paper industry and consumes large amounts of energy. Energy conservation and pollution reduction of the industry have become the focus of China's national development strategy. Energy efficiency is an important index which directly determines the amounts of energy consumption and pollution emissions. To understand the energy efficiency evolution of China's paper industry, this paper establishes an input-output data of the paper industry for 29 provinces in China and applies DEA method and econometric models to estimate and comprehensively discuss the energy efficiency issues based on the framework of total factor efficiency. Our results indicate that China's paper industry has a large energy saving potential even though its energy efficiency has improved during the period 1990–2013. The saving potential is about 65% under the meta-frontier and 44% under the group-frontier. Moreover, there are significant differences between different regions in production technology and energy efficiency. The performance of eastern China is better than other regions. But the technology gaps between the different regions are shrinking and converging over time. Finally, some policy recommendations are proposed to improve the energy efficiency of the industry. [ABSTRACT FROM AUTHOR]

Low-quality materials contained in separately collected (SC) packaging waste generate environmental and economic burdens associated to both sorting operations of Material Recovery Facilities (MRFs) and landfilling of non-recyclable materials. In this study, based on quantification of both impurities and recyclable fractions, the quality of SC municipal packaging waste streams was determined by compositional analysis of the waste entering a MRF throughout a year. Foreign materials (% w/w) found in the monitored SC glass, paper plus cardboard and lightweight packaging waste, were on average 5.0, 14.7 and 23.0, respectively, while landfilled materials (% w/w) after MRF sorting operations were on average 4.3, 10.3 and 22.0, respectively. A Life Cycle Assessment study was conducted to determine the environmental impact of SC packaging waste streams quality of three different scenarios: current situation (CS), better (BS) and ideal (IS) scenario with reduced presence and absence, respectively, of improper materials in the three examined SC packaging waste streams. Emission of 32.1 kg CO 2 eq/t waste was calculated for the current situation with a reduction by 66.1% and 98.0% in CO 2 eq emission for BS and IS scenario, respectively. Similar emission reductions were calculated for ozone depletion, ionizing radiations, particle matter formation, fossil fuel depletion and primary energy demand impact categories. The environmental life cycle costing study demonstrated that total savings of € 35.2 and € 66.6 for each ton of SC packaging waste stream entering the MRF could be obtained for BS and IS scenario, respectively. [Display omitted] • Impurities in packaging waste streams generate environmental and economic burdens. • 23.0% of impurities were found in separately collected lightweight packaging waste. • Plant sorting operations generate 32.1 kg CO 2 eq for each ton of packaging waste. • € 35.2/ton of sorted packaging waste could be saved by reducing impurities content. [ABSTRACT FROM AUTHOR]

Straw pulp in China, which is the world's largest producer of this material, suffers from water and energy shortages during its entire life cycle. However, limited systematic studies have focused on these issues, and decision makers need be provided with improvement methods for the environmental performance. Thus, an impact-oriented energy and carbon coupled water footprint analysis was conducted in this study based on ISO standards. Results showed that the impact of energy consumption and carbon emissions exceeded that of water footprint. Carcinogens, non-carcinogens, and freshwater ecotoxicity also played effective roles in improving the environmental performance. Optimizing key indirect processes, including chemicals production, steam preparation, electricity generation, wood pulping, and fertilizer recovery, dominated the reduction in environmental burdens. Direct freshwater consumption and wastewater disposal played additional effective roles in controlling water footprint. The water network was thus optimized by a water pinch analysis to decrease the freshwater consumption and pollutant emissions by maximum values of 91.5% and 99.7% after optimization, respectively. Meanwhile, carbon dioxide, methane, chromium, arsenic, mercury, titanium, copper, strontium, total nitrogen, total phosphorus, BOD 5 , and COD were the main pollutants. Overall, the environmental impact can be further reduced by diminishing coal power ratio in national energy structure, adopting recovered steam, and considering multistage regeneration water network to cope with different water use demands. • LCA-based energy and carbon coupled water footprint of straw pulp paper was applied. • Optimizing water network by water pinch method gained marked environmental benefit. • Electricity, steam, and chemicals exerted high impact among all inputs considered. • CO 2 , CH 4 , heavy metals, coal, and water were key contributors to footprint impact. • Improving national energy structure and adopting recovered steam were recommended. [ABSTRACT FROM AUTHOR]

The advancement in plastic and plastic based products in last two decades has imposed a serious threat to the environment. This has led to an increase in the demand for sustainable and biobased products. Paper and paper products are good alternatives to their plastic counterparts. A key element of paper industry is the raw material (wood, bamboo and nonwood agricultural residues such as bagasse, straws etc.) from which pulp is produced. The pulp is then utilized for production of paper. There are many pulping processes to prepare pulp of various qualities. For fine grade pulp, chemical pulping is used. The chemical pulp is produced by soda, kraft and sulphite pulping processes. However, for newsprint grade pulp, stone ground wood (SW), thermomechanical (TMP), chemi-thermomechanical (CTMP), chemi-mechanical (CMP) or refiner mechanical (RMP) corresponding pulping processes are employed. The method of pulp preparation (pulping process) consumes large amount of energy and chemicals. A new pulping process with electron irradiation using biowaste (bagasse) as a raw material is discussed in this work. Bagasse pulping process is found to reduce about 50% of energy consumption during pulping process. The process is referred to as 'ECTMP' (Energy Efficient Chemi-Thermo Mechanical Pulping). The paper produced from aforesaid method also reflected no loss of strength properties with respect of TMP reference pulps. Henceforth, preliminary calculation based on experimental results shows that the proposed bagasse ECTMP process explored the scope of energy savings of the order of 50%. • Energy efficient thermochemical process for biowaste conversion into paper was explored. • The effects of high energy electron irradiation pre-treatment were investigated. • Chemical pretreatment improved the strength properties of paper. • Specific energy consumption of bagasse pulping was significantly reduced. • The approach of pre-irradiation can be implemented for other raw materials also. [ABSTRACT FROM AUTHOR]

Worldwide pulp and paper industry is recognized as a serious threat due to the discharge of various toxic contents present in its effluent to the surrounding environment. To combat this challenge, the role of oleaginous yeast to utilize the pulp and paper industry effluent for the integrated toxic contents removal and sustainable biodiesel production were undertaken. Oleaginous yeast Rhodosporidium kratochvilovae HIMPA1 was used as a model organism for its unique ability to utilize pulp and paper industry effluent as a culture medium and accumulate high quantity of triacylglycerol or neutral lipids as large size lipid droplets of 4.56 ± 0.24 μm within its cellular compartment. The maximum cell dry weight (13.87 g/L) with total lipid yield of 8.56 g/L was obtained after 144 h of cultivation. Data showed significant reduction in effluent toxic components i.e. color, 89%; lignin, 94.27%; phenol, 99.60%; biochemical oxygen demand, 77.36%; total dissolved solids, 84.59%; and chemical oxygen demand, 94.22%. Fatty acid methyl esters profile revealed high quantity of long chain monounsaturated fatty acids (45.43%) and polyunsaturated fatty acids (15.91%) that improves biodiesel quality under low temperature condition in terms of low cold filter plugging point along with good oxidative stability and cetane number as per American Society for Testing and Materials D6751-02 and European Committee for Standardization - EN14214 guidelines. [ABSTRACT FROM AUTHOR]

Life Cycle Assessment (LCA) is a well-established and informative method of understanding the environmental impacts of consumer products across the entire value chain. However, companies committed to sustainability are interested in more methods that examine their products and activities' impacts. Methods that build on LCA strengths and illuminate other connected but less understood facets, related to social and economic impacts, would provide greater value to decision-makers. This study is a LCA that calculates the potential impacts associated with Bounty ® paper towels from two facilities with different production lines, an older one (Albany, Georgia) representing established technology and the other (Box Elder, Utah), a newer state-of-the-art platform. This is unique in that it includes use of Industrial Process Systems Assessment (IPSA), new electricity and pulp data, modeled in open source software, and is the basis for the development of new integrated sustainability metrics (published separately). The new metrics can guide supply chain and manufacturing enhancements, and product design related to environmental protection and resource sustainability. Results of the LCA indicate Box Elder had improvements on environmental impact scores related to air emission indicators, except for particulate matter. Albany had lower water use impacts. After normalization of the results, fossil fuel depletion is the most critical environmental indicator. Pulp production, electricity, and fuels for product production drive fossil fuel depletion. Climate change, land occupation, and particulate matter are also relevant. Greenhouse gas (GHG) emissions by pulp, electricity, papermaking, and landfill methane from the disposed product, drive climate change impacts. Pulp provides significant offsets to balance climate change impacts due to sequestration of atmospheric carbon dioxide. Ninety-nine percent of land occupation is for the growth of the trees for pulp production. Papermaking, electricity, and pulp production cause the most potential particular matter formation. [ABSTRACT FROM AUTHOR]

China has become the world largest paper and paperboard producer. However, pulp and paper industry has involved high resource consumption and severe pollution especially for water. This research has assessed the eco-efficiency of China's pulp and paper industry at the national level and provincial level. An overview regarding the cleaner production of China's pulp and paper industry was presented to reveal the measures for reducing environmental impact in the last two decades. Slacks-based measure was used to analyze the efficiency levels of 16 provinces' pulp and paper industries. To uncover the underlying causes of eco-efficiency performance, Malmquist–Luenberger index was calculated to discover the drivers of productivity growth of pulp and paper industries. Our results showed that the pollution treatment of China's pulp and paper industry has made progress in terms of water consumption and water pollution, although the absolute amount of pollution discharge is still large. Chemical oxygen demand emissions are still the first critical influencing factor of pulp and paper industry's inefficiency. Furthermore, efficiency progress was the dominating contribution of the industry's productivity growth between 2010 and 2013. The policies for adjusting the industrial structure of pulp and paper industry have resulted in the scale effects through eliminating backward production capacity and accelerating merger and acquisitions. Moreover, the productivity of pulp and paper industry was underestimated when the undesirable outputs were ignored. It indicates that the stricter environmental regulations have positive effects on paper companies to internalize environmental pressures in the production activities through environmental management. In the future, pulp and paper companies should further internalize the cost of pollution treatment through scale effects and technology improvement. [ABSTRACT FROM AUTHOR]

In this study, a mathematical model has been developed for sustainable inventory, in which the effects of environmental factors on social factors, have been investigated. To this end, first, we revised Economic Order Quantity (EOQ) model by adding income from waste sales to this model. Next, considering the emission of sulfur oxides (SO x ), nitrogen oxides (NO x ) gases, Biochemical Oxygen Demand (BOD) and chemical oxygen demand (COD) indicators in waste water as a measure of water organic pollutants, we proposed a Green Economic Order Quantity (GEOQ) model. Then in order to examine interdependency between environmental aspects and social aspects, we introduced the sustainable model by adding environmental ergonomics in the terms of the effect of SO 2 emission on human health. Since the structure of the model consists of nonlinear objective function and linear constraints, the model could be solved based on an exact nonlinear constrained solution method. Finally, we examined the effectiveness of the proposed model demonstrated in a real case study of pulp and paper mill. Validation of the model was done by comparing the cost function of the proposed model with the pure economic model and the actual data. The results of study showed that proposed sustainable model plays a significant role in determining the order quantity and reduction of cost function, sulfur oxides (SO x ) and nitrogen oxides (NO x ) emissions, and Biochemical Oxygen Demand (BOD) and chemical oxygen demand (COD) in waste water. [ABSTRACT FROM AUTHOR]

Purpose The aim of this work is to quantify the greenhouse gas (GHG) emissions savings potential in magazine paper production through the application of the innovative manufacturing strategies using advanced sheet structure design and fibre modifications. Methods The study applies Life Cycle Assessment (LCA) methodology to two different magazine paper products: supercalendered (SC) paper and light-weight coated (LWC) paper. A cradle-to-gate approach is used aiming to assess the environmental benefits gained through the implementation of new manufacturing strategies in both products. The functional unit of the system was defined as the production of one square meter of finished paper for printing magazines. Conventional and new production processes have been compared. Results and discussion The strategies applied to SC paper resulted in reduction of GHG emissions by 22.9%, with a total of 10.7 gCO 2 eq emissions saved per square meter of SC paper. In the case of LWC paper, GHG emissions are reduced by 20.3%, which are equal to a total of 19.7 gCO 2 eq saved per square meter of LWC paper. The influence of certain methodological approaches -functional unit, electricity mix and avoided impacts- in the final results is also discussed in the paper. Conclusions The manufacturing strategies implemented show a remarkable potential for reducing GHG emissions. Taking into account that the pulp and paper industry is a very energy-intensive sector and one of the main GHG emitters, the potential of the strategies for the improvement of the environmental performance of the papermaking processes is significant. [ABSTRACT FROM AUTHOR]

Recycling of waste paper was investigated with the aim of boosting the use of recycled materials and reducing the impact of waste paper on environment. Commercially important cyanoethyl cellulose product from waste paper was synthesized successfully through a cycle of chemical treatments. Waste paper was functionalized to cyanoethyl cellulose in an alkaline heterogeneous reaction environment with acrylonitrile under different reaction conditions with respect to degree of substitution. The variables studied were: Sodium Hydroxide and acrylonitrile concentration, reaction time and temperature for alkalization and cyanoethylation. All the cyanoethyl cellulose products were assessed for solubility, degree of polymerization and degree of crystallinity. The optimum conditions for cyanoethyl cellulose synthesis comprised of 8.34 M/anhydro glucose unit aqueous sodium hydroxide concentration, 30 °C alkalization temperature, 60 min alkalization time, 70 M/anhydro glucose unit acrylonitrile concentration, 60 min reaction time for cyanoethylation and 50 °C cyanoethylation reaction temperature. The optimized cyanoethyl cellulose product was characterized with fourier transform infrared spectroscopy, proton magnetic resonance spectroscopy, X-ray diffraction and scanning electron microscopy. This investigation helped to find the proper cleaner production approach towards sustainable environment management by synthesizing valuable cyanoethyl cellulose product and demonstrated that waste paper have the capacity to produce upgraded and high quality cyanoethyl cellulose for variety of applications. [ABSTRACT FROM AUTHOR]

This work assesses six different agricultural residues with the aim of finding alternative raw materials for a soda semichemical pulping process: stems of bell and chili pepper ( Capsicum annuum ), broad bean ( Vicia faba ), asparagus ( Asparagus officinalis ), pea ( Pisum sativum ), and okra ( Abelmoschus esculentus ). Pulping yields higher than 60% (m/m) were obtained, except for pea stems (43%). The drainability of all the pulps, expressed as the Schopper-Riegler index (ºSR), had values of over 70 ºSR. The Kajaani analyses of the fibers showed acceptable fiber lengths in all cases (0.64–0.92 mm), but on average shorter than the lengths of pulps from a commercial fluting paper (Old corrugated Container, OCC), that was found to be 1.27 mm. Handsheets of paper were produced both with the pulps under study and with mixtures of these pulps with OCC pulp. Several properties were measured to assess the use of the new fibers in a paper for cardboard production. The property showing the greatest differences was the Gurley porosity, ranging from 25 mL/min (asparagus) to 1300 mL/min (broad bean). Of the six residues tested, the okra residue fiber showed better properties than the commercial paper fiber (Concora Medium Test indexes: 1.5 N m 2 /g and 1.1 N m 2 /g respectively, Burst Indexes: 2.3 kPa m 2 /g and 1.7 kPa m 2 /g, respectively), yielding similar mechanical properties to those of high quality fibers obtained from miscanthus ( Miscanthus giganteus ). Broad bean residue could also be a promising raw material, though its properties are not as good as okra’s. [ABSTRACT FROM AUTHOR]

Recycling and recovery of materials from used products is one of the major avenues to reduce material throughput. Ideally, all materials are anticipated for being reused by the economy an infinite number of times. In reality, recovery of secondary materials may be difficult because of high costs, or because of degraded quality compared with virgin materials. The search for potential reduction of throughput in material cycles should be based on a knowledge of the limits to repeated cycles. To gain understanding of recycling limits, we developed a method to estimate the actual reduction potential for each throughput in a material's multi-cycle life. First, we investigated the material flow system of paper in Taiwan, and developed a supply chain network of paper flows. Systematic elaboration of the flows revealed where paper can be recycled and where paper can be lost. Second, we estimated the reduction potential with a material input–output Markov chain model, which maps the distribution and loss of materials on the supply chain processes. The model estimated the quantities and the life pathways of recycled materials across continuous life-cycles. An indicator was used to quantify the total performance of the material across repeated life-cycles. This method offers an opportunity to examine practices that approach the limit of reduction. This case study shows that the use and separation of paper waste after discarding may need to be reformed to extend the life-cycles of the material. [ABSTRACT FROM AUTHOR]