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This paper investigates the influence of thermal pretreatment on kinetic parameters based on four kinetic models: Modified Gompertz, transference and logistic functions and first order equation. The kinetic modeling was applied on experimental results of previous study on producing methane from anaerobic digestion of Recycled Pulp and Paper Sludge (RPPS) under mesophilic conditions. We observed that the thermal pretreatment improve considerably improved the kinetic parameters mainly the methane production rate and the lag phase. Indeed, it can be noted that methane production rate μ increases significantly from a value of 4.72 to 16.27 Nml/h using logistic function for 1 g VS/L added load. Then the lag phase parameter λ has dramatically decreased from 5.46 to 1.04 h using logistic function for 1,5g VS/L added load. This means that the thermal pretreatment of RPPS accelerates the methane production process and saves time.

Alstonia boonei, an abundant lesser utilized species within the West African Subregion, was evaluated as an alternative raw material for pulp and paper production. The basic density (BD), fibre characteristics [fibre length (FL), fibre diameter (FD), lumen diameter (LD) and wall thickness (WT)], derived anatomical indices [Flexibility Ratio (FR), Slenderness Ratio (SR), Rigidity Coefficient (RC), Luce’s Shape Factor (LSF), Solids Factor (SF) and Runkel Ratio (RR)] and chemical composition (lignin, holocellulose, 1% NaOH solubility and ash contents) of A. boonei were studied to evaluate variation along the trunk (base, middle and top portions) and ascertain its suitability for pulp and paper production. Significant variations were observed in the density and fibre characteristics along the trunk of the tree. Although the FD was large, the observed adequate FL, thin-wall and large LD implied easy beating of fibres and manufacture of dense, smooth and strong papers. The favourable SF, RR, FR, RC, and LSF values obtained for the fibres would produce papers with suitable burst and tearing strengths and folding endurance. Chemically the lower lignin (< 30%), ash and 1% NaOH solubility and the high holocellulose contents of A. boonei, will generate a higher pulp yield. A. boonei although a low-density species, will be desirable for pulp and paper production.

We present how harmful different wood extractives carried over to paper mill with unbleached softwood Kraft pulp are for the strength of packaging papers and boards. The investigations were done by simulating industrial papermaking conditions in laboratory-scale trials for handsheet production. It was found that fatty acids are the most relevant compounds in the carryover pitch extractives (CPEs), as they readily interfere in fiber–fiber bonding strength, control the properties of CPE micelles, and are furthermore the most abundant compounds. Addition of cationic starch improved strength and evened out the strength differences of handsheets with different CPE compounds. Oleic acid (unsaturated fatty acid) was an exception, as it was above average harmful for paper strength without cationic starch and also heavily impaired the functioning of cationic starch. As a whole, these findings demonstrate that fatty acids, especially unsaturated ones, are the most relevant CPE compounds contributing to the reduced efficiency of cationic starch and decreased strength of unbleached softwood Kraft paper. This makes the cleaning of process waters by precipitating CPEs on the pulp fibers harmful for paper strength.

Scaling biosynthesis of bacterial nanocellulose (BNC) allowed samples of composite paper with an increased proportion of BNC to be obtained. This work aims to study BNC samples and bleached soft wood kraft pulp (BSKP) composite paper with a ratio of components varying across a wide range: 10:90, 30:70, 50:50, 60:40, 70:30, 90:10. The method of paper manufacturing was chosen based on the determinations of strength and deformation properties of composite samples with the BNC:BSKP ratio of 20:80. Surface application of BNT on BSKP handsheet provided for an increase in the strength values (tear resistance – by 37%, burst index – by 17%) and deformation characteristics (tension stiffness – by 66%, fracture work – by 8%, breaking length – by 4%) compared to a reference sample. The formation of composites is confirmed in all samples. Scanning electron spectroscopy revealed that paper composites comprise interlaced micro BSKP and nano BNC fibres. As the proportion of BNC in composites elevated, densification of the structure was observed due to an increased fraction of cross-linked nanosized elements. IR spectroscopy indicated the resemblance of cellulose structure in all samples. It was found that an increase in the degree of polymerisation of composite paper is directly proportional to an increase in the BNC amount in the samples. The filtering ability of composite paper samples against microorganisms in the culture liquid of the Medusomyces gisevii Sa-12 producer was studied. It should be noted that yeast retention is achieved with 70% BNC in the paper composite. The presented properties of the new material determine prospects for its use in filtering microorganisms.

Biodegradable paper cups coated with rice bran wax and whey protein isolate were designed to package popcorn. Coatings with different concentrations of whey protein isolate (5.5, 7.75, and 10% w/v) and rice bran wax (0.2, 0.4, and 0.6% w/v) were applied on the outer surface of the paper cups. Thickness, color changes, Young's modulus and tensile strength, water vapor transmission rate (WVTR) of the coated and uncoated cups, and also popcorns properties (pH, texture, and sensory properties) were evaluated. Water vapor transmission rate, Young's modulus, thickness, total color change index, and tensile strength of coated cups with the optimal coating formulation was 19.785 (g/m2 day), 11.810 (MPa), 276.583 (µm), 1.839, and 11.222 (MPa), respectively. The results showed that paper cup coating increased thickness and yellowness and reduced the brightness, Young's modulus, and WVTR. Coating had a positive effect on the pH and texture of popcorns packaged in coated cups than samples packed in uncoated cups (p, Biodegradable packaging is one of the best types of packaging that wishes not to harm the environment. Paper packaging coated with materials, such as rice bran wax and whey protein isolate, both of which are food waste, can improve paper color and resistance, and provide a good moisture barrier. This type of coating can be used in paper packaging of food such as snacks, noodle packaging, semi‐prepared foods, etc. This type of packaging can also maintain the physicochemical and sensory properties of food for a long time. Also, due to the edible nature of this type of coating, this coating can be used inside the package so that the printability of the packaging surface is not affected.

The aim of this study was to investigate the effect of using whey powder (different concentrations and treatment repetitions) as a probiotic agent on the quantitative and qualitative properties of stored bagasse intended for use in the pulp and paper industry. For this purpose, whey powder was added in three concentrations and the treatment was applied once or twice. After that, soda pulp was prepared under conventional conditions. Then, handsheets (80 g/m2) were made and tested in terms of paper properties, and the results were compared. The findings revealed that increasing the concentration of whey powder and the number of treatments significantly improved the pulp and paper characteristics, thus, using the treatment with 2% whey powder twice and 0.4% whey powder once led to the best results for bagasse protection in terms of quality of the raw material, pulp and handsheets.

Paper manufacturing on a global scale is a highly competitive market which requires to constantly improve the manufacturing process to be competitive. To decrease production cost paper manufactures, add filler material prior to sheet forming to replace costly wood fiber based raw material. This research project investigates the use of in-situ precipitated calcium carbonate produced in the presence of eucalyptus fiber material at a 41.0% filler level prior to beating. The in-situ filler containing eucalyptus fiber suspension was used on a 12’ (304mm) wide Laboratory Fourdrinier Paper Machine together with non-filler containing eucalyptus fiber material, and a commercial precipitated calcium carbonate filler material. The manufactured in-situ fiber suspension resulted in a higher ash retention compared to the addition of the powdered commercial PCC filler material. In addition to commercial filler material retention is improved at higher filler addition above 30%. The increased ash retention is linked to the increased micro fibrillation fiber material of the in-situ filler-fiber suspension forming neckless like particles on the fibers microfibrils. Mechanical paper properties showed an improvement for in-situ precipitated filler material compared to commercial filler material addition. Optical properties could be improved in comparison to the eucalyptus fiber without filler addition for in-situ precipitated filler material and a combination of in-situ and commercial filler material.

Transition towards carbon neutrality will require application of negative carbon emission technologies (NETs). This creates a new opportunity for the industry in the near future. The pulp and paper industry already utilizes vast amounts of biomass and produces large amounts of biogenic carbon dioxide. The industry is well poised for the use of bioenergy with carbon capture and storage (BECCS), which is considered as one of the key NETs. If the captured carbon dioxide can be used to manufacture green fuels to replace fossil ones, then this will generate a huge additional market where pulp and paper mills are on the front line. The objective of this study is to evaluate future trends and policies affecting the pulp and paper industry and to describe how a carbon neutral or carbon negative pulp and paper production process can be viable. Such policies include, as examples, price of carbon dioxide allowances or support for green fuel production and BECCS implementation. It is known that profitability differs depending on mill type, performance, energy efficiency, or carbon dioxide intensity. The results give fresh understanding on the potential for investing in negative emission technologies. Carbon capture or green fuel production can be economical with an emission trade system, depending on electricity price, green fuel price, negative emission credit, and a mill’s emission profile. However, feasibility does not seem to evidently correlate with the performance, technical age, or the measured efficiency of the mill.

The pulp and paper industry is highly energy-intensive. In mills that use chemical pulping, roughly half of the higher heating value of the cellulosic material used to manufacture the product typically is incinerated to generate steam and electricity that is needed to run the processes. Additional energy, much of it non-renewable, needs to be purchased. This review considers publications describing steps that pulp and paper facilities can take to operate more efficiently. Savings can be achieved, for instance, by minimizing unnecessary losses in exergy, which can be defined as the energy content relative to a standard ambient condition. Throughout the long series of unit operations comprising the conversion of wood material to sheets of paper, there are large opportunities to more closely approach a hypothetical ideal performance by following established best-practices.

The adsorption of locust bean gum (LBG) onto Northern Bleached Softwood Kraft (NBSK) pulp improved paper tensile and burst strength and lowered refining energy by strengthening inter-fibre bonding. Adsorption kinetics and isotherms were investigated to develop a fundamental understanding of the adsorption mechanism. The adsorption rate followed pseudo-second-order kinetics and the activation energy was 99.34 kJ·mol−1, suggesting chemisorption. The adsorption rate constant increased rapidly with temperature from 25 to 45 °C (k = 1.93 to 24.03 g·mg−1·min−1), but the amount adsorbed at equilibrium decreased (qe = 1.91 to 0.48 mg·g−1 o.d. fibre). LBG adsorption to NBSK at 25 °C was consistent with the Langmuir adsorption model for LBG n = 5.00, and the equilibrium constant Kf = 2.57 mg·g−1·(mg·L−1)−1/n at 25 °C. Favorable adsorption conditions for negatively charged LBG were identified: 25 °C for 10 min, low dosage level ( 150 r.p.m.), acidic or neutral conditions (pH 2–7) without salt addition. Graphic abstract

Introduction. The Shchuchiy Bay is located in the western part of the skerry area of Lake Ladoga near the town of Priozersk. For almost 20 years, the bay has experienced an anthropogenic impact from the ingress of untreated wastewater from the Priozersk Pulp and Paper Mill (PPM). Systematic microbiological studies of the Shchuchiy Bay ecosystem were started in the middle of the 1970s by the Institute of Limnology of the Russian Academy of Sciences and continued after the PPM closure in 1986. Materials and methods. The ecosystem of the bay was studied in detail during the growing season of 2013–2014; periodic studies were carried out in 2015–2018. Retrospective data were also used for the analysis. Water samples were taken at four stations from the surface horizon. The following microbiological indicators were determined: the abundance of bacterioplankton and the percentages of various morphological types of bacterial cells. Results and discussion. A comparison of the quantitative level of development of the bacterial community in the bay in different periods showed a gradual decrease in the abundance of bacterioplankton as the anthropogenic impact weakened after the closure of the Priozersky PPM from 12.40 million cells ml–1 in 1987 to an average value of 2.62±1.03 million cells ml–1 in 2013–2018. A positive correlation was found between the concentration of bacteria and water temperature. The percentage of rod-shaped microorganisms in the water of the bay also decreased as the anthropogenic impact weakened from 73.4 % in 1987 to 53.1±7.6 % in 2013–2018, which indicated an improvement in water quality. Conclusion. A stable decrease in the abundance of bacteria from the level characteristic of highly polluted and eutrophic water bodies to the level characteristic of mesotrophic and mesotrophic-eutrophic water bodies is a reliable criterion for the restoration of the ecosystem of the Shchuchiy Bay to the state characteristic of similar bays of Lake Ladoga.

Paper based lateral flow systems are widely used biosensor platforms to detect biomolecules in a liquid sample. Proteins, bacteria, oligonucleotides, and nanoparticles were investigated in the literature. In this work we designed a magnetic platform including dual magnets and tested the flow of micron size immunomagnetic particles alone and when loaded with cells on two different types of papers. The wetting conditions of the paper and the applied external magnetic field are the two dominant factors affecting the particle and cell transport in paper. The images recorded with a cell phone, or with a bright field optical microscope were analyzed to measure the flow of particles and cells. The effect of wetting conditions and magnetic force were measured, and it was shown that in the worst case 90% of the introduced cells reached to the edge of the paper. The paper based magnetophoretic lateral flow systems can be used for cell assays.

Lean manufacturing (LM) is established as a best practice to improve the performance of manufacturing industries. Not all the manufacturing industries realize the benefits of LM practices specifically continuous process industries. The present research work is intended to study the advantages of implementing LM practices in an ethical paper industry which is a continuous production industry. Presently, the industry suffers with the problems such as lack of productivity, raw material wastes, underutilized resources, and lack of standard practices in the production. Gemba technique is adapted to record the information related to the present manufacturing environment. Based on the current state analysis, the feasible lean tools are selected and implemented such as 5S, Kaizen, and Total Productive Maintenance (TPM). The improvements have been noted as reduced tool change over time, reduced material wastes, effective utilization of resources and provide safety guidelines to workers and operations. The implications of these improvements increased the productivity also.

Xylan is the primary hemicellulose in most hardwood species, especially in birch. Research has highlighted the exploitation of xylans as a strength-enhancing additive to paper due to the current trend for the effective utilization of biomass. In this paper, a new pulping process was proposed, which involved the extraction of xylan prior to pulping, followed by the re-adsorption of the pulp after the final stage in the digester, followed by a suitable bleaching process. The aim of this work was to bleach hardwood kraft pulp (brown pulp) with adsorbed birch xylan via hydrogen peroxide and study the effect of the bleaching parameters on the paper properties. The results showed that the optical properties of paper decreased; however, the mechanical properties increased after the brown pulp adsorbed birch xylan. During the bleaching process, better mechanical properties were obtained with shorter bleaching times and lower bleaching temperatures, initial pHs, and MgSO4 dosages. However, the optical properties were improved as the bleaching time, temperature, initial pH, and MgSO4 dosage were increased. The adsorption of birch xylan could effectively modify the mechanical properties of paper made from brown pulp under various phases.

The pulp and paper industry is primarily dependent on fibrous wood for pulp and paper production. However, this over-dependence on fibrous wood poses serious environmental challenges such as the diminishing of the fibrous wood stocks, deforestation, emission of greenhouse gases, and global warming. Therefore, to mitigate these environmental challenges associated with its utilization for paper and pulp production, other sustainable raw material sources can also be considered for the production of paper and pulp. There are enormous benefits associated with the utilization of non-wood fibres as an alternative and sustainable raw materials source for the production of paper and pulp. These benefits have in the recent past prompted millers in China, India, Brazil, and the USA to consider the utilization of non-wood fibres in paper and pulp production. In Kenya, the pulp and paper industry is very much dependent on fibrous wood for production and the industry is yet to fully embrace the utilization of nonwood fibres for paper and pulp production. Further, the dependence on fibrous wood has contributed significantly to the decline of paper pulp and paper production, deforestation, and rise in paper importations due to insufficient raw material supplies. The importation of paper and pulp products has further led to the collapse of the paper industry in Kenya. The sector stands a chance of revival and vibrancy through the utilization of the abundant agricultural residues and feedstocks lying in the agricultural fields across the country. Similar experiences elsewhere have proved that the abundance of agricultural waste can be utilized for the production of paper and pulp due to their excellent fibre content for specialty papers, and easy pulpability. The agricultural residues are therefore considered a quintessential alternative and sustainable source of raw materials for the pulp and paper industry. Moreover, their utilization will mitigate environmental impacts such as deforestation, climate change, and pollution .

High per- and polyfluorinated alkyl substance (PFAS) concentrations have been detected in agricultural soils in Southwest Germany. Discharges of PFAS-contaminated paper sludge and compost are suspected to be the cause of the contamination. Perfluorinated carboxylic acids (PFCAs) have been detected also in groundwater, drinking water, and plants in this area. Recently, previously unknown compounds have been identified by high-resolution mass spectrometry (HRMS). Major contaminants were polyfluorinated dialkylated phosphate esters (diPAPs) and N-ethyl perfluorooctane sulfonamide ethanol–based phosphate diester (diSAmPAP). In this study, HRMS screening for PFAS was applied to 14 soil samples from the contaminated area and 14 impregnated paper samples which were from a similar period than the contamination. The paper samples were characterized by diPAPs (from 4:2/6:2 to 12:2/12:2), fluorotelomer mercapto alkyl phosphates (FTMAPs; 6:2/6:2 to 10:2/10:2), and diSAmPAP. In soil samples, diPAPs and their transformation products (TPs) were the major contaminants, but also FTMAPs, diSAmPAP, and their TPs occurred. The distribution patterns of the carbon chain lengths of the precursor PFAS in soil samples were shown to resemble those in paper samples. This supports the hypothesis that paper sludge is a major source of contamination. The presence of major degradation products like PFCAs, FTSAs, or PFOS and their distribution of carbon chain lengths indicate the activity of biotic or abiotic degradation processes and selective leaching processes from the upper soil horizons. Graphical abstract Supplementary Information The online version contains supplementary material available at 10.1007/s00216-021-03463-9.

The fibre characteristics of five Spondia mombin stands were studied to determine their suitability for pulp and paper production. Wood slivers obtained parallel to grain at three (3) different positions along the bole were macerated in combined identical amounts of glacial acetic acid plus hydrogen peroxide under heat at between 80-100o C. Macerated fibres were washed clean of mixture and mounted on slide for microscopic examination of fibre characteristics. Completely Randomized Design (CRD) was employed for the experiment. Data were analysed using one-way Analysis of Variance (ANOVA) while, the Duncan’s Multiple Range Test (DMRT) was used to separate means of significant differences among the treatments. Results show that significant differences existed in fibre characteristic of sampled trees, however the fibre length ranged from 0.98-1.0 mm, fibre diameter (18.22-21.47 um), lumen width (10.90-12.98 um) and cell wall thickness (3.86-4.60 um). Significant differences were also observed among the derived fibre characteristics, the Runkel ratio ranged from 0.66-8.89, elasticity coefficient (57.22-60.50 %), coefficient of rigidity (19.78-22.24 %), slenderness ratio (43.27-46.5). This implied that, the fibres of S. mombin were short and elastic which make the wood species an appropriate raw material for pulp and paper making especially when blended with other long fibre species.

Cellulose based nanomaterials have the great potential to be applied to paper as bulk additive or coating material to improve overall final properties, especially in secondary fiber. In the present work, the effect of applying different kinds of cellulose nanofibrils (CNF) to papers obtained from recycled fibers using size press on physical, mechanical and barrier properties was investigated and compared with the sole use of starch as coating material. The coating process of CNF was carried out by the addition of size press grade starch to coating suspension. As a cellulose source, wheat straw was evaluated and CNF was obtained through oxidative and enzymatic pretreatments. Results indicate that starch/CNF suspension improves the overall paper properties. As a result of the deposition of coating suspension contains of 4 % wt. periodate-oxidized CNF onto paper surface, tensile and burst indices of papersheets increased as 52.2 % and 194.4 %. Significant decreases were observed in air permeability as 69.8 %. Compression tests also have been conducted to evaluate papersheets end-use properties. In comparison to the other pretreated CNF, due to is lower viscosity, applying periodate-oxidized CNF as size press significantly increased the mechanical properties of the papers fabricated from the recycled pulps. TUBITAK-TEYDEBTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [1505]; Scientific and Technological Research Council of Turkey, Technology and Innovation Funding Programs Directorate [1505, 5180044] This work was supported by TUBITAK-TEYDEB 1505 (The Scientific and Technological Research Council of Turkey, Technology and Innovation Funding Programs Directorate 1505), Project No. 5180044. WOS:000703585400013 2-s2.0-85108063350

In this study, it was aimed to investigate the chemical and morphological suitability of using pseudo-stem which are formed in large amounts during the fruit harvesting of the banana plant (Musa sapientum) with a widespread agricultural area in the world, as raw material in the paper industry. The main chemical constituents of banana pseudo-stem holocellulose, α-cellulose and lignin were determined as %77.5, %51.0 and %12.7, respectively. Hot water solubility was 17.3%, cold water solubility 13.0%, alcohol and 1% NaOH solubility values were 9.2% and 33.3%, respectively. It has been determined that banana pseudo-stem waste fibers, which are similar to softwood fibers in terms of fiber length and hardwood fibers in terms of fiber width, have high slenderness and flexibility ratios with low Runkel ratio, rigidity coefficient and Mühlstep ratio. The results obtained from chemical and morphological analyzes indicated that banana pseudo stem waste is a suitable raw material for pulp and paper production., Bu çalışmada dünyada yaygın bir tarım alanına sahip muz bitkisinin (Musa sapientum) meyve hasadı sırasında oldukça fazla miktarda oluşan gövde atıklarının, kağıt endüstrisinde hammadde olarak kullanılabilirliğinin kimyasal ve morfolojik açıdan uygunluğunun araştırılması amaçlanmıştır. Muz yalancı gövdesinin başlıca kimyasal bileşenleri holoselüloz, α-selüloz ve lignin sırasıyla %77.5, %51.0 ve %12.7 olarak tespit edilmiştir. Sıcak su çözünürlüğü %17.3, soğuk su çözünürlüğü %13.0, alkol ve %1 NaOH çözünürlük değerleri ise sırasıyla %9.2 ve %33.3 olarak bulunmuştur. Lif uzunluğu bakımından iğne yapraklı ağaç odunu liflerine, lif genişliği bakımından ise yapraklı ağaç odunu liflerine benzeyen muz yalancı gövde atığı liflerinin düşük Runkel oranı, rijitlik katsayısı ve Mühlstep oranı ile yüksek narinlik ve esneklik oranlarına sahip olduğu tespit edilmiştir. Kimyasal ve morfolojik analizlerden elde edilen sonuçlar, muz yalancı gövde atıklarının kağıt hamuru ve kağıt üretimi için uygun bir hammadde olduğunu göstermiştir.

The evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has highlighted the need for versatile diagnostic assays that can discriminate among emerging variants of the virus. Here we report the development and performance benchmarking of an inexpensive (approximately US$0.30 per test) assay for the rapid (sample-to-answer time within 30 min) colorimetric detection of SARS-CoV-2 variants. The assay, which we integrated into foldable paper strips, leverages nucleic acid strand-displacement reactions, the thermodynamic energy penalty associated with single-base-pair mismatches and the metal-ion-controlled enzymatic cleavage of urea to amplify the recognition of viral RNAs for the colorimetric readout of changes in pH via a smartphone. For 50 throat swab samples, the assay simultaneously detected the presence of SARS-CoV-2 and mutations specific to the SARS-CoV-2 variants Alpha, Beta and Gamma, with 100% concordance with real-time quantitative polymerase chain reaction and RNA sequencing. Customizable and inexpensive paper-based assays for the detection of viruses and their variants may facilitate viral surveillance.

The suitabilities of major agricultural residues were assessed as papermaking feedstocks. All the examined agricultural residues were assumed as potential candidates for substituting hardwood fibers in mixed pulp blends from a fiber morphological perspective. Wheat, barley, rice, rapeseed, maize, sunflower, sugarcane bagasse, coconut husk, and two genotypes of miscanthus grass underwent identical maceration. The fiber length, fiber width, cell wall thickness, and lumen diameter were measured to calculate the slenderness ratio, flexibility coefficient, and Runkel ratio. The average fiber length ranged from 0.50 mm ± 0.32 mm (MG-S-02-V) to 1.15 mm mm ± 0.58 mm (sugarcane bagasse). The fiber width ranged from 10.77 μm ± 3.28 μm (rice straw) to 22.99 mm ± 5.20 mm (sunflower stalk). The lumen diameter ranged from 4.52 μm ± 2.52 μm (rice straw) to 13.23 μm ± 4.87 μm (sunflower stalk). The cell wall thickness ranged from 3.02 μm ± 0.95 μm (rice straw) to 4.80 μm ± 1.48 μm (sunflower stalk). The slenderness ratio, flexibility coefficient, and Runkel ratio values ranged between 28.08 to 58.11, 37.97 to 60.8, and 0.62 to 1.68, respectively. Wheat, maize, rapeseed, sugarcane bagasse, and coconut husk were found to be appropriate residue sources for papermaking feedstocks.

In order to obtain a lignin-based adsorbent with low cost, simple operation and no further modification, a calcium lignin adsorbent was prepared from chemical mechanical pulping (CMP) waste liquor by directly calcification from lime. The calcium lignin was characterized by BET, SEM, TEM, FT-IR and solid-state NMR analyses. The results showed that the molecular structure of the calcium lignin particles did not change when compared to sodium lignin, the formation mechanism of calcium lignin was revealed. The initial COD and lignin contents of CMP waste liquid were 54858 mg/L and 24.39 g/L, the conversion rate of lignin can reach 71.36% when was deal with lime. Thus, most of the lignin resources in the waste liquid were recovered. The middle-stage wastewater (MSWW) of pulping and papermaking was dealt with calcium lignin, the COD removal rate was up to 85.83%. The adsorption isotherms and kinetics were well fitted by the Langmuir model and pseudo-second-order kinetic model, respectively. Lime was regenerated from the used calcium lignin with high-temperature calcination, the conversion rate of calcium ions can reach 83.56%. Overall, the calcium lignin prepared by the one-step method exhibited great potential for effectively removing COD from middle-stage wastewater.

The rapid economic growth and environmental concerns have led to high demands on paper and paper-based products in terms of variety, quantity, quality, and specialty. Enhancement and functionalization with additives are constantly required. Moving away from traditional petroleum-based additives, researchers have attempted to use “green” nanoadditives by introducing renewable environmentally friendly nanocellulose. This article studies the functions of nanocellulose as bio-additives (enhancer, retention and filtration reagent, and coating aid) in paper and paper products, and overviews the research development of nanocellulose-based additives and their applications in the paper industry for both efficient production and paper functionalization. The review shows that (1) a variety of nanocellulose-based bioadditives have been reported for various applications in paper and paper-based products, while commercially viable developments are to be advanced; (2) nanocellulose was mostly formulated with other polymer and particles as additives to achieve their synergistic effects; (3) major interests have concentrated on the nanocellulose in the specialty papers as representing more value added products and in the efficient utilization of recycled fibers, which remains most attractive and promising for future development. This report shall provide most useful database information for researchers and industries for paper recycling and enhancement, and paper-based products innovation and application.

The sorption properties of organomineral composite sorbents have been investigated by ICP-MS method. The diatomite of the Jradzor deposit and bentonite of the Sarigyuh deposit (Armenia) were used as inorganic constituents. Diatomite serves as a structure-forming component and provides mass transfer due to its high porosity (V = 2.0 cm3/g) and large pore sizes (150–200 nm). Bentonite is responsible for the functionality of the sorbents. The organic component is also responsible for the functionality of the obtained sorbents. Paper pretreated with acids (nitric and phosphoric) was used as an organic component. A synthetic solution containing cations of heavy metals was used as an object of study. The experiments were carried out in static mode on a Jar-Test device.

An approach of green in situ synthesis single-step method was applied to produce antibacterial paper. The objective was to investigate the effect of precursor addition on the formation of zinc oxide particles using an in situ single-step method. Zinc chloride concentrations of 0.1, 0.3, 0.5, and 0.7 M were prepared and added into a solution of algae extract and bamboo pulp. The prepared pulps were tested and made into handsheets using a papermaking machine based on TAPPI T205 (2006). Morphological observation of treated papers was conducted using a field emission scanning electron microscope (FESEM). An average of 400 to 570 nm zinc oxide spherical-shaped particle was observed on the fibers of paper. The percentage of element composition of the treated paper were 15.08% to 34.08% of zinc and 17.45% to 32.59% of oxygen captured via scanning electron microscopy with energy dispersive X-ray (SEM-EDX) analysis. The crystallinity test was performed using X-ray dispersion (XRD). A higher percentage of precursors exhibited a more amorphous structure. A measurement of more than 30% increment of inhibition zone was obtained from 10.00 to 25.00 mm against S. aureus, S. choleraesuis, and E. coli. Precursors addition of more than 0.3 M would have the most potential to enhance the growth of zinc oxide via in situ preparation, hence providing better antibacterial properties of the prepared papers.

Natural yellow plant dyes and traditional medicines were used widely on historical papers in ancient China for religious reasons and conservation considerations. This study aims to evaluate some traditional yellow botanical sources of dyes that contain different chemical colorant compositions in order to understand their effects on the properties of traditional handmade paper. The physical and chemical changes in paper specimens treated with plant dyes were studied by examining properties such as the color, pH, thermogravimetric (TG) characteristics, tensile strength, folding endurance and microstructure by scanning electron microscopy (SEM). The results indicated that different colorants had different toning effects and that the main components, including carboxyl and ketone groups, could affect the paper stability at high temperatures. The results also revealed that the mechanical properties of paper specimens were improved after treatment with plant dyes. The significant improvements in the tensile strength and folding endurance and the slightly higher decomposition temperature of Amur cork tree-dyed paper could be ascribed to the strong interaction between the colorants’ main components and the fibers. The scientific evaluation of the property changes is therefore valuable information for weighing the advantages and disadvantages of the various yellow toning materials for paper conservation treatment.

A new coating method was developed, based on cellulose regenerated from an N-methylmorpholine N-oxide (NMMO) solution applied to paper. In particular, the purpose of this study was to compare the effectiveness of the “deep coating” method using cellulose regenerated from NMMO solution and the classic pulp refining process as methods to improve paper mechanical properties and overall quality. The “deep coating” name comes from the fact that the coating process is combined with subsequent heating of the coating before its final solidification. As a result of this operation, deep penetration of the cellulosic solution into the paper structure occurs. This increases the contact surface of the solution with the cellulosic fibers, which increases the strength properties of the paper structure. It was found that the cellulosic coating increased the apparent density of the paper, the tensile strength, the elongation, the resistance to bursting, and the double fold number. However, the coating also decreased the air permeability and the tear resistance of the paper samples. Despite some technological difficulties, this method could be an attractive solution in the case of a need for additional functionalization of a paper structure.

Excellent mechanical and electrical properties of graphene-based paper-like materials are essential for applications in flexible conductors, energy-storage devices, etc. The graphene oxide (GO) supernatant separated by centrifugation and ultrasonication has been used to prepare graphene oxide paper and reduced graphene oxide paper (rGOP) with high strength and conductivity. However, this method has cumbersome steps and low supernatant concentration, which greatly increases time and energy consumption, and is not suitable for rapid batch preparation of high-strength and high-thickness rGOP. Herein, a high-speed mechanical shearing method has been used to efficiently exfoliate graphite oxide suspension into high-concentration GO slurry with large lateral size, and rGOP has been further prepared by blade coating and HI acid chemical reduction. Compared with the product prepared by ultrasonic exfoliation method, the average area of GO sheets obtained via the mechanical shear exfoliation method can reach around 16.31 μm2. As a result, the mechanical properties and conductivity of the prepared rGOP have been increased by 30% and 23.5%, respectively, with the tensile strength and electrical conductivity of 478.2 MPa and 208.4 S/cm being obtained. The developed method is of great significance for the large-scale production and emerging applications of lightweight and high-performance rGOP.

Background and Objectives: The use of endophytic fungi for management of phenol residue in paper and pulp industries has been shown as cost-effective and eco-friendly approach. In this study, isolation of endophytic fungi from roots, stems, and leaves of Hibiscus sabdariffa was conducted. Additionally, the isolated fungi were examined for their ability to degrade phenol and its derivatives in paper and pulp industrial samples, using different growth conditions. Materials and Methods: Out of 35 isolated endophyitc fungi, 31 were examined for their phenol biodegradation capacity using Czapek Dox broth medium containing Catechol and Resorcinol as a sole carbon source at final concentrations of 0.4, 0.6 and 0.8%. Results: A total of 35 fungal species belonging to 18 fungal genera were isolated and identified from different parts of H. sabdariffa plants. All strains have the capability for degrading phenol and their derivatives with variable extents. The optimum condition of degrading phenol in paper and pulp effluent samples by Fusarium poae11r7 were at pH 3-5, temperature at 28-35°C, good agitation speed at no agitation and 100 rpm. Conclusion: All endophytic fungal species can utilize phenol and its derivatives as a carbon source and be the potential to degrade phenol in industrial contaminants.

The purpose of present work was to obtain bactericidal materials using heulandite-clinoptilolite from the Rkoni plot of the Tedzami deposit, Eastern Georgia, to study their properties and use them as a filler for the production of bactericidal paper. Silver-, copper-, and zinc-containing microporous materials have been prepared using ion-exchange reactions between preliminary acid-treated zeolite microcrystals and a salt of a corresponding bioactive metal in the solid phase followed by washing with distilled water. Synthesized in such way adsorbent-ion-exchangers are characterized by X-ray energy dispersion spectra, powder X-ray diffraction patterns, and Fourier transform infra-red spectra. Obtained materials remain the zeolite crystal structure and contain over 130 mg/g of silver, 70 mg/g of copper, and 55 mg/g of zinc. Prepared materials show bacteriostatic activity towards gram-negative bacterium Escherichia coli, gram-positive bacteria Staphylococcus aureus and Bacillus subtilis, fungal pathogenic yeast Candida albicans, and a fungus Aspergilus niger. It was found that the mixtures of various forms exhibit a synergistic effect, and the silver form with additives of copper and zinc forms is most active against staphylococcus, and against other microorganisms, mixtures of copper and zinc forms are most effective.

This research is an analysis of quality control process on paper production on the soft roll production process of Bel Papyrus Ltd located in Ogba, Lagos State, Nigeria. The research was done with the aim of determining the conformity of the industry’s product to quality standard, identifying and eliminating the possible causes of variation in their production process, with reference to Percentage Elongation. The researchers used primary data in form of periodic laboratory test result done on soft rolls.Data presentations were made using simple statistical tools like Mean, Ranges, Standard Deviations, and Tables reflecting the primary data obtained at equal interval of production. The researchers made use of variable control charts for the purpose of analysis. The

"Moringa oleifera (drumstick) wood was evaluated in terms of its chemical composition, morphological features, Kraft pulping behavior, ECF bleaching and mechanical strength properties – important parameters for pulp and paper making – in comparison with Acacia mangium. Moringa oleifera was found to have the following composition: holocellulose 65.5%, lignin 20.5%, pentosan 11.6%, -cellulose 40.5% and extractives content of 5.15%, which made it comparable with the Acacia mangium wood sample. The alkali prehydrolysis of Moringa oleifera was carried out using 2% NaOH at 150 °C. The prehydrolysis liquor (PHL) was found to contain 50.9 mg/kg of calcium, 5140 mg/kg of potassium and 312 mg/kg of iron content. The prehydrolysis step was followed by Kraft pulping in order to obtain chemical grade pulp of kappa number 15-16 under optimized conditions. The Moringa oleifera pulp was bleached using the DEpD bleaching sequence to reach 85% brightness (ISO). The bleached pulp had an average fiber length of 1.21 mm, which was higher than that of Acacia mangium – 0.782 mm. The mechanical strength properties of the unbleached and bleached pulps, such as tear, tensile and burst indices, were also determined to show their suitability for pulp and paper production."

A wide variety of biomass is available all around the world. Most of the biomass exists as a by-product from manufacturing industries. Pulp and paper mills contribute to a higher amount of these biomasses mostly discarded in the landfills creating an environmental burden. Biomasses from other sources have been used to produce different kinds and grades of biomaterials such as those used in industrial and medical applications. The present review aims to investigate the availability of biomass from pulp and paper mills and show sustainable routes for the production of high value-added biomaterials. The study reveals that using conventional and integrated biorefinery technology the ample variety and quantity of waste generated from pulp and paper mills can be converted into wealth. As per the findings of the current review, it is shown that high-performance carbon fiber and bioplastic can be manufactured from black liquor of pulping waste; the cellulosic waste from sawdust and sludge can be utilized for the synthesis of CNC and regenerated fibers such as viscose rayon and acetate; the mineral-based pulping wastes and fly ash can be used for manufacturing of different kinds of biocomposites. The different biomaterials obtained from the pulp and paper mill biomass can be used for versatile applications including conventional, high performance, and smart materials. Through customization and optimization of the conversion techniques and product manufacturing schemes, a variety of engineering materials can be obtained from pulp and paper mill wastes realizing the current global waste to wealth developmental approach.

Usage of cellulosic nanofibers, starch-nanocellulose, and polyacrylamide-nanocellulose hybrid systems were investigated for the replacement of imported long bleached kraft fibers in the production of durable papers. In this study, imported softwood kraft pulp was added to cotton pulp at four levels. Nanofibrillated cellulose (NFC) prepared from chemimechanical pulp was added to cotton pulp at a 5% level with optional 1% cationic starch or 0.1% cationic polyacrylamide. Comparative tests were done without NFC at three levels of either cationic starch or cationic polyacrylamide. For each condition, 80 gm-2 handsheets were made, and the physical, mechanical, and optical properties of the paper were compared. The results showed that increases of NFC yielded higher surface smoothness, tensile strength, resistance to bursting, tearing energy, folding endurance, yellowness, and opacity. It also reduced brightness and porosity whether added singly or in combination with cationic starch or polyacrylamide. Increasing cationic starch also increased surface smoothness, tensile strength, resistance to bursting, and folding endurance, but paper opacity was reduced. The field emission-scanning electron microscopy results showed that increased NFC reduced porosity, the paper surface became smoother, and the pores were relatively filled. Finally, the combined treatment of 5% NFC and 1% cationic starch is introduced as a suitable combination.

Fraudulent papers from paper mills are a serious threat to the entire scientific community. Naunyn-Schmiedeberg’s Archives of Pharmacology has become the target of a massive attack of fraudulent papers originating from paper mills. This editorial highlights 20 important features we observed with paper mills and explains how the journal is responding to this serious threat to restore the integrity of science. Hopefully, this editorial is also helpful for editors of other scientific journals.

Soybean-oil-based polymer is a promising bio-based water barrier coating on paper packaging but the application is challenged due to its poor water dispersibility. In this present study, 3-aminopropyltriethoxysilane (APTES) modified nanocrystalline cellulose (NCC) was used to implement a stable dispersion of acrylated epoxidized soybean oil (AESO) in water and thus synergistically improved the water vapor barrier properties after coating on paper. APTES-NCC was successfully prepared, and displayed a better interface compatibility with AESO through the Michael addition reaction. Compared with NCC, APTES-NCC displayed an improved hydrophobicity and wettability with AESO, with an increase of contact angle from 38.0° to 76.4°, and a decrease of interfacial tension from 91.5±3.5 mN/m to 82.9±1.8 mN/m. As an emulsifier, APTES-NCC can be more effectively adsorbed on the oil-water interface to form a more stable emulsion than NCC, with a decrease of AESO droplets size from 4.8 µm to 3.1 µm, and a remarkable improvement in static and centrifugal stability. In rheological measurement, the APTES-NCC/AESO emulsion showed a wider linear viscoelastic region (3.4%), better viscoelasticity and thermal curing properties than that of NCC/AESO emulsion, which further explained that the stability of APTES-NCC/AESO emulsion were improved. Therefore, APTES-NCC/AESO emulsion as a coating on paper cured into a continuous barrier film can effectively improve the water vapor barrier properties of paper, and the water vapor transmission rate (WVTR) of paper can be reduced from 1392.8 g/m2•24h (NCC/AESO emulsion-coated) to 1286.3 g/m2•24h (APTES-NCC/AESO emulsion-coated), both are significantly lower than that of base paper (1926.7 g/m2•24h). CLSM testing showed that APTES-NCC could interact effectively with AESO to forming a tight barrier on paper surface and at the same time, sealing the pores inside the paper to resist water vapor penetration. The high-stable AESO emulsion prepared by APTES-NCC is expected to facilitate the utilization of NCC and AESO as a value-added material in making sustainable barrier packaging.

Dual-purpose coated paper, which enables in-line inkjet printing with web offset, can be used for both offset and inkjet prints. This product has potential to meet the ever-increasing demand for printing individualized information on commercial printing materials. In this work, commercial samples were printed in the two presses. It was deduced that low permeability correlates with large color gamut volume. The correlation would be useful to design coating formulations for good printability. Also, we examined the packing of coating layers to identify a coating formulation that provides good printing quality in both offset and inkjet printing. Many combinations of pigments were tested, and the effects of particle shape on viscosity and packing were examined. For all coating colors, pigment mixtures with a weight ratio of 3:1 gave the highest packing density. The mixture of GCC 90 and delaminated clay with a weight ratio of 3:1 was the best selection studied for dual-purpose coated paper. Among commercial paper samples, a web offset coated paper showed the best overall performance, indicating that coating formulations with minimal blistering are suitable for dual-purpose coated paper.

To provide an international standard for the safe management and operation of ships and for pollution prevention, the International Maritime Organization (IMO) introduced the International Safety Management (ISM) Code (adopted in 1993 and entered in force on 1st July 1998). The Code, through its guidelines and recommendations, provides seafarers (ship’s crew) the course of action for the safety and quality assurance process on ships. Traditionally a paper-based system, the ISM Code is now being digitalized in every aspect to streamline the processes to improve ship operations. This paper presents findings of a review of existing literature available on the world wide web to highlight areas of the Code that have been impacted by technology and the benefits that are being reaped. However, recent cyber attacks on ships and the maritime industry require a discussion on various implications associated with ships becoming increasingly reliant on technology and the advancing digital world. This paper highlights and explains the related implications and suggests strategies to address them.

This paper presents the research results that established the main technological conditions in the production of greaseproof paper, used as the packaging of dry food as the proportion of pulp types, the degree of the beating of pulp, the use of chemicals and oil and greaseproof resistant agent to the properties of the paper on a laboratory scale. At the same time, experimental production and technology conditions were regulated on a 3 ton/day capacity line. The paper quality produced is equivalent to the imported paper products of the same type which is consumed in the market: basis weight: 42.5 g/m2; tensile breaking length: MD (Machine Direction): 7,520 m, CD (Cross Direction): 3,740 m; tear index: MD: 6.8 mN.m2/g, CD: 5.4 mN.m2/g; burst index: 5.6 kPa.m2/g; Cobb60: 17.2 g/m2; KIT rating: 8; ensuring food safety and hygiene.

It remains a challenge to prepare special engineering paper with excellent mechanical properties, high temperature resistance and chemical resistance. The emergence of high-performance fiber provides support for the technical progress of special engineering paper. Herein, a novel method to obtain a novel self-reinforced poly (ether ether ketone) (PEEK) composite paper (SR-DI-PEEK/paper) by vacuum filtration, impregnation and hot pressing. Specially, PEEK fibers were used as the skeleton fiber and a small amount of aramid pulp was added as the decanted fiber. By optimizing the process of SR-DI-PEEK/paper preparation, the best mechanical properties of SR-DI-PEEK/paper was presented. Compared with the composite paper prepared with Phenolic solution (PF-PEEK/paper) and Polyimide solution (PI-PEEK/paper), the mechanical properties of SR-DI-PEEK/paper was significantly improved. In particular, when the concentration of impregnation was 3 wt%, the tensile index of SR-DI-PEEK/paper reached 51.10 N m g−1 (tensile strength 47.16 kN m−1), which is 16.48 times than that of the un-impregnated PEEK/paper (2.86 kN m−1). SR-DI-PEEK/paper also exhibited excellent chemical resistance among acid, alkali, and polar solvents, while the tensile index maintained 96.3% after 40 wt% H2SO4 treatment. Besides, SR-DI-PEEK/paper showed superior thermal performance, while the temperatures corresponding to the weight loss of 5% were 574 °C.

Currently, most of the collected waste medium-density fiberboards (MDF) is incinerated or landfilled, as economically viable recycling methods are yet to be developed. By steam refining waste medium-density fiberboards (MDF), it is possible to hydrolyze the incorporated resins and isolate a high yield fiber fraction. Further refining of the steam treated fibers might enable the fibers to be utilized in applications such as paper packaging, facilitating a cascading use of the waste material stream. To this end, intimate knowledge of the material is needed. In this study, the steam refined fibers of two waste MDF samples containing differing amounts of softwood and hardwood underwent refining and beating. The resulting fibers were characterized regarding their morphology and paper test sheets were produced to evaluate their strength (compression-, tensile- and tear-strength). Distinct differences in response to refining between the MDF samples were apparent. For the sample with the higher hardwood share an increase in strength properties with increasing steam treatment severities could be observed and it was possible to produce test sheets with comparable compression strength to recycled pulp for industrial corrugated paperboard. For the sample with a higher share of softwood, the steam treatment severity did not show any influence on fiber morphology or paper properties, and the resulting paper strength was low in comparison to the other steam refined waste MDF sample. Graphic Abstract

The growth of pulp and paper industries has encouraged the expansion of the industrial plantation forests for pulp wood. The exotic species planted for pulp wood initially maintained a relatively high productivity, however it decreases in the following rotation cycles. The peat land wood species of Sumatera could be an alternative for exotic species. However, the insufficient information on the wood properties has brought about they are less considered. This paper examined the fiber quality of Sumatran local peat-wood and its possibility as a raw material of pulp and paper. For specific gravity, samples were selected based on three different diameter groups in each plot. Fiber properties (dimension and fiber derivative values) used to asses the suitability of the wood for pulp and paper raw material were determined in accordance with the method of the Forest Product Laboratory (FPL). The resulted data and information were compared to those of krasikarpa (Acacia crassicarpa Benth.). The results showed that the fiber quality of sekubung wood was classified into grade II, while gerunggang and mahang putih were classified into grade III. The specific gravity of gerunggang wood was higher than these of other woods and comparable to that of krasikarpa. Although the growth of Sumatran local peat-wood is still low, however, conformity with government regulations (Government Regulation Number 57-2016 and Ministry of Environment and Forestry Regulation Number 17-2017) and fiber quality, the local peat-wood could potentially substitute the exotic wood species.

The study was carried out on the physico-mechanical properties of plaster of Paris (Gypsum plaster) reinforced with paper pulp in order to improve the weight of plaster paste and to obtain materials of lighter weight that solve problems such as poor flexural strength, and crack propagation. To do this experiment, the considerable basis of a standard of 2 kg of plaster of Paris was taken as the test sample. Gradually plaster of Paris was substituted with paper pulp paste in a water basin in proportions K0, K1, K2, K3, K4, K5 and K6 representing the different percentages of 0%, 10%, 20%, 40%, 60%, 80%, 100% of mixture respectively. After the above observations, the following parameters on fresh and hardened samples were tested: the start time of reaction, and end time of hardening, consistency, the flexural and compressive strength, shrinkage, and apparent density. At the end of these tests, it was determined that, the incorporation of small amounts of paper pulp (2 kg samples) into the plaster paste improves its flexural properties. But from k0 to k6, properties related to bending and compression began to gradually fall which is a consequence of the augmentation of the amount of paper paste in the plaster paste. The presence of paper pulp in the plaster of Paris paste increases the time of hardening of the plaster cement from one proportion to another, reduces the workability of the mixed paste, significantly solves the problem of removal, the apparent density drops when waste paper paste is increased in the mixed plaster. Because of its light weight, low density, its acceptable Mechanical properties, these new materials are recommended for exploitation in the manufacturing of popular lightweight construction finishing like panels for ceiling or walls, staff works and other applications.

The objective of the research carried out in this paper highlights the critical sustainability parameter of reusability of waste materials in the construction sector of India. This paper followed firstly the intense literature survey to identify the waste materials for the replacement in the concrete mix, hereafter Paper Pulp (P.P) and Crusher Dust (C.D) indicates the similar nature like cement and sand respectively. Secondly, an assumed proportion of replacement of P.P by 2.5%, 5%,7.5%,10%, and 12.5% by cement, and 10%, 20%, and 30% replacement of C.D by sand is adopted in M20 mix design by volume method. Thirdly, the casting of 48 sample cubes size of 150 mm × 150 mm × 150 mm is performed for Average Compressive Strength test, and casting of 48 cylindrical cubes of 150 mm in diameter and 300 mm long for Split Tensile Strength. Fourthly, the results are carried out for 7th day testing along with 28th day testing for both tests along with slump variation of different samples. It is observed after the experimental analysis that the elite results compared to normal M20 mix are exhibited when the replacement variation of P.P is 5% along with 10% variation of C.D for both Average Compressive Strength and Split Tensile test. In addition to it, the highest slump is obtained for replacement variation of 12.5% P.P and 10%C.D.

Paper and pulp mills generate substantial quantities of cellulose-rich sludge materials that are disposed in landfills at a large scale. For sustainability purposes, sludge materials can be bioprocessed to produce renewable fuels and useful chemicals. The enzymatic hydrolysis of cellulose is the process bottleneck that affects the conversion economics directly by using zero-cost raw materials. In order to study and optimize the process, the characteristics of the sludge raw materials should be first evaluated. In this work, sludge samples were obtained from paper mills located at different locations in Wisconsin and Minnesota. Part of the sludge samples was washed (de-ashed) with hydrochloric acid while the other part remained unwashed. The samples were subjected to multiple spectroscopic analyses techniques to evaluate the morphological properties of cellulose fibers and to estimate the total structural carbohydrate content. The results showed that the de-ashing process changed some fiber characteristics and cellulose crystallinity structure in all sludge samples. Sludge sample A (obtained from Kraft pulp and recycled paper mill region) showed a high percentage of fiber, with crystalline cellulose, compared to the other two sludge samples suggesting that sludge A is a valuable source to make value-added products. Aspen Plus mass and energy calculations performed in view of the ‘zero’ cost and the reliable supply of sludge raw materials producing 2 mol H2/mol glucose. Moreover, the results showed that extracting crystalline cellulose from these sludge samples is more profitable than crystalline cellulose made from the other lignocellulosic feedstocks. The results reported here showed that the utilization of these sludge materials would be an economically attractive and promising alternative for the production of hydrogen.

This study evaluates the use of fermentation to increase nutrient availability in pulp and paper bio-sludge (PPBS) as feed for black soldier fly larvae (BSFL). Rearing of BSFL on fermented PPBS was carried out in a climate chamber in order to assess nutrient availability and larvae survival and growth. The PPBS used came from a chemo-thermomechanical pulp/groundwood pulp mill. The PPBS was fermented at 35 °C and 55 °C, respectively, at initial pH of 10. The effects of sediment and liquid from fermented PPBS on larvae dry weight, survival rate until the prepupae stage, bioconversion, and reduction rate of PPBS were measured. The bioconversion of the liquids (4.1–6.6%) was substantially higher than for both the sediments and untreated PPBS (≤ 0.4%). The survival rate, on the other hand, was substantially lower (26.3–30.9 %) than for the sediments and untreated PPBS (49.5–52.6%). Neither the sediments nor the liquids had significant effects on the larvae weight or on the PPBS reduction rate. The sediments had no significant effect on the survival rate or the bioconversion. This study demonstrates that fermentation dissolves a part of the PPBS and that dissolved substances in the fermentation liquid readily convert to larvae biomass. However, the bulk of the lignocellulose is not dissolved, and most of PPBS nutrients remain unavailable for growth of the larvae. Further research should focus on improved pretreatment of PPBS to increase availability of nutrients and thereby improve the feasibility of BSFL as a recycling method for PPBS.

The aim of this study was to investigate a potential biorefinery process to realize the high utilization of Camellia oleifera shell (COS), which is an agricultural by-product mainly composed of cellulose, hemicellulose, and lignin. Before treatment by steam explosion, the COS was impregnated with water, 3.0 wt% NaOH solution, or 3.0 wt% H2SO4 solution. The morphological structure and chemical composition of the steam-exploded COS pulp were investigated. The results indicated that the impregnation treatments increased the cellulose content of the steam-exploded COS pulp and decreased the hemicellulose and lignin content. The morphology of steam-exploded COS fiber was short, coarse and stiff. Hydrophobic and colorful handsheets were fabricated by mixing proportional bleached softwood fiber. This study demonstrated that COS was a potential material for the papermaking industry, and the combination of water impregnation and steam explosion treatment for COS was a good pulp process.

Achieving an efficient catalyst in the ATRP system with a simple design, preparation from available materials, and high recyclability is a significant challenging issue. To attain the goal, herein, we used chitosan (CS)-modified cellulose filter paper (FP) as a green support for the synthesis of dip catalyst. The preparation of this catalyst involved surface treatment of the FP strips by CS coating through a dipping method, which increased the affinity of the substrate for adsorbing copper ions in the next step. The Cu@CS-FP catalyst was prepared without the requirement of any ligands. The synthesized dip-catalyst, in the form of the strips, was employed for the first time in the ATRP reaction of methyl methacrylate to assay catalytic activity. Catalytic insertion/ removal (ON/OFF) experiments were carried out during the polymerization. A reasonable control over the molecular weight with high conversion (68%) and polydispersity index of 1.32 under mild reaction conditions were obtained. Significantly, because of the facile separation of the catalyst, the amount of copper that remained in the polymer was very low (2.7 ppm). Also, the recyclability of the catalyst was investigated for five runs. The conversion in the final run was 64% without a loss of catalyst efficiency.

Анализ результатов многочисленных исследований показывает, что регулирование свойств волокнистых полуфабрикатов, а также стабильность качества бумаги и картона возможны при условии учёта специфики процессов структурообразования в дисперсных системах, дисперсионной средой в которых является вода или её растворы на каждом этапе в многоступенчатых системах переработки целлюлозосодержащих материалов. В результате исключения изтеоретических основ технологии и практики целлюлозно-бумажного производства понятия об индивидуальности природных волокон целлюлозы, предназначенной для производства бумаги, все исследования физико-химических свойств целлюлозы производились на образцах целлюлозы, предназначенной для дальнейшей химической переработки. При этом представления о гидрофильности волокон гидратцеллюлозы были перенесены и на волокна природной целлюлозы. В связи с этим отрицалась мозаичность поверхности растительных волокон и, следовательно, исключалась возможность реализации гидрофобных взаимодействий в системе «целлюлоза-вода». Характер и степень изменения параметров взаимодействия волокон с образованием фазовых связок в структуре волокон и между волокнами в листе бумаги рассматривает физико-химическая механика дисперсных систем, а выявленные закономерности учитываются в методах золь-гель технологии модифицирования поверхности волокон целлюлозы. Обобщение научно-технической информации на основе единого подхода к проблеме структурообразования в системе «целлюлоза-вода», базирующегося на представлениях физико-химической механики дисперсных систем и физико-химии полимеров, показало, что данные вопросы требуют тщательного и углубленного изучения с целью регулирования и достижения требуемых свойств целлюлозосодержащих материалов. Analysis of the results of numerous studies shows that the regulation of the properties and stability of the quality of paper and cardboard is possible subject to the specifics of the processes of structure formation in dispersed systems, the dispersion medium in which is water or its solutions, at each stage in multi-stage systems for processing cellulose-containing materials. As a result of excluding the concept of the individuality of natural cellulose fibers intended for paper production from the theoretical foundations of pulp and paper production technology and practice, all studies of the physical and chemical properties of cellulose were performed on samples of cellulose intended for further chemical processing. At the same time, ideas about the hydrophilicity of hydrate cellulose fibers were transferred to natural cellulose fibers. In this regard, the mosaic surface of plant fibers was denied and, consequently, the possibility of hydrophobic interactions in the «cellulose-water» system was excluded. The nature and degree of changes in the parameters of the interaction of fibers with the formation of phase bonds in the structure of fibers andbetween fibers in a sheet of paper is considered only by physical and chemical mechanics, and the revealed regularities are taken into account in the methods of Sol-gel technology for modifying the surface of cellulose fibers. Generalization of scientific and technical information based on a unified approach to the problem of structure formation in the "cellulose-water" system, based on the concepts of physical and chemical mechanics of dispersed systems and physical chemistry of polymers, showed that these issues require careful and in-depth study in order to regulate and achieve the required properties of cellulose-containing materials.