Forest Waste Research Articles

3D printing of biodegradable biocomposites based on forest industrial residues by fused deposition modeling

This study investigated the impact of industrial forest residues (IFR) type and proportion on 3D-printed biocomposites (BC). Fused deposition modeling (FDM) produced BC containing up to 20 % Jack pine sawdust, wood ashes, cellulose fibers, and polylactic acid (PLA). The BC thermal stability, surface chemistry, microstructure, and physical and mechanical were investigated. Thermal stability investigations revealed that adding IRF resulted in a decline in the PLA degradation temperature, an increase in the residual mass, a decrease in the glass transition temperature, and an improvement in crystallinity. Add IRF to PLA showed an important reduction in ductility, a consistent reduction of the tensile and flexural strengths with increasing proportion but only a slight or a non-significant reduction the modulus of elasticity. Adding forest waste filler to pure PLA increased the water absorption (WA) and dimensional accuracy (TA) of the biocomposites, which was expected due to the hydrophilic character of fillers. The microstructural analysis demonstrated that a higher filler level resulted in a greater porosity, roughness, and visible filler pull-out on the filament and printed parts surfaces. Surface chemistry analysis suggested poor interactions between the PLA and the fillers and consequently poor interfacial adhesion. Furthermore, the rheological investigations confirmed that the complex viscosity and storage modulus of PLA-Jack pine's sawdust and PLA-cellulose fibers increased with filler. In contrast, the PLA-wood ashes showed opposite results. Using 3D-printed biodegradable biocomposites provided a sustainable option for reducing dependence on non-renewable plastic, valorizing the value chain of forest products, and promoting the circular economy.

New Eco-Cements Made with Marabou Weed Biomass Ash

Biomass ash is currently attracting the attention of science and industry as an inexhaustible eco-friendly alternative to pozzolans traditionally used in commercial cement manufacture (fly ash, silica fume, natural/calcined pozzolan). This paper explores a new line of research into Marabou weed ash (MA), an alternative to better-known conventional agro-industry waste materials (rice husk, bagasse cane, bamboo, forest waste, etc.) produced in Cuba from an invasive plant harvested as biomass for bioenergy production. The study entailed full characterization of MA using a variety of instrumental techniques, analysis of pozzolanic reactivity in the pozzolan/lime system, and, finally its influence on the physical and mechanical properties of binary pastes and mortars containing 10% and 20% MA replacement content. The results indicate that MA has a very low acid oxide content and a high loss on ignition (30%) and K2O content (6.9%), which produces medium–low pozzolanic activity. Despite an observed increase in the blended mortars’ total and capillary water absorption capacity and electrical resistivity and a loss in mechanical strength approximately equivalent to the replacement percentage, the 10% and 20% MA blended cements meet the regulatory chemical, physical, and mechanical requirements specified. Marabou weed ash is therefore a viable future supplementary cementitious material.

Self-adhesive ionic cable derived from natural bark as osmotic energy generator

Osmotic energy conversion technology plays an increasingly important role as clean energy alternatives. However, the excessive use of non-renewable materials in osmotic energy harvesting can lead to serious environmental pollution. Herein, we design a low-cost, eco-friendly, and high-ion-conductance ionic cable directly from natural Eucommia ulmoides bark owing to its unique sandwich structure and abundant charged nanochannels within the well-aligned lignocellulose nanofibers. In the cable, the natural biopolymer E. ulmoides gum (EUG) acts as a bio-adhesive tightly holding cellulose fibers together, rendering it with high morphological stability. The as-prepared ionic cable shows excellent ion conductance of 3.36 × 10−3 S cm−1, far surpassing the performance of natural bark (2.58 × 10−4 S cm−1). This work utilizes the natural E. ulmoides bark components and its unique lignocellulose-EUG sandwich structure to construct fully biomass-based cable with high-ion-conductance and water-stable, providing a sustainable strategy to accelerate the implementation of clean osmotic energy harvesting and forest waste utilization.

Metabolic pathway analysis of the biodegradation of cellulose by Bacillusvelezensis

A green strategy that using Bacillus velezensis to degrade cellulose in bamboo forest waste was demonstrated. The cultivation conditions of microorganism, identified as Bacillus velezensis by 16S rDNA, were optimized by response surface methodology (RSM). Results showed that with a temperature of 35 °C, a pH of 6 in a Luria-Bertani (LB) medium, and a rotation speed of 140 r/min, the bamboo forest waste powder was added to the purified bacteria at a dose of 1 % (w/v), the cellulose degradation rate reached the highest value of 33.12 %. Besides, the fourier-transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and liquid chromatography-mass spectrometry (LC-MS) indicated that cellulose could be effectively degraded, with possible products including cellobiose, uridine diphosphate (UDP)-glucose, D-glucuronic acid, etc. The metabolic pathways involved in cellulose degradation by this strain include the pentose phosphate, starch, sucrose, and glucuronic acid pathways.

Utilization of Forest Residues for Cellulose Extraction from Timber Species in the High Montane Forest of Chimborazo, Ecuador

The present study explored the extraction of cellulose from forest residues of four timber species, namely Cedrela montana Moritz ex Turcz, Buddleja incana Ruiz & Pav, Vallea stipularis L. f. and Myrsine andina (Mez) Pipoly, in the high montane forest of Chimborazo province, Ecuador, for the sustainable utilization of leaves, branches, and flowers. An alkaline extraction method was used on the residues without the need for prior degreasing. An ANOVA analysis was applied to evaluate significant differences in cellulose extraction yields among the species’ residues. The characterization techniques used were Fourier transform infrared spectroscopy (FTIR) and polarized light optical microscopy, which confirmed the successful extraction of cellulose with characteristics comparable to standard cotton cellulose and other traditional species. The results showed significant variations in cellulose yield among the species, with Vallea stipularis L. f achieving the highest yield of 80.83%. The crystallinity of the samples was clearly evidenced by the polarity of the light in the samples during microscopy, demonstrating that the residues can be a viable and sustainable source of cellulose, contributing to a circular economy and reducing the environmental impact of forest waste.

Fabricating whole pine needles biomass with phenylhydrazine-4-sulphonic acid for effective removal of cationic dyes and heavy metal ions from wastewater

We applied a holistic, sustainable, and green approach to develop an effective multipurpose adsorbent from whole pine needles (PNs), a forest waste lignocellulosic biomass. The PNs were oxidized and modified with phenylhydrazine-4-sulphonic acid (ɸHSO3H) to OPN-ɸHSO3H. The latter was characterized and tested as an adsorbent for cationic dyes, malachite green (MG), methylene blue (MB), crystal violet (CV), and metal ions (Hg2⁺ and Pb2⁺). The adsorption followed different kinetic models: Elovich for MG and MB, pseudo-second-order for CV, and pseudo-first-order for Hg2⁺ and Pb2⁺. Langmuir isotherm indicated maximum adsorption capacities of 303.4 ± 8.91 mgg−1 (MG), 331.4 ± 17.50 mgg−1 (MB), 376.6 ± 22.47 mgg−1 (CV), 210.8 ± 28.86 mgg−1 (Hg2⁺), and 172.9 ± 20.93 mgg−1 (Pb2⁺) within 30 min. Maximum removal efficiencies were 99.0% (MG), 98.0% (MB), 96.04% (CV), 95.5% (Hg2⁺), and 89.8% (Pb2⁺). The adsorbent demonstrated significant regeneration and reusability over ten cycles, proving highly efficient for both cationic dyes and metal ions, with wide potential for practical applications where more than one adsorbate is present.

Teak leaf biochar production for sustainable forest waste management at low temperatures

This study investigates the possibilities of producing biochar from teak leaves as an environmentally beneficial approach to managing forest waste in a sustainable manner. Teak leaves, a readily available forest by-product, were converted into biochar through a low-temperature pyrolysis process using a top-lit updraft mechanism. The results demonstrate the efficiency of this approach, yielding a substantial biochar output of 37.4 wt%, with its thermal field modelled perfectly via Levenberg-Marquardt algorithm in ANN topology. Elemental analysis of the teak leaf biochar revealed a high carbon content of 64.40%, positioning it as a valuable carbon-rich material suitable for various applications. Textural properties analysis indicated a significant surface area of 371.78 m2/g and a total pore volume of 0.175 cm³/g, enhancing its potential for various applications. Scanning Electron Microscopy (SEM) investigations showed a diverse network of pores and a rough surface structure, reinforcing the biochar’s versatility. This study shows the environmental benefits of low-temperature teak leaf biochar production, because it provides a carbon-content-preserving, sustainable alternative for handling forest wastes.

Valorization of a high-sulfur petroleum coke for energy and fuels through its co-processing with a forest waste, using concrete wastes for sulphur and carbon dioxide capture under mild conditions

Current work provided a comprehensive assessment on the pyrolysis, combustion and gasification of a high-sulfur pet coke (PEC) and its blends with a forest waste (FOP). The potential of waste concrete fractions to capture SO2 and CO2 emissions was explored. The experiments were conducted in a fixed bed system and a thermogravimetric-mass spectrometric unit. Thermal behavior, reactivity, conversion, synergy, structural and chemical characteristics of solid materials, quantitative analysis of products and heating value, chemical, mineralogical and fusibility analysis of ashes were studied as a function of temperature, blending ratio and sorbent/fuel ratio. Addition of sorbent at a ratio Ca/S = 2 resulted in a desulfurization extent of 76–81 % during combustion. Quarry dust sorbent captured up to 95.4 % of CO2 emitted below 700 °C. At 1000 °C H2 content was 64.8–72.9 % mol and syngas yield 1.1–1.8 m3/kg. The gasification performance of PEC was improved upon blending with FOP.

New Frontiers for Raw Wooden Residues, Biochar Production as a Resource for Environmental Challenges

Biochar has gained significant interest in the agroforestry sector, mainly because of its ability to improve soil quality and sequester carbon in the atmosphere. Among the feedstocks of possible use for biochar production is biomass, understood as products and residues of plant origin from agriculture and forestry. The quality of the biomass used for biochar production is important because the physicochemical characteristics of the final product depend on it. This review examines the use of biochar produced from forest wastes and its impact on agriculture, forest ecosystems and the environment in general. This work demonstrates that the use of biochar not only improves agricultural productivity and production, but also that the sustainable management of the environment and forests and contributes to forest fire risk mitigation. The authors, examining the physico-chemical properties of biochar produced by forest waste, noted that the most critical variable is the process (pyrolysis temperature, residence time and heating rate), but the type of biomass used as a raw material and the forest species used also have a significant impact in determining the characteristics of the final product.

Synthesis and characterization of polyurethane acrylate with bio-oil modification for photo-curing 3D printed flexible structures

The use of renewable resources for additive manufacturing has grown significantly as a means of advancing the ongoing shift to a green economy. This study uses bio-oil generated from the rapid pyrolysis of forest waste as a bio-based chemical to partially replace polyethylene glycol to synthesize a new type of bio-oil modified polyurethane acrylate, used in photo-curing 3D printing technology. The study explores the impact of the ratio of bio-oil to polyethylene glycol on the properties of polyurethane resin. As the amount of bio-oil added increases, the molecular weight of polyurethane acrylate decreases. Modified photosensitive resin showcases better suitability for photo-curing 3D printing, with lower viscosity and volume shrinkage, and its printed samples exhibit enhanced mechanical strength and improved thermal stability. In particular, when the bio-oil substitution rate is 20 wt%, the tensile strength of the 3D printed sample increases by 70 %, and the double bond conversion rate reaches 58.07 %. Meanwhile, the hollow and branching structures of 3D printing have the characteristics of high precision and flexibility. Introducing bio-oil into 3D printing technology not only expands the application fields of bio-oil but also provides new considerations for the transition of photosensitive resins from petroleum-based to renewable fields.

Integrated biorefinery approach for utilization of wood waste into levulinic acid and 2-Phenylethanol production under mild treatment conditions

In a bid to explore the on-site biorefinery approach for conversion of forestry residues, lignocellulosic biomass into value-added products was studied. The bark white pine wood was subjected to the microwave technique of fast and slow hydrolysis under varying acid and biomass concentrations to produce levulinic acid (LA). The HCl (2% v/v) and plant biomass (1% w/v) were identified as the optimum conditions for fast wood hydrolysis (270 ºC for 12 sec), which led to maximum LA yield of 446.68 g/kgPB. The proposed sustainable approach is mild, quick, and utilized a very low concentration of the HCl for the production of LA. The hydrolysate was used as a medium for Kluyveromyces marxianus growth to produce 2-phenylethanol (2-PE). K. marxianus used 74–95% of furfural from hydrolysate as a co-substrate to grow. The proposed model of the integrated biorefinery is an affordable on-site approach of using forest waste into localized solutions to produce LA and 2-PE.

The production of a novel adsorbent from forest waste (Platanus orientalis L.) for dye adsorption: Adsorption process optimization and experimental design

In the study, a novel activated carbon material was produced using forest waste commonly found in nature. The activation was completed by modifying the surface of the material with H3PO4. Using this adsorbent material, we investigated the adsorption of the hazardous dyestuff, methylene blue, from the water environment. The adsorbent was characterized using BET, SEM, and FT-IR analyses. The characterization processes revealed that the adsorbent has a wealth of functional groups and many cavities and protrusions on its surface. Moreover, according to the BET analysis result, it was observed that it is an adsorbent with a high surface area (876.01 m2 g−1). Kinetic, equilibrium and thermodynamic studies have been conducted to fully understand the nature of methylene blue adsorption. The pseudo-second order kinetic model best represents the adsorption process data, and the Langmuir isotherm aligns with the equilibrium data. According to the Langmuir isotherm data, the maximum adsorption capacity (qmax) was determined to be 198.01 mg g−1. The thermodynamic results showed that the process of adsorption of methylene blue on various surfaces is spontaneous and occurs via physisorption. Additionally, in addition, the effects of the parameters (adsorbent dose, time, and concentration) determined for the methylene blue adsorption process were optimized using the surface response method. Activated carbon from plane tree fruits (Platanus orientalis L.) has the potential to be a novel adsorbent due to its unique surface morphology and strong adsorption capabilities.

Laccase‐mediated polymerization of tannins from a pine bark extract: Toward an eco‐friendly valorization of forest wastes

AbstractThe valorization of tannins from forest by‐products is a major opportunity for the sustainable development of the forestry industry. Herein we report the laccase‐mediated polymerization of tannins obtained from an aqueous pine bark extract. The reaction was conducted under an oxygen atmosphere at 50°C for 60 min and followed by UV–Vis, fluorescence intensity, phenol content, and viscosity measurements. An insoluble polymer was obtained after 45 min, which was attributed to coupling reactions triggered by phenoxyl radicals within the tannins mixture. The polymer showed a marked increase in thermal stability compared with the precursor pine bark extract, with a total mass loss of less than 12% at temperatures up to 500°C, suggesting potential practical applications in flame retardant materials. Additionally, the polymer showed an 85% DPPH activity and a 60% attenuation of singlet oxygen release upon light irradiation, which supports antioxidant and photoprotective properties for the prepared material. To the best of our knowledge, this is the first report to describe the formation of an insoluble polymer by direct enzymatic reaction of an aqueous tannin extract. In this case, soluble tannins are the sole reactants used to produce a promising versatile material for forest waste valorization.

Critical review of the role of ash content and composition in biomass pyrolysis

In the face of environmental challenges (e.g., dramatically increasing greenhouse gas emissions and climate change), it is utmost of importance to sustainable energy systems. Biomass consisting of agricultural and forest waste, municipal solid waste, and aquatics, has been identified as alternative and promising fuel sources. Thermochemical conversion approaches like pyrolysis can turn various types of biomass into three valuable product streams, namely, bio-oil, biochar, and syngas. To date, past review articles have considered the major operating parameters of kinetics, chemistry, and the application of pyrolysis products. However, ash content is one of the key biomass components that lacks investigation on its influence during biomass pyrolysis with respect to products yield and properties. This review article examines: i) the ash content and composition in different types of biomass; ii) effects of ash content on catalytic pathway and biomass thermal degradation; iii) ash related problems in the thermal degradation of biomass; and iv) available deashing techniques for biomass. The review aims to provide new understandings and insights regarding the effects of ash content and composition on biomass pyrolysis.

Unraveling the influence of biomaterial’s functional groups in Cd biosorption: a density functional theory calculation

Abstract Several biomass wastes, including forest wastes, bagasse, algae, and others, have been studied to determine their biosorption capability for adsorbing different ranges of heavy metals in the literature. Most experimental studies have not clearly shown the impact of functional groups in biomaterials discovered by FTIR analysis on the investigated biosorption processes. Because of this, the findings of this study indicate that it is necessary to theoretically investigate the influence of identified functional groups (as determined by FTIR analysis) on the biosorption activities of the sorbent or biomaterial prepared for the removal of cadmium metal from an effluent. Using the most geometrical structure for cadmium (Cd) metal, a series of identified functional groups for the sorbent were analyzed using FTIR to determine their mode and intensity of interaction to computationally understand better how they each influence the biosorption of cadmium. This was done to determine how each functional group contributes to the intensity of the cadmium biosorption, using a ground-state B3LYP density functional theory calculation performed in a Spartan 20 simulation package utilizing the 6-31G* and LANL2DZ > Kr basis sets. According to the study’s findings, carboxylate (–COO*) had the most significant effect on cadmium biosorption activity of all the functional groups studied due to the stronger binding strength obtained for it. Therefore, this research suggests exploring biomaterials with greater intensity for carboxylate function, which would aid cadmium sorption efficiency in an effluent treatment process.

Biochars from wood biomass as effective methylene blue adsorbents

Forest waste is a significant ecological and economic problem, requiring effective solutions that will not only reduce its quantity but also contribute to the protection of the natural environment. This research paper focuses on the use of sawdust from mixed trees, as one of the main forest wastes, for production of biochars characterized by adsorption properties. Sawdust, a by-product of the wood industry, has a porous structure, which makes it an attractive precursor to biochar. Using pyrolysis technology and hydrothermal activation under various conditions, sawdust was transformed into biochars with a developed specific surface area. The studies proved that the parameters of the pyrolysis process have a significant impact on the structural, surface and adsorption properties of biochars. The materials were characterized based on the results of N<sub>2</sub> adsorption, scanning electron microscopy SEM/EDS, thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Raman spectroscopy. The surface characterization was made using the Boehm titration and pH<sub>pzc</sub> determination. The sorption capacity of methylene blue (MB) was studied. It was stated, that the obtained materials were characterized by a large specific surface area (227.5 – 1019 m<sup>2</sup>/g), the micro/mesoporous structure and the large pores volume (0.106 – 0.784 cm<sup>3</sup>/g). The surface oxygen functionalities allowed for large adsorption of MB. The adsorption process follows the Langmuir theory (qm,cal from 357.1 to 434.8 mg/g) and can be described using the kinetic pseudo-second-order model (R<sup>2</sup> = 0.99). The obtained biochars showed high adsorption capacity of methylene blue impurities which indicates their significant potential for use in water purification.

English

The expanding population is leading to a continuous rise in the quantity of generated waste. Due to this, there is a need to recycle the waste generated so that it can be reused. Composting is a highly attractive method to manage and recycle waste generated, both because of the ease of management and for the lower cost compared to other treatments. In this study, eight different combinations of waste with wastewater treatment plant (WWTP) sludge as the principal waste and other plant waste in different proportions (garden waste, grape stalks, forest waste, olive and almond tree pruning cuttings, straw, and sawdust) were prepared. Composting in outdoor piles was carried out for 220 days, with weekly turning and watering as needed. At the end of the process eight composts were obtained with nutrient contents ranging from 2.23-3.24% total nitrogen (TN), 1.04-3.06% P2O5 and 0.37-1.99% K2O, with characteristics suitable for use in agriculture. Phytotoxicological and ecotoxicological evaluations showed that the generated composts had a growth-stimulation effect (germination rate greater than 100%) and very low environmental risk coefficients (risk coefficient less than 1).

CO2 adsorption on carbonaceous materials obtained from forestry and urban waste materials: a comparative study.

The increasing emissions of gaseous pollutants of anthropogenic origin, such as carbon dioxide (CO2), which causes global warming, have raised great interest in developing and improving processes that allow their mitigation. Among them, adsorption on porous materials has been proposed as a sustainable alternative. This work presents a study of CO2 equilibrium adsorption at low temperatures (0, 10, and 20°C) over a wide range of low pressures, on activated carbon derived from Eucalyptus (ES) and Patula pine (PP) forest waste, and carbonaceous material derived from waste tires (WT). The precursors of these materials were previously prepared, and their physicochemical properties were characterized. ES and PP were thermochemically treated with phosphoric acid, and WT was oxidized with nitric acid. Additionally, these materials were used to obtain monoliths using uniaxial compaction techniques and different binding agents, with better results obtained with montmorillonite. A total of six adsorbent solids had their textural and chemical properties characterized and were tested for CO2 adsorption. The highest specific surface area (1405 m2g-1), and micropore properties were found for activated carbon derived from Eucalyptus whose highest adsorption capacity ranged from 2.27mmolg-1 (at 0°C and 100kPa) to 1.60mmolg-1 (at 20°C and 100kPa). The activated carbon monoliths presented the lowest CO2 adsorption capacities; however, the studied materials showed high potential for CO2 capture and storage applications at high pressures. The isosteric heats of adsorption were also estimated for all the materials and ranged from 16 to 45kJmol-1 at very low coverage explained by the energetic heterogeneity and weak repulsive interactions among adsorbed CO2 molecules.

Development of Pinaceae and Cupressaceae Essential Oils from Forest Waste in South Korea.

The growing awareness of environmental issues has garnered increasing interest in the use of waste material in a wide variety of applications. From this viewpoint, developing essential oils from forest waste can bring new cost opportunities for the effective and sustainable management of unused forestry biomass. However, better knowledge of the production, chemical constituents, and application of essential oils is necessary. Among the species considered to be of interest from the point of view of their essential oils and forest biomass, Pinaceae and Cupressaceae were selected in this study as potential candidates for commercial essential oils based on previous studies. This current study focuses on investigating Pinaceae (Larix kaempferi, Pinus densiflora, and Pinus koraiensis) and Cupressaceae (Chamaecyparis obtusa and Chamaecyparis pisifera) essential oils extracted from various parts from the perspective of their bioactive compounds and potential applications. This is followed by an overview of the essential oils industry in South Korea, with particular attention being paid to utilising unused forest biomass. Therefore, this is a comprehensive review suggesting that Pinaceae and Cupressaceae essential oils extracted from various parts of forest waste could be utilised in various industries, adding value to the aspect of sustainable industry. Furthermore, our study contributes towards capturing the value of forest resources through the utilisation of native essential oils in South Korea.

Bioethanol production by enzymatic hydrolysis from Aspergillus calidoustus employing different lignocellulosic wastes

Cellulolytic enzymes were necessary for the decomposing of forest waste cellulose present in the environment. Based on the molecular characterization, the N6.2 potent cellulolytic fungal isolate was identified as determined Aspergillus calidoustus. The physical parameters of 5 days of incubation at 30 °C with seven pH resulted in high yield of cellulase enzymes. The endoglucanase activity was determined 87.36 U/ml, followed by β-glucosidase activity of 43.11 U/ml and exoglucanase, 21.03 U/ml under optimized conditions. Treatment of cellulosic substrate Pongamia and wood wastes by Aspergillus calidoustus resulted in breakdown of ligocellulosic waste with exoglucanase activity 234.50 ± 2.13 & 125.00 ± 2.50 U/ml, followed by endoglucanase activity 208.55 ± 4.03 & 112.08 ± 1.51 U/ml and β-glucosidase of around 90.57 ± 0.72 & 54.71 ± 2.50 U/ml. Further, the fermentation of pre-treated cellulosic polymer broth resulted in the production of bioethanol production of around 4.4 g/l/g of Pongamia leaves waste and 2.2 g/l/g of wood waste by the action of Saccaharomycetes spp. Hence, the current work outlines the cellulosic substrates utilization for sustainable two-step bioethanol synthesis, and potential implications for extensive research.