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• Pulp and paper mill sludge (PPMS) landfill sites have GHG assessment challenges. • GHG fluxes measured by chambers with (F +) and without (F-) a frame were compared. • Flux relationships up to 80 % were shown between F- and F + chambers (the standard) • Correction factors for F- chambers were built to estimate fluxes from F + chambers. • The approach can refine GHG inventories on PPMS landfill sites. Assessments of greenhouse gas (GHG) emissions in managed areas are facing various challenges. A non-flow-through, non-steady-state (NFT-NSS) chamber coupled to a frame permanently inserted into the landfilled substrates is a standard method for quantifying GHG emissions in managed areas, such as pulp and paper mill sludge (PPMS) landfill sites. Frequent measurements are needed to minimize uncertainties on GHG emission factors at the landfill site scale. However, maintaining a frame inserted into the substrates for a long time period is often impossible due to landfilling management operations. Therefore, GHG measurements using NFT-NSS chambers placed directly on substrates' surface could be an interesting option. Our objectives were to determine the relationships between CO 2 , CH 4 , and N 2 O fluxes measured with (F +) and without (F-) a frame inserted in the substrates' surface and to develop correction factors for fluxes measured without a frame. Measurements were made at different PPMS landfill sites in the province of Québec, Canada. Stronger GHG flux relationships were observed at the provincial (across sites) than the specific site scale: the variance in GHG fluxes from F- chambers explained up to 80 % of variance in fluxes from F + chambers. The measured CO 2 , CH 4 , and N 2 O fluxes in F- chambers were on average 53, 78, and 63 % lower, respectively, than those estimated by the models at provincial scale. The correction factors developed with this approach could greatly extend the number of sites where in situ GHG measurements can be done and would help refining GHG inventories at the provincial and national levels. [ABSTRACT FROM AUTHOR]

• The PBAT/PLA coated paper shows high methane yield under AD condition. • Plastic film residues remain after the digestion of PBAT/PLA coated paper. • The decrease of hydrophobicity for PBAT/PLA bags is due to the formation of PLA monomers. • The bacterial community shows difference between PBAT/PLA coated paper and bags. • Methanoculleus is enriched on the plastic surface under mesophilic AD. Poly (lactic acid) (PLA) and Poly(butylene adipate-co-terephthalate) (PBAT) are two of biodegradable plastics with the highest production capacities in 2021. Bioplastic waste management can be easily integrated with organic waste management, especially when bioplastics are used as food packaging material, since they are potentially biodegradable. The aim of this study was to assess the biodegradability of biodegradable polymer-coated paper (BPCP) and bioplastic bags made from PBAT/PLA blend during mesophilic and thermophilic anaerobic digestion (AD) and to reveal the changes in the physicochemical properties of the bioplastics. BPCP obtained 155 NmL-CH 4 /g VS and 307.3 NmL-CH 4 /g VS under mesophilic and thermophilic conditions, respectively, but left bioplastic film residues. The bioplastic bags did not exhibit significant biodegradation during the AD processes. 1H NMR results indicated that the ratio of PLA to PBAT decreased significantly after AD of the BPCP film and that PLA monomers were formed from the bioplastic bags, leading to a decrease in the hydrophobicity on the surfaces of the materials. Methanoculleus was found to be enriched on the bioplastic surface after mesophilic AD. From the perspective of coupling bioplastic waste management with the food waste management, the incorporation of BPCP into the AD reactor not only enhances system stability and methane production to a greater extent than biodegradable plastic bags but also raises concerns regarding the residual biofilm when utilizing the digestate for direct land applications. [ABSTRACT FROM AUTHOR]

• Water retention curves (WRCs) of municipal solid wastes (MSWs) • Hysteresis of WRCs of MSWs with decomposition. • Effects of decomposition and paper content on the WRCs. • Unsaturated hydraulic and gas conductivity of MSWs. This paper investigates the drying and wetting water retention curves (WRCs) of municipal solid wastes (MSWs) with different paper contents, dry unit weights and degrees of biodegradation (DOBs). Fresh synthetic samples were prepared based on the field composition of the MSWs at Mugga Lane Landfill, the Australian Capital Territory (ACT), Australia. The degraded samples were prepared in simulators with MSWs of different initial dry unit weights and decomposition periods with leachate recirculation. The water retention curves (WRCs) of the MSWs were determined using pressure plate tests, in both drying and wetting phases. The outflow from MSWs was analysed using Gardner's method to obtain the unsaturated hydraulic conductivity. The results indicate that the WRCs of the MSWs are greatly affected by the DOB, paper content and dry unit weight. When DOB < 30 %, as DOB increases, the air-entry pressure of MSWs with paper increases, and the residual moisture content decreases regardless of paper content. With DOB > 30 %, the air entry pressure and residual water content depend on the balance between organic matter and highly decomposed organic constituents. The paper content affects the WRCs of MSWs due to its water retention capacity and change in the particle size distribution with decomposition. The increase in the dry unit weight of MSWs significantly increases the air entry pressure and residual moisture content, similar to the borehole samples with combined effects of biodegradation and increase in stress level from literature. Hysteresis effects have been observed during the drying and wetting of MSWs. The hysteresis of WRCs increases with the paper content and DOB. [ABSTRACT FROM AUTHOR]

[Display omitted] • Semi-automated generation of regionalized paper recycling life-cycle inventories. • National impacts on climate change of recycling three paper grades in 191 countries. • Life-cycle assessment case study of Quebec's mixed wastepaper recycling system. Recycling is a commonly acknowledged strategy to reduce the environmental impacts linked to primary resource exploitation. Large regional variations can be observed in recycling processes' parameters, like efficiency, energy mix and treatment of rejects. Life-cycle assessment (LCA) is widely used to evaluate the environmental impacts of recycling processes, but existing studies are neither harmonized nor sufficient to provide a comprehensive geographical and technological coverage of recycling processes. The purpose of this research is to develop an efficient and iterative approach for the parametrized generation of semi-automated regionalized life-cycle inventories that take into account technological and geographical variabilities in the recycling sector. The regionalization framework is then applied to create a parametrized paper recycling regionalization tool. This tool is used in the results section to compare the national climate change impacts of recycling three paper grades. Results show a significant global warming impact variability between countries for recycled graphic paper (0.36 to 2.25 kg CO 2 -Eq/kg wastepaper recycled), newsprint (0.27 to 1.84 kg CO 2 -Eq/kg wastepaper recycled) and corrugated cardboard (0.28 to 1.68 kg CO 2 -Eq/kg wastepaper recycled) productions. A regionalized LCA of the international recycling of the mixed wastepaper exported from Quebec's (Canada) sorting centers is also performed with the tool and compared to the non-regionalized mixed wastepaper recycling process available in the ecoinvent database. Only nine midpoint ReCiPe impact categories remain environmentally advantageous compared to virgin paper production when applying the regionalization methodology, compared to sixteen when using the ecoinvent process, illustrating how regionalization can substantially influence LCA results. [ABSTRACT FROM AUTHOR]

[Display omitted] Scheme 1. Schematic illustration of the procedures for activation of WP. • Activating WP with K 2 C 2 O 4 , H 3 PO 4 or ZnCl 2 forms products of distinct nature. • H 3 PO 4 /ZnCl 2 catalyzes formed more bio-oil but less gas, and K 2 C 2 O 4 is opposite. • K 2 C 2 O 4 and ZnCl 2 are more effective than H 3 PO 4 for creating pores from WP. • ZnCl 2 creates abundant macropores via converting fibers in WP to graphitic crystals. • K 2 C 2 O 4 shows lower environmental impact than ZnCl 2 in activating WP. Waste paper (WP) is rich in cellulose, which can be activated to produce porous carbon, bio-oil, and combustible gases. During chemical activation of WP, the use of varied chemical agents not only generates activated carbon of distinct pore structure but also bio-oil/gases of different property. In this study, the activation of WP with varied chemical agents was conducted. The distinct characteristics of activated carbon and also bio-oil/gases were correlated with the different nature of the used chemical agents. The results indicated that H 3 PO 4 and ZnCl 2 catalyzed polymerization reactions for producing more bio-oil while less gases owing to their Brønsted and Lewis acidic sites. K 2 C 2 O 4 showed high activity for cracking/gasification reactions, forming bio-oil with higher abundance of organics with smaller π-conjugated structures. In addition, ZnCl 2 could create a very coarse porous structure with abundant macropores via destroying fiber structure in WP and promoting the growth of graphitic crystals. In comparison, K 2 C 2 O 4 hindered the aromatization and facilitated the formation of amorphous activated carbon. K 2 C 2 O 4 and ZnCl 2 were much more effective than H 3 PO 4 for creating micropores and mesopores from WP, the derived activated carbon showed superior performances as the electrode of supercapacitor and adsorbent for adsorption of oxytetracycline from aqueous solution. In addition, K 2 C 2 O 4 as activating agent showed lower environmental impact than ZnCl 2 in terms of energy consumption, environmental pollution and the greenhouse effect. [ABSTRACT FROM AUTHOR]

• Co-pyrolysis of homogeneous polypropylene plastic and paper wastes. • Analysis of physicochemical characteristics, and synergetic effects. • Energy analysis of mixed municipal waste conversion. Co-pyrolyzing mixed wastes of the different physicochemical kinds is often a challenge. This study reports the co-pyrolysis of homogeneous polypropylene plastic and paper wastes, highlighting their characteristics, synergetic effects, and kinetic and thermodynamic parameters using robust thermal gravimetric analysis technique. Results show that 20% paper in the blend improved the bulky density, fuel ratio from 0.09 to 0.13, maximum degradation temperature from 369.55 to 447.88 °C and thermal stability from 381.60 to 393.82 °C. The average activation energies of the blend from Flynn-Wall-Ozawa, Friedman and Coats-Redfern were 148.73 ± 7.87, 133.98 ± 11.59 and 143.74 ± 13.83 kJ/mol, respectively, lower than at least one of the homogenous wastes. All the enthalpy and Gibbs free energy values were positive, thus, endothermic non-spontaneous pyrolysis. In addition, average enthalpies for the mixed sample were lower than homogeneous polypropylene (from 159.57 ± 11.86, 153.74 ± 16.07 and 181.27 ± 28.90 to 143.60 ± 24.42, 128.86 ± 34.61 and 138.61 ± 41.32 kJ/mol, respectively) in all models, respectively. The entropy values for all samples were negative. They decreased with increasing conversion rates for mixed waste samples, indicating ease to reach thermodynamic equilibrium during pyrolysis. There is an insignificant difference between the experimental and the calculated TGA/DTG curves, signifying meagre synergetic effects. In addition, the 3D surface response for the conversion rate against temperature and heating rate showed closeness in results between the homogeneous and mixed waste. The results of this study are vital in handling municipal solid waste without any need for isolation during the conversion process to valuable products. [ABSTRACT FROM AUTHOR]

• Adding kaolin reduces the volatility and leachability of heavy metals. • Xerogel with high porosity was successfully synthesized for heavy metal adsorption. • Silica-alumina xerogel can effectively adsorb heavy metals in pyrolysis gas. • Heavy metal species can form ionic or covalent bonds with kaolinite. It is of great significance to reduce the secondary risk of heavy metals during the pyrolysis of paper sludge. This study used kaolin and alumina-silica-based xerogels to control heavy metals released during sludge pyrolysis. Pyrolyzing a mixture of sludge and 7% kaolin at 400 °C achieved high retention rates for Cu (95.85%), Zn (95.97%), Pb (97.15%), Cd (84.23%), and Cr (84.05%) when the pyrolysis tail gas was treated with 9 g of xerogel. The addition of kaolin facilitated the transformation of Cu, Zn, Pb, and Cr from the unstable fraction to the stable fraction in pyrolysis biochar, reducing their leachability. The xerogels also played a crucial role in adsorbing and stabilizing the heavy metals. The results of thermodynamic equilibrium calculations showed that Pb(g), PbS(g), PbCl 2 (g), PbCl(g), Zn(g), ZnCl 2 (g), and Cd(g) were the main gaseous products of Zn, Pb, and Cd during paper sludge pyrolysis. The Pb atoms in PbCl 2 and PbS, and the Zn atoms in ZnCl 2 bond with the oxygen atoms on the kaolin surface by covalent bonds, while the Cl atoms in PbCl and the Pb atoms of elemental lead form ionic bonds with H and O atoms on the kaolinite surface, respectively. These experimental and simulation results offer new ideas for controlling heavy metals during sludge pyrolysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • PCB was co-pyrolyzed in fixed and fluidized bed (FB) pyrolyzers with Ca-based additives. • Catalytic and dehalogenation capacities of CaO, Ca(OH)2, and CaO + Ca(OH)2 were compared. • CaO reduced the halogen content of bio-oil up to 80 and 92% in fixed bed and FB. • Halide fixation in the solid phase by additives was more effective in FB than fixed bed. • Up to 40.6% liquid recovery was achieved in a FB containing CaO + Ca(OH) 2. This study compares the impact of the calcium-based additives and the pyrolyzer on the recovery and the halide content of the oil produced from the pyrolysis of paper-laminated phenolic resin printed circuit boards (FR2-PCB). The preliminary experiments showed that the maximum liquid recovery (40.6%) was achieved in a fluidized bed pyrolyzer containing a 50:50 mixture of CaO and Ca(OH) 2 operating at T = 620 °C and PCB-to-additive ratio (FR2/A) = 5.4 g/g for 22 min. Extra tests were then carried out under these conditions in fixed and fluidized bed pyrolyzers to separately explore the impact of CaO, Ca(OH) 2 , and CaO + Ca(OH) 2 on the liquid recovery (L R) and the halogen content of the non-solid products. In the fluidized bed, L R in the presence of CaO, Ca(OH) 2 , and CaO + Ca(OH) 2 was 34.5%, 41.2%, and 38.9 wt%, respectively. The fraction of phenolic compounds in the pyrolysis oil ranged from 86% to 93%, about 1–3% higher than the corresponding values in the fixed bed. Using additives led to lower halide content in the pyrolysis oil of the fluidized bed than that of the fixed bed. However, the opposite trend was observed in the absence of additives. Regardless of the type of pyrolyzer, Ca(OH) 2 was more successful than CaO in increasing L R , whereas CaO was more effective than Ca(OH) 2 in pyrolysis oil dechlorination. Co-pyrolysis of FR2-PCB and CaO + Ca(OH) 2 in a fluidized bed reactor was identified as a practical approach to enhance the recovery of pyrolysis oil comprising only 5% of the original halogen content of the feedstock. [ABSTRACT FROM AUTHOR]

• Achieving high waterproofing in modified cellulose sheets using silylated starch. • Accelerating to biodegradation rate of starch-modified cellulose material by water. • Increasing service life and decay acceleration by fungi for modified paper. Modifying natural polymers with silicones gives new possibilities for packaging products and waste management. In this study, the innovative papers produced were altered following the reaction of polysaccharides and organosilicon compounds. The susceptibility of the studied material to biodegradation caused by a brown-rot fungus was assessed. Strength properties by tensile strength and dynamic mechanical analysis and hydrophobic properties by water uptake test and water contact angle analysis were evaluated. Moreover, elemental analysis by ICP method was controlled. The durability against fungi and the hydrophobic properties were increased by the modification. The fungal decay resistance of the silanized paper was reduced by water storage, which allows for managing paper waste. Cellulose-based paper treated with starch-modified methyltrimethoxysilane showed potential as a packaging material due to its reduced water uptake. Possible application areas could be corrugated boxes, cellulose thermoformed products for electronics, and food packaging. However, the water-repellent effect is limited to short-term exposure in humid conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • The optical pure l -lactic acid (99.5%) can be produced by non-engineered Bacillus. • Paper mill sludge with low ash content benefits cellulase enzyme production. • The use of paper mill sludge as feedstock is cost-effective. • On-site enzyme production ensures economic viability. Paper mill sludge (PMS) raises critical environmental issues due to its disposal problem, but its high sugar content and well-dispersed structure make it a great feedstock for biochemical production. The technical feasibility of integrating cellulase enzyme production into lactic acid (LA) fermentation from PMS was investigated in this study. The low ash content of PMS suggests a great potential for cellulase production. The enzyme produced using PMS without any treatment gave an activity of 7.8 FPU/ml, a performance comparable to the commercial enzyme, Cellic CTec 2. The LA yield from PMS with in-house enzyme was 64.7% and 73.7% at the enzyme loading of 10 and 15 FPU/g-glucan, respectively. The LA obtained was optically pure L- isomer with over 99% purity. The optimal condition of LA production by Bacillus coagulans was found to be 50 °C and pH 5.3 (with 50 g/L CaCO 3). The nutrient effect of yeast extract (YE) and corn steep liquor (CSL) was substrate dependent, and CSL could substitute YE as an inexpensive nutrient when using PMS as a substrate. [ABSTRACT FROM AUTHOR]

• Index of recycling sustainability for assessing waste paper recycling. • Integrating methodology of GIS and value chain model. • Historical changes of informal recyclables distribution sites in Beijing. • Value chain of waste paper recycling in Beijing may face challenges in the future. • Policy implications to improve waste paper recycling in Beijing. China established a self-organized and market-driven recycling system, which was dominated by the informal sectors. In recent years, the amount of domestically-recycled waste paper grew slower than expectation in China, which may be resulted from a decline in economic sustainability of current recycling system. For understanding the waste paper recycling system in most cities in China, the economic mechanism remains unclear and the city-level data is extremely insufficient. In this work, an index of recycling sustainability (IRS, benefit divided by cost) is analyzed with a resolution of 1 km2 grid in Beijing City, by adopting value chain and GIS methodology. Five degrees of IRS are defined, from high-degree (IRS > 1.10) to low-degree (IRS < 0.95). Different stakeholders in the informal waste paper recycling system were interviewed to fill the data gap. Results show that: (1) from 2015 to 2018, the informal recycling of waste paper accounted for approximate 80% in Beijing; (2) the number of informal recyclables distribution sites decreased from 27 to 11, and their average distance to the city-center rose from 27.5 km to 40.9 km; (3) in 2015 and 2018, the grids with high-degree IRS accounted for 99.5% and 89.2%, respectively, indicating a sustainable waste paper recycling industry in Beijing; and (4) according to the scenario analysis, if the operating cost rises by 30%, the grids with low-degree IRS accounts for 98.5%, indicating a nontrivial challenges when the recycling cost keeps increasing in the future. Policy recommendations are put forward for a more sustainable paper waste recycling system in China. [ABSTRACT FROM AUTHOR]

A range of energy fuels (ethanol, char, oil/wax and gas) was produced from fibre waste contaminated with plastic through the application of a fermentation-pyrolysis route. The fibre component was first converted to ethanol by simultaneous saccharification and fermentation (SSF), achieving an ethanol concentration of 39.8 g/L. The residue, enriched in lignin and plastics, was subjected to fast pyrolysis at temperatures between 350 and 550 °C. A wax product with a higher heating value (HHV) higher than 28 MJ/kg was obtained for temperatures higher than 450 °C, while values lower than 15 MJ/kg were observed for the oils produced from the untreated waste stream. Pyrolysis at 550 °C produced a wax with an HHV as high as 32.1 MJ/kg, where 51.8% of the energy content of the fermentation residue was transferred. The attractive energy contents of the pyrolysis products were enabled by oxygen removal from the feedstock during fermentation to ethanol. [ABSTRACT FROM AUTHOR]

• The content of potentially toxic metal in KB and PB was low. • Terminal temperature remarkably affected the morphology of potentially toxic metals in biochar. • PB and KB were not hazardous waste with low environmental risk. • PB and KB can fix potentially toxic metal in Tibet soil admirably. This study investigated the morphology and potentially toxic metal concentrations of paper waste-based biochar (PB) and kitchen waste-based biochar (KB) obtained at 500 and 700 °C. The morphology and potentially toxic metals (Cr, Mn, Cu, Cd, Pb, Zn, Ag, and Ba) concentrations in the biochars were determined by SEM and FT-IR analysis. The Cr, Mn, Cu, and Cd concentrations in PB were low, while the Ba content was relatively high at 0.1 mg∙kg−1. An increase in the terminal temperature led to an increase in the concentrations of Fe/Mn oxide-bound potentially toxic metals of PB, and a decrease in the concentrations of organic matter-bound potentially toxic metals. The Fe/Mn oxide-bound Cr, Mn, Cu, Pb, and Zn concentrations of KB decreased with an increase in the terminal temperature. Therefore, increasing the terminal temperature could reduce the bioavailability of potentially toxic metals in PB and KB. The environmental risk of the different biochars when used for soil remediation was assessed by the potential ecological risk index (RI), and a case study of a Tibetan soil was also conducted. The potentially toxic metal concentrations leached from both PB and KB were lower than the relevant standards. The findings showed that both PB and KB can be safely used for soil remediation. [ABSTRACT FROM AUTHOR]

• Paper cup with polyethylene coating remains undegraded in environment. • Cellulolytic enzyme activity was studied both qualitatively and quantitatively. • Potential cellulolytic bacteria help in decreasing the duration of degradation. • Paper cup waste degradation is substantiate by insilco analysis. In the current scenario, used paper cups are disposed of without any proper treatment, thereby damaging the environment. Hence, the vermicomposting technique is preferred for managing these wastes. The ability of bacterial strains on cellulase enzyme (Endoglucanase, exoglucanase and β-glucosidase) production at altered pH and temperatures were focused in this study. Among nine bacterial strains Acinetobacter baumannii was found to have high enzyme activity. HPLC analysis confirms that about 45% of cellulose degradation occurred due to the action of bacterial consortia at 37 °C with pH 7. The overall period required for degradation takes only three months with the help of bacterial consortia while comparing to our previous study, which takes six months. The insilico study on three cellulose-degrading enzymes sequence were retrieved from NCBI, and analysed for multiple sequence alignment and phylogenetic tree construction. From the analysis, the endoglucanase SVK46152 (Acinetobacter baumannii) sequence got docked with cellopentaose with a high score value −11.07. Thereby we confirm that organism Acinetobacter baumannii was effective in paper cup degradation. [ABSTRACT FROM AUTHOR]

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

• Characterization of solid wastes is an important to analysis of the final disposal. • Chemical, thermal, mineral, physical and environmental conditions were evaluated. • Waste from the paper industry is classified as non-inert non-harmful; • The best disposal methodology from the paper industry waste is sanitary landfills. • Some exceptions of disposal can be found, depending on the type of paper. The world paper industry produces a great amount of industrial solid waste that undergoes a treatment process that can be either primary, secondary, or tertiary, in order to adapt the waste for correct disposal. The paper manufacturing industries search for the best way to dispose of their wastes, generally in landfills, but there are few studies proving the effectiveness of such measure from the environmental, technological and economic points of view. Knowing the characteristics of this waste and understanding the treatment process it is submitted to are fundamental issues to manage it and comply with environmental demands. The purpose of this paper is to perform a chemical, mineralogical, thermal, morphological, physical and environmental characterization of the paper and pulp industry wastes, in order to assess alternatives for their adequate disposal, such as controlled landfills, sanitation, incineration, and sea dumping. It was observed that the material presents physical, chemical, and morphological features that indicate the possibility of reusing it in other production chains, such as the ceramic industry, besides being classified as non-hazardous wastes. Furthermore, disposal in sanitary landfills presents advantages in environmental and technological terms. [ABSTRACT FROM AUTHOR]

• Preservation of rumen fluid at 20 °C inhibits the hydrolysis of the waste paper. • Preservation at 35 °C increases the loss of organic carbon from rumen fluid. • Fibrolytic enzyme activity and protozoa of rumen fluid are retained at 4 °C. • Preservation at 4 °C reduces the loss of CO 2 production from rumen fluid. It is necessary to preserve rumen fluid for transport from slaughterhouses to the pretreatment facilities for use in treating lignocellulosic biomass. In this study, we investigated how the preservation of rumen fluid at various temperatures affects its use in hydrolysis of waste paper. Rumen fluid was preserved anaerobically at 4, 20, and 35 °C for 7 days. The number of protozoa and fibrolytic enzyme activity after preservation at 4 °C were significantly higher than that after preservation at either 20 or 35 °C. Waste paper was subsequently treated with preserved rumen fluid at 37 °C for 48 h. Preservation at 20 °C remarkedly decreased the hydrolysis of waste paper. Xylanase activity in rumen fluid preserved at 35 °C increased during the treatment, which enhanced the solubilization of waste paper as comparable to the control and preservation at 4 °C. Pretreatment of waste paper with rumen fluid preserved at 4 °C showed that the fluid retained high fibrolytic activity, and reduced the loss of organic carbon as substrate for methanogens. Our results suggest that preservation of rumen fluid at 4 °C is most suitable for efficient pretreatment and methane fermentation of waste paper. [ABSTRACT FROM AUTHOR]

[Display omitted] • The physical and chemical properties of PS and PC were studied systematically. • The reactivity of PC combustion reaction was significantly affected by PS. • PC:PS = 4:1 has the lowest combustion activation energy. • The Kissinger Akahira Sunose model shows a good fitting effect. The co-combustion reactivity and kinetics of petroleum coke (PC) and paper sludge-derived hydrochar (PS) were investigated via thermogravimetric analysis. The physical and chemical structure features were also systematically tested. The results show that the combustion process of PS could be divided into three stages, while for PC only one stage could be clarified. Due to high volatile content, developed pore structure and low carbon-order degree, the combustion reactivity of PS was higher than that of PC. Although the ignition property of the blends could be significantly improved by addition of PS, it changed little for the burnout temperature and as a result the combustion intensity was deteriorated. For the samples with addition of PS from 20 % to 80 %, the comprehensive combustion index decreased from 3.69 × 10-15 to 2.12 × 10-15. The Kissinger AkahiraSunose model-free method was used in the co-combustion reaction of PC and PS, and good fitting results were obtained. For different samples with varying addition of PS, the activation energies were in the range of 107.51–198.44 kJ/mol, with the lowest value obtained at 20 % of PS, which was also the optimum proportion for co-combustion of PC and PS. [ABSTRACT FROM AUTHOR]

[Display omitted] • A total of 20 different paper sludges were investigated. • A wide range of biomethane potentials was determined. • Inhibiting substances for some paper sludge were identified. • Co-digestion resulted in methane yield increase of 5–10%. • The possibility of anaerobic co-digestion could be demonstrated. In this work, the feasibility of the anaerobic digestion of paper sludge as a co-substrate in anaerobic digestion mechanical–biological treatment (MBT) plants is investigated. In the first phase, the biochemical properties, biomethane potential (BMP), and pollutant contents of 20 different industrial paper sludges are determined. Following the general evaluation in the BMP tests, the second phase of the project involves the semi-continuous co-digestion of six paper sludges in continuous stirred reactors (CSTR). Paper sludges are categorized according to their origin within the pulp and paper mills: Deinking Sludge (DS), Primary Sludge (PS) and Biological Sludge (BS). The analysis of potentially inhibiting elements shows that the concentrations of chlororganic compounds, mineral oil and some heavy metals are highest in DS, while the mean heavy metal loads in all paper sludges are relatively low compared to other industrial sludges. Large differences in total solids (TS) and volatile solids (VS) contents are observed among the different paper sludges investigated, with DS having the highest TS due to the high inorganic contents. The BMP of the investigated sludges ranges from 90 to 355 NL CH 4 kg−1 VS. In subsequent semi-continuous co-digestion experiments simulating MBT conditions, three DS and two fiber sludges (a mixture of PS and BS) show good methane generation rates, while one fiber sludge causes inhibition and indicates an increase in viscosity. In general, co-digestion of paper sludge in anaerobic digestion MBT plants can be a viable option for energy production and also facilitates a safe disposal of the paper sludge digestates. [ABSTRACT FROM AUTHOR]

Primary paper mill sludge (PPMS) is the major waste expelled from the pulp and paper industries contributing soil and water pollution through the recalcitrant organic and inorganic constituents. These pollutants can, however, be transformed into a high-value soil ameliorating material with nominal investment and time. Current study therefore evaluated the potential of rotary drum composting PPMS for 20 days to delineate an environmentally sustainable option. Five trials with proportions of PPMS, cow dung and saw dust: Trial 1 (10:0:0), Trial 2 (8:1:1), Trial 3 (7:2:1), Trial 4 (6:3:1) and Trial 5 (5:4:1) were performed for evaluation of degrading and nutritive ability along with the fate of pollutants for total mass of 150 kg. Trial 4 exhibited highest metabolic activity contributing higher temperature evolution and longer thermophilic phase (10 days) owing to optimum addition of innoculum and nitrogen through the cattle manure. Moreover, degradation of 16.8% organic matter was also best achieved in Trial 4 following up first-order kinetics. Furthermore, BOD, COD and C/N ratio also explains degradation to be maximum in trial 4 (6:3:1) with reduction of 59.3%, 60.1% and C/N ratio from 55.1 to 18 respectively, proving to be the essential determining factors. Phosphorus availability increased by around 67% in trial 4. PPMS can be thus transformed into a potential valued added product and safe for subsequent land application. [ABSTRACT FROM AUTHOR]

High ash-containing paper sludge which is rich in various metal oxides is employed in herb residue pyrolysis to enhance the yield of fuel gas and reduce tar yield in a drop tube fixed bed reactor. Effects of heat treatment temperature and blending ratio of paper sludge on the yields and composition of pyrolysis products (gas, tar and char) were investigated. Results indicate that paper sludge shows a significantly catalytic effect during the pyrolysis processes of herb residue, accelerating the pyrolysis reactions. The catalytic effect resulted in an increase in gas yield but a decrease in tar yield. The catalytic effect degree is affected by the paper sludge proportions, and the strongest catalytic effect of paper sludge is noted at its blending ratio of 50%. At temperature lower than 900 °C, the catalytic effect of paper sludge in the pyrolysis of herb residue promotes the formation of H 2 and CO 2 , inhibits the formation of CH 4 , but shows slight influence on the formations of CO, while the formation of the four gas components was all promoted at 900 °C. SEM results of residue char show that ash particles from paper sludge adhere to the surface of the herb residue char after pyrolysis, which may promote the pyrolysis process of herb residue for more gas releasing. FT-IR results indicate that most functional groups disappear after pyrolysis. The addition of paper sludge promotes deoxidisation and aromatization reactions of hetero atoms tars, forming heavier polycyclic aromatic hydrocarbons and leading to tar yield decrease. [ABSTRACT FROM AUTHOR]

In the anaerobic digestion of lignocellulosic materials such as waste paper, the accessibility of microorganisms to the fermentable sugars is restricted by their complex structure. A mechanical pretreatment with a Hollander beater was assessed in order to reduce the biomass particle size and to increase the feedstock’ specific surface area available to the microorganisms, and therefore improve the biogas yield. Pretreatment of paper waste for 60 min improves the methane yield by 21%, from a value of 210 ml/gVS corresponding to untreated paper waste to 254 ml/gVS. 30 min pretreatment have no significant effect on the methane yield. A response surface methodology was used to evaluate the effect of the beating time and feedstock/inoculum ratio on the methane yield. An optimum methane yield of 253 ml/gVS was achieved at 55 min of beating pretreatment and a F/I ratio of 0.3. [ABSTRACT FROM AUTHOR]

Efficient ethanol production from waste paper requires the addition of expensive nutrients. To reduce the production cost of ethanol from waste paper, a study on how to produce ethanol efficiently by adding kitchen waste (potentially as a carbon source, nutrient source, and acidity regulator) to waste paper was performed and a process of successive liquefaction, presaccharification, and simultaneous saccharification and fermentation (L+PSSF) was developed. The individual saccharification performances of waste paper and kitchen waste were not influenced by their mixture. Liquefaction of kitchen waste at 90 °C prior to presaccharification and simultaneous saccharification and fermentation (PSSF) was essential for efficient ethanol fermentation. Ethanol at concentrations of 46.6 or 43.6 g/l was obtained at the laboratory scale after fermentation for 96 h, even without pH adjustment and/or the addition of extra nutrients. Similarly, ethanol at a concentration of 45.5 g/l was obtained at the pilot scale after fermentation for 48 h. The ethanol concentration of L+PSSF of the mixture of waste paper and kitchen waste was comparable to that of PSSF of waste paper with added nutrients (yeast extract and peptone) and pH adjustment using H 2 SO 4 , indicating that kitchen waste is not only a carbon source but also an excellent nutrient source and acidity regulator for fermentation of the mixture of waste paper and kitchen waste. [ABSTRACT FROM AUTHOR]

A global, comprehensive review of terms and definitions related to paper recycling was conducted in this article. Terms and definitions related to paper recycling have varied in the course of time. Different terms and different definitions for the same thing are being used in different geographical regions and by different organizations. Definitions are different based on varying conceptions of waste paper as a raw material . Definitions of how to make various calculations related to paper recycling activity are inconsistent. Even such fundamental basic definitions like how to calculate recycling rate and paper consumption are not uniform. It could be concluded that there is no uniform system of terms and definitions related to paper recycling and the implications of this deficiency are profound. For example, it is difficult to reliably compare with each other statistics from different times and from different geographical regions. It is not possible to measure if targets for recycling activities are met if the terms describing the targets are not uniformly defined. In cases of reporting data for recycling targets, the lack of uniform terminology can, for example, impede the necessary transparency between different stakeholders and may allow for deception. The authors conclude there is a pressing need to develop a uniform system of terms and definition for terms related to paper recycling . [ABSTRACT FROM AUTHOR]

In this survey, a refuse derived fuel (RDF) was produced from paper industry wastes through a mechanical treatment (MT). The two main wastes generated from a recovered paper mill were rejects and de-inking sludge, which were produced principally in the pulping and de-inking processes, respectively. This work presents raw wastes characterization, fuel preparation and gasification tests performed in a circulating fluidized bed (CFB) gasifier pilot plant. The characterization was carried out by proximate and ultimate analysis. Several blends of pre-conditioned rejects and de-inking sludge were densified by means of pelletizing, studying the energy consumption and its quality properties. Besides, thermal degradation of blends was studied under thermogravimetric analysis (TGA). The experimental runs were made from 30 to 900 °C in nitrogen atmosphere at three heating ranges, β = 5, 10 and 20 °C/min. Two thermal stages were identified during the thermal degradation, which are linked to cellulose and plastic degradation. In addition, kinetics parameters were estimated by the application of non-isothermal methods: Kissinger–Akahira–Sunose (KAS), Flynn–Ozawa–Wall (FOW) and Coats and Redfern. The activation energy values were about 140–160 kJ/mol and 60–80 kJ/mol for plastic and cellulosic materials, respectively. Regarding waste valorisation, a blend composed of 95% of rejects and 5% of de-inking sludge was selected for gasification tests. The energy consumption during the preparation was recorded and a gasification tests were done to prove the usability of these pellets in a CFB gasifier. The main results were a net calorific value (NCV) of 5 MJ/Nm 3 and a total tar content of 11.44 g/Nm 3 at an equivalence ratio (ER) of 0.3. [ABSTRACT FROM AUTHOR]

Paper product manufacturing involves a variety of chemicals used either directly in paper and pulp production or in the conversion processes (i.e. printing, gluing) that follow. Due to economic and environmental initiatives, paper recycling rates continue to rise. In Europe, recycling has increased by nearly 20% within the last decade or so, reaching a level of almost 72% in 2012. With increasing recycling rates, lower quality paper fractions may be included. This may potentially lead to accumulation or un-intended spreading of chemical substances contained in paper, e.g. by introducing chemicals contained in waste paper into the recycling loop. This study provides an overview of chemicals potentially present in paper and applies a sequential hazard screening procedure based on the intrinsic hazard, physical–chemical and biodegradability characteristics of the substances. Based on the results, 51 substances were identified as potentially critical (selected mineral oils, phthalates, phenols, parabens, as well as other groups of chemicals) in relation to paper recycling. It is recommended that these substances receive more attention in waste paper. [ABSTRACT FROM AUTHOR]

Sewage fine sieved fraction (FSF) is a heterogeneous substrate consisting of mainly toilet paper fibers sequestered from municipal raw sewage by a fine screen. In earlier studies, a maximum biodegradation of 62% and 57% of the sewage FSF was found under thermophilic (55 °C) and mesophilic (35 °C) conditions, respectively. In order to research this limited biodegradability of sewage FSF, this study investigates the biodegradation of different types of cellulosic fibers-based hygiene papers including virgin fibers based toilet paper (VTP), recycled fiber based toilet paper (RTP), virgin pulp for paper production (VPPP) as a raw material, as well as microcrystalline cellulose (MCC) as a kind of fiberless reference material. The anaerobic biodegradation or digestibility tests were conducted under thermophilic and mesophilic conditions. Results of the experiments showed different biomethane potential (BMP) values for each tested cellulose fiber-based substrate, which might be associated with the physical characteristics of the fibers, type of pulping, presence of lignin encrusted fibers, and/or the presence of additive chemicals and refractory compounds. Higher hydrolysis rates (K h ), higher specific methane production rates (SMPR) and shorter required incubation times to achieve 90% of the BMP (t 90% CH 4 ), were achieved under thermophilic conditions for all examined substrates compared to the mesophilic ones. Furthermore, the biodegradability of all employed cellulose fiber-based substrates was in the same range, 38–45%, under both conditions and less than the observed FSF biodegradability, i.e. 57–62%. MCC achieved the highest BMP and biodegradability, 86–91%, among all cellulosic substrates. [ABSTRACT FROM AUTHOR]

Highlights: [•] The waste generated by the suppliers of the Spanish paper industry is estimated. [•] An Economic Input Output Life Cycle Assessment Models (IO-LCA) is employed. [•] No direct relationship between impact on output and on waste generation was found. [•] The major contributors to waste generation were mining and forestry. [ABSTRACT FROM AUTHOR]

• 72% − 80% of fibre was recovered from disposable coffee cups. • 2% and 3% consistency shredded cups required > 100 kWh/tonne to repulp with 3 refiner passes. • Pulp quality did not significantly diminish after repulping using a single-disk refiner. Over 64 billion paper-plastic laminate (PPL) coffee cups are consumed between the United States and Canada annually, the majority accumulating in landfills due to a hydrophobic plastic inner-lining. Recycling can mitigate environmental damage and provide economic value from repurposed products. We found that standard repulping methods were insufficient to separate fiber from plastic due to the low intensity of treatment. To increase process intensity, we mechanically refined shredded PPL coffee cups and Kraft eucalyptus sheets (control) at 2%, 3%, and 4% consistencies with three passes to determine the energy required to separate fibers from plastic and the effects on fiber quality. 2% and 3% consistency PPL cups measured under 40 kWh/tonne of input material for one refiner pass and ∼ 80 kWh/tonne for 4% consistency PPL cups. Recovered fiber fraction totaled 87.7%, 85.3%, and 80.5% of input mass of Kraft eucalyptus and 72.3%, 72.6%, and 79.6% of input mass of PPL cups at 2%, 3%, and 4% consistency, respectively. Fines content of PPL cups jumped from 8% pre-refining to ∼ 30% post-refining while Kraft eucalyptus fibers were unaffected, suggesting that breaking the plastic-fiber bonds results in fines generation. Mean fiber length of PPL cups slightly decreased with consistency and tensile strength improved. Freeness decreased with consistency only in PPL cup samples. These results demonstrate a low energy requirement to effectively separate fiber and plastics in PPL cups as well as minimal impact on fiber quality using existing refining technology, and provides an estimate of the financial costs of local recycling efforts. [ABSTRACT FROM AUTHOR]

The aim of this paper is to analyse the effects of the presence of printed electronics on the paper waste streams and specifically on paper recyclability. The analysis is based on a case study focussed on envelopes for postal and courier services provided with these intelligent systems. The smart printed envelope of the study includes a combination of both conventional (thin flexible batteries and resistors) and printed electronic components (conductive track layout based on nanosilver ink). For this purpose, a comparison between envelopes with and without these components (batteries, resistors and conductive track layouts) was carried out through pilot scale paper recycling tests. The generation of rejects during the recycling process as well as the final quality of the recycled paper (mechanical and optical properties) were tested and quantitatively evaluated. The results show that resistors are retained during the screening process in the sieves and consequently they cannot end up in the final screened pulp. Therefore, mechanical and optical properties of the recycled paper are not affected. Nevertheless, inks from the conductive track layouts and batteries were partially dissolved in the process water. These substances were not totally retained in the sieving systems resulting in slight changes in the optical properties of the final recycled paper (variations are 7.2–7.5% in brightness, 8.5–10.7% in whiteness, 1.2–2.2% in L ∗ values, 3.3–3.5% in opacity and 16.1–27% in yellowness). These variations are not in ranges able to cause problems in current paper recycling processes and restrict the use of recycled paper in current applications. Moreover, real impacts on industrial recycling are expected to be even significantly lower since the proportion of paper product with printed circuits in the current paper waste streams are much lower than the ones tested in this work. However, it should be underlined the fact that this situation may change over the next years due to the future developments in printed electronics and the gradual penetration of these types of devices in the market. [ABSTRACT FROM AUTHOR]

Abstract: The recovery and utilization of recovered paper have increased over past decades all over the world due to economic, environmental, and social issues. However, it is well known that an extended recovered paper collection is detrimental to its quality, either by the exploitation of lower quality sources such as households, or the spreading of commingled systems instead of selective collection systems. The influence of these two factors was assessed by analyzing the quality of different recovered paper grades used as raw material in a mill located in Madrid (Spain) producing newsprint and light weight coated paper from recovered paper. Part 1 of the paper deals with the impact of increased collection rates on the quality of recovered paper and Part 2 with the use of commingled collection systems. Results of Part 1 show that increased collection rates have a large impact on the quality of the recovered paper. The quality, measured as total unusable material and moisture contents, had deteriorated very rapidly in only 4years (2005–2008) as a consequence of increased collection rates. Collection rates increased in Spain from 58.5% to 68.6% during this period, resulting in more than 50% increase of total unusable material and 25% of moisture content. The downgrading of the quality of recovered paper is one of the major threats for extending the current limits of paper recycling. Therefore, future challenge is to increase its availability but maintaining its quality. [Copyright &y& Elsevier]

Abstract: Waste recycling for paper production is an important component of waste management. This study constructs a physical input–output life-cycle assessment (PIO-LCA) model. The PIO-LCA model is used to investigate environmental impacts of four categories of waste recycling in China’s paper industry: crop straws, bagasse, textile wastes and scrap paper. Crop straw recycling and wood utilization for paper production have small total intensity of environmental impacts. Moreover, environmental impacts reduction of crop straw recycling and wood utilization benefits the most from technology development. Thus, using crop straws and wood (including wood wastes) for paper production should be promoted. Technology development has small effects on environmental impacts reduction of bagasse recycling, textile waste recycling and scrap paper recycling. In addition, bagasse recycling and textile waste recycling have big total intensity of environmental impacts. Thus, the development of bagasse recycling and textile waste recycling should be properly limited. Other pathways for reusing bagasse and textile wastes should be explored and evaluated. Moreover, imports of scrap paper should be encouraged to reduce large indirect impacts of scrap paper recycling on domestic environment. [Copyright &y& Elsevier]

Abstract: The results of assays carried out on plates used in the construction industry, manufactured entirely with solid wastes of a recycled paper plant, are presented and compared with the results obtained using agglomerated wood and plywood plates. Previous results had shown that wastes are composed essentially of polymers when these wastes are generated by recycled paper produced with the “waved type II” shavings. These solid wastes were placed in a mold that was heated and pressed with a hydraulic press in order to obtain the plates. The waste-produced plates were submitted to tests for humidity, swelling, water absorption, density, modulus of rupture-static bending, modulus of elasticity and direct screw withdrawal. These same assays had been carried out on two types of commercial wood plates, agglomerated wood and plywood, in order to compare the results with those obtained with the waste plate. Waste plates had similar behavior to the agglomerated wood plate, but it was possible to distinguish greater flexibility in the waste-produced plate and a significant difference in the tests for swelling and water absorption which showed the waste plate had a better performance than the agglomerated wood and plywood plates. [Copyright &y& Elsevier]

We conducted an event study on the concealment of the blending ratio of waste paper with virgin pulp in Japan. By investigating 10 companies in the paper industry between May 30, 2007 and January 18, 2008, we clearly show that stock prices of the relevant companies were affected by the news on the concealment of the blending ratio of waste paper. In addition, the impact of the second event was found to be greater than that of the first event. Therefore, the concealment of major companies negatively affects the stock prices of non-major companies, which did not conceal information during this period. Thus, bad news is negatively assessed by the market, and this influence has spread in the paper industry in general. [Copyright &y& Elsevier]

Pulp and paper mills are indispensable for any nation as far as the growth of the nation is concerned. Due to fast growth in population, urbanization and industrialization, the demand and consumption of paper has increased tremendously. These put high load on our natural resources and force the industry to look for alternative raw material. Rice straw is a lignocellulosic material abundantly available in wood short countries like China, India, Bangladesh, etc. and can be used as raw material for this industry. Open burning of rice straw releases noxious green house gases to the air and poses serious threats to global air chemistry and human health. So, it is a dual benefit option (for farmers and industries) to use rice straw as a raw material in pulp and paper industry. Organosolv pulping using acids are the prominent choices of researchers to convert this residue into valuable pulp but in developed countries only. Developing world favours the soda and soda-AQ processes as these are economical. As a virtue of less lignin content in comparison to wood, rice straw requires less harsh conditions for cooking and can be easily pulped. Bleaching is a crucial step of paper making but also responsible for causing water pollution. Many studies revealed that during the process more than 500 chlorinated compounds are released that are highly toxic, bioaccumulative and carcinogenic in nature. Most of the industries over the globe switch on to the elemental chlorine free short sequence bleaching methods using chlorine dioxide, hypochlorite and hydrogen peroxide. This paper presented the effective need of ecofriendly, economically reliable pulping and bleaching sequences in case of rice straw to eliminate the problems of chlorinated compounds in wastewater of paper mills. Such approach of using waste as a raw material with its environmentally safe processing for making paper can prove to be valuable towards sustainable growth. [ABSTRACT FROM AUTHOR]

• A waste valorization approach is proposed to achieve a sustainable bioeconomy. • Lanthanide triflates are highly effective to convert paper wastes into lactic acid. • Chemocatalytic conversion strategy was found to be economically feasible. • Paper wastes can serve as important feedstock for high-value coproduct stream. The efficient strategy for waste conversion and resource recovery is of great interest in the sustainable bioeconomy context. This work reports on the catalytic upcycling of waste corrugated cardboard (WCC) into lactic acid using lanthanide triflates catalysts. WCC, a primary contributor to municipal solid wastes, has been viewed as a feedstock for producing a wide range of renewable products. Hydrothermal conversion of WCC was carried out in the presence of several lanthanide triflates. The reaction with erbium(III) triflate (Er(OTf) 3) and ytterbium(III) triflate (Yb(OTf) 3) resulted in high lactic acid yields, 65.5 and 64.3 mol%, respectively. In addition, various monomeric phenols were readily obtained as a co-product stream, opening up opportunities in waste management and resource recovery. Finally, technoeconomic analysis was conducted based on the experimental results, which suggests a significant economic benefit of chemocatalytic upcycling of WCC into lactic acid. [ABSTRACT FROM AUTHOR]

Abstract: After performing a series of batch type experiments using a lab-scale combustor, consideration was given to the use of an internally cycloned circulating fluidized bed combustor (ICCFBC) for a paper mill sludge. Operation parameters including water content, feeding mass of the sludge, and secondary air injection ratio were varied to understand their effects on combustion performance, which was examined in terms of carbon conversion rate (CCR) and the emission rates of CO, C x H y and NO x . The combustion of paper mill sludge in the ICCFBC was compared to the reaction mechanisms of a conventional solid fuel combustion, characterized by kinetics limited reaction zone, diffusion limited reaction zone, and transition zone. The results of the parametric study showed that a 35% water content and 60g feeding mass generated the best condition for combustion. Meanwhile, areal mass burning rate, which is an important design and operation parameter at an industrial scale plant, was estimated by a conceptual equation. The areal mass burning rate corresponding to the best combustion condition was approximately 400kg/hm2 for 35% water content. The secondary air injection generating swirling flow enhanced the mixing between the gas phase components as well as the solid phase components, and improved the combustion efficiency by increasing the carbon conversion rate and reducing pollutant emissions. [Copyright &y& Elsevier]

• European Waste Statistics Regulation focuses on waste as a post-factum problem. • At least 76,7% of waste disposing entities do not comply to the existing guidance. • Waste producer responsibility falls on the entities that pay waste management costs. • Circular economy transition requires changes in European Waste Statistics. The announcement of a new Circular Economy Action Plan as part of the European Green Deal policy has created an urgent need for the reliable information on resource flows to monitor and support the transition. An updated Monitoring Framework is set to rely as much as possible on European Statistics, however at this point there are no changes introduced in supranational statistics regulations. This raises a question whether regulations that have been created before the paradigm shift are still able to supply us with statistics necessary to inform policy makers about current successful practices, remaining barriers, positive and negative impacts of the transition and overall progress towards the set goals. This paper focuses on the Waste Statistics Regulation, specifically the relationship between the types of waste and economic activities which are considered to be the waste producers. Dutch National Waste Registry is used as a case study to compare the guidelines on pan-European waste data collection to the actual waste reports. The task of this publication is to explore to which extent the guidelines available in the Waste Statistics Regulation correspond to the operational reality. To do so it presents a computational method to link waste producers to their economic activities using a national Trade Registry. An extensive discussion of the results provides insights and recommendations for the future guidelines of waste statistics to support circular economy transition. [ABSTRACT FROM AUTHOR]

Paper sludge is a waste product from the paper and pulp manufacturing industry that is generally disposed of in landfills. Pyrolysis of paper sludge can potentially provide an option for managing this waste by thermal conversion to higher calorific value fuels, bio-gas, bio-oils and charcoal. This work investigates the properties of paper sludge during pyrolysis and energy required to perform thermal conversion. The products of paper sludge pyrolysis were also investigated to determine their properties and potential energy value. The dominant volatile species of paper sludge pyrolysis at 10°C/min were found to be CO and CO2, contributing to almost 25% of the paper sludge dry weight loss at 500°C. The hydrocarbons (CH4, C2H4, C2H6) and hydrogen contributed to only 1% of the total weight loss. The bio-oils collected at 500°C were primarily comprised of organic acids with the major contribution being linoleic acid, 2,4-decadienal acid and oleic acid. The high acidic content indicates that in order to convert the paper sludge bio-oil to bio-diesel or petrochemicals, further upgrading would be necessary. The charcoal produced at 500°C had a calorific value of 13.3MJ/kg. [Copyright &y& Elsevier]

The presence of paper in municipal solid waste (MSW) interferes with the efficiency of composting plants. The compost feedstock to these plants is between 12% and 27% paper on a dry weight basis, with an initial C:N ratio ranging from 32:1 to 57:1. Tests of the last aerobic biodegradability (LAB) of the type of paper present in paper and cardboard packaging were carried out, following UNE-EN 14046 standards. The results obtained, measured through the quantity of CO2 generated over 45 days, compared with the maximum that could be produced (ThCO2), showed that the presence of paper retards, to a great degree, the biodegradation of organic material in general. Specifically, the presence of papers with a degradation D (%) >60% at 45 days (white (W) and recycled paper (R)) could be allowed, but always in proportions that did not exceed 27% in dry weight. These results can be achieved with an industrial level process, pre-treated by trituration. [Copyright &y& Elsevier]

Abstract: Nowadays, the increasing amount of wastes is a concerning reality and the environmental aspects has become a major priority. Following this worry, the purpose of this experimental study was to investigate the possibility of using pulp and paper inorganic wastes, named dregs and grits, in bituminous mixtures as aggregate replacement to reduce environmental effects of these wastes disposal. First, the wastes were chemically and physically characterized and also tested primarily taking into account the requirements for aggregates in bituminous mixtures. Then, formulations were prepared replacing aggregates with wastes in different amounts. The mechanical properties of these mixtures containing wastes were compared with reference samples based on standard methods. According to the results it was possible to verify that grits had a good performance and it might be directly tested industrially as an aggregate in road construction. On the other hand, dregs need to be treated before incorporation to guarantee stable mixes in terms of water sensitivity. [Copyright &y& Elsevier]

This work presents the current waste management system at the pulp and paper mill complex of Stora Enso Oyj Veitsiluoto Mills at Kemi, Northern Finland. This paper covers examples of case studies carried out at the mill and describes how the wastes and by-products are utilized as a neutralizing agent for acidic wastewaters (i.e., green liquor dregs from the causticizing process), as a hardener in filling mine cavities (i.e., ash from the fluidized bed boiler), as a landscaping agent (i.e., ash as well as the fibre clay from chemical wastewater treatment plant), as a hydraulic barrier material for landfills (i.e., fibre clay), and as a soil enrichment agent (i.e., calcium carbonate from the precipitated calcium carbonate plant). In addition, the wood waste from the wood-handling plant, sawmill, packaging pallet plant and from the groundwood mill, as well as the biosludge from the biological wastewater treatment plant, are all incinerated in the fluidized bed boiler for energy production. Due to effective utilization of the solid wastes generated at the mills, the annual amount of waste to be disposed of in the landfill has decreased between 1994 and 2004 from 42,990 to 6083tonn (expressed as wet weight). The paper also gives an overview of the relevant European Union legislation on the forest industry and on waste management, as well as of the pulping process and of the generation of major solid wastes in the pulp and paper mills. [Copyright &y& Elsevier]

This paper presents the results on a study to use paper mill sludge for particleboard production. Single-layer board and three-layer board, with paper sludge on the surface, were fabricated. Four levels of mixing ratios of paper sludge to wood particles (0:100, 15:85, 30:70, and 45:55) were used. The boards were produced with 3% and 4% methylene diphenyl diisocyanate (MDI), and 10% and 12% urea-formaldehyde (UF) adhesives. The bending and shear strengths, water absorption, and thickness swelling of the boards were investigated. The results indicated that the mechanical properties of the boards were negatively affected by the paper sludge amount. Overall, UF-bonded particleboards gave superior mechanical performance, water resistance, and thickness swell than MDI-bonded particleboards. The strengths of the UF-bonded board decreased much more than those of MDI-bonded board as paper sludge content increased. The three-layer boards made from 15% paper sludge with 12% UF satisfied fully the minimum requirements set by EN, ASTM D 1037-99, and ANSI A208.1 standards for general uses. [Copyright &y& Elsevier]

Disposable Paper cups are a threat to the environment and are composed of 90% high strength paper with 5% thin coating of polyethylene. This polyethylene prevents the paper cup from undergoing degradation in the soil. Hence, in the present study two different approaches towards the management of paper cup waste through vermicomposting technology has been presented. The experimental setup includes 2 plastic reactors namely Vermicompost (VC) (Cow dung + Paper cup waste + Earthworm ( Eudrillus eugeinea )) and Vermicompost with bacterial consortium (VCB) (Cow dung + Paper cup waste +  Eudrillus eugeinea  + Microbial consortia such as Bacillus anthracis, B. endophyticus, B. funiculus , B. thuringiensis , B. cereus , B. toyonensis , Virigibacillius chiquenigi , Acinetobacter baumanni and Lactobacillus pantheries ). After treatment the physicochemical parameters were analysed. The results showed that the values of TOC (26.52 and 37.47%), TOM (36.01 and 33.13%) and C/N (15.02 and 11.92%) ratio are reduced in both VC and VCB whereas, the values of pH (8.01 and 7.56), EC (1.2–1.9 µs −1 and 1.4–1.9 µs −1 ), TP (46.1 and 51%), TMg (50.52 and 64.3%), TCa (50 and 64%), TNa (1.39 and 1.75%) and TK (1.75 and 1.86%) have increased. This study substantiates the addition of the microbial consortia augmenting the degradation in VCB reactor by reducing the period of process from 19 to 12 weeks. Further the characterisation of the vermicompost prepared from paper cup with FT-IR shows high degradation of carboxylic and aliphatic group; SEM analysis shows the disaggregation of cellulose and lignin; XRD shows the degradation of cellulose. All these analyses endorse the degradation of the paper cup waste faster with microbes (VCB). Thus, this present study high lights management of the paper cup waste in a relatively short period of time. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Municipal solid waste paper was used as raw material for cellulose nanofibres (CNFs). • Pulping, washing and flotation were used as pre-treatments before nanofibrillation. • Despite different amounts of impurities in waste fibres, CNFs were obtained. • Properties of waste CNFs were affected by the used pre-treatment. Abstract When aiming for higher resource efficiency, greater utilization of waste streams is needed. In this work, waste paper separated from mixed municipal solid waste (MSW) was studied as a potential starting material for the production of cellulose nanofibres (CNFs). The waste paper was treated using three different techniques, namely pulping, flotation and washing, after which it was subjected to an ultrafine grinding process to produce CNFs. The energy consumption of the nanofibrillation and nanofibre morphology, as well as properties of the prepared nanofibers, were analysed. Despite the varying amounts of impurities in the waste fibres, all samples could be fibrillated into nanoscale fibres. The tensile strengths of the CNF networks ranged from 70 to 100 MPa, while the stiffness was ∼7 GPa; thus, their mechanical strength can be adequate for applications in which high purity is not required. The contact angles of the CNF networks varied depending on the used treatment method: the flotation-treated networks were more hydrophilic (contact angle 52.5°) and the washed networks were more hydrophobic (contact angle 72.6°). [ABSTRACT FROM AUTHOR]

Because paper sludge discharged from the waste paper recycling process contains high levels of lignin and ash, it is not hydrolyzed effectively during anaerobic digestion. In this study, we investigated the effects of pretreatment with rumen fluid on paper sludge and on the methane fermentation process. Paper sludge was pretreated with rumen fluid at 37 °C for 6 h. Following pretreatment, 4.5% of the total solids in paper sludge were degraded and converted, and the dissolved chemical oxygen demand and volatile fatty acid concentration increased. Batch methane fermentation was conducted at 37 °C for 20 days. During methane fermentation, the degradation and hydrolysis of paper sludge were enhanced by pretreatment with rumen fluid. The amounts of total methane production from pretreated paper sludge (excluding methane generated from rumen fluid), rumen fluid and untreated paper sludge were 650.4, 819.9 and 190.8 ml, respectively. The volume of methane gas produced from pretreated paper sludge was 3.4 times larger than that from untreated paper sludge. These results indicate that pretreatment with rumen fluid enhances methane production from paper sludge. [ABSTRACT FROM AUTHOR]

Co-firing of coal and paper mill sludge was conducted in a 103 MWth circulating fluidized bed boiler to investigate the effect of the sludge feeding rate on emissions of SOx, NOx, and CO. The preliminary results show that emissions of SOx and NOx decrease with increasing sludge feeding rate, but CO shows the reverse tendency due to the decrease in combustion temperature caused by a large amount of moisture in the sludge. All emissions met the local environmental requirements. The combustion ashes could be recycled as feed materials in the cement manufacturing process. [Copyright &y& Elsevier]

Graphical abstract Leaching of boiler fly ashes from Kraft pulping process: effect of pH and concentration on sulfate recovery efficiency. Highlights • The effects of operating conditions on ash leaching were evaluated. • Sodium sulfate recovery is dependent on ash concentration, T and pH. • The optimal conditions are attained at 50 wt% of ash, 60 °C and pH 9.0. Abstract The non-process-elements (NPE's) in the pulp and paper production, in particular chloride (Cl−) and potassium (K+), eventually accumulate in a sodium sulfate recovery cycle of a paper plant, especially on boiler fly ashes (flue gas cleaning). This accumulation often leads to fouling and corrosion. Thus, in order to reduce such problems, a leaching unit is typically integrated aiming to remove Cl− and K+ and recover sodium sulfate (Na 2 SO 4) from boiler fly ashes. In this context, this research is focused on investigating the effects of temperature, ash concentration and pH on the separation efficiency (Cl− and K+ removal and Na 2 SO 4 recovery) of recovery boiler fly ashes using design of experiments in a devised laboratory setup. As expected from the literature, the results obtained reveals that concentration has the most significant effect on the response variables followed by temperature; whereas pH, not mentioned in this application so far, also has a significant effect. The optimum operating condition, which yields 84 wt% of Na 2 SO 4 recovery and 97 wt% of Cl− and K+ removal, is achieved at 60 °C, 50 wt% of ash and pH 9.0. For practical applications, this optimal condition reduces the accumulation of NPE's and mitigates the risks of fouling and corrosion. [ABSTRACT FROM AUTHOR]

Highlights • First report on cellulase production by Bacillus velezensis using waste paper. • Pretreatment increased the cellulose content without any inhibitors formation. • Central composite design increased the cellulase production by three fold. • Cost-effective approach of waste management is achieved. Abstract This paper reports the cellulase (FPase) production by newly isolated Bacillus velezensis ASN1 using waste office paper (WOP) as feedstock and optimization of production conditions through two level factorial design, steepest ascent/descent and second order response surface methodology (RSM). Various fermentation parameters, like chemical factors (potassium dihydrogen phosphate, potassium chloride, yeast extract, magnesium sulphate, sodium nitrate, Tween 80, and waste office paper), physical factors (temperature, pH and time) and biological factor (inoculum size) were examined using two level full factorial design to check the key factors significantly affecting the cellulase production. The central composite design (CCD) was used to optimize the vital fermentation parameters, such as carbon (WOP), nitrogen, pH, and inoculum concentration in the medium for achieving higher cellulase production. The optimum medium composition was found to be WOP (9 g/L), sodium nitrate (0.35 g/L), inoculum size (6.56%) and pH 4.72. The model prediction of 2.46 U/mL cellulase activity at optimum conditions was verified experimentally as 2.42 U/mL. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is an industrial chemical produced in large volumes. Its main use is associated with polycarbonate plastic, epoxy resins and thermal paper. In contrast to other applications, thermal paper contains BPA in its un-reacted form as an additive, which is subjected to migration. Receiving a significant amount of attention from the scientific community and beyond, due to its controversial endocrine-disrupting effects, the industry is attempting to substitute BPA in variety of applications. Alternative phenolic compounds have been proposed for use in thermal paper; however, information to what extent BPA alternatives have been used in paper is sparse. The aim of the present work was to quantify BPA and its alternatives (bisphenol S (BPS), bisphenol E (BPE), bisphenol B (BPB), 4-cumylphenol (HPP) and bisphenol F (BPF)) in waste paper and board from Danish households, thermal paper receipts, non-carbon copy paper and conventional printer paper. BPA was found in all waste paper samples analysed, while BPS was identified in 73% of them. Only BPB was not identified in any of the samples. BPA and BPS were found in the majority of the receipts, which contained no measurable concentrations of the remaining alternatives. Although receipts showed the highest concentrations of BPA and BPS, office paper, flyers and corrugated boxes, together with receipts, represented the major flux of the two compounds in waste paper streams. [ABSTRACT FROM AUTHOR]