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Highlights • Pulp and paper mills generate huge amount of wastewater. • Physicochemical processes have several limitations to treat wastewater. • Integrated microbial based technology improves the quality of wastewater. • Eco-friendly MBBR process creates opportunity for reuse of treated wastewater., From the beginning of the paper-making process, the pulp and paper industry has utilized a large amount of water and generated a vast amount of highly polluted wastewater. The paper industry faces global pressure to reduce water use and lower environmental pollution. However, traditional physicochemical methods of wastewater treatment need high energy input, and their ecological impact is questionable. Due to the zero discharged policy, the industries urgently require novel eco-friendly, sustainable, and efficient treatment techniques. Microbial technology is the most recommended option to treat wastewater and support sustainable growth. The present article describes the overview of traditional and novel methods, including membrane bioreactor (MBR) and moving-bed biofilm reactor (MBBR) technology's with their current state and their limits for treating pulp and paper wastewater. It is expected to integrate the novel methods with advanced hybrid technology to fulfill wastewater treatment criteria and prospects. Furthermore, coupling MBR and MBBR technology make energy and water recovery possible, and recycling wastewater will be economically and environmentally feasible., Graphical abstract Image, graphical abstract

Paper derived from lignocellulose has great advantages over plastics as packaging material, nevertheless, the poor water- and oil-resistances of paper-derived products limited their application in high-end field. Herein, novel dimer acid-based waterborne polyurethanes (DWPUs) with different content of dimer acid-based polyester polyol (DG) were prepared and used as water- and oil-resistant coating for paper substrate. The effects of DG contents on water- and oil-resistances, mechanical properties and thermal stability of DWPUs coated papers were systematically investigated. When the content of DG reached up to 7 wt% (based on polyester glycol), the paper coated by DWPU exhibited 88.06% decrease in Cobb 60 value, 8.7 times increase in kit rating compared with uncoated paper. Meanwhile, DWPUs coated papers showed good mechanical properties and thermal stability. These improvements are attributed to the flexible long-alkyl chain, and six-ring structure of DWPUs as well as the continuous and homogeneous DWPU-derived membrane on the surface of paper. This study provides a new framework for the preparation of high quality, multifunctional, environmentally friendly water- and oil-resistant coatings for paper substrates.

To study the influence of different concentrations of zinc oxide (ZnO)/silicon dioxide (SiO2) composite coating on hydrophobic property and mechanical stability of paper mulch film, three kinds of ZnO/SiO2 composite coating paper mulch films (2%, 4%, 6%) with different coating substance contents were prepared by brush coating method. Through particle size analysis, contact angle, rolling angle and mechanical stability test, combined with scanning electron microscope, three-dimensional morphology and roughness measuring instrument, the optimal concentration of ZnO/SiO2 composite coated paper mulch film was screened out. Through acid-base salt corrosion test, silver mirror reaction and surface self-cleaning, the optimal concentration of composite coated paper mulch film was compared with the original paper mulch film to prove its excellent chemical stability and hydrophobicity. The results show that the paper mulch film with 4% coating material has excellent hydrophobicity and mechanical stability, can effectively reduce the surface roughness of paper mulch film, and has remarkable effects in resisting acid, alkali and salt and self-cleaning.

Sustainable and low-cost cellulose-based metallisation is the prerequisite for wearable and disposable electronics fabrication. In this paper, to realize the simplified, low-cost and high efficient metallisation, a new method had been proposed without both the noble metal activators and the corrosive chemicals. The modified electroless plating processes had been employed in activation and deposition procedure. The nickel ions were first physiadsorbed on the cellulose paper (CP) fibers and then reduced into clusters by reducing agent which can act as the seeds to initiate the electroless plating process. The gold galvanic displacement was conducted further to modify the nickel surface. Via these processes, the cellulose paper was metallised with Ni-P and Au/Ni-P successfully. The morphological and microstructural properties of the resulted Ni-P/CP and Au/Ni-P/CP hybrids were evaluated. The Ni-P/CP composites had a low surface resistance below 0.5 Ω sq-1 while the Au/Ni-P/CP composites are below 0.1 Ω sq-1. The relationship between the mechanical and electrical properties with the plating parameters is discussed. The results indicated that Au/Ni-P/CP had good electrical conductivity and mechanical flexibility. Finally, the application demonstration for supercapacitor with the modified metallisation method was exhibited. This work offers a facile and non-toxic path to develop high-performance metallisation for functional cellulose-based materials.

This study's focus was to develop a potential pathway for recycling of the paper mill sludge compost (PMSC) in brick making. Composting reduces the paper mill sludge (PMS) moisture content considerably and shredding becomes easier. The addition of PMSC leads to an increase of porosities in bricks and makes them lighter, besides delivering energy to the firing process from burning organics. Lighter construction materials help minimize construction outlay by reducing labour and transportation costs and lesser expense on foundation construction. The variability in the experimental data and the brick properties were investigated for two types of soils, typical in the brick industry of India (alluvial and laterite soil), blended with PMSC in five mix ratios (0%, 5%, 10%, 15% and 20%). The samples of oven-dried bricks were fired at two different temperatures (850 and 900 °C) in an electrically operated muffle furnace representing typical conditions of a brick kiln. Various properties of bricks were analyzed which included linear shrinkage, bulk density, water absorption and compressive strength. Conclusions were drawn based on these properties. It was found that the addition of PMSC to the alluvial and laterite soil by up to 10% weight yield mechanical properties of fired bricks compliant with the relevant Indian and ASTM codes. Toxicity characteristic leaching procedure (TCLP) tests showed that PMSC incorporated fired bricks are safe to use in regular applications as non-load-bearing and infill walls. This study is timely in light of the European Green Deal putting focus on circular economy. Besides, it fulfills the objective of UN sustainable development goals (SDG). © 2021 Elsevier Ltd

Europe represents 25% of the world’s production of pulp and paper, being the second largest producer in the world. Waste paper fly ash (WPFA) is a material generated by the incineration of by-products in the manufacture of paper from recycled paper. WPFA has binding properties that allow it to be used as a replacement for cement or lime in soil stabilization. This chapter describes the full-scale application of WPFA in civil works (road projects), from less complex applications than those with high physical-mechanical requirements. The three applications presented here are part of the PaperChain project, funded by the European Union, and are as follows: soil stabilization on a rural road, granular soil stabilization in a local road and, finally, a soil-cement on a regional road. The results obtained show the viability of using WPFA as an alternative binder material to cement or lime.

India is a vast country with around 850 large paper industries. It is ranked 17 in the highest polluting industries in India, approximately 190–200 m3 of water is needed to produce a ton of paper. Around 240–250 chemicals have been identified in effluents, which are produced at different stages of papermaking in paper industry. The pulp and paper industry is typically associated with pollution problems related to color, suspended solids, high biochemical oxygen demand (BOD), chemical oxygen demand (COD), organic halogens lignin and its derivatives, dioxin, furan, and chlorinated compounds. These compounds are highly toxic in nature causing strong mutagenic effects, physiological impairment, and they are ecoestrogens. Although numerous studies have looked at methods for the treatment of color, COD, BOD, etc. of pulp and paper effluents, the problem still persists. Biological treatment uses a number of microorganisms including bacteria, fungi, and actinomycetes to degrade the xenobiotic compounds present in pulp and paper industry effluent. The need for cleaner production programs has been felt in recent times by the paper industry by way of a resource and waste minimization concept. In India efforts have been going on for years to improve housekeeping, optimize process parameters, increase recycling, and adopt improved technology. This chapter aims at highlighting the processes used during the manufacture, sources, and types of waste generated and treatment options available for improving the quality of waste to be discharged.

The discharged wastes from the pulp paper industry contain ligninocellosic material along with other co-pollutants even after secondary treatment. Moreover, the effluent contains a high amount of pH, total suspended solid, total dissolved solid, total solid, biological oxygen demand, and chemical oxygen demand along with heavy metals above the permissible limits. Several studies have concluded that white-rot fungi produced extracellular phenol oxidases which can effectively decompose lignin and other organic pollutants from the contaminated site. Furthermore, various types of persistent organic pollutants and endocrine-disrupting chemicals i.e. nonacosane; heptacosane; pentadecanoic acid, 2-benzisoxazole; hexadecanoic acid and octadecenoic acid are also present in pulp paper industry effluent that can cause aquatic toxicity and hormonal disturbance in the environment. The ligninolytic enzymes of white-rot fungi get a wide substrate particularity and have been involved in the transformation and mineralization of organic pollutants to systemic similarities to lignin. Moreover, continuous widespread land and groundwater pollution as well as surface water have brought this issue to the forefront, and cleaning up of such pollution is still a severe economic challenge for the society. The use of indigenous white-rot fungi for remediation of wastes from the disposal site of the pulp paper industry gives a very relatively novel economic solution for many of our risky environment challenges.

Enzyme use has provided boost to the technoeconomics of many industrial processes. In this chapter, we summarize different cellulase-based industrial processes for preparation of paper, pulp, brewing products, and different foods. This review presents a brief chemistry and mechanism of cellulose degradation by the cellulase enzyme. Also, cellulase production abilities of many microbial species have been addressed in this chapter. Cellulase plays a major role in production of good-quality paper and pulp. It’s used to debark the biomass and to remove lignocellulosic part. This enzyme also has application in recycling of used paper by deinking and biobleaching. Cellulase enhances freeness and drainage ability of the fibers without compromising the brightness of the fibers. In brewing industry, cellulase in combination of other enzymes is used to extract the more sugar for better-quality alcohol production. Cellulases have a wide range of potential applications in food and beverage processing, production of fruit and vegetable juices, and improvement of methods for extraction, clarification, and stabilization.

In this paper, we report the performance of paper pulp as an innovative viscosity modifying admixture (VMA) for cement composites. Two different levels of fineness were obtained by mechanical milling of the same source of paper pulp. Their effects on viscosity modification, hydration kinetics, autogenous shrinkage, and compressive strength of cement grouts were measured, and their structural integrity at high pH was assessed. A new parameter was proposed to quantify nonlinearity induced by VMAs. Results showed that the hierarchical structure of paper pulp makes it possible to activate bridging flocculation and swelling mechanisms of hydrophile paper pulp fibers at different levels to produce versatile VMAs. The coarser milled paper pulp fibers mainly influences the plastic viscosity. By contrast, the milled paper pulp consisting of ultra-fine fibers significantly modifies both plastic viscosity and dynamic yield stress, induces more nonlinearity in the mixtures, and increases compressive strength of mortars at low dosages.

With the objective to obtain more sustainable production processes, the biorefinery network is integrated with traditional pulp and paper industries. A systematic framework with computer-aided tools consisting of synthesis, design and innovation stages has been applied to determine the biorefinery-integrated pulping process. An integrated network of succinic acid production and black liquor gasification for dimethyl ether (DME) production linked to an existing Soda pulping process is identified as the best option for increased profit, which also reduces pollutant emissions through integration of innovative CO2 capture and utilization (CCU) steps to form the biorefinery-integrated-Soda-pulping network (BIS). This paper aims at also designing a sustainable biorefinery-integrated-Kraft-pulping network (BIK). Three integration scenarios are considered for further study: (I) the production of gasification-based dimethyl ether (DME); (II) the coproduction of DME and succinic acid (SA); and (III) the co-production of DME and SA coupled with CCU. The best scenario is found to be Scenario II, which exhibits the best economic performance with 74% increase in profit compared to the conventional process. Scenario III achieves the highest energy efficiency at 39% and improved environmental performance, a 65% reduction of CO2 emission compared to the conventional process, with only 0.7% profit reduction. The BIK option shows improved performance in terms of economic and environmental improvements compared to the BIS network, confirming that the integrated biorefinery network can transform the conventional Kraft pulping process to a more sustainable process with increased profit.

During recent years, the socio political pressure to develop suitable technologies capable of treating wastewater from the paper and pulp industry has increased due to strict environmental regulations. System closure could potentially lead to substantial operating and discharge cost savings. This study evaluates the potential of combining an aerobic moving bed biofilm reactor (MBBR) (biological) and a Fenton-like system (advanced oxidation processes) for treating recycle mill effluent (RME). The performance of the moving bed biofilm reactor (MBBR) was evaluated at three different hydraulic residence times (HRT). The HRT used were 24, 16 and 5 h and the corresponding total chemical oxygen demand (COD) removals were 55, 49 and 43% respectively. The volatile organic acids (VOA) removals were 63.5, 58.7 and 53% respectively. The Kincannon-Stover model was used to describe the kinetic behaviour of the MBBR. The calculated KB and Umax parameters for the COD were 26.37 g.L−1.d−1 and 15.06 g.L−1.d−1 respectively. For the VOA, the KB and Umax parameters were 11.81 g.L−1.d−1 and 8.87 g.L−1.d−1. The Fenton-like experiments were carried out in batch runs. The first experiments were carried out to determine the optimal reaction parameters. Maximum COD removals were found to be at a pH of 3.33, Fe3+ dosage of 1,000 mg/L and H2O2 of 14.55 mM. Pseudo-first order reaction kinetics was used to describe the kinetic characteristics of the Fenton-like treatment system. The calculated kinetic parameters ηmax (%) and kCOD (min−1) were 53.8% and 0.112 min−1 respectively at a pH of 3.24, Fe3+ dosage of 250 mg/L and a H2O2 dosage of 77 mM. Keywords: Moving bed biofilm reactor (MBBR), Fenton-like system, Recycle mill effluent (RME)

Significative growth and demanding for premium tissue products, in which softness and absorbency are key consumer requests, pointed out the need for the establishment of relations between fiber properties and tissue paper properties. For this purpose, an experimental plan was designed using a representative group of pulp fibers, six hardwood, and six softwood, for the production and characterization of low basis weight paper structures (20 g/m2). The pulp fibers morphology and chemical content were evaluated, and hardwoods showed lower fiber length (0.70–0.84 vs 1.57–1.96 mm), coarseness (6.71–9.56 vs 16.77–19.66 mg/100 m) and higher pentosan content (6.3–21.1 vs 7.6–10.3%). Even though the paper structures were produced with the same basis weight, they presented a broad range for bulk (3.46–8.04 cm3/g), tensile index (2.00–11.45 N.m/g), softness (65.7–86.9) and absorption capacity (8.08–9.48 g/g). The results indicated that softness was directly influenced by structural properties, increasing with bulk, while tensile strength correlated inversely. Therefore, the correlations obtained were used to identify the most suitable pulp fibers properties for each type of tissue paper. Keywords: Absorption, Cellulose fiber materials, Pulp fiber morphology, Softness, Tissue papers

In the present manuscript, novel effluent treatment processes for pulp and paper mill effluents are divided into two categories: a) those involving the use of chemical additives and b) those which are free of such chemicals. It is especially of high importance for pulp and paper industry to adopt the most efficient and cost-effective treatment methods. This paper critically reviews the recent studies on the treatment of pulp and paper mill effluents while providing suggestions for further studies on the application of various physic-chemical and biological methods for the treatment of such complex effluents containing a number of recalcitrant pollutants. Keywords: Pulp and paper industry, Industrial effluents, Chemical additives, Non-additive treatment processes

D0bleaching wastewater from E. globulus Kraft pulping industry was treated by Fenton and photo-Fenton processes. The aim was to optimize the operational conditions for adsorbable organic halides (AOX) removal, namely oxidant concentration, [H2O2], catalyst concentration, [Fe2＋], and treatment time, using the central composite experimental design (CCED) tool. Temperature and pH were set at 60 ºC and 2, respectively, which are similar to the natural values of the D0bleaching wastewater. Both processes showed potential to remove AOX from D0with 177 - 178 mM H2O2 and 10 min reaction time. Maximum AOX removal was 85 % for the Fenton process with 8.5 mM Fe2＋, and 95 % for the photo-Fenton process with 2.0 mM Fe2＋ and UV irradiance 142 W.m− 2. For both methods, the only statistically significant variable (p=0.05) was the concentration of oxidant, [H2O2]. Keywords: AOX, Bleaching wastewater, CCED, Fenton, Photo-Fenton, Pulp and paper industry

This chapter highlights the importance of anaerobic digestion in pulp and paper mill waste (PPMW) treatment. Due to increasing environmental concerns and strict laws about the effluents from industries, it becomes imperative to use such a technology. PPMW contains a vast amount of organic contaminants that are recalcitrant. Postaerobic treatment, a considerable amount of sludge is generated, and to cope up with this, anaerobic digestion, which results in much-reduced sludge volumes, is one of the best methods. Anaerobic digestion of PPMW offers additional benefits through the generation of renewable value-added bioproducts such as biogas, biomethane, biohydrogen, and biofertilizer, along with the treatment of waste. The present chapter describes the importance of anaerobic treatment of PPMW for both sludge and wastewater and the simultaneous generation of value-added products. In the end, the various challenges associated with anaerobic treatment and their mitigation strategies are also discussed.

The paper and pulp industry generates different waste from the processing of raw material to paper production. The characteristics of the waste vary with the process and can be categorized as liquid discharge, solid and gaseous. Among these the liquid discharge is the major concern as it possesses organic as well as toxic load. The existing treatment process doesn't focus on material recovery and hence the materials are lost with the waste stream. The integration of biochemical and thermochemical processes can aid in designing a paper and pulp waste biorefinery which will produce value-added chemicals, fuel, and energy. The concept of the biorefinery is based on the integration of the existing conversion processes to achieve material and energy recovery in the light of circular economy.

Fly ash (FA) from biomass combustion and biological sludge (S), both wastes from the pulp and paper industry, were granulated in different proportions (90% FA + 10% S, and 70% FA + 30% S w/w, dry weight basis, dw) and used to recover the functionality of soils affected by mining activities (Aljustrel, Iberian Pyrite Belt), with and without the application of municipal solid waste compost (MSWC). Application doses of both mixtures were 2.5, 5.0 and 10% (w/w, dw). These materials corrected soil acidity to circumneutral values and increased extractable P and K concentrations. A significant increase in soil organic matter (from 0.6 to 0.8–1.5% w/w, dw) and N content (from 0.04 to 0.09–0.12% w/w, dw) was also observed, but only when MSWC was applied. The soil was already heavily contaminated with Cu, Pb and Zn and the application of amendments did not increase their pseudo-total concentrations. The CaCl2 extractable fractions of both Cu and Zn decreased to very low values. The improvement in soil quality, compared to fertilizer only treatment, was further evidenced by the increase in some soil enzymatic activities (dehydrogenase, β-glucosidase and cellulase), with a better response for the granules with the higher proportion of biological sludge, as well as by the decrease in the soil-water extract toxicity towards different organisms (Daphnia magna, Thamnocephalus platyurus, and Pseudokirchneriella subcapitata). Agrostis tenuis germinated and grew during the first month only in the amended pots, but, after that, a considerable phytotoxic effect was evident. This was mainly attributed to salt stress or to some specific ionic toxicity. In conclusion, to establish a long-term plant cover in mining soils amended with biomass ash-based materials, the selection of plants with higher resistance to salinity and/or the stabilization of the amendments, to reduce their soluble salt content, is recommended.

This work is concerned with the electrochemical detection of new psychoactive substances (NPSs), in particular 2,5-dimethoxy-N-(2-methoxybenzyl) phenethylamine structures (NBOMes) and the analogous 2,5-dimethoxy phenethylamine structures (2C-X group) on boron-doped diamond (BDD) electrodes. Fast square-wave voltammetry was used to identify the substances in question. The antifouling properties of the BDD surface resulted in stable, repeatable, sensitive and unique voltammetric responses for these NPSs, producing different voltammetric signatures. Different NBOMes were identified by voltammetric methods in blotting paper seized from the drug market, without any interference from LSD, another psychedelic drug distributed via blotting paper. The proposed method achieved detection limits lower than 0.1μmolL−1 with high precision (RSD

The performance of an amine-based post-combustion CO2 capture and storage (CCS) process in an existing Kraft pulp mill and an existing pulp and board mill was assessed. The pulp and paper industry is an energy-intensive industry, with significant amounts of CO2 emitted onsite. The majority of this CO2 originates from the combustion of biomass, which renders it carbon neutral if the biomass used by the industry is grown and harvested in a sustainable manner. If the CO2 emissions from the pulp and paper industry were to be captured and permanently stored, then this could make the industry a potential carbon sink. In this evaluation, different configurations of capturing CO2 from the flue gases of the recovery boiler, the multi-fuel boiler and the lime kiln were assessed. For a stand-alone Kraft pulp mill, the excess steam available is sufficient to cover the demand from the CO2 capture plant. For an integrated pulp and board mill, there is less excess steam available for the CO2 capture plant and an auxiliary boiler may be required. The retrofit of a post-combustion CO2 capture plant into an existing pulp mill increases the steam demand by 1-8 GJ/air dried tonne (adt) pulp, depending on the volume of the flue gas treated. This translates to a reduction in the amount of electricity exported to the grid by 0.1-1.0 MWh/adt pulp for a stand-alone Kraft pulp mill, and by 0.1-0.5 MWh/adt pulp for an integrated pulp and board mill. The total potential for negative CO2 emissions amounts to just under 2.0 Mt CO2/a both for the market pulp mill and for the integrated pulp and board mill.

The process of bioconversion of solid organic wastes through vermicomposting justifies the environmental message for sustainability such as reduce, recycle and reuse of wastes. In the present study, wastes derived from two different types of paper mill sludge (primary and secondary), was used for their bioconversion through the vermicomposting process using an indigenous species of earthworm (Perionyx excavatus). The maturity and stability stage of vermicompost production was assessed using FT-IR, GC-MS and TG analyses. During vermicomposting, different biochemical functional groups present in the wastes have shown differential chemical alteration and turnover as revealed by FT-IR spectroscopy. This study has also confirmed the trend of biodegradation of complex substances like lignin, cellulose, proteins etc. and thereby demonstrates the extent of mineralization. TG spectral analysis had revealed a mass loss of 80% and 71% in vermicompost produced from primary and secondary sludge respectively. GC-MS studies have also shown the presence of several humic acids like octadecanoic acid, heptadecanoic acid etc. in the decomposing substances demonstrating as an indicator of the maturity of products. This was further confirmed by the decrease of humification index which focuses the combined action of both earthworms and microbes in the degradation of organic wastes. The present study has highlighted the role of an indigenous earthworm in converting specific industrial wastes especially by recording the point of maturation using humic acids an indicator of the quality of decomposing of wastes following several instrumental applications.

The paper and pulp industry (PPI) is regarded as one of the most polluted, as it produces high quantities of solid and liquid discharge. On average, in a developed country, up to 10 million tons of waste is generated each year and considerable amounts of capital and other resources goes toward its treatment. The discharge from PPIs mainly constitutes solid and liquid waste with high organic content. This discharge is a potential feedstock containing a high percentage of lignin, cellulose, and hemicellulose, which can be used as a valuable raw material for the production of bioenergy, platform chemicals, and biofuels. At present, most of this waste is recycled using a conventional approach, through biological and chemical processes, incurring high costs and low returns. Therefore, strategies relying on any one of the conventional treatment technologies do not lead to optimal utilization of the valuable resources in the waste. Instead, cascading approaches such as coupling the generation of conventional bioenergy and high-value bioproducts within a biorefinery context could address this challenge. Therefore, this chapter initially provides a detailed account of the availability of paper and pulp waste and pretreatment methods. Various high-value bioproducts that can be produced in a biorefinery approach are discussed in order to pinpoint the most recent trends and future directions in research and development. It also focuses on technologies that have moved beyond the laboratory phase, identifies the problems, and summarizes the main interventions that can help overcome these issues. The chapter thus provides systemic insight into developing efficient, economically feasible, and sustainable biorefineries that could meet the technical and market requirements and improve the valorization of paper and pulp waste.

For the first time the feasibility of using an alkaline wastewater coming from the pulp and paper industry as an activator, partially (50 vol%) replacing commercial sodium hydroxide, in the production of cork-based activated carbons was evaluated. The activated carbons showed the highest value of specific surface area ever reported for cork-based activated carbons (1670 m2/g), surpassing several other commercial and waste-based ones. These eco-friendly cork and paper waste-based activated carbons were then evaluated as methylene blue adsorbent materials. The influence of contact time, methylene blue initial concentration and adsorbent amount on the methylene blue removal efficiency by the activated carbons was studied. Extremely fast (>99.9% removal in 5 min) and efficient methylene blue adsorption (uptake of 350 mg/g) by the cork and paper waste-based adsorbents was achieved, which demonstrates the huge potential of these innovative adsorbents. These activated carbons were produced using two unexplored industrial by-products (alkaline wastewater and cork) and, therefore, may be an inexpensive source of activated carbons, which can be used for the effective removal of dyes from wastewaters. Furthermore, despite the very large surface area and high removal efficiency this is not a nano material (being around 30–50 μm in size), its capabilities being due to its unique cork-derived microstructure, and hence it can be handled and removed/filtered much more easily than nanocarbons, and without any associated health or environmental risks. This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. R.C. Pullar wishes to thank FCT grant IF/00681/2015 for supporting this work, and R.M. Novais wishes to thank FCT project H2CORK (PTDC/CTM-ENE/6762/ 2014). published

The use of fibre-based materials as substrates in printed electronics has been increasing, mainly due to its attractive characteristics, such as low-cost or wide availability. Additionally, paper enables recycling and it shows attractive features, such as high thermal stability, when compared to traditional polymer-based substrates (Tobjörk and Österbacka, 2011 [1]). Nevertheless, one of the drawbacks of using paper substrates is that the surface usually is very rough, typically, showing roughness values above 10 μm2. In most cases, printing structures that need to be highly uniform, without disruptions, require additional coating. Inkjet printing provides sharp detail reproduction and strict lines on printed structures. Sintering is required for drying the ink. Thermal sintering is the traditionally used method, but requires long periods of time and promotes the ageing of the paper due to a long exposure at high temperature. When printing conductive structures on paper alternative photonic sintering methods such as IR-sintering show some attractive characteristics. IR-sintering is compatible with roll-to-roll fabrication, providing low-cost, fast and localized sintering, which makes it suitable for fibre-based substrates (Tobjörk et al., 2012 [3]). This work has been carried out to study and compare the efficiency of thermal and IR sintering of conductive structures on different paper and polymer substrates. All substrates were printed using silver based ink, which was applied on the substrate surface by inkjet. Resistivity values of the printed structures were used to compare the performance on the substrates. IR-sintering showed the best results in terms of achieved conductivity of the printed lines when using short sintering time of no more than 10 min. The conductivity values of the inkjet-printed silver lines on Lumi silk substrate reached about 40% of the bulk silver value after IR-sintering, whereas with thermal-sintering this value only reached about 20% of the bulk silver value. IR-sintering improves the sintering process, increasing the conductivity of the printed structures and at the same time reducing significantly the sintering time. In the case of Lumi silk substrate, high conductivity was observed after only two minutes of sintering time when IR-oven was used. Both techniques can be used in a roll-to-roll mass manufacturing process, enabling the fabrication in large scale of flexible electronic devices, on paper substrates, without the need for extra steps, such as coatings.

In pulp and paper production black liquor is burnt to recover base chemicals and to generate electricity and steam which is e.g. used in papermaking machines. In the event of paper tearing excess steam has to be condensed usually. We propose a latent thermal energy system to recover that energy and re-use it in the papermaking machines. A storage model was developed and experimentally verified by a lab-scale prototype. For the specific process, we designed a tube-bundle storage using thermally conductive HDPE as PCM and show that up to 30 MWh can be recovered per day. Finally, we describe the potential of storages to improve energy generation and efficiency in plants.

Nowadays, the need to attain a sustainable society increasingly demands for the development of an economy based on biorefineries. In Southwestern Europe, agrofood and forest industries produce significant amount of wastes that could satisfy the demand for renewable biomass to be used in a biorefinery scheme alternatively to traditional uses of these residues. This chapter will primarily cover the current scenario regarding the annual volume of residues generated by agrofood (cheese whey, vine pruning waste, and brewer's spent grains) and pulp and paper industry (sawdust, chips, bark, and sludge). Additionally, the present-day use and final destination of these wastes and their main environmental issues will be described and discussed; besides, advanced valorization strategies (e.g., fuels and chemicals) involving a biorefinery approach will be approached, based on current reports according to the chemical composition of each waste. Finally, new insights on valorization of wastes from agrofood and pulp and paper industries, its challenges, and trends for future research will be presented.

Cellulose nanopaper (CNP) is a fascinating free-standing thin film material, prepared from renewable nanocellulose and displaying special properties such as transparency, haze, thermal stability, mechanical strength, and flexibility. The nanostructured nature of CNP enables gas barrier films and high specific surface areas for interface functionalization. Re-engineering CNP by physical and chemical design allows to tailor its properties, enabling hydrophobic and transparent paper, smart sensors, substrates for optoelectronic devices, and conductive or luminescent papers. This chapter rationally describes the chemical and physical manipulations that can be performed on CNP to modulate its properties, classifying them as: covalent chemical modification on nanocellulose before processing them into nanopaper thin films; covalent chemical modification on CNP surface; and noncovalent modification of CNP by coating or blending nanocellulose with other materials.

Paper and board recycling is now a central issue in papermaking. Understanding of material flows, as a part of the total production chain, as well as, fibrous and non-fibrous component flows needs further clarification. These flows are studied at a European level, with special focus on Germany and Sweden. Non-fibrous components are discussed in terms of a material which hampers the processing of paper and board. Resource-efficiency improvements, in conjunction with economic benefits, are sought and recycling has been able to fulfil both of these. The main drivers to maximize the use of recovered paper in paper and board manufacturing, have been improved over the last decades. These drivers are cost, environmental image and good technical properties to be used as raw material. The increased recycling rate has reduced the quality of the collected paper, produced recycled paper, and replaced virgin pulp. Also, recycling as a process, like deinking, produces large amounts of waste material that has challenges to find proper utilization. These problem areas are addressed in this paper, too. One focus area in the analysis of statistical information is an estimation of the share of non-fibrous components and fibre volumes of paper in Europe (EU) for the year 2010.

Measures for reduction of water consumption in pulp and paper mills are presented in this chapter. These include: in-pulp mill water conservation, modification of pulping and bleaching processes, separation of process and nonprocess waters, process modification, improvement in quality and management of paper machine wastewater, and system closure and integration of water systems/application of pinch technology.

The pulp and paper industry in the global market and a basic overview of pulp and paper manufacturing process are presented in this chapter.

The generation of three-dimensional superb packages of compact hexagonal periodic assembly with multifaceted layers was demonstrated using Poly (styrene-butylcrylate-acrylic acid) on glass substrates. The synthesized P(St-BA-AA) microspheres were used to formulate a fast drying UV curable terpolymer microspheres printing ink for the generation of colloidal crystal microdots on ink-jet paper with remarkable colours. The terpolymer microspheres and their formulated terpolymer ink undergo self-assembly to form blue monochromatic and viewing angle dependent tunable colours, thus affirming the photonic nature of the generated colloidal crystal films. Unlike other printing techniques which usually make use of specialized tools, this study generated a well ordered coloured tunable assembly of spherical shaped core-shell colloidal crystal microdots on the surface of an inkjet-paper by manually writing the as-synthesized P(St-BA-AA) UV curable printing ink microdots on it. The TEM analysis showed core and shell sizes of 198/50nm and 176/30nm for P(St-BA-AA)1 and P(St- BA-AA)2 respectively. Whenever the prepared terpolymer microspheres are used within the heating and transition temperatures of 383 °C and 110 °C, their thermal stability is retained. This simple technique of generating crystals microdots on inkjet paper may find use in optical devices, security applications and other colour coating applications., Materials science; Nanotechnology; Poly(styrene-butyalcrylate-acrylic acid); Photonic crystals; Monodisperse core/shell; Terpolymer; Colloidal ink; Colloidal crystal microdots

Since the Second World War, the pulp and paper industry has become one of the most important industries in the world based on its economic benefits. Unfortunately, it is usually associated with high water usage and high electricity expenditure. Currently, pulp and paper mills are faced with various challenges forcing them to follow stringent environmental regulations and adopt sustainable waste management strategies as well as utilizing best available technologies to treat the effluent. While the discharge of hazardous effluent is certainly a growing concern, the pulp and paper industry is making great progress in reducing the quantity of wastewater it expends along with the amount of hazardous materials found in the effluent. This chapter provides a brief overview of waste generation and management in pulp and paper mills, and it also discusses the combined novel and conventional aerobic effluent treatment methods.

In this work, several cellulose board grades, including waste board, fluting, and waste milk container board, were pretreated with green choline chloride-urea deep eutectic solvent (DES) and nanofibrillated using a Masuko grinder. DES-treated bleached chemical birch pulp, NaOH-swollen waste board, and bleached chemical birch pulp were used as reference materials. The properties of the nanofibrils after disc grinding were compared with those obtained through microfluidization. Overall, the choline chloride-urea DES pretreatment significantly enhanced the nanofibrillation of the board pulps in both nanofibrillation methods—as compared with NaOH-treated pulps—and resulted in fine and long individual nanofibrils and some larger nanofibril bunches, as determined by field emission scanning electron microscopy and transmission electron microscopy. The nanofibril suspensions obtained from the DES pretreatment had a viscous, gel-like appearance with shear thinning behavior. The nanofibrils maintained their initial crystalline structure with a crystallinity index of 61%–47%. Improved board handsheet properties also showed that DES-treated and Masuko-ground waste board and paper nanocellulose can potentially enhance the strength of the board. Consequently, the DES chemical pretreatment appears to be a promising route to obtain cellulose nanofibrils from waste board and paper.

The pulp and paper industry uses large volumes of water. Much water is lost to evaporation during production resulting in high demand for fresh water. The industry has made steady progress over the past three decades in reducing its relative water footprint. A growing market for equipment and services in pulp and paper water and wastewater treatment is seen. In this chapter water usage and consumption are presented. Water consumption standards are also presented.

The pulp and paper industry is one of the largest industries in the world with very high capital investments. Over 400 million metric tons of paper and cardboard are produced worldwide every year, with China being responsible for around one-quarter of the total production. Global pulp and paper production and consumption are presented in this chapter.

Paper is recycled at a relatively high rate in the U.S. Rates are particularly high for corrugated boxes, which are predominantly recovered from businesses rather than from households. Packaging is a major source of recycled paper, as well as a major market for the recycled fiber. Paper coated with plastic or wax is difficult to recycle. The paper-recycling process involves re-suspending the fibers in the slurry, and separating contaminants. Recycled fibers tend to be shorter and weaker than virgin fibers. Contaminants in the recycled paper can cause problems with operation of the process as well as with paper performance. With proper design, recycled paper can perform very similarly to paper made from virgin fiber.

While paper and paperboard are being used in many applications, their largest application is as materials for packaging applications. Paper and paperboard could be made into a wide range of packaging, either with or without additional treatments, alone or combined with other materials. They are made from renewable resources and recovered paper; and are recyclable. This article provides an overview of paper and paperboard making process, including a brief history; and characterizations of paper and paperboard and properties.

Wood is the dominant raw material for paper and paperboard production. More than 50% of the average global paper furnish is from virgin wood-based pulp. The other sources are recycled fiber (RCF) from recovered paper (RCP), nonwood fiber, and mineral pigments. This article presents the types and characteristics of pulpwood resources, occurrence, availability, and productivity of wood resources. The trends in wood usage in the pulp and paper industry were discussed. A critical concern for the global pulp and paper industry there will be reasonable access to the vast softwood resources in Siberia.

Pulp and paper mills are highly complex and integrate many different process areas. Processing options and the type of wood processed are often determined by the final product. A basic overview of pulp and paper manufacturing process, greenhouse gas (GHG) emission sources, and energy requirements in various pulp and paper processing steps are presented in this chapter.

The paper and packaging industry is an important part of the global economy and plays a critical role in the world economy. Cellulase, a complex enzyme produced by a number of microorganisms, has tremendous potential application in the pulp and paper industry. Cellulase contributes 10% of the worldwide industrial enzyme demand, and there is tremendous potential for cellulase biotechnology in pulp and paper manufacturing to grow steadily commercially, and to give rise to new possibilities. Cellulase, xylanase, laccase, and lipase are the most important enzymes that can be used in the pulp and paper processes. This prospective study aims to enhance the understanding of the most important advanced uses of cellulases for providing benefits to the pulp and paper industry in various areas like increased pulp yield, improved fiber properties, enhanced paper recycling, reduced processing and environmental problems, and energy efficiency.

Chemical additives used in papermaking fall into three groups—general (commodity) and two classes of specialty chemicals—process and functional. Process chemicals are used to optimize the production process by increasing machine speed, runnability, providing deposit control and reducing steam consumption. Retention aids, defoamers, fixative agents, biocides, and defoamers/antifoam additives are some typical examples of process chemicals. Functional chemicals directly affect paper quality and paper properties—color, water repellency, strength, printability, etc. Typical examples of such functional chemicals are dyes, coating binders, and strength and sizing additives. The boundary between process and functional chemicals is not very definite as process chemicals may either significantly influence performance of functional chemicals and/or affect sheet properties directly. About 90% of all chemical additives belong to functional additives. The remaining 10% are process chemicals, with retention aids (including fixatives, coagulants, flocculants and microparticles) representing the biggest and most important part. The in-depth and thorough coverage of chemical additives in the pulp and paper industry are presented. Various sections deal with pulping chemicals, bleaching chemicals, process chemicals, functional chemicals, pigments for fillers, coating pigments, aluminum, starch, chemicals used in paper recycling, and chemicals used for stickies control and tissue and towels.

Two organic–inorganic hybrid sol–gel coatings were developed in order to modify the surface energy and moisture behaviour of the commercial impregnated paper. The surface characteristics of the paper samples were studied by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectrometry (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectroscopy (ToF-SIMS). It was found that the applied sol–gel coatings as well as the curing process changed the surface structural and chemical properties of the impregnated paper. The chemical bonding between the hydroxyl groups present on paper surface and silanol groups from sol–gel coatings was confirmed by the FTIR spectra. The measured surface energies divided into polar and dispersive components indicated that the coating B resulted in less polar surface than did the coating A which was more polar than the reference (the impregnated paper with water and heat treatment). Coating B brought about the lowest total surface energy. It was obtained that the water repellence of the impregnated paper was improved by both coatings and the curing process.

In parallel with the development of nanoparticle coatings for protection of paper substrates, detailed descriptions of the surface topography with micro-to nanoscale roughness features are needed. In this work, papers have been coated with poly(styrene-co-maleic anhydride) nanoparticles including different types of vegetable oils and the surface roughness was evaluated at 2000 x 2000 mu m(2) to 0.2 x 0.2 mu m(2) length scales by combining non-contact optical profilometry (NCP) and atomic force microscopy (AFM). The relationships between roughness data were studied for statistical roughness parameters, spatial roughness parameters and in the frequency domain. In order to compare AFM roughness more accurately, the original images were flattened to remove effects of the underlaying fibrous substrate and highlight features of the nanoparticle coating. More detailed information on the coating topography could be obtained by considering bearing ratio curves and histograms, where it was concluded that the oil-filledcoatings form a rather thin and continuous coating that closely follows the shape of the cellulose fibers. The relation between statistical roughness parameters from NCP and AFM follows an exponential trend with relatively low coefficient of determination. The increase in surface roughness with length scale showed a transition point attributed to short-and long-range surface features. Therefore, the correlation length was used as a spatial roughness parameter that provides a successful extrapolation of the average roughness over different length scales in a double logarithmic diagram with very high coefficient of determination. Based on the power spectral density, it was difficult to exactly distinguish between the different types of SMI/oil coatings, as they include similar nanoscale features. The frequency roughness parameters were better suited for extrapolation than statistical roughness parameters but little less efficient than the spatial roughness parameters. (C) 2015 Elsevier Ltd. All rights reserved.

The art, science, and technology of papermaking may be traced to 200 BC in China. Papermaking has played an important role in cultures all over the world and has evolved from simply pouring pounded pulp onto a fabric screen into the modern technology used today. This article traces the evolution of papermaking, the growth of paper technology, the variation in papermaking techniques, and reviews the economic and social reasons behind these changes.

Papermaking deposits can be classified as being organic, inorganic, or microbiological. Most paper machine deposits contain a combination of some or all of these major component types. Although inorganic deposits tend to be more of a problem in the stock and flow-piping systems of the paper mill, organic deposits tend to be more problematic in the headbox, wet end, and press section of the paper machine. These contaminants form tacky deposits that can plug forming fabrics and wet press felts. Microorganisms in paper mill systems take two forms: planktonic and sessile. Planktonic organisms do not readily cause problems in the system; however, in the sessile form, these same organisms can become problematic. Inorganic and organic deposits offer a readily available food source for sessile organisms, which attach themselves to deposit surfaces. Several of these organisms classified as slime formers are able to secrete a protective polysaccharide coating around themselves known as biofilm. The slime formers, in combination with inorganic and organic process additives and contaminants, can form deposits that coat process equipment and create sheet quality and runnability problems. In addition to slime formers, anaerobic bacteria can form under deposits. The most common type of anaerobic bacteria found in paper mills is sulfate-reducing bacteria, which is capable of converting sulfate in the system to highly corrosive hydrogen sulfide.

The pulp and paper industry is one of the largest industries in the world, with very high capital investments. The world's total paper production amounted to 403 million tons in 2013. The majority of manufacturing facilities in the paper industry are integrated. Most paper mills begin with wood chipping at the front end, followed by pulping, bleaching, papermaking, and recycling of post consumer products. The paper and paperboard industry in the global market and general aspects of pulp and papermaking processes are presented.

Company profiles of major pulp and paper chemical suppliers such as Kemira, Akzo Nobel NV, Eka Chemicals AB, Ashland, Inc., BASF, Buckman Laboratories International, Inc., Clariant, and Nalco Chemicals are presented. Major and niche enzyme suppliers—Novozymes, Enzymatic Deinking Technologies, Genencor, AB enzymes, DSM (Netherlands), Diversa (USA), Kao (Japan), and Tritex etc.—are also presented.

Pick-up felts and deposits in wet end splash areas and in storage tanks of paper machines contained large amounts of thiosulfate (80– 16 000 mg kg −1 , wet weight) and oxalate (20– 2300 mg kg −1 , wet weight). These anions were absent ( mg l −1 ) in process water and found in raw materials only in low concentrations (5– 10 mg kg −1 , wet weight). Similar and larger amounts of thiosulfate, sulfite and oxalate were generated de novo from sulfate and sheets of chemical pulp in a splash area simulator fed with artificial paper machine white water in the laboratory. Stainless steel UNS S30400 coupons placed in the simulator developed significant corrosion pits within 4 weeks. Pitting was most extensive under or vicinal to patches where large amount of thiosulfate and oxalate accumulated in the pulp sheet. Pitting of UNS S31600 occurred only vicinal to the pulp sheet. The pitted steel surfaces accumulated large amounts of silicon containing material. The biogenic conversion of sulfate into compounds of lower oxidation states occurred more extensively on stainless steel UNS S30400 than on UNS S31600.