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The pulp and paperboard industries are the major industrial sector that consumes significant amounts of fresh water and generates large volumes of wastewater. The treatment of this wastewater resulted in the production of a substantial amount of sludge, which posed serious environmental challenges. This study explored a sustainable solution by converting PBS into biochar through slow pyrolysis of temperatures up to ≤ 500 °C, offering an alternative approach to waste management and resource conservation. The physicochemical parameters of paper board sludge biochar (PBSB) exhibited a neutral pH of 7.49, electrical conductivity of 0.09 dS m -1 , organic carbon of 38.12% and CaCO 3 of 24.5%. Proximate analysis of PBSB revealed an increased fixed carbon of 76.43%, total organic carbon (TOC) of 7.13%, and reduced volatile matter and moisture levels. The TGA analysis of the dried paperboard sludge sample showed a 20% mass reduction when heated to 350 °C. During this process, more than 90% of the volatile components were removed.. The micro nutrients viz., Fe 5.06 mg L -1 , Mn 419.3 mg L -1 , Cu 26.3 mg L -1 , and Zn 66.1 mg L -1 contents were observed in PBSB. FT-IR analysis identified the presence of various carbon-containing functional groups, including C-Cl, C-N, C-C, H-C = O, C-H, and -C≡C-H, indicating substantial chemical transformations during pyrolysis. SEM-EDX analysis revealed that PBSB has fine particle size and a coarse fluffy spongy porous structure ideal for water adsorption. Elemental analysis (XRD) showed high carbon and oxygen content with significant amounts of aluminosilicates, carbonates, and nutrients like phosphorus and potassium, suggesting PBSB as a potential slow-release fertilizer. This research highlights the potential of biochar derived from paperboard waste as a sustainable solution for waste management and resource recovery., Competing Interests: Declarations. Ethics approval: This research is entirely original, with no content copied from other sources. All ideas and work from others have been properly cited. The results are reported honestly, without any fabrication or manipulation of data. Additionally, the study’s limitations are transparently explained. Only individuals who have made significant contributions to the research are listed as authors, and all authors have reviewed and approved the final version of the manuscript before submission. Conflict of interest: The authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Imported waste paper and recycled pulp may contain pollutants, posing potential environmental risks to the ecosystem of China. This study examined the presence and distribution patterns of heavy metals, phthalate esters (PAEs), and adsorbable organic halogens (AOX) in recycled pulp and production wastewater after various recycling processes of three typical restricted types of imported waste paper. The results indicated that the concentration ranges of heavy metals, PAEs, and AOX in the three types of imported recycled waste paper were 21.61-40.38 mg/kg, 15.35-27.88 mg/kg, and 19.21-57.72 mg/kg, respectively. The comparative analysis with the initial waste paper demonstrated a reduction in heavy metal content in the recycled pulp by 17.80-49.75%, PAEs by 65.42-90.55%, and AOX by 32.80-42.34%. The average concentrations of these pollutants in wastewater were 0.85-1.66 mg/L, 27.28-59.86 mg/L, and 1.15-3.34 mg/L, respectively. Chromium and lead were identified as the primary heavy metals present in the waste paper. Following pulping, No. 1 and No. 2 met the arsenic and lead levels specified in the "Reuse Fiber Pulp" standard (GB/T24320-2021), whereas No. 3 met these criteria after de-inking only. The main PAEs detected in the waste paper were dibutyl phthalate and di(2-ethylhexyl) phthalate, most of which were removed during the pulping stage. Significantly higher levels of AOX were observed in No. 2 and No. 3 than in No. 1, with a minimal impact on AOX removal from the pulp during the recycling process., Competing Interests: Declarations. Ethics approval: Not applicable. Consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this study, the phytoremediation potential of Taro (Colocasia esculenta L. Schott) plant was examined, utilizing horizontal subsurface flow constructed wetlands with and without an electric current supply for the purpose of removing pollutants from paper mill effluent. For this, different wetlands were set up with varying concentrations of effluent: CW (Control), CW1 (25%), CW2 (50%), CW3 (75%), CW4 (100%). After 45 days, the highest plant height (85.13 ± 4.24 cm), leaf area index( 250.83 ± 10.14), fresh biomass (565.30 ± 6 .10 g), root biomass (392.85 ± 4.34 g), root-to-shoot ratio (2.41 ± 2.10), relative growth rate (0.044 ± 0.002 gg -1 d -1 ), and chlorophyll content (3.29 ± 0.07 mg/g fwt) was observed in CW2 with current supply, along with significant removal of pollutants (pH: 7.13 ± 0.15, EC: 2.33 ± 0.07 dS/m, TDS: 192.52 ± 6.12 mg/L, COD: 490.17 ± 5.01 mg/L, BOD: 206.74 ± 5.92 mg/L, potassium: 73.27 ± 4.11 mg/L, sodium: 46.62 ± 2.27 mg/L, phosphate phosphorus: 34.08 ± 1.43 mg/L, and nitrate nitrogen: 104.85 ± 5.94 mg/L) and highest first-order rate constant (k) values. Furthermore, the microbial community assessment of constructed wetlands using V3-V4 16S rRNA sequence data was prepared on the Illumina MiSeq framework. The major phyla identified were Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Chloroflexi, Acidobacteria, Nitrospirae, Planctomycetes, and others. The findings offer innovative insights for sustainable wastewater treatment strategies through phytoremediation of paper mill effluent using Taro plants in modified constructed wetlands and highlight the role of diverse microbial communities capable of degrading various pollutants in wastewater., Competing Interests: Declarations. Competing interest: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

A synergistic photocatalytic system based on Fe-based perovskite with persulfate was constructed for alkali lignin (AL) degradation in pulp and paper wastewater. The degradation performance and mechanism on AL were carried out under ambient temperature and pressure, accompanied by visible light irradiation. The results showed that the synergistic photocatalytic system exhibited much better performance on AL degradation than the single catalytic system. The degradation efficiency reached 73.5% under the optimal conditions and was constant at around 65% over the pH range from 2 to 8. A significant escalation of the AL degradation was observed at pH 10, reaching 80.1%. The photogenerated holes, 1 O 2 and SO 4 - ·, generated by the system were involved in the degradation, and the holes played a dominant role. During the degradation process, the efficient promotion of cleavage events in lignin methoxy, β-O-4 bond, and benzene ring was observed. Consequently, the depolymerization process led to the generation of high-value compounds, namely p-hydroxybenzaldehyde and vanillin. Remarkably, the yields of the high-value compounds in the synergistic photocatalytic system were five times larger than those in the control. This study offered a viable method to activate persulfate for alkali lignin degradation and to achieve a mutually beneficial strategy for wastewater treatment and recycling., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Neonicotinoid insecticides are used against agricultural, forest, and urban insect pests. Evaluation of dry neonicotinoid residues on treated filter paper is a commonly used method to determine the toxicity of active ingredients towards target and non-target organisms. Dry residues of four neonicotinoids, acetamiprid, dinotefuran, imidacloprid, and thiamethoxam, on filter paper did not cause significant levels of mortality in Hippodamia convergens (Guérin-Méneville) (Coleoptera: Coccinellidae) and Nezara viridula (L.) (Hemiptera: Pentatomidae) when compared to paired untreated groups. Conversely, nearly 100% mortality was observed when test insects were exposed to dry neonicotinoid residues on leaf discs and glass plate surfaces. On the other hand, dry residues of the pyrethroid bifenthrin on filter paper, leaf disks, and glass plates killed significantly more test insects when compared to untreated groups. Additional bioassays tested the toxicity of acetamiprid and thiamethoxam by evaluating the toxicity of dry residues on (1) the upper and (2) lower surfaces of treated filter paper, (3) on a glass plate underneath treated filter paper, (4) on the upper surface of treated filter paper treated with insecticide and adjuvant, and (5) dried residues on a glass plate after dipping treated filter paper in water and letting the solvent dry on the inert test surface. The results indicated that neonicotinoid insecticides applied to filter paper were adsorbed. Toxic compounds possibly move in between and binding to paper fibers so that no toxic residues were left on treated surfaces. However, adsorbed insecticides were still biologically active when washed out of filter paper and dried on an inert glass surface. The results reported here clearly demonstrate that the toxicity of neonicotinoid insecticides should not be evaluated using filter paper as a test surface., (© 2024. Sociedade Entomológica do Brasil.)

Green liquor dregs (GLD) is an alkaline by-product from the pulp and paper industry with a pH between 10 and 14. Today most of the produced GLD in Sweden is landfilled. As a fine-grained alkaline material, it might be possible to use it for acid-generating mining waste remediation. To increase the utilization, quality characteristics and environmental performance need to be determined. In this study samples were collected 5 times from 16 mills during a period of 2.5 years, and were characterized by analyzing dry matter content, loss on ignition (LOI) 550 °C and LOI 950 °C, elemental analysis, pH, electrical conductivity, and calorific value. The results were then evaluated using multivariate statistics (PCA) as well as being compared to other studies and Swedish till. The results show that even if GLD is heterogenous (both within a mill and between different mills) trends can be seen for samples from most mills. When samples do stand out, it is predominately related to the same four mills. Most of the studied parameters showed characteristics favorable for use as a remediant; however, TOC, sulfur, and some of the elements require further study. In general, this study concludes that GLD can be a viable option for the remediation of small orphaned sulfidic mining sites and thus worthy of further studies on the interaction between GLD and acidic mining waste.Overall, GLD can be a good alternative for cost-effective remediation of smaller orphaned mining sites. It is readily available in large quantities, has the qualities needed for remediation of many orphaned acidic mining sites, and can often be locally sourced near the mining site. The use of GLD for mining site remediation is likely also a more sustainable method compared to traditional remediation methods., (© 2024. The Author(s).)

Paper mill sludge (PMS) is featured with a high content of cellulose and hemicellulose, and using its characteristics to make paperboard can achieve a high-value utilization of PMS, which has attracted growing interest. In this study, currently prevalent landfill, incineration technologies (generating heat and electricity by incineration), and three paperboard technologies (medium density fiberboard, pulp board, and corrugated paper) were evaluated and compared via life cycle assessment (LCA) and life cycle costing (LCC) methods. LCA results show that the PMS-to-pulp board outperforms others with an energy conservation and emission reduction (ECER) value of - 2.86 × 10 -8 , while the landfill exhibits the highest overall environmental impact with an ECER value of 4.80 × 10 -9 . LCC results reveal that the PMS-to-pulp board delivers the highest economic profit with $257.357, while the landfill is the lowest with $ - 35.63. The PMS paperboard technologies are more economically friendly than the incineration technologies due to additional electricity/steam consumption during the PMS pre-drying process in incineration. In addition, different scenarios were set up to explore national GHG emission reduction potential by increasing paperboard technologies application rate and reducing the proportion of landfill and incineration. The scenario analysis suggests that replacing 90% of landfill and incineration ratio with PMS paperboard technologies could tremendously improve the overall emission reduction performance with - 9.08 × 10 10 kg CO 2 eq. This result indicates that the PMS treatment technology transformation has a significant favorable impact on the achievement of the "carbon neutrality" target., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

To overcome the human and animal survivability risk, sustainable development is the only option on earth that can be achieved through the maximum use of renewable environmental resources. Recycling of waste paper is an emerging waste management approach to conserve natural resources. Herein, we studied enzyme-mediated process to recycle the xerographic paper by using the crude fungal extract from indigenously isolated fungi identified as Aspergillus assiutensis. The fungal enzyme cocktail has been characterized for the production of multiple enzymes namely cellulase, amylase, xylanase, pectinase, and protease. All these enzymes have pH optima in the acidic range and except cellulase and all the enzymes are stable from 10 to 80 C. In the zymogram analysis, pectinase, xylanase, amylase, and cellulase were detected at 68 kDa, ~ 54 kDa, 38 kDa, and 30 kDa, respectively. Also, the presence of protease was confirmed by the clear zone at 68, 31, and 16 kDa. A 26% decrease in the kappa number and reduction in Hex A of the pulp was observed on the treatment of the pulp with enzyme as compared to the control pulp without any treatment. The physical and chemical properties of the pulp were also improved by enzyme-mediated pulping as compared to the control The physiochemical parameter of the effluent like TDS was reduced (397 ppm) significantly in comparison to chemical deinking process and it was within the permissible limit. BOD and alkalinity were reduced when the enzymes and chemical dosage were used in combination. These results indicate that chemi-enzymatic deinking is most promising to reduce or remove the pollution parameters including ink and this approach can be used in the paper and pulp industry for sustainable development., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

To ensure the safety of food contact materials, a liquid chromatography method was established to determine the migration of formaldehyde in paper packaging with various food simulants (10%, 25%, 50%, 75%, and 95% ethanol by volume) and to investigate the migration behavior of formaldehyde after various durations and with various materials. The results showed that the method has good linearity with a correlation coefficient of R 2  > 0.9990, a detection limit of 0.0011 ~ 0.0027 mg L -1 , and a spiked recovery of 89.7 ~ 103.2% in the range of formaldehyde determination; the migration of formaldehyde in all six paper contact materials showed a trend of gradual increase with time until equilibrium was reached. At the same time and temperature, the migration of formaldehyde in paper packaging was the highest in low-concentration ethanol. With the same food simulants and materials, the maximum migration of formaldehyde in printed materials was greater than that in nonprinted materials; with different materials and the same food simulant, the thickness value was higher, with the use of water-based ink as a printing material, and the maximum migration value of formaldehyde by offset printing technology was low., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Globally, per- and polyfluoroalkyl substances (PFAS)-related research on paper products has focused on food packaging with less consideration on the presence of PFAS at different stages of the paper recycling chain. This study analysed the prevalence of PFAS in paper grades used for the manufacture of recycled paperboard. The presence of PFAS was attributed to the use of PFAS-containing additives, consumer usage, exposure to packed goods as well as contamination during mingling, sorting, collection, and recovery of paper recycling material. Q Orbitrap mass spectrometry was used to analyse the paper samples after accelerated solvent extraction and solid phase extraction. The distribution and possible propagation of 22 PFAS were determined in pre-consumer, retail and post-consumer paper products. Post-consumer samples had the highest combined average concentration (ΣPFAS) at 213 ng/g, while the ΣPFAS in retail (159 ng/g) and pre-consumer samples (121 ng/g) was detected at lower concentrations. This study showed that waste collection and recycling protocols may influence PFAS propagation and that measures must be developed to minimise and possibly eliminate exposure opportunities., (© 2024. The Author(s).)

Spilled plant-based oils behave very differently in comparison to petroleum oils and require different clean-up measures. They do not evaporate, disperse, dissolve, or emulsify to a significant degree but can polymerize and form an impermeable cap on sediment, smothering benthic media and resulting in an immediate impact on the wildlife community. The current study explored the application of rapid up-to-date direct analysis in real time (DART) with high-resolution mass spectrometry for plant-based oil typing. The study introduced a new concept of using hydrophobic paper to collect and analyze oil samples, thus minimizing sample preparation and expenses. Application of this technique showed its ability to speedily distinguish plant-based from petroleum-based oils. A microcosm experiment exposing plant-based oil samples to weathering processes for comparison with petroleum-based oils demonstrated the ability of the method to classify weathered oil samples and identify their source oil. It was observed that canola and peanut oil were the most resistant to weathering processes. The developed DART-TOFMS method was shown to be accurate for short-term weathered oil spills up to between 12 and 26 days of exposure. The developed method performed identification in less than a day compared to the established multi-day method for oil spill forensics requiring careful sample collection in glass containers, time-consuming laboratory clean-up, lengthy gas chromatography sequences, and careful integration including integration of retention time markers., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. Crown.)

Abstract There is a high demand of paper-based flexible thermoelectric generators due to their ability to operate at room temperature within a limited temperature range. Oxides and graphite are very promising materials for different applications due to their unique structural properties and wide range of tunable properties. Here, we demonstrated the solid-state based synthesis and thermoelectric behavior of a Na1.4Co2O4 and graphite that was traced on ordinary paper. We measured its electrical and thermoelectric properties, suggesting a suitable candidateship of these materials to be utilized to design thermoelectric device. The device was fabricated with four alternate pair of Na1.4Co2O4 and graphite traces, yielding of an output voltage of 31 mV at temperature gradient of 85 K. However, at present the stability of the device was not up to the mark due to presence of Na in CoO2 matrix, the protocol of demonstrating a very simple, easy, and fast technique to develop a flexible device on paper and measurement of its performance was successfully achieved.

Abstract Renewable materials and material circularity are key priorities for the coming decades. While paper is the most utilized material in the packaging sector, its applications in food packaging are limited due to low barrier properties. Coating it with petroleum-based polymer barrier coatings renders it unrecyclable both mechanically and biologically. Bio-coated paper packaging, made from agricultural waste or by-products, presents environmentally favorable solutions that can benefit the biological cycle of the circular economy. The main objective of this study is to assess the applicability of grain and beer production by-products in wood pulp food packaging materials. It examines the effects of different grain by-products (industrial wheat grain processing residues and wheat bran) particles and concentrations (15 wt% and 40 wt%), as well as the impact of brewer’s yeast (Saccharomyces cerevisiae) at a concentration of 10 wt%, on the physical–mechanical and barrier properties of Northern bleached softwood kraft (NBSK) and chemithermomechanical (CTMP) pulps. Material composites were fabricated using a standard sheet forming method. Physical–mechanical properties were analyzed through tensile strength, strain at break, tear resistance, and bending stiffness tests. Barrier-related properties were analyzed through roughness, air permeance, and water contact angle tests. Results revealed that the vast majority of physical–mechanical properties decreased with the increase of both types of grain production fillers. Industrial wheat grain processing residues had a lower impact on physical–mechanical properties than wheat bran filler. A higher percentage of property decrease was absorbed in NBSK pulp than in CTMP. Roughness of CTMP can be improved by adding both industrial wheat grain processing residues and wheat bran. Wheat bran particles can increase hydrophobicity. CTMP pulp strength properties can be increased with the addition of yeast; however, the yeast additive’s effect on air permeance demonstrated a negative impact. In the case of NBSK pulp, which has higher primary strength properties, the addition of yeast does not make any significant changes. The conducted experiments demonstrated that, overall, the addition of these fillers resulted in a decline in physical–mechanical properties such as tensile strength, strain at break, tear resistance, and bending stiffness. This decline was more pronounced with higher concentrations of fillers. In the case of CTMP pulp, both types of fillers exhibited similar trends in affecting properties, whereas for NBSK pulp, wheat bran had a more significant impact compared to wheat grain processing residues. The addition of yeast generally led to a reduction in physical–mechanical properties, particularly in tensile strength and tear resistance. However, samples containing yeast displayed increased flexibility compared to controls. The influence on barrier properties varied: while yeast increased air permeability, it also enhanced surface hydrophobicity, thereby reducing the paper’s receptivity to liquids.

Abstract A number of two-dimensional (2D) materials have been explored for various applications, from electronic transistors to energy generation and storage. In this work, we explored the possibility of using reduced graphene oxide (rGO) in emerging two terminal memory devices using a printing technique. The fabricated memory devices were analysed using scanning electron microscopy, Raman spectroscopy, optical microscopy, and in-depth electrical measurements. We experimentally demonstrated that rGO memory devices fabricated via inkjet printing exhibit bipolar switching without the required electroforming step, with an on/off ratio of 3 orders of magnitude. The inkjet-printed approach allows for the layering of memory devices on each other, leading to an increase in information storage density.