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1.
Environ Int ; 186: 108629, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38582060

RESUMO

Recently, extreme wildfires occur frequently around the world and emit substantial brown carbon (BrC) into the atmosphere, whereas the molecular compositions and photochemical evolution of BrC remain poorly understood. In this work, primary smoke aerosols were generated from wood smoldering, and secondary smoke aerosols were formed by the OH radical photooxidation in an oxidation flow reactor, where both primary and secondary smoke samples were collected on filters. After solvent extraction of filter samples, the molecular composition of dissolved organic carbon (DOC) was determined by Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS). The molecular composition of dissolved BrC was obtained based on the constraints of DOC formulae. The proportion of dissolved BrC fractions accounted for approximately 1/3-1/2 molecular formulae of DOC. The molecular characteristics of dissolved BrC showed higher levels of carbon oxidation state, double bond equivalents, and modified aromaticity index than those of DOC, indicating that dissolved BrC fractions were a class of organic structures with relatively higher oxidation state, unsaturated and aromatic degree in DOC fractions. The comparative analysis suggested that aliphatic and olefinic structures dominated DOC fractions (contributing to 70.1%-76.9%), while olefinic, aromatic, and condensed aromatic structures dominated dissolved BrC fractions (contributing to 97.5%-99.9%). It is worth noting that dissolved BrC fractions only contained carboxylic-rich alicyclic molecules (CRAMs)-like structures, unsaturated hydrocarbons, aromatic structures, and highly oxygenated compounds. CRAMs-like structures were the most abundant species in both DOC and dissolved BrC fractions. Nevertheless, the specific molecular characteristics for DOC and dissolved BrC fractions varied with subgroups after aging. The results highlight the similarities and differences in the molecular compositions and characteristics of DOC and dissolved BrC fractions with aging. This work will provide insights into understanding the molecular composition of DOC and dissolved BrC in smoke.


Assuntos
Aerossóis , Carbono , Fumaça , Madeira , Carbono/análise , Carbono/química , Fumaça/análise , Madeira/química , Aerossóis/análise , Aerossóis/química , Oxirredução , Incêndios Florestais , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Processos Fotoquímicos
2.
Ying Yong Sheng Tai Xue Bao ; 35(3): 587-596, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38646745

RESUMO

To investigate the longitudinal variation patterns of sapwood, heartwood, bark and stem moisture content along the trunk of artificial Larix olgensis, we constructed mixed effect models of moisture content based on beta regression by combining the effects of sampling plot and sample trees. We used two sampling schemes to calibrate the model, without limiting the relative height (Scheme Ⅰ) and with a limiting height of less than 2 m (Scheme II). The results showed that sapwood and stem moisture content increased gradually along the trunk, heartwood moisture content decreased slightly and then increased along the trunk, and bark moisture content increased along the trunk and then levelled off before increasing. Relative height, height to crown base, stand area at breast height per hectare, age, and stand dominant height were main factors driving moisture content of L. olgensis. Scheme Ⅰ showed the stable prediction accuracy when randomly sampling moisture content measurements from 2-3 discs to calibrate the model, with the mean absolute percentage error (MAPE) of up to 7.2% for stem moisture content (randomly selected 2 discs), and the MAPE of up to 7.4%, 10.5% and 10.5% for sapwood, heartwood and bark moisture content (randomly selected 3 discs), respectively. Scheme Ⅱ was appropriate when sampling moisture content measurements from discs of 1.3 and 2 m height and the MAPE of sapwood, heartwood, bark and stem moisture content reached 7.8%, 11.0%, 10.4% and 7.1%, respectively. The prediction accuracies of all mixed effect beta regression models were better than the base model. The two-level mixed effect beta regression models, considering both plot effect and tree effect, would be suitable for predicting moisture content of each part of L. olgensis well.


Assuntos
Larix , Caules de Planta , Água , Larix/crescimento & desenvolvimento , Larix/química , Caules de Planta/química , Caules de Planta/crescimento & desenvolvimento , Água/análise , Água/química , Análise de Regressão , Madeira/química , Modelos Teóricos , Previsões
3.
Int J Biol Macromol ; 264(Pt 2): 130718, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38460651

RESUMO

Chinese quince fruits (Chaenomeles sinensis) contain substantial amounts of lignin; however, the exact structure of lignin remains to be investigated. In this study, milled wood lignins (Milled wood lignin (MWL)-1, MWL-2, MWL-3, MWL-4, MWL-5, and MWL-6) were extracted from fruits harvested once a month from May to October 2019 to investigate their structural evolution during fruit growth. The samples were characterized via High-performance anion exchange chromatography (HPAEC), Fourier transform-infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), thermogravimetric (TGA), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and NMR (2D-heteronuclear single quantum coherence (HSQC) and 31P). The MWL samples in all fruit growth stages were GS-type lignin and lignin core undergoing minimal alterations during fruit development. The predominant linkage in the lignin structure was ß-O-4', followed by ß-ß' and ß-5'. Galactose and glucose were the main monosaccharides associated with MWL. In MWL-6, the lignin exhibited the highest homogeneity and thermal stability. As the fruit matured, a gradual increase in the ß-O-4' proportion and the ratio of S/G was observed. The results provide comprehensive characterization of the cell wall lignin of quince fruit as it matures. This study could inspire innovative applications of quince fruit lignin and provide the optimal harvest time for lignin utilization.


Assuntos
Lignina , Rosaceae , Lignina/química , Frutas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Rosaceae/química , Madeira/química , China
4.
Int J Biol Macromol ; 264(Pt 2): 130770, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38467230

RESUMO

Traditional adhesives easily release toxic gases during the preparation process or apply to wood composite products, which have adverse effects on the human body and the environment. Herein, an all-water-based high-performance wood adhesive is prepared using TEMPO-oxidized cellulose nanofiber (TOCNF), acrylamide (AM), and tannic acid (TA) through free radical polymerization. Different characteristics of the prepared composites, including morphology, injectability, and adhesion properties, have been investigated. Results showed that the TA/TOCNF/PAM composite has excellent injectability. The addition of TA can enhance the lap shear strength of the TA/TOCNF/PAM composites and with the increment of TA content, the lap shear strength gradually decreases. The formation of effective hydrogen bonds and Van der Waals interaction among the rich functional groups in the composite, lead to strong lap shear strength on different substrates. The composite with 5.0 g of AM, 5.0 g of the TOCNF suspension and 0.1 g TA possesses a high lap shear strength of 10.5 MPa on wood and 1.5 MPa on aluminium. Based on strong adhesion properties and excellent injectability, the TA/TOCNF/PAM composites have great potential in the furniture construction and building industries.


Assuntos
Celulose Oxidada , Nanofibras , Polifenóis , Humanos , Adesivos/química , Celulose/química , Nanofibras/química , Madeira/química , Água/análise , Celulose Oxidada/análise
5.
Bioresour Technol ; 399: 130645, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38554759

RESUMO

Hardwood kraft lignin from the pulping industry is burned or discarded. Its valorization was conducted by subjecting fractionation, amination with ethylenediamine, diethylenetriamine, and monoethanolamine, and crosslinking with formaldehyde or glyoxal to obtain bio-based wood adhesives. Acetone-soluble and insoluble hardwood kraft lignin were prepared and subjected to amination and then crosslinking. Fourier transform infrared, 13C NMR, 15N NMR, and X-ray photoelectron spectroscopy results revealed successful amination with amide, imine, and ether bonds and crosslinking of all samples. Hardwood kraft lignin aminated with diethylenetriamine/ethylenediamine and crosslinked using glyoxal exhibited excellent results in comparison with samples crosslinked using formaldehyde. Acetone-insoluble hardwood kraft lignin aminated and crosslinked using diethylenetriamine and formaldehyde, respectively, exhibited excellent adhesion strength with plywood, satisfying the requirements of the Korean standards. The amination and crosslinking of industrial waste hardwood kraft lignin constitute a beneficial valorization method.


Assuntos
Acetona , Aldeídos , Aminação , Madeira/química , Adesivos/análise , Adesivos/química , Poliaminas/análise , Glioxal/análise , Glioxal/química , Lignina/química , Formaldeído/análise , Etilenodiaminas
6.
Mycorrhiza ; 34(1-2): 33-44, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38520554

RESUMO

Although the absence of normal leaves is often considered a sign of full heterotrophy, some plants remain at least partially autotrophic despite their leafless habit. Leafless orchids with green stems and capsules probably represent a late evolutionary stage toward full mycoheterotrophy and serve as valuable models for understanding the pathways leading to this nutritional strategy. In this study, based on molecular barcoding and isotopic analysis, we explored the physiological ecology of the leafless orchid Eulophia zollingeri, which displays green coloration, particularly during its fruiting phase. Although previous studies had shown that E. zollingeri, in its adult stage, is associated with Psathyrellaceae fungi and exhibits high 13C isotope signatures similar to fully mycoheterotrophic orchids, it remained uncertain whether this symbiotic relationship is consistent throughout the orchid's entire life cycle and whether the orchid relies exclusively on mycoheterotrophy for its nutrition during the fruiting season. Our study has demonstrated that E. zollingeri maintains a specialized symbiotic relationship with Psathyrellaceae fungi throughout all life stages. However, isotopic analysis and chlorophyll data have shown that the orchid also engages in photosynthesis to meet its carbon needs, particularly during the fruiting stage. This research constitutes the first discovery of partial mycoheterotrophy in leafless orchids associated with saprotrophic non-rhizoctonia fungi.


Assuntos
Agaricales , Micorrizas , Orchidaceae , Micorrizas/fisiologia , Isótopos de Carbono/análise , Madeira/química , Madeira/metabolismo , Simbiose , Carbono/metabolismo , Orchidaceae/microbiologia
7.
J Environ Radioact ; 274: 107399, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38442434

RESUMO

The article considers the issues of working out the suitable approaches for identifying zones with the presence of underground near-surface waters with increased concentrations of tritium discharged into a surface reservoir. The following methods were used as possible methods: determination of tritium content in snow cover, determination of tritium content in vegetation in the form of tritium of free water and organically bound tritium, determination of tritium content in river water and coastal vegetation. The studies were carried out at a previously identified site where groundwater with a tritium concentration of up to 6000 Bq/l is present, located in the vicinity of the city of Obninsk (Kaluga region, Russia). As a result of the conducted research, it was concluded that the analysis of the distribution of tritium in vegetation is an excellent methodological technique for identifying areas of location of near-surface underground waters contaminated with tritium. As a control parameter, both the concentration of tritium in the free water of plants and the content of organically bound tritium can be used. To detect underground tritium contamination the most promising use is the following indicator - the content of OBT in the shoots of woody plants. This parameter is very informative, and the sampling procedure for its determination has no seasonal restrictions, unlike such parameters as the content of tritium in grass and leaves, the content of tritium in snow cover, surface waters, which are preferably collected only in summer or winter. It should be noted that the control of surface waters of the groundwater discharge zone may not be a sufficiently informative indicator for identifying areas of polluted water inflow, since it depends on the ratio of the volumes of leaking polluted groundwater and the annual flow of the watercourse.


Assuntos
Monitoramento de Radiação , Trítio/análise , Monitoramento de Radiação/métodos , Ecossistema , Madeira/química , Água
8.
Int J Biol Macromol ; 265(Pt 1): 130906, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38493611

RESUMO

The pre-hydrolysis liquor (PHL) produced during pulp dissolution and biomass refining is mainly composed of hemicellulose and lignin, and it is a potential source for production of value-added materials and platform chemicals; however, their utilization has been a serious challenge. In this study, we proposed a green and simple strategy to simultaneously prepare size-controlled functional lignin nanoparticles (LNPs) and levulinic acid (LA) from PHL as the raw material. The as-prepared LNPs exhibited remarkable stability thanks to the presence of saccharides with abundant oxygen-containing groups and surface charges, which prevented aggregation and maintained long-term storage stability. Trace amounts of the LNPs (≤ 0.2 wt%) could stabilize various Pickering emulsions, even with oil-to-water ratios as high as 5:5 (v/v). Subsequently, the remaining PHL was directly used to produce LA without adding a catalyst; under optimal conditions (160 °C and 1 h), the yield of LA was 56.3 % based on the dry saccharide content in the raw PHL. More importantly, p-toluenesulfonic acid (p-TsOH), the only reactive reagent used during the entire preparation process, including the two preparation steps of the LNPs and LA, was reusable, and the recovery rate was >70 % after five cycles. Overall, this green and simple strategy effectively and comprehensively utilized the PHL and showed potential for producing biobased nanomaterials and platform chemicals.


Assuntos
Ácidos Levulínicos , Nanopartículas , Populus , Lignina/química , Hidrólise , Madeira/química , Carboidratos/análise
9.
Environ Pollut ; 348: 123767, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38492753

RESUMO

Sustainable drainage system (SuDS) for stormwater reclamation has the potential to alleviate the water scarcity and environmental pollution issues. Laboratory studies have demonstrated that the capacity of SuDS to treat stormwater can be improved by integrating biochar and compost in the filter media, whereas their performance in scaled-up applications is less reported. This study examines the effectiveness of a pilot-scale SuDS, bioswale followed by bioretention, amended with wood waste biochar (1, 2, and 4 wt.%) and food waste compost (2 and 4 wt.%) to simultaneously remove multiple pollutants including nutrients, heavy metals, and trace organics from the simulated stormwater. Our results confirmed that SuDS modified with both biochar (2 wt.%) and compost (2 wt.%) displayed superior water quality improvement. The system exhibited high removal efficiency (> 70%) for total phosphorus and major metal species including Ni, Pb, Cd, Cr, Cu, and Zn. Total suspended solids concentration was approaching the detection limit in the effluent, thereby confirming its capability to reduce turbidity and particle-associated pollutants from stormwater. Co-application of biochar and compost also moderately immobilized trace organic contaminants such as 2,4-dichlorophenoxyacetic acid, diuron, and atrazine at field-relevant concentrations. Moreover, the soil amendments amplified the activities of enzymes including ß-D-cellobiosidase and urease, suggesting that the improved soil conditions and health of microbial communities could possibly increase phyto and bioremediation of contaminants accumulated in the filter media. Overall, our pilot-scale demonstration confirmed that the co-application of biochar and compost in SuDS can provide a variety of benefits for soil/plant health and water quality.


Assuntos
Compostagem , Poluentes Ambientais , Metais Pesados , Eliminação de Resíduos , Poluentes do Solo , Purificação da Água , 60659 , Madeira/química , Alimentos , Chuva , Abastecimento de Água , Carvão Vegetal , Solo , Poluentes do Solo/análise
10.
Int J Biol Macromol ; 262(Pt 2): 130025, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38340917

RESUMO

Application of nanomaterials is gaining tremendous interest in the field of wood science and technology for value addition and enhancing performance of wood and wood-based composites. This review focuses on the use of nanomaterials in improving the properties of wood and wood-based materials and protecting them from weathering, biodegradation, and other deteriorating agents. UV-resistant, self-cleaning (superhydrophobic) surfaces with anti-microbial properties have been developed using the extraordinary features of nanomaterials. Scratch-resistant nano-coatings also improve durability and aesthetic appeal of wood. Moreover, nanomaterials have been used as wood preservatives for increasing the resistance against wood deteriorating agents such as fungi, termites and borers. Wood can be made more resistant to ignition and slower to burn by introducing nano-clays or nanoparticles of metal-oxides. The use of nanocellulose and lignin nanoparticles in wood-based products has attracted huge interest in developing novel materials with improved properties. Nanocellulose and lignin nanoparticles derived/synthesized from woody biomass can enhance the mechanical properties such as strength and stiffness and impart additional functionalities to wood-based products. Cellulose nano-fibres/crystals find application in wide areas of materials science like reinforcement for composites. Incorporation of nanomaterials in resin has been used to enhance specific properties of wood-based composites. This review paper highlights some of the advancements in the use of nanotechnology in wood science, and its potential impact on the industry.


Assuntos
Lignina , Nanoestruturas , Lignina/análise , Madeira/química , Nanotecnologia , Celulose/química , Nanoestruturas/química
11.
Ultrason Sonochem ; 104: 106826, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38422810

RESUMO

Ageing wine in barrels is an historical practice used to improve the aromatic complexity of wine, but due to the high cost and the long ageing period, alternative approaches have been developed, such as the use of wood chips and ultrasound treatment. The present paper reports the results of an investigation performed on wine (cv. Primitivo). Three treatments were investigated: a) control wine untreated; b) wine with toasted vine-shoot chips (10 g/L); c) wine with toasted vine-shoot chips (10 g/L) and treated by ultrasound. Wines were analysed after 7, 14, 21, and 28 days. The application of ultrasound combined with vine-shoot chips promoted tannin evolution, thereby accelerating the ageing process of wine. The chips addition decreased the total anthocyanins content and increased the stilbenes (trans-resveratrol and trans-piceid) and wood-related aromas (i.e., furfural, 5-methylfurfural) concentration. Finally, wines added with chips were richer in woody, vanilla, oak, and chocolate notes and more preferred by the tasters.


Assuntos
Quercus , Vinho , Vinho/análise , Antocianinas/análise , Resveratrol/análise , Madeira/química
12.
Lett Appl Microbiol ; 77(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38409949

RESUMO

Equine farming generates a significant amount of waste, prompting the need for effective management. Composting enhanced by filamentous fungi holds promise for this purpose. This study focused on inoculating Aspergillus fumigatus isolates in composting horse bedding made with wood shavings (Pinus elliottii). The experiment lasted 90 days, with two treatment groups, control and inoculated, analyzing temperature, pH, electrical conductivity, total organic carbon and nitrogen content, and cellulose, hemicellulose, and lignin contents. Both treatments entered the thermophilic phase by the fourth day, reaching temperatures above 55°C and mesophilic maturation at 35 days (41 ± 0.2°C). The inoculated treatment exhibited higher electrical conductivity after 30 days and a more pronounced reduction in the total carbon content (42.85% vs. 38.29%) compared to the control. While there was no significant nitrogen difference, the inoculated treatment had a sharper reduction in carbon/nitrogen ratio, and cellulose and hemicellulose contents. Both treatments showed low coliform counts, no Salmonella sp., and reduced Strongyloides sp. larvae. Inoculating A. fumigatus in saturated horse bedding made from wood shavings improved compost quality, providing a possibility for sustainable equine farming waste treatment.


Assuntos
Compostagem , Cavalos , Animais , Madeira/química , Aspergillus fumigatus , Solo , Celulose , Nitrogênio/análise , Carbono
13.
Sci Total Environ ; 922: 170971, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38408660

RESUMO

Sustainable and effective remediation technologies for the treatment of soil contaminated with per- and polyfluoroalkyl substances (PFAS) are greatly needed. This study investigated the effects of waste-based biochars on the leaching of PFAS from a sandy soil with a low total organic carbon content (TOC) of 0.57 ± 0.04 % impacted by PFAS from aqueous film forming foam (AFFF) dispersed at a former fire-fighting facility. Six different biochars (pyrolyzed at 700-900 °C) were tested, made from clean wood chips (CWC), waste timber (WT), activated waste timber (aWT), two digested sewage sludges (DSS-1 and DSS-2) and de-watered raw sewage sludge (DWSS). Up-flow column percolation tests (15 days and 16 pore volume replacements) with 1 % biochar indicated that the dominant congener in the soil, perfluorooctane sulphonic acid (PFOS) was retained best by the aWT biochar with a 99.9 % reduction in the leachate concentration, followed by sludge-based DWSS (98.9 %) and DSS-2 and DSS-1 (97.8 % and 91.6 %, respectively). The non-activated wood-based biochars (CWC and WT) on the other hand, reduced leaching by <42.4 %. Extrapolating this to field conditions, 90 % leaching of PFOS would occur after 15 y for unamended soil, and after 1200 y and 12,000 y, respectively, for soil amended with 1 % DWSS-amended and aWT biochar. The high effectiveness of aWT and the three sludge-based biochars in reducing PFAS leaching from the soil was attributed largely to high porosity in a pore size range (>1.5 nm) that can accommodate the large PFAS molecules (>1.02-2.20 nm) combined with a high affinity to the biochar matrix. Other factors like anionic exchange capacity could play a contributing role. Sorbent effectiveness was better for long-chain than for short-chain PFAS, due to weaker, apolar interactions between the biochar and the latter's shorter hydrophobic CF2-tails. The findings were the first to demonstrate that locally sourced activated wood-waste biochars and non-activated sewage sludge biochars could be suitable sorbents for the ex situ stabilization and in situ remediation of PFAS-contaminated soil, bringing this technology one step closer to full-scale field testing.


Assuntos
Ácidos Alcanossulfônicos , Fluorocarbonos , Poluentes do Solo , Esgotos/química , Madeira/química , Carvão Vegetal/química , Solo/química , Fluorocarbonos/análise , Poluentes do Solo/análise , Água/química
14.
Mar Pollut Bull ; 200: 116164, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38364645

RESUMO

The study presents the results of the survey of beached litter on the two opposite shores of the Fields Peninsula (King George Island) conducted during the austral summer seasons of 2022 and 2023, as part of the 67th and 68th Russian Antarctic expeditions. Beaches situated on the coast of the Drake Passage were much more polluted compared to the beaches on the Maxwell Bay side. Plastic accounted for 86 % of all found items on the shores of the Drake Passage, with the majority of items related to fisheries or shipping. On the Maxwell Bay beaches, only 36 % of litter was plastic, with other categories like wood and metal dominating the total number. The average density of marine litter is 0.32 items/m (0.017 items/m2), comparable to other similar surveys conducted on Antarctic islands; however, this is at least 15-20 times lower than beach litter densities in the Arctic.


Assuntos
Monitoramento Ambiental , Resíduos , Resíduos/análise , Regiões Antárticas , Monitoramento Ambiental/métodos , Plásticos , Madeira/química , Praias
15.
Sci Total Environ ; 921: 171069, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38395157

RESUMO

Air pollution is the leading environmental risk factor for mortality worldwide. In Australia, residential wood heating is the single largest source of pollution in many regions of the country. Estimates around the world and in some limited locations across Australia have shown that the health burden attributable to wood heating PM2.5 is considerable, and that there is great potential to reduce this burden. Here, we aimed to calculate the mortality burden attributable to wood heating emissions (WHE)-related PM2.5 throughout Australia and estimate the potential health benefits of reducing WHE-related air pollution, by replacing wood heaters with cleaner heating technologies. In summary, we used a four-stage process to (1) compile a nationwide WHE inventory, (2) generate annual exposure estimates of WHE-PM2.5, (3) estimate the annual mortality burden attributable to wood heater use across Australia for the year 2015, and (4) assess the potential health benefits of replacing existing wood heaters with cleaner heating technologies. We estimated that population weighted WHE-PM2.5 exposure across Australia for 2015 ranged between 0.62 µg/m3 and 1.35 µg/m3, with differing exposures across State/Territories. We estimated a considerable mortality burden attributable to WHE-PM2.5 ranging between 558 (95 % CI, 364-738) and 1555 (95 % CI, 1180-1740) deaths annually, depending on the scenario assessed. We calculated that replacing 50 % of the current wood heater stock, with zero or lower emission technologies could produce relevant health benefits, of between $AUD 1.61 and $AUD 1.93 billion per year (303-364 attributable deaths). These findings provide a preliminary and likely conservative assessment of the health burden of wood heater smoke across Australia, and an estimation of the potential benefits from replacing the current wood heater stock with cleaner technologies. The results presented here underscore the magnitude of the health burden attributable to wood heating in Australia.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Material Particulado/análise , Fumaça/efeitos adversos , Poluentes Atmosféricos/análise , Madeira/química , Poluição do Ar/análise , Austrália/epidemiologia , Exposição Ambiental/análise
16.
Sci Rep ; 14(1): 4083, 2024 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-38374095

RESUMO

Acetylation of wood with acetic anhydride reduces the wood-moisture interaction, improves the dimensional stability and resistance against biodegradation. However, the adhesive bonding is affected by the modification, which is crucial to manufacture engineered wood products, such as laminated veneer lumber (LVL). In this study we report the bonding of 8-layered acetylated beech (Fagus sylvatica L.) LVL boards to 2-layered LVL beams. The beams were glued together at room temperature adding three common load-bearing construction adhesives: melamine-urea-formaldehyde (MUF), phenol-resorcinol-formaldehyde (PRF), and one-component polyurethane (PUR). The bonding performance was tested by assessing its dry and wet tensile shear strength (TSS) and wood failure percentage (WF). Also evaluated were the material's density and moisture content (MC). The surface was characterized prior to bonding by its pH, roughness, and contact angle (CA). The adhesive penetration was observed by fluorescence microscopy. Aside from MUF, applying PRF and PUR adhesives achieved good bonding performance on acetylated LVL and references. Acetylated LVL displayed a more hydrophobic behaviour, a higher pH, a somewhat smoother surface, and an increased density.


Assuntos
Fagus , Madeira/química , Formaldeído/química , Microscopia de Fluorescência , Adesivos/química
17.
Int J Biol Macromol ; 259(Pt 2): 129306, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38216008

RESUMO

When wood is used as a stressed component of building materials, the parts most prone to failure are the upper and lower surfaces which can be called the weak structure. In a hydrothermal environment, lignin and hemicellulose in wood readily soften and dissolve, thus leading to their designation as the weak structure. The weak structures results in the wood having a low strength. In this paper, the sandwich beam material can be obtained by two steps from the skin self-reinforcement method, whereby the weak structure of the wood surface was removed by the delignification, and then the wood surface was densified. The authenticity of the sandwich structure is proved by a scanning electron microscope (SEM) and density profile analysis. When the moisture content (MC) is 10 %-12 % and the mass loss ratio is 23.04 %, the optimal resilience of the sandwich beam is only 1 %, the maximum modulus of rupture (MOR) and modulus of elasticity (MOE) are 1.42 and 2.1 times greater than those of natural wood, respectively. This finding shows that our method strengthens the weak structure of natural wood, which has good flexural performance and springback ratio.


Assuntos
Lignina , Madeira , Lignina/química , Madeira/química , Polissacarídeos/química , Fenômenos Físicos
18.
Environ Sci Pollut Res Int ; 31(8): 11842-11856, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38221559

RESUMO

This study aimed to construct a transboundary marine governance mechanism in the Kinmen-Xiamen waters through literature review, field survey, in-depth interview, and expert opinion survey. The study finds that monsoons, ocean currents, and tides are the main factors affecting the drift of marine debris in the Xiamen Sea area to the beaches of Kinmen. The marine debris mainly included marine plastic debris (MPD), bamboo, and wood in Kinmen and was documented impacting a variety of species, including the horseshoe crab to marine mammals the IndoPacific dolphin. In addition, the problem of marine micro-plastic pollution is becoming increasingly worrisome and hazardous to rare creatures in the Xiamen Sea area. The pollution sources of MPD in Xiamen Bay included coastal tourism activities, micro-plastic discharged from sewage treatment plants, plastic waste produced by lost and discarded marine aquaculture, and plastic drifting terrestrial waste transported from the Jiulong River Basin. Our results show that microplastic pollution in the Kinmen-Xiamen waters may have a greater impact on marine ecology and the surrounding environment. The relevant transboundary marine governance mechanisms are discussed in this study.


Assuntos
Microplásticos , Plásticos , Animais , Taiwan , Resíduos/análise , Madeira/química , Monitoramento Ambiental/métodos , Mamíferos
19.
Environ Sci Pollut Res Int ; 31(8): 12229-12244, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38225496

RESUMO

Based on partial data, this paper uses BP neural network optimised by particle swarm optimisation algorithm to predict the total greenhouse gas (GHG) emissions of the line in the construction phase. The GHG emission efficiency is analysed by SBM (Slacks-Based Measure) super efficiency method. Finally, the grey relational analysis (GRA) is applied to sort the GHG emission correlation factors. Based on the existing design and quota document data of 16 stations and 16 sections of the Wuhu Monorail Line 1, we have employed a neural network optimized by particle swarm optimization algorithm to predict the total emissions of greenhouse gases during the construction phase of the entire line consisting of 25 stations and 24 sections. The GHG emissions of all stations and sections are 29,300 tons and 21,000 tons. The technical efficiency, pure technical efficiency, and scale efficiency of the stations and sections were high. As for stations, the order of influence degree is metal material consumption (0.9731) > cost (0.9486) > electric energy consumption (0.9481) > station area (0.9109) > concrete and cement consumption (0.9032) > other material consumption (0.8831) > gasoline and diesel consumption (0.7258). For the section, the order of influence degree is cost (0.9766) > concrete (0.9581) > steel reinforcement (0.9483) > other steels (0.874) > section length (0.8337) > power energy consumption (0.7169) > wood consumption (0.6684).


Assuntos
Gases de Efeito Estufa , Gases de Efeito Estufa/análise , Efeito Estufa , Inteligência Artificial , Gasolina , Madeira/química
20.
Int J Biol Macromol ; 258(Pt 2): 129132, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38171433

RESUMO

Adhesives are used extensively in the wood industry. As resource and environmental issues become increasingly severe, the development of green and sustainable biomass-based adhesives has attracted increasing attention. In this work, a green wood adhesive is developed from poly(vinyl alcohol) and lignin with molecular designs of lignin extending beyond those in nature. The lignin undergoes extraction from corncob residue, aldehydration, and phenolisation (phenol, resorcinol, and catechol) to significantly increase the phenolic hydroxyl groups (over 7.92 mmol/g), which has the effect of enhancing the hydrogen bonding force between the adhesive and the wood, thereby greatly improving adhesive performance. Compared with pure PVA, polyphenol lignin-containing PVA showed improved adhesion strength and hydrophobicity. PVA/resorcinol-lignin has the significantly improved wood lap shear strength (6.27 MPa, 77.6 % improvement) and hydrophobicity (almost 100 % increase in wet shear strength). This research not only provides a green and high-performance alternative raw material for wood adhesives but also broadens the path for large-scale application of biomass.


Assuntos
Lignina , Polifenóis , Polifenóis/análise , Lignina/química , Álcool de Polivinil , Adesivos/química , Madeira/química , Fenóis/química , Metanol , Cloreto de Polivinila , Resorcinóis
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