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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.

Starch and derivatives thereof have proven their usefulness in paper coating processes. Among these derivatives, cationic starch has been widely used in the paper industry as a flocculation, dispersion and ink fixing agent. In another context, nanoscale cellulosic materials have been shown to improve the strength, retention of fillers, the barrier properties of packaging paper products, and printing qualities. This review summarizes the recent studies on the general components used in paper coating, describes the conventional and alternative synthetic processes of cationic starches and nanocellulose, and deals with their current and potential applications in papermaking, focusing primarily on surface treatments. Moreover, environmental applications have been considered to expand the understanding and usefulness of these materials. Further research on modified polysaccharides is encouraged to replace, in a feasible way, petro-based components of coating formulations, and to provide paper surfaces with new properties.

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

The recycling of waste paper has been an effective way to achieve the environmental-friendly growth of papermaking industry. Focusing on the mixed-pulping process which has been generally employed, to ensure the required properties of the deinking pulp (DIP) and minimize the purchase cost of waste paper, an intelligent model scheduling the mixing ratio of waste paper was developed in the study. Primarily, driven by the field data of mixing ratio of waste paper and DIP properties, the prediction models of DIP properties were developed by SVM, GA-SVM, and BP-NN algorithms. Subsequently, based on the best prediction model, the scheduling model for the mixing ratio of waste paper was set up by NSGAII algorithm. The experimental results showed that, based on the obtained best BP-NN prediction model of DIP properties, the developed NSGAII scheduling model for the ratio of waste paper could achieve excellent scheduling results under the rigorous constraints and multi-objective. Compared with the previous study, the developed prediction and scheduling models in this study reduced the purchase cost of waste paper by 2.16%, and improved the acceptable proportion of DIP property from 56.07% to 100%.

Industrialization and urbanization are the key drivers to threaten the environmental quality and natural resources. Traditionally, pulp and paper industry has been highly reliant on forest based resources for its escalation. Shortage of forest based raw materials, strict environmental regulations and policies have compelled the industry to seek for alternate raw materials for its production. Mills are now focusing on exploring the potential of different agro wastes such as cereal straws and bagasse etc. In present research, sugarcane trash, one of the most abundant agro residues in India, was investigated for its capability in pulping and bleaching. Chemical characterization of sugarcane trash showed that it contains 40.4% cellulose, 33.2% hemicelluloses, 17.4% lignin and 6.45% ash content with 2.76% silica. To cook sugarcane trash with soda pulping method, 14% alkali charge, 15 min time and 162 °C temperature was found to be optimum and pulp of kappa no. 19.8 was prepared that exhibited good strength properties. Bleaching of pulp was carried out using elemental chlorine (Cl2), hypochlorite and chlorine dioxide (ClO2) based sequences. Replacement of Cl2 with ClO2 has significant impact on strength properties and effluent characteristics. Oxygen delignification stage was incorporated prior to ClO2 that resulted in improved optical properties of pulp with noticeable reduction in wastewater load. This paper elaborates the need of using sugarcane trash in paper mills with environment friendly pulping and bleaching processes to combat with the problem of waste management, wastewater load reduction during bleaching and substitute for wood based raw materials in papermaking.

Cellulose is an important component of green plants cell wall and other organisms. Cellulose from plants is mainly used to produce paper. Because of the widespread use of paper throughout the world, it causes the use of wood in large quantities that involves cutting down trees which can lead to negative impacts on ecosystems. Many research studied to find other raw materials that could replace wood and some focused on coconut coir because it contains high amount of cellulose which is enough to use in manufacturing. Coconut pulp is also the residue from coconut. It has 59 % cellulose. This makes it possible to use coconut pulp in paper industry. Paper for chromatography uses fiber from wood as an important component too. So, the purpose of this study was to identify whether cellulose from coconut pulp can replace the original material of chromatography paper. The procedure started from extracted impurity from coconut pulp and used the remaining for making chromatographic paper. Washed coconut pulp and removed residue coconut milk. Boiled clean coconut pulp for 10 minutes and dried in oven at 60 degree Celsius. Remove the residue fat with hexane. Drained hexane and dried in oven at 60 degree Celsius. Extracted cellulose by the soda process. Cellulose yield was 50.85%. Used extracted cellulose as raw material for making chromatographic paper. Tried different amount of cellulose per area of sieve to find the suitable for making paper. The appropriate paper area per extracted cellulose weight was about 81.25 cm2/g. Then trailed the paper used as stationary phase for color separation. The appropriate condition of mobile phase in chromatographic technique (ethyl-methyl ketone, acetone and water) to separate standard colors was also studied. The appropriate ratio of mobile phase which could separate standard solutions was 7:3:3, respectively. The results show that this paper was effective in serving as a stationary phase. This paper has the potential to be developed to use as a substitute material in Bio manufacturing.

Conjugated amino acid with nano-biodegradable polymer was applied as ecofriendly and edible coating. Polystyrene sulfate (PSS) was highly investigated with dynamic light scattering (DLS) to measure the particle size and over charge (zeta potential measurements) of nano-polymer system as well as the homogeny of particle distribution in presence and absence of Lysine mixture (AA). In addition, topographical structure of the coating was studied for PSS, AA and conjugated one as well as Fourier transform infrared (FTIR) and Differential Scanning Calorimetry (DSC). Antimicrobial test cleared that the prepared conjugate described as broad-spectrum antibacterial agent as well as antifungal with different concentrations. The hydrophilic active ingredient is absorbed into fiber, distributed homogenously and kept out the fiber loaded with antimicrobial properties over all areas. Tensile strength of the paper sheets coated with uni-layer 200 µ thickness presented good improving in physical and mechanical properties of coated paper sheets as well as gives more fiber condensation according to Scanning Electron Microscope (SEM) topography.

The present study was conducted to form polysaccharide-based multilayers of cationic starch (CS)/anionic starch (AS), and CS/carboxymethyl cellulose (CMC) on broke chemi-mechanical pulp (BCMP) fibers. It aimed to examine the buildup of CS/AS and CS/CMC polyelectrolyte multilayers (PEM) on the fibers surface, and explore the effects of PEM formation on the properties of the resulting papers. The assembly of PEM was analyzed by using zeta (ζ-) potential, water retention value (WRV), SEM micrographs, and paper properties such as thickness and strength. The results of ζ-potential inversions indicated successful constitution of PEM on the BCMP fiber surface by assembling CS/AS or CS/CMC multilayers. Further, larger ζ-potential variations occurred in depositing CS/CMC PEM, due to more charge of CMC, which presumably formed a layer with greater potential of absorption. Based on the SEM images, the surface of PEM-treated fibers was rougher, compared to the untreated fibers due to the coating with starch. Furthermore, the PEM fabrication resulted in creating fibers with higher degree of WRV, which was consistent with the significant improvement of the sheet strengths. Finally, the strength enhanced papers made from PEM-treated fibers with tensile index of about 37.33 ± 1.47 N m/g vs 22.24 ± 1.23 N m/g or 11.60 ± 0.57 N m/g for the papers made from original CMP and untreated BCMP fibers, respectively, may diminish the challenges related to web breaks in the paper machine conveying BCMP broke fibers.

Life Cycle Assessment (LCA) has been used to evaluate the life-cycle Greenhouse Gas (GHG) emissions of pulp and paper production, and most previous studies rely on process-based models for specific product types (e.g., printing paper), industry-average data, or information from a few mills. In this work, a data-driven approach is used to quantify GHG emissions intensities of different paper products manufactured by the U.S. mills. Facility-level emission data collected from publically available governmental databases and mill-level production data collected from the private sector were integrated to track the GHG emissions for different product lines and paper products in mills (in total, 165 mills were matched and analyzed). The results highlight the ranges of GHG emissions intensities by different product groups and categories, and can be used as a transparent data source for LCA practitioners, policymakers, and the pulp and paper industry to perform further analysis on carbon accounting and strategic planning for GHG mitigation.

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.

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

The biological deinking method using microbial enzymes is quite promising and rather eco-friendly. In this paper, we discuss about the impact of enzymatic deinking of newspaper pulp using ligno-cellulosic (cellulase, xylanase and laccase) and lipolytic enzymes. The individual treatment of paper pulp with enzymes (cellulase/xylanase) could enhance the paper brightness to about 32.86% whereas combinational effect could enhance only about 28.67%. There was a release of chromophores from phenolic and hydrophobic compounds released during the deinking process. Physico-chemical parameters of effluents were also found to be within the standard limits and the metals like iron, lead and zinc were not detected in the enzyme assisted deinking effluent sample. The heavy metals in the paper pulp was found to be reduced after enzyme treatment. The obtained effluent was found have low phytotoxicity and was safe for agricultural applications. Hence, the present report was found to be a suitable enzymatic deinking process which was eco-friendly that results in non-toxic effluents. The method also provides an avenue in water resource recycling within industries.

This work aims at developing sustainable processes for pulp and paper industry by integration of the biorefinery concept to an existing pulp and paper process. A systematic methodology employing a superstructure-based process synthesis approach is employed with support from computer-aided tools to determine potential pathways for a long-term sustainable growth objective. A superstructure of the multi-product biorefinery process network for the pulp and paper industry is developed. It is divided into three sub-networks, a chemical pulping section, a biochemical production section and a black liquor utilization section. Superstructure optimization is performed with the objective to maximize profit to determine optimal integrated networks for three scenarios. The obtained results provide useful insights for further development of the optimal networks as sustainable integrated biorefinery combined with pulp and paper mills.

In this work, two pulps, bleached (BP) and raw pulp (RP), derived from the paper production process, were used as precursors of non-activated and activated carbons (ACs). In the case of non-ACs, the production involved either pyrolysis or pyrolysis followed by acid washing. For ACs production, the pulps were impregnated with K2CO3 or H3PO4, and then pyrolysed and acid washed. After production, the materials were physically and chemically characterized. Then, batch adsorption tests on the removal of two pharmaceuticals (the anti-epileptic carbamazepine (CBZ) and the antibiotic sulfamethoxazole (SMX)) from ultra-pure water and from Waste Water Treatment Plant (WWTP) effluents were performed. In ultra-pure water, non-ACs were not able to adsorb CBZ or SMX while ACs showed good adsorption capacities. In WWTP effluents, although ACs satisfactorily adsorbed CBZ and SMX, they showed lower adsorption capacities for the latter. Tests with WWTP effluents revealed that the best adsorption capacities were achieved by carbons produced from BP and activated with H3PO4: 92 ± 19 mg g−1 for CBZ and 13.0 ± 0.6 mg g−1 for SMX. These results indicate the potential of paper pulps as precursors for ACs that can be applied in wastewater treatment.

The wood pulping process and the production of paper products generate wastewater with a variety of toxic pollutants in high concentrations. Pulp and paper wastewater (PPW) contains complex organic and inorganic pollutants depending on the type of pulping process. This paper provides an overview of biological treatment of PPW. Conventional biological processes such as activated sludge struggle to treat PPW to the required standard. Over recent years, a push towards more innovative solutions such as membrane bioreactors (MBR), sequential batch reactors (SBR), aerated lagoons and anaerobic filters have been suggested for the treatment of PPW. However, these technologies present several operational issues. A novel biotechnology, aerobic granular sludge (AGS), has emerged with strong potential to provide the desired treatment. Compared to activated sludge, granular sludge provides smaller footprints, better settleability, higher biomass retention, tolerance to toxicity, and resistance to shock loading, which are vital to PPW treatment. Early results on the application of AGS technology for PPW indicate very promising removal. However, pilot-scale testing is required to establish optimal operational conditions.

Aeration, as a process in pulp and paper wastewater treatment, uses the greatest share of the energy. Therefore, if the energy efficiency of the treatment has to be improved, the focus must be on aeration. A key finding from the trials conducted for this paper, with effluent from a paper and pulp mill, was that the oxygen transfer coefficient could be doubled and the chemical oxygen demand could be decreased by 25%, if the effluent was pre-treated with 30 mg/l of aluminium coagulant (equivalent to 9.4 tonnes per day of AVR to 20000 cubic metres of effluent). Decrease in oxygen requirement implies decreases in aeration energy use. Pulp and paper mill effluents are not as biodegradable as municipal sewage, and the improvement in oxygen transfer properties of the effluent will have a positive influence over a longer period of time in the biological treatment. If the sludge is digested anaerobically, pre-treatment will also result in doubling the potential for methane generation. A holistic analysis of modifications to processes entails a study of the economic and environmental consequences as well. While the economic aspect is beyond the scope of this paper, only the net global warming as an environmental impact category has been studied, by taking recourse to specific emission coefficients. Of the four dosages of ferric aluminium sulphate considered in this analysis, the net greenhouse gas emissions are the least – 426 kg carbon dioxide equivalent per day when the daily consumption is 9.4 tonnes.

The pulping industry generates vast amounts of bark residues and wastewater treatment sludges, which are combined and stored for varying periods in stacks, often in the open air, prior to utilization for energy via combustion. In order to optimize the storage strategy, the effects of incorporating sludge into bark on heating value and storage-related environmental impacts were investigated in laboratory and outdoor studies. Biological degradation activity was found to be higher in treatments containing 25% sludge (B75S25) and 50% sludge (B50S50) on a fresh mass basis, in comparison with pure bark (B100). Mean monthly dry mass loss was 2.1% (B100), 3.3% (B75S25), and 3.7% (B50S50) in the laboratory and 2.7%, 4.2%, and 4.8%, respectively, outdoors. Sludge addition was found to maintain degradation activity at low temperatures (+ 3°C). Co-storage of sludge and bark led to loss of energy, mainly due to increased loss of biomass and increased moisture content. Overall, biomass moisture content governed the heating value. Cumulative methane emissions over the storage period were higher from the sludge-containing treatments than from pure bark, but emissions of nitrogen-containing gases (N2O and NH3) were negligible throughout. Sludge addition roughly halved the cumulative chemical oxygen demand (COD) of leachate and minimized its concentration of phosphate-P. However, larger amounts of inorganic elements were released to the percolating water from the sludge-containing treatments. Overall, these results indicate that finding alternative uses for the sludge fraction would be beneficial.

Paper is a perfect example of the circular economy as it remains the furthermost recycled product in Europe, creating significant environmental benefits and raw materials resources to the industry. Indeed, maintaining a consistent level of quality whilst limiting the environmental footprint of the product has become a major challenge for the industry. In this direction, paper is proving to be the promising feedstock for biorefinery and biomaterials. The future of paper recycling is slowly going beyond fibre recovery to address the needs of other industries because for the earth's environmental well-being various paper products need to be recycled and reused persistently. In this article, we outline the ambitious use of wastepaper (WP) for high-value applications such as; production of cellulose nanocrystals (CNC), composite reinforcement, high performance electrical components and biofuels.

Anaerobic treatment of sedimented fibers collected from bottom of a bay that had been receiving pulp and paper mill wastewater for about 70 years were studied for the first time in semi-continuously fed continuously stirred tank reactors (CSTR). Anaerobic treatment of the fiber sediment was shown to be feasible, without dilution and with nitrogen and buffer supplement, at organic loading rates (OLR) up to 2.5 kg VS/m3d and hydraulic retention times (HRT) of 60 d resulting in methane yields of 201 ± 18 L CH4/kg VS. Co-digestion of sedimented fiber with sewage sludge at an OLR of 1.5 kg VS/m3d and HRT of 20 d resulted in a methane production of 246 ± 10 L CH4/kg VS. The techno-economic feasibility of mono and co-digestion process together with several case dependent factors such as maximum operable OLR, digestate utilization needs to be evaluated before making further conclusions for larger scale remediation applications. acceptedVersion

The paper and cellulose manufacturing industry generates significant quantities of waste, including an extremely humid sludge, which is considered to be an effluent with high environmental liability for the manufacturer. Studies have shown that this waste sludge may be utilized in construction material, such as mortar for fixing blocks, as well as for ceiling and wall coatings that use ceramic masonry as a sealant. The recycling of pulp and paper industry waste sludge has important environmental benefits, by preventing soil and water pollution caused by inadequate disposal and by reducing the depletion of natural resources, such as lime, used in cementitious materials. This study analyzed the sustainability of incorporating such waste into cement-based mortars. Tests were conducted replacing lime, one of the most expensive mortar components with high environmental impact, with waste sludge in contents of 5%, 10%, 15%, and 20%. Analysis was then performed on the samples to assess the primary technical characteristics of these incorporated mortars, such as the consistency index, heat of hydration, content of incorporated air, water retention, mechanical strength and the capillarity coefficient. The results were compared with the results of the characterization tests that were performed on the waste material. The results showed that for use in wall and ceiling mortar coatings, the level of incorporation should not exceed 10%, because higher levels yield lower values of mechanical strength resistance, incompatible with market requirements. This result is probably due to the low heat of hydration of the waste material which generates slower reactions. On the other hand, higher levels of waste material content, above 10%, are appropriate convenient for mortar used to fill small repairs in masonry that do not require control of properties.

Properties of cellulosic materials, such as average molar mass (MMvis), crystallinity index and hemicelluloses content may influence the efficiency of the enzymatic conversion of cellulose to glucose. Studies on the simultaneous influence of these parameters have been scarcely found in the literature. In the present study, the conversion of cellulose to glucose was investigated using cellulosic materials with different MMvis, crystallinity, and hemicelluloses content: microcrystalline cellulose (MCC, MMvis = 22104 g mol−1, CI = 79%, no hemicelluloses detected), sisal pulp (SP, MMvis = 94618 g mol−1, CI = 66%, hemicelluloses content = 2.6%) and filter paper (FP, MMvis = 98530 g mol−1, CI = 63%, hemicelluloses content = 19.2%). During the reactions, aliquots were withdrawn and, in addition to the liquors, the unreacted cellulosic materials were evaluated by MMvis, CI, SEM, length and thickness, which can help further understand the reaction as a whole. The liquors were characterized by high-performance liquid chromatography (HPLC) and Miller's method (or DNS). The highest yield for the conversion of cellulose to glucose was observed for SP (88%), followed by MCC (64%) and FP (52%). The results indicated that the presence of high hemicelluloses content (FP) had a more significant interference effect than high crystallinity (MCC).

Organosolv lignin was used as stabilizer to synthesize Bentonite-Lignin nano zero-valent iron (BL-nZVI). Then FTIR, XRD, SEM and TEM were carried out to characterize this new material. Results proved that organosolv lignin can effectively prevent the aggregation of nano zero-valent iron particles. BL-nZVI was applied as particle electrodes and formed a three-dimensional (3D) electrode system with ruthenium/iridium coated titanium plates and acted as tertiary treatment process to dispose the pulp and paper secondary wastewater. The removal efficiency of the chemical oxygen demand (COD) and color of the effluent were selected as indicators to check the performance of the system. It was found that the removal efficiency of COD and color depended on the current density, electrolysis time, distance of electrode plates, initial pH value and particle electrode dosage. The optimal parameters of each factor were also determined by a series of single factor experiments. Under the optimum conditions, removal efficiency of COD and color can reach 87.6% and 93.1% respectively. Possible mechanism of the 3D electrode system with BL-nZVI particle electrodes for treatment of pulp and paper wastewater was also proposed.

Highlights • Numerical simulations of acoustophoresis in pulp flow is conducted. • Parametric study of fiber characteristics, pulp flow regimes and acoustic parameters are conducted. • A feasibility study of industrial acoustophoresis for pulp concentration is performed. • A potential concentration gain of 15% is obtained experimentally., In pulp and paper mills, mechanical processes such as screening and washing are commonly used to remove accumulated solid suspensions and concentrate the pulp. For environmental reasons and to optimize paper production, an emerging challenge is to develop alternative methods to concentrate paper pulp between 3 % and 6 % consistency for which the mixed pulp-water flow is complex. Among the proposed solutions in the literature, solutions based on acoustic levitation, also referred as acoustophoresis, of low-consistency pulp have been demonstrated as a potential solution for efficient pulp concentration and water recirculation. However, no sensitivity analysis on the ultrasound and physical parameters was proposed, limiting the extension to a realistic application. Thus, this paper presents a numerical modeling of acoustophoresis for pulp flow concentration in a pipe. For this purpose, the pulp flow is defined as a pseudo-homogenous fluid with a turbulent Low Re k- ∊ formalism, and the pulp particles are considered spherical and deflected by two acoustic forces, namely the acoustic radiation force and the Stokes drag force, both induced by an ultrasound wave generated along the walls of a circular pipe. The combined action of these two forces in the pulp flow enables to concentrate the particles at the center of the pipe. The influences of particle size and mechanical properties, fluid properties and ultrasound parameters are analyzed within a parametric study to optimize the particle deflection and the pulp concentration. The experimental feasibility of the industrial use of acoustophoresis for the concentration of paper pulp is demonstrated with a concentration gain up to 15 %.

Pulp and paper mills are known large emitters of air pollution creating potential environmental challenges and human health impacts. This study assesses air pollution and associated impacts from connected pulp and paper facilities which operate in Edmundston, New Brunswick, Canada, and Madawaska, Maine, United States (US). Despite operating within two regulatory jurisdictions on both sides of the international border (in Canada and the US), the mills have exceeded their approvals to operate and national air quality regulations multiple times between 2010 and 2017. Previous studies have linked many types of cancer as well as respiratory and cardiovascular diseases to air pollution emitted by pulp and paper mills, making this an important regional issue in Canada and the US. While potential environmental and community impacts are likely similar on both sides of the international border, emissions from each side are not reported on the other, and few studies have been conducted on either side. Historic and ongoing lack of local epidemiological health and environmental impact studies and recommendations for improvements to mill operations to improve environmental and human health are presented.

Water plays several essential roles in paper manufacturing. It serves as a suspending medium and a swelling agent for the fibres, dispersing and forming them into a uniform sheet during the initial stage of the papermaking process. It also serves as the solvent for a variety of chemicals and additives to adjust product quality. Water reclamation has always been a momentous task in the pulp and paper (P&P) industry. The main driving forces for the adoption of process water and wastewater treatment technologies are environmental regulations, costs of wastewater discharge and the high cost of freshwater. Recent developments have made it possible to not only reduce water consumption and environmental impacts, but also to recover treated water and valuable compounds such as fibres, making water recycling technologies cost-efficient. Thus, the economic viability of these technologies has played an important role in their application. The technologies applied, the level of reduction in water consumption and the extent of water recycling are different for each mill, since the quality of whitewater and wastewater varies depending on the raw materials and products. The maintenance of the balance between partial equilibria of process variables such as water flowrates, pulp consistency, physiochemical, thermal and microbiological properties through water management is important for maintaining efficient water use and lowering the need for consumption of additional fresh water.

The aim of this study was to explore the potential of crude xylano-pectinolytic enzymes in bio-pulping of rice straw, in order to reduce environmental pollution. In this study, the effect of integration of bio-pulping strategy before chemical pulping of rice straw has been investigated. The bio-pulping efficiency was found to be maximum at xylanase:pectinase dose of 400:120 IU/g rice straw, temperature 55 °C, treatment time 3 h, Tween 80 (1%), pH 8.5 and pulping consistency 1:10 (g/mL). Bio-pulping enhanced the permeability of pulping chemicals, generated pulp with higher yield, brightness, along with higher residual active alkali content of black liquor in comparison to the pulp obtained after chemical pulping. Bio-pulping also resulted in 10% reduction of alkali dose and improved paper quality, with increase in breaking length (13.9%), burst index (27.0%), double fold (39.3%), gurley porosity (18.75%) and viscosity (8.77%) of unbleached bio-pulp. Bio-pulping also improved the bleachability by removing the D2 step of bleaching and produced pulp with higher physical strength properties, breaking length (15.92%), burst index (20.47%), tear index (3.87%), double fold (36.0%), gurley porosity (25.0%) and viscosity (28.36%). Hence, this environmentally sustainable bio-pulping approach can decrease the chemical load and ultimately pollution, along with enhance the yield and quality of paper. This is the first report demonstrating cleaner pulping of rice straw using crude xylano-pectinolytic enzymes, produced by a bacterial isolate.

The aim of the study was to use black liquor produced during the soda pulping process in a pulp and paper mill to increase methane production during pulp and paper industry sludge treatment and decrease the treatment cost. The effects of black liquor on sludge solubilization and methane production were assessed and the economic feasibility of the process was evaluated. Black liquor and NaOH were found to be equivalent in the thermochemical pretreatment process to solubilize sludge and disintegrate flocs. However, adding black liquor increased the background chemical oxygen demand and volatile fatty acid concentration and increased the amount of methane produced by approximately 7-30%. A start-up delay was emphasized by first-order kinetics model due to black liquor addition while methane production remained stable. Economic assessments of five scenarios were performed. It was found to be economically feasible to use black liquor to replace NaOH for the thermal pretreatment process. The surplus methane generated suggested that co-digestion of sludge and black liquor allows surplus bioenergy to be produced during the thermochemical pretreatment anaerobic digestion process.

Graphical abstract, Highlights • A new and rigorous approach for assessing the effect of enzymatic pretreatment on AD is proposed. • Enzymes can improve anaerobic digestion increasing biogas yields by up to 26%. • First study to isolate the effect of catalytic activity and organic load from enzymes to evaluate enzymatic pretreatment. • Enzymes did not appear to be inhibited or denatured in the presence of biosludge., Anaerobic digestion of biosludge has not yet been implemented in pulp mills due to low biogas yields. Enzymatic pretreatment of biosludge has shown improvements in biogas yields but results are varied. A key limitation of previous studies is that they fail to consider the COD contribution from the enzyme solutions. The aim of this study was to systematically investigate the potential for enzymatic pretreatment on the anaerobic digestibility of pulp mill biosludge. Out of the six enzymes tested, four enhanced the anaerobic digestibility of biosludge. At the end of the BMP, a maximum improvement of 26% in biogas yield was observed with protease from B. licheniformis. There was no correlation between enzymatic activities on standard substrates and/or on biosludge and the effect of enzymes on biogas yields. Enzymes have potential for improving biosludge anaerobic digestibility but more research on optimal conditions and potential synergies with other pretreatment is needed.

The corrosion-resistance properties of modified ultra-thin carbon paper (CP) different graphene oxide (GO) content used in proton exchange membrane fuel cells (PEMFC) are studied for the first time. Results show that CP with 1 wt% GO has distinguished corrosion-resistance property (corrosion current: 5.539E − 8A.cm−2, minimum weight loss and contact angle variation). And mechanism analysis was found that the CP-1GO-P had uniform florine coating on some area of carbon fiber while T-CP-P has little. Moreover, the addition of GO could introduce more C O and C O groups which interact with the florine atom, thus can strengthen the bonding of PTFE and matrix carbon effectively.

Synthetic styrene-butadiene (SB) and styrene-acrylic (SA) latex binders used in paper coating formulations are common and based on unsustainable petroleum sources. Today's papermaking industry turns towards sustainable substitutes that do not compromise quality, and reduce carbon emission, toxic substance release and waste disposal concerns related to fossil fuel sources. In this study, colloidal starch-based latex nanoparticles that do not require cooking were used for pigment coating and coated on the paper surfaces. The effects of these new biobased binders on the structural and mechanical strength properties, liquid absorption, wetting and surface topography of the paper were investigated and compared with the properties of coated paper that SB latex was used as a coating binder. The results demonstrated that the biobased latex decreases the grammage of paper while maintaining an identical thickness relative to the SB latex samples. The porosity, permeability and roughness of biobased latex are found higher than the SB latex. The biobased latex successfully replaced SB latex at 1:1 ratio and enabled an equivalent of bursting, tear, tensile strength and structural properties.

Owing to its excellent heat resistance, lightness, insulation, and mechanical properties, aramid paper has been widely used in aerospace, rail transit, military, and other high-tech areas. With the rapid development of modern industries, para-aramid paper-based materials have become the development direction and trend of the specialty paper industry. In this study, para-aramid chopped fibers/polyphenylene sulfide (ACFs/PPS) composite paper sheets were fabricated by modern wet papermaking. The tensile strength, tensile index, and tear index of the hot-pressed ACFs/PPS composite paper sheets were substantially improved, reaching 103.5 MPa, 80.9 N m/g, and 119.1 mN m2/g under optimal speed of hot-pressing roller (0.2 m/min), hot-pressing temperature (310 °C), hot-pressing pressure (0.2 MPa), and ACFs content (70 wt%). The mechanical properties of hot-pressed ACF/PPS composite paper were markedly superior. Besides, the dielectric constant of the composite paper remained stable even when the temperature reached 100 °C. Briefly stated, ACFs/PPS composite paper exhibits desirable mechanical performance, thermostability, high breakdown strength, and low dielectric constant, delivering great potentials in the high-tech areas.

Reducing waste materials through reuse has in the recent past contributed to sustainable manufacturing in many industries. With the development of large-scale poultry farming, the treatment of large amounts of chicken feathers has become a problem and threatened its use as a renewable resource. This paper examines the use of chicken feathers in the paper making process; a process which would traditionally use wood as the raw material. The effects of combining feather fibre and wood pulp on paper performance were studied and compared to the properties of handsheets made with 100% wood pulp. With the increase of feather content, properties such as tightness, tensile index and bursting index decreased, whilst air permeability improved. There was no significant difference in water absorbency between various chicken feather/wood pulp handsheet samples however, the water absorbency started to decrease above 80% of chicken feather content. This could potentially open up a new avenue for the use of chicken feathers in applications that are meant to tolerate high humidity conditions, e.g., packaging products.

This paper presents the first estimate of global water use in the forestry sector related to roundwood production for lumber, pulp, paper, fuel and firewood. For the period 1961–2010, we estimate forest evaporation at a high spatial resolution level and attribute total water consumption to various forest products, including ecosystem services. Global water consumption for roundwood production increased by 25% over 50 years to 961 × 109 m3/y (96% green; 4% blue) in 2001–2010. The water footprint per m3 of wood is significantly smaller in (sub)tropical forests compared to temperate/boreal forests, because (sub)tropical forests host relatively more value next to wood production in the form of other ecosystem services. In terms of economic water productivity and energy yield from bio-ethanol per unit of water, roundwood is rather comparable with major food, feed and energy crops. Recycling of wood products could effectively reduce the water footprint of the forestry sector, thereby leaving more water available for the generation of other ecosystem services. Intensification of wood production can only reduce the water footprint per unit of wood if the additional wood value per ha outweighs the loss of value of other ecosystem services, which is often not the case in (sub)tropical forests. The results of this study contribute to a more complete picture of the human appropriation of water, thus feeding the debate on water for food or feed versus energy and wood.

The potential health and environmental impacts associated with the improper management of chemically treated wood waste demands the adoption of recycling, and disposal practices. Chemically treated wood waste has several physical and chemical properties which makes it usable for the manufacture of another product to multiple use, among which the production of paper and fuel. This paper presents the initial life cycle assessment (LCA) study on wood waste used for paper production. The study boundary is limited with raw materials (raw wood or waste wood) processing and paper production itself, thus corresponds to “gate-to-gate” life cycle with a special focus on life cycle inventory data on waste wood treatment via hydrolysis process. The results of the analysis demonstrate competitiveness of the waste wood use for paper production vs. raw wood in such environmental categories as human health and ecosystem quality.

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

Enzyme-aided Cl 2 bleaching is widely considered as promising replacements for conventional Cl 2 bleaching in wood pulp and paper mills. However, the effects of using enzyme-aided bleaching on the formation of polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs) in the non-wood pulp and paper mills are unclear. A field study was performed to investigate PCDD/F formation when enzyme-aided Cl 2 bleaching was used to replace conventional Cl 2 bleaching in non-wood pulp and paper mills. Unexpectedly, the PCDD/F toxic equivalents (TEQs) in solid samples were higher when using enzyme-aided bleaching (0.49–5.4 pg TEQ/g) than that using conventional Cl 2 bleaching (0.15–2.44 pg TEQ/g). Large amounts of octachlorodibenzo- p -dioxin were formed during the enzyme-aided bleaching process. This could have been because enzyme strongly promoted the release of organic molecules bound to lignin and thus accelerated the formation of octachlorodibenzo- p -dioxin through organic molecular precursors. Although enzyme-aided Cl 2 bleaching was previously considered to be efficient for reducing PCDD/F releases and to be the best available technologies and best environmental practices for wood pulp and paper mills, the results obtained in this study suggested the necessity and urgency to evaluate the suitability of enzyme-aided Cl 2 bleaching for non-wood pulp and paper mills that intensively practiced in developing countries.

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

Superhydrophobic/superoleophilic paper with excellent self-cleaning and antibacterial activity was prepared via combination of in-situ growing Cu metal-organic frameworks (Cu-MOFs) nanoparticles on paper surface by simple layer-by-layer assembly together with subsequent polydimethylsiloxane (PDMS) treatment under ambient conditions. The surface chemical composition, crystalline pattern, surface chemical functional group, surface morphology and wettability of the modified paper samples were investigated by X-ray photoelectron spectroscopy, X-ray diffraction, fourier transform infrared spectroscopy, scanning electron microscope and water contact angle measurement. The synergetic effect of Cu-MOFs nanoparticles and PDMS was crucial and essential for achieving a superhydrophobic surface. The PDMS/(Cu-MOFs)5@paper not only showed self-cleaning, antibacterial activity and superhydrophobicity/superoleophilicity, but also exhibited excellent oil-water separation performance for oil-water mixture and emulsion. In addition, this obtained superhydrophobic paper showed good mechanical and chemical durability. In summary, the proposed method provides a new perspective into preparing superhydrophobic paper for oil spills treatment and environmental remediation.

The present study has aimed to evaluate the role of vermitechnology in the qualitative enrichment of compost during the valorization process of solid paper mill wastes. A maximum mass reduction of 77% (primary sludge) and 76% (secondary sludge) were noticed through thermogravimetric (TG) analysis. The biodegradation of complex xenobiotics such as lignin, cellulose, etc. were found in spectral bands of FTIR spectroscopy which had attributed to extent of mineralization among compost samples. A significant correlation between the decrease of the C/N ratio and the rise of the 2921/1633 peak ratio of FTIR had conferred the maturity among vermicompost samples. Furthermore, the presence of different macromolecular humic acid-like substances such as benzene dicarboxylic acid, propanedioic acid, glutaric acid, etc. was found in the vermicompost samples through GC–MS analysis. In addition to such qualitative enrichment, microbial diversity was manifested using PLFA biomarkers which had revealed a huge bottleneck in terms of microbial populaces designating ecological succession upon vermicomposting. Therefore, the present study can be considered as a comprehensive eco-biochemical approach which will open up a new vista the importance in context to paper mill solid waste management.

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

Chlorine bleaching technology (C process, CEH process, H process and theirs combination), which was identified as a primary formation source of PCDD/Fs, is still widely used by the vast majority of Chinese non-wood pulp and paper mills (non-wood PMs). The purpose of this study was to provide information and data support for further eliminating dioxin for non-wood PMs in China, and especially to evaluate the PCDD/Fs release reduction for those mills converting their pulp bleaching processes from CEH to ECF. The PCDD/Fs concentrations of the bleached pulp and bleaching wastewater with ECF bleaching were in the ranges of 0.13–0.8 ng TEQ kg −1 , and 0.15–1.9 pg TEQ L −1 , respectively, which were far lower than those with CEH process, indicating that the ECF process is an effective alternative bleaching technology to replace CEH in Chinese non-wood PMs to reduce dioxin release. The release factor via flue gas of the alkali recovery boiler in Chinese non-wood PMs was first reported to be 0.092 μg TEQ Ad t −1 in this study. On the assumption that pulp bleaching processes of all Chinese non-wood PMs were converted from CEH to ECF, the annual release of PCDD/Fs via the bleaching wastewater and bleached pulp would be reduced by 79.1%, with a total of 1.60 g TEQ.

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

The effects of doping of ZnO and Nb2O5 solids with Fe2O3 (1.4 wt%) and Ag2O (1.4 wt%) on its surface and catalytic properties were investigated, as well as its photocatalytic performance on the degradation of a pulp and paper wastewater (PPW). The catalysts were characterized by XRD, SEM, photoacoustic spectroscopy (PAS), NH3-TPD and textural analysis. The results obtained revealed that Fe2O3 doping of Nb2O5 conducted at 500 °C resulted in an increase of about 116% for SBET while Ag2O treatment exerted a decrease of 33% for SBET of the doped adsorbents. Doping ZnO with Fe2O3 or Ag2O led to an increase of 80% for SBET. Iron and silver doping also led to a decrease in band gap energy of at least 6%. The addition of 1.4 wt% Ag2O on ZnO followed by calcination at 500 °C resulted in an increase of 11% in the value of the reaction rate constant (kap) for COD reduction under UV radiation. The treatment of Nb2O5 with 1.4 wt% Ag2O increased by a factor of 2.04 the value of kap for the reaction taking place under VIS radiation. The catalysts partially reduced the organic load and the real colour of the wastewater, allowing the achievement of the specifications for release into rivers, so photocatalysis could be an alternative for pulp and paper wastewater final polishing.

Ceramic paper discs were made by employing a dual papermaking technique and by partially substituting cellulosic fibres by SiO2-Al2O3ceramic ones. Ulexite (NaCaB5O6(OH)6�5(H2O)), extracted from the natural mineral, was added as a binder to give ceramic paper the necessary strength for its manipulation and catalytic use. Either La,Co or Ba,Co was incorporated in order to give ceramic paper the capability of trapping NOx and oxidizing soot particles. Structured catalysts were characterised by SEM, FTIR and XRD, and the mechanical properties were also determined. Lanthanum was deposited on ceramic fibres as La2O2CO3aggregates and barium as BaCO3filaments, being cobalt deposited as Co3O4flakes. Mechanical properties indicated that the ceramic paper obtained from natural ulexite proved to be stronger, though less flexible than those prepared using colloidal suspensions as a binder. Diesel soot oxidation activity was determined by TPO either adding or not 0.1% NO into the feeding stream. The thus prepared systems resulted in being active towards soot oxidation, being the value of maximum combustion rate 420 �C, which is within the temperature range of diesel exhaust gases. Fil: Leonardi, Sabrina Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentina Fil: Zanuttini, Miguel Angel Mario. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentina Fil: Milt, Viviana Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentina

Ideally, if the corrosion resistance coating on carbon paper (CP) can be endowed with the self-healing property, the service life and the reliability of the carbon paper will be greatly increased as the gas diffusion layer. In this paper, different cycles of s branched poly (ethyleneimine) (bPEI) and poly (acrylic acid) (PAA) were modified on the surface of the carbon paper via layer-by-layer (LbL) self-assembly technology. The prepared polyelectrolyte multilayered coatings can not only protect the carbon fiber from corrosion, but also take advantages of the surrounding water to quickly repair themselves after damaged. The effects of the assembly cycles on morphology, resistance, air permeability and the contact angle of carbon papers were investigated, then the differences of the carbon papers in electrolysis process were explored. The results reveal that all the prepared coatings can protect carbon papers from corrosion, while when the assembly cycles was 10, the coatings are most efficient.

Due to the scarcity of natural resources, the option for the recovery of industrial waste for new processes has increased over the last years. However, seeking natural raw materials, some industrials do not perform treatment or separation of some of its components from waste to be reused. This research focuses on the characterization and purification of waste from the industrial pulping of white paper shavings, obtaining kaolin and CaCl 2 . The waste was subjected to heat treatment at 400 °C to burn the cellulose. To separate the CaCO 3 of kaolin, a hydrochloric acid (HCl) solution was used to purify the materials, converting CaCO 3 into CaCl 2 and water in a chemical reaction. To find the best HCl ratios, tests were carried out at three different concentrations: 1.5, 1.8, 2.1 M. Residual water was evaporated to recover the CaCl 2 , and the resulting kaolin from pulp was oven-dried and turned into metakaolin. The analysis performed for the characterization of the materials were: X-ray Fluorescence (XRF) before and after treatment of the material; X-ray Diffraction (XRD); Differential Thermal Analysis (DTA) and Thermogravimetric Analysis (TGA). Scanning Electron Microscope (SEM) was used on the surface structure, morphology and shape studies.

International audience; An energy audit is a primary step toward improving energy efficiency at the facility level and ensuring a clean production. The pulp and paper sector is one of the most energy-intensive industries in Morocco. This article aimed at identifying energy conservation opportunities at a Small and Medium-sized paper industry. The audit results together with their financial viability are presented regarding the analysis of energy consumption and electrical quality issues. The paper introduces an action plan for a more efficient energy use of some specific applications such as furnaces and compressed-air installations as well. The recommended energy efficiency measures have the potential of saving about 347.85 MWh of electrical energy and 101.78 MWh of thermal energy corresponding to reductions of 11.48% and 2.22%, respectively. The total investments related to the application of the action plan is approximately 290.53 kMAD and the global payback period does not exceed one year. It was also shown that a total quantity of 283.39 t of CO2 emissions can be saved annually.

Pulp and paper production is a highly energy intensive process and improvement of energy efficiency in this process is considered as promising measures for reducing industrial greenhouse gases emissions (GHG). This study focuses the Pakistan's pulp and paper industry which consumes around 7% of the country's industrial energy and contributes to over 317,269 tonnes of CO 2 emissions. With rising demands for fuels and consequently as harp increase in CO 2 emissions due to the growth of the paper sector in Pakistan, this article aims to analyse the energy efficiency and carbon dioxide emissions reductions potential through the incorporation of cogeneration technologies. The cogeneration technologies studied are agas turbine, steam turbine and combined cycle and are evaluated from the energetic and economic point of view to propose a best suitable technology for each paper mill. The proposed cogeneration technologies are selected on the basis of high energy utilisation factor, as implepayback period of five years or less with least Annualised life cycle cost. The result shows that a theoretical energy saving potential equivalent to 16.9% of the actual thermal energy requirement of mills can be achieved through cogeneration which will lead to 14.3% reduction of the present carbon emissions levels in Pakistan's paper sector.

The conventional package paper was coated with biodegradable montmorillonite/chitosan nanocomposite, in order to extend the application scope of paper. The effect of coating weight, montmorillonite dispersion rate, montmorillonite and dispersant content on the surface and penetration properties of montmorillonite/chitosan nanocomposite coated paper were being investigated. The surface properties of the coated paper were observed by using scanning electron microscope (SEM) and atomic force microscope (AFM). The water permeation and water vapor barrier properties were confirmed through penetration dynamics analyzer (PDA) and water vapor permeability tester (WVP), respectively. The results indicated that montmorillonite/chitosan nanocomposite had a poorer formation than pure chitosan, but it had better water vapor barrier properties. The paper coated with lower content of montmorillonite, or with higher dispersion speed and dispersant content, had better smoothness and elongation. Additionally, the coated paper had excellent barrier properties under the conditions of high montmorillonite and dispersant content, dispersion rate and coating weight.

Valorisation involves conversion of toxic compounds into value added products. The present study has tried to evaluate the potential of vermicomposting in management of different types of toxic paper mill wastes such as primary waste (VCP) and secondary waste (VCS) using Eisenia fetida for 60 days. The procedure was performed using sundried samples of paper mill wastes, cow dung and straw in different trial sets using different ratios. The study had revealed that the trial sets (VCP1 and VCS1) using ratio of paper mill waste: Cow dung: Straw (5:4:1) were effective in maintaining physiochemical parameters and different population attributes of earthworm. The present study had also demonstrated the enzymatic enrichment of vermicompost in terms of 19 enzymes such as α-Glucosidase, lipase, leucine aminopeptidase etc. in maintenance of C/N ratio of the compost. A significant reduction of heavy metals were noticed in vermicomposting of primary waste (VCP1) as Zn (40%) ​> ​Pb (36%) ​> ​Cr (28%) ​> ​Cu (25%) and secondary waste (VCS1) as Zn (44%) ​> ​Pb (41%) ​> ​Cu (19%) ​> ​Cr (13%). Such reduction of heavy metal was highly correlated with the reduction of C/N ratio of the vermicompost. The process of bioremediation was further manifested through the regular monitoring of bioaccumulation factor (BAF) among earthworm population in vermicomposting of primary waste (VCP1) as Zn (0.40) ​> ​Cu (0.23) ​> ​Cr (0.18) ​> ​Pb (0.11) and secondary waste (VCS1) as Zn (0.47) ​> ​Cu (0.25) ​> ​Cr (0.21) ​> ​Pb (0.14). Therefore, the study concludes that the ratio of paper mill waste, cow dung and straw (5:4:1) can be an efficient formulation in qualitative enrichment of different toxic organic paper mill wastes through vermicomposting.