Search

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.