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1.
Nature ; 630(8016): 381-386, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38811733

RESUMO

Lignocellulose is mainly composed of hydrophobic lignin and hydrophilic polysaccharide polymers, contributing to an indispensable carbon resource for green biorefineries1,2. When chemically treated, lignin is compromised owing to detrimental intra- and intermolecular crosslinking that hampers downstream process3,4. The current valorization paradigms aim to avoid the formation of new C-C bonds, referred to as condensation, by blocking or stabilizing the vulnerable moieties of lignin5-7. Although there have been efforts to enhance biomass utilization through the incorporation of phenolic additives8,9, exploiting lignin's proclivity towards condensation remains unproven for valorizing both lignin and carbohydrates to high-value products. Here we leverage the proclivity by directing the C-C bond formation in a catalytic arylation pathway using lignin-derived phenols with high nucleophilicity. The selectively condensed lignin, isolated in near-quantitative yields while preserving its prominent cleavable ß-ether units, can be unlocked in a tandem catalytic process involving aryl migration and transfer hydrogenation. Lignin in wood is thereby converted to benign bisphenols (34-48 wt%) that represent performance-advantaged replacements for their fossil-based counterparts. Delignified pulp from cellulose and xylose from xylan are co-produced for textile fibres and renewable chemicals. This condensation-driven strategy represents a key advancement complementary to other promising monophenol-oriented approaches targeting valuable platform chemicals and materials, thereby contributing to holistic biomass valorization.


Assuntos
Compostos Benzidrílicos , Biomassa , Fracionamento Químico , Lignina , Fenóis , Compostos Benzidrílicos/química , Compostos Benzidrílicos/metabolismo , Catálise , Celulose/química , Celulose/metabolismo , Fracionamento Químico/métodos , Hidrogenação , Lignina/química , Lignina/metabolismo , Fenóis/química , Fenóis/metabolismo , Madeira/química , Xilanos/química , Xilanos/metabolismo , Xilose/química , Xilose/metabolismo , Combustíveis Fósseis , Têxteis
2.
Nature ; 631(8022): 796-800, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39048683

RESUMO

Methane is an important greenhouse gas1, but the role of trees in the methane budget remains uncertain2. Although it has been shown that wetland and some upland trees can emit soil-derived methane at the stem base3,4, it has also been suggested that upland trees can serve as a net sink for atmospheric methane5,6. Here we examine in situ woody surface methane exchange of upland tropical, temperate and boreal forest trees. We find that methane uptake on woody surfaces, in particular at and above about 2 m above the forest floor, can dominate the net ecosystem contribution of trees, resulting in a net tree methane sink. Stable carbon isotope measurement of methane in woody surface chamber air and process-level investigations on extracted wood cores are consistent with methanotrophy, suggesting a microbially mediated drawdown of methane on and in tree woody surfaces and tissues. By applying terrestrial laser scanning-derived allometry to quantify global forest tree woody surface area, a preliminary first estimate suggests that trees may contribute 24.6-49.9 Tg of atmospheric methane uptake globally. Our findings indicate that the climate benefits of tropical and temperate forest protection and reforestation may be greater than previously assumed.


Assuntos
Atmosfera , Florestas , Metano , Árvores , Madeira , Atmosfera/química , Metano/metabolismo , Metano/análise , Taiga , Árvores/química , Árvores/metabolismo , Árvores/microbiologia , Clima Tropical , Madeira/química , Madeira/metabolismo , Madeira/microbiologia , Gases de Efeito Estufa/análise , Gases de Efeito Estufa/metabolismo , Isótopos de Carbono , Agricultura Florestal , Aquecimento Global/prevenção & controle , Aquecimento Global/estatística & dados numéricos , Efeito Estufa/prevenção & controle , Efeito Estufa/estatística & dados numéricos
3.
Nature ; 616(7958): 740-746, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37020018

RESUMO

Tropical peatlands cycle and store large amounts of carbon in their soil and biomass1-5. Climate and land-use change alters greenhouse gas (GHG) fluxes of tropical peatlands, but the magnitude of these changes remains highly uncertain6-19. Here we measure net ecosystem exchanges of carbon dioxide, methane and soil nitrous oxide fluxes between October 2016 and May 2022 from Acacia crassicarpa plantation, degraded forest and intact forest within the same peat landscape, representing land-cover-change trajectories in Sumatra, Indonesia. This allows us to present a full plantation rotation GHG flux balance in a fibre wood plantation on peatland. We find that the Acacia plantation has lower GHG emissions than the degraded site with a similar average groundwater level (GWL), despite more intensive land use. The GHG emissions from the Acacia plantation over a full plantation rotation (35.2 ± 4.7 tCO2-eq ha-1 year-1, average ± standard deviation) were around two times higher than those from the intact forest (20.3 ± 3.7 tCO2-eq ha-1 year-1), but only half of the current Intergovernmental Panel on Climate Change (IPCC) Tier 1 emission factor (EF)20 for this land use. Our results can help to reduce the uncertainty in GHG emissions estimates, provide an estimate of the impact of land-use change on tropical peat and develop science-based peatland management practices as nature-based climate solutions.


Assuntos
Florestas , Gases de Efeito Estufa , Solo , Madeira , Dióxido de Carbono/análise , Gases de Efeito Estufa/análise , Indonésia , Metano/análise , Óxido Nitroso/análise , Madeira/química , Incerteza
4.
Nature ; 621(7979): 511-515, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37553075

RESUMO

Plywood is widely used in construction, such as for flooring and interior walls, as well as in the manufacture of household items such as furniture and cabinets. Such items are made of wood veneers that are bonded together with adhesives such as urea-formaldehyde and phenol-formaldehyde resins1,2. Researchers in academia and industry have long aimed to synthesize lignin-phenol-formaldehyde resin adhesives using biomass-derived lignin, a phenolic polymer that can be used to substitute the petroleum-derived phenol3-6. However, lignin-phenol-formaldehyde resin adhesives are less attractive to plywood manufacturers than urea-formaldehyde and phenol-formaldehyde resins owing to their appearance and cost. Here we report a simple and practical strategy for preparing lignin-based wood adhesives from lignocellulosic biomass. Our strategy involves separation of uncondensed or slightly condensed lignins from biomass followed by direct application of a suspension of the lignin and water as an adhesive on wood veneers. Plywood products with superior performances could be prepared with such lignin adhesives at a wide range of hot-pressing temperatures, enabling the use of these adhesives as promising alternatives to traditional wood adhesives in different market segments. Mechanistic studies indicate that the adhesion mechanism of such lignin adhesives may involve softening of lignin by water, filling of vessels with softened lignin and crosslinking of lignins in adhesives with those in the cell wall.


Assuntos
Adesivos , Lignina , Madeira , Adesivos/química , Formaldeído/química , Lignina/química , Fenóis/química , Ureia/química , Água/química , Madeira/química , Biomassa , Temperatura Alta
5.
Nature ; 614(7948): 463-470, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36792743

RESUMO

Aerial seeding can quickly cover large and physically inaccessible areas1 to improve soil quality and scavenge residual nitrogen in agriculture2, and for postfire reforestation3-5 and wildland restoration6,7. However, it suffers from low germination rates, due to the direct exposure of unburied seeds to harsh sunlight, wind and granivorous birds, as well as undesirable air humidity and temperature1,8,9. Here, inspired by Erodium seeds10-14, we design and fabricate self-drilling seed carriers, turning wood veneer into highly stiff (about 4.9 GPa when dry, and about 1.3 GPa when wet) and hygromorphic bending or coiling actuators with an extremely large bending curvature (1,854 m-1), 45 times larger than the values in the literature15-18. Our three-tailed carrier has an 80% drilling success rate on flat land after two triggering cycles, due to the beneficial resting angle (25°-30°) of its tail anchoring, whereas the natural Erodium seed's success rate is 0%. Our carriers can carry payloads of various sizes and contents including biofertilizers and plant seeds as large as those of whitebark pine, which are about 11 mm in length and about 72 mg. We compare data from experiments and numerical simulation to elucidate the curvature transformation and actuation mechanisms to guide the design and optimization of the seed carriers. Our system will improve the effectiveness of aerial seeding to relieve agricultural and environmental stresses, and has potential applications in energy harvesting, soft robotics and sustainable buildings.


Assuntos
Materiais Biomiméticos , Sementes , Agricultura/métodos , Germinação , Sementes/química , Sementes/metabolismo , Solo , Luz Solar , Madeira/análise , Madeira/química , Molhabilidade , Fertilizantes , Materiais Biomiméticos/análise , Materiais Biomiméticos/química , Tamanho da Partícula
6.
Plant Physiol ; 195(3): 2428-2442, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38590143

RESUMO

Despite lignin being a key component of wood, the dynamics of tracheid lignification are generally overlooked in xylogenesis studies, which hampers our understanding of environmental drivers and blurs the interpretation of isotopic and anatomical signals stored in tree rings. Here, we analyzed cell wall formation in silver fir (Abies alba Mill.) tracheids to determine if cell wall lignification lags behind secondary wall deposition. For this purpose, we applied a multimodal imaging approach combining transmitted light microscopy (TLM), confocal laser scanning microscopy (CLSM), and confocal Raman microspectroscopy (RMS) on anatomical sections of wood microcores collected in northeast France on 11 dates during the 2010 growing season. Wood autofluorescence after laser excitation at 405 and 488 nm associated with the RMS scattering of lignin and cellulose, respectively, which allowed identification of lignifying cells (cells showing lignified and nonlignified wall fractions at the same time) in CLSM images. The number of lignifying cells in CLSM images mirrored the number of wall-thickening birefringent cells in polarized TLM images, revealing highly synchronized kinetics for wall thickening and lignification (similar timings and durations at the cell level). CLSM images and RMS chemical maps revealed a substantial incorporation of lignin into the wall at early stages of secondary wall deposition. Our results show that most of the cellulose and lignin contained in the cell wall undergo concurrent periods of deposition. This suggests a strong synchronization between cellulose and lignin-related features in conifer tree-ring records, as they originated over highly overlapped time frames.


Assuntos
Abies , Parede Celular , Celulose , Lignina , Microscopia Confocal , Lignina/metabolismo , Celulose/metabolismo , Parede Celular/metabolismo , Abies/metabolismo , Madeira/química , Madeira/anatomia & histologia , Imagem Multimodal/métodos , Análise Espectral Raman/métodos
8.
Mass Spectrom Rev ; 42(4): 1174-1220, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34859471

RESUMO

Aging of wines and spirits in wooden barrels is an industrial process used to stabilize the color, to improve the limpidity and to enrich the sensorial characteristics of the products. In red wines, the oxygen that permeates through the wood staves promotes the oxidization of polyphenols and the formation of new pigments with consequent stabilization of the wine color. Barrel aging of spirits, such as brandy, whisky, rum, and grappa is finalized to enrich their aroma and improve their sensorial characteristics by the contribute of the compounds released by the wood. Oak is the wood type mostly used in making barrels; however, an increasing interest in the use of chestnut, cherry, acacia, and in less extent, ash and mulberry, has been observed in the recent years. Gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry are the main techniques used to characterize respectively the volatile and polar metabolites released by the wood barrels in the products. In this article are reported the recent advancements in this field.


Assuntos
Vinho , Vinho/análise , Madeira/química , Espectrometria de Massas , Cromatografia Gasosa-Espectrometria de Massas/métodos , Polifenóis/análise
9.
Biopolymers ; 115(4): e23577, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38526043

RESUMO

Bacterial nanocellulose (BNC) has various unique qualities, including high mechanical strength, crystallinity, and high water-holding capacity, which makes it appropriate for a wide range of industrial applications. But its lower yield coupled with its high production cost creates a barrier to its usage. In this study, we have demonstrated the better yield of BNC from an indigenous strain Komagataeibacter rhaeticus MCC-0157 using a rotary disc bioreactor (RDB) having a wooden disc. The RDB was optimized based on the type of disc material, distance between the disc, and rotation speed to get the highest yield of 13.0 g/L dry material using Hestrin-Schramm (H-S) medium. Further, the bioreactor was compared for the BNC production using reported medium, which is used for static condition; the RDB showed up to fivefold increase in comparison with the static condition reported. Komagataeibacter rhaeticus MCC-0157 was previously reported to be one of the highest BNC producing stains, with 8.37 g/L of dry yield in static condition in 15 days incubation. The designed RDB demonstrated 13.0 g/L dry yield of BNC in just 5 days. Other characteristics of BNC remain same as compared with static BNC production, although the difference in the crystallinity index was observed in RDB (84.44%) in comparison with static (89.74%). For the first time, wooden disc was used for rotary bioreactor approach, which demonstrated higher yield of BNC in lesser time and can be further used for sustainable production of BNC at the industrial level.


Assuntos
Acetobacteraceae , Reatores Biológicos , Celulose , Celulose/química , Celulose/biossíntese , Acetobacteraceae/metabolismo , Acetobacteraceae/química , Madeira/química , Biopolímeros/química , Biopolímeros/biossíntese , Nanoestruturas/química , Fermentação
10.
Chem Res Toxicol ; 37(5): 675-684, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38598786

RESUMO

Air pollution consists of complex mixtures of chemicals with serious deleterious health effects from acute and chronic exposure. To help understand the mechanisms by which adverse effects occur, the present work examines the responses of cultured human epidermal keratinocytes to specific chemicals commonly found in woodsmoke. Our earlier findings with liquid smoke flavoring (aqueous extract of charred wood) revealed that such extracts stimulated the expression of genes associated with oxidative stress and proinflammatory response, activated the aryl hydrocarbon receptor, thereby inducing cytochrome P4501A1 activity, and induced cross-linked envelope formation, a lethal event ordinarily occurring during terminal differentiation. The present results showed that furfural produced transcriptional responses resembling those of liquid smoke, cyclohexanedione activated the aryl hydrocarbon receptor, and several chemicals induced envelope formation. Of these, syringol permeabilized the cells to the egress of lactate dehydrogenase at a concentration close to that yielding envelope formation, while furfural induced envelope formation without permeabilization detectable in this way. Furfural (but not syringol) stimulated the incorporation of amines into cell proteins in extracts in the absence of transglutaminase activity. Nevertheless, both chemicals substantially increased the amount of cellular protein incorporated into envelopes and greatly altered the envelope protein profile. Moreover, the proportion of keratin in the envelopes was dramatically increased. These findings are consistent with the chemically induced protein cross-linking in the cells. Elucidating mechanisms by which this phenomenon occurs may help understand how smoke chemicals interact with proteins to elicit cellular responses, interpret bioassays of complex pollutant mixtures, and suggest additional sensitive ways to monitor exposures.


Assuntos
Queratinócitos , Madeira , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Madeira/química , Fumaça/efeitos adversos , Furaldeído/análogos & derivados , Furaldeído/farmacologia , Células Cultivadas , Receptores de Hidrocarboneto Arílico/metabolismo
11.
Langmuir ; 40(18): 9676-9687, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38663019

RESUMO

Prehydrolysis liquid (PHL) from dissolving pulp and biorefinery industries is rich in saccharides and lignin, being considered as a potential source of value-added materials and platform molecules. This study proposed an environmentally friendly and simple method to prepare morphologically controllable hollow lignin nanoparticles (LNPs) and levulinic acid (LA) from PHL. In the first step, after hydrothermal treatment of PHL with p-toluenesulfonic acid (p-TsOH), lignin with a uniform molecular weight was obtained to prepare LNPs. The prepared LNPs have an obvious hollow structure, with an average size of 490-660 nm, and exhibit good stability during 30 days of storage. When the as-obtained LNPs were used as a sustained-release agent for amikacin sulfate, the encapsulation efficiency reached over 70% and the release efficiency within 40 h reached 69.2% in a pH 5.5 buffer. Subsequently, the remaining PHL that contains saccharides was directly used for LA production under the catalysis of p-TsOH. At 150 °C for 1.5 h, the LA yield reached 58.4% and remained at 56% after 5 cycles of p-TsOH. It is worth noting that only p-TsOH was used as a reactive reagent throughout the entire preparation process. Overall, this study provided a novel pathway for the integrated utilization of PHL and showed the immense potential of the preparation and application of LNPs.


Assuntos
Portadores de Fármacos , Ácidos Levulínicos , Lignina , Nanopartículas , Populus , Ácidos Levulínicos/química , Lignina/química , Nanopartículas/química , Populus/química , Portadores de Fármacos/química , Madeira/química , Hidrólise , Tamanho da Partícula
12.
Langmuir ; 40(31): 16291-16302, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39041625

RESUMO

Carboxymethyl Salix psammophila wood powder-imprinted membranes (CMSM-MIPs) were prepared by using wet spinning technology and molecular-imprinting technology for the selective removal of tetracycline from wastewater. Scanning electron microscopy, X-ray diffraction, thermogravimetry, and X-ray photoelectron spectroscopy characterizations demonstrate that CMSM-MIPs retain the membranous structure of Carboxymethyl Salix psammophila wood powder membranes, successfully encapsulate thin layers of imprinted polymers on the membrane surface, and exhibit excellent thermal stability. The adsorption results showed that CMSM-MIPs had the highest selective adsorption capacity for tetracycline, which was 253.8 mg/g. In addition, the adsorption capacities for oxytetracycline and chlortetracycline were 208.8 and 188 mg/g, respectively. It can be observed that CMSM-MIPs not only exhibit a high adsorption capacity for tetracycline but also demonstrate good adsorption capacities for oxytetracycline and chlortetracycline. The experimental results showed that CMSM-MIPs were best fitted with pseudo-second-order kinetics and most consistent with Freundlich fitting. The regeneration experiment showed that CMSM-MIPs still had good regeneration performance after 5 regeneration cycles. In conclusion, the CMSM-MIPs can not only have the natural adsorption performance of Salix psammophila wood powder but also give it higher selectivity through molecular imprinting, so as to achieve efficient removal of target organic pollutants in water.


Assuntos
Salix , Tetraciclina , Madeira , Adsorção , Madeira/química , Tetraciclina/química , Tetraciclina/isolamento & purificação , Salix/química , Pós/química , Membranas Artificiais , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Impressão Molecular/métodos , Antibacterianos/química , Antibacterianos/isolamento & purificação
13.
Biomacromolecules ; 25(6): 3532-3541, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38750618

RESUMO

Despite the potential of lignocellulose in manufacturing value-added chemicals and biofuels, its efficient biotechnological conversion by enzymatic hydrolysis still poses major challenges. The complex interplay between xylan, cellulose, and lignin in fibrous materials makes it difficult to assess underlying physico- and biochemical mechanisms. Here, we reduce the complexity of the system by creating matrices of cellulose, xylan, and lignin, which consists of a cellulose base layer and xylan/lignin domains. We follow enzymatic degradation using an endoxylanase by high-speed atomic force microscopy and surface plasmon resonance spectroscopy to obtain morphological and kinetic data. Fastest reaction kinetics were observed at low lignin contents, which were related to the different swelling capacities of xylan. We demonstrate that the complex processes taking place at the interfaces of lignin and xylan in the presence of enzymes can be monitored in real time, providing a future platform for observing phenomena relevant to fiber-based systems.


Assuntos
Lignina , Madeira , Xilanos , Celulose/química , Celulose/metabolismo , Endo-1,4-beta-Xilanases/metabolismo , Endo-1,4-beta-Xilanases/química , Hidrólise , Cinética , Lignina/química , Lignina/metabolismo , Microscopia de Força Atômica , Madeira/química , Madeira/metabolismo , Xilanos/química , Xilanos/metabolismo
14.
Rapid Commun Mass Spectrom ; 38(14): e9716, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-38738638

RESUMO

RATIONALE: This study overcomes traditional biomass analysis limitations by introducing a pioneering matrix-free laser desorption/ionization (LDI) approach in mass spectrometry imaging (MSI) for efficient lignin evaluation in wood. The innovative acetic acid-peracetic acid (APA) treatment significantly enhances lignin detection, enabling high-throughput, on-site analysis. METHODS: Wood slices, softwood from a conifer tree (Japanese cypress) and hardwood from a broadleaf tree (Japanese beech), were analyzed using MSI with a Fourier transform ion cyclotron resonance mass spectrometer. The developed APA treatment demonstrated effectiveness for MSI analysis of biomass. RESULTS: Our imaging technique successfully distinguishes between earlywood and latewood and enables the distinct visualization of lignin in these and other wood tissues, such as the radial parenchyma. This approach reveals significant contrasts in MSI. It has identified intense ions from ß-O-4-type lignin, specifically in the radial parenchyma of hardwood, highlighting the method's precision and utility in wood tissue analysis. CONCLUSIONS: The benefits of matrix-free LDI include reduced peak overlap, consistent sample quality, preservation of natural sample properties, enhanced analytical accuracy, and reduced operational costs. This innovative approach is poised to become a standard method for rapid and precise biomass evaluation and has important applications in environmental research and sustainable resource management and is crucial for the effective management of diverse biomass, paving the way towards a sustainable, circular society.


Assuntos
Biomassa , Lignina , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Madeira , Madeira/química , Lignina/análise , Lignina/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Fagus/química
15.
Environ Sci Technol ; 58(32): 14293-14305, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39093591

RESUMO

Environmentally persistent free radicals (EPFRs) play an important role in aerosol effects on air quality and public health, but their atmospheric abundance and sources are poorly understood. We measured EPFRs contained in PM2.5 collected in Fairbanks, Alaska, in winter 2022. We find that EPFR concentrations were enhanced during surface-based inversion and correlate strongly with incomplete combustion markers, including carbon monoxide and elemental carbon (R2 > 0.75). EPFRs exhibit moderately good correlations with PAHs, biomass burning organic aerosols, and potassium (R2 > 0.4). We also observe strong correlations of EPFRs with hydrocarbon-like organic aerosols, Fe and Ti (R2 > 0.6), and single-particle mass spectrometry measurements reveal internal mixing of PAHs, with potassium and iron. These results suggest that residential wood burning and vehicle tailpipes are major sources of EPFRs and nontailpipe emissions, such as brake wear and road dust, may contribute to the stabilization of EPFRs. Exposure to the observed EPFR concentrations (18 ± 12 pmol m-3) would be equivalent to smoking ∼0.4-1 cigarette daily. Very strong correlations (R2 > 0.8) of EPFR with hydroxyl radical formation in surrogate lung fluid indicate that exposure to EPFRs may induce oxidative stress in the human respiratory tract.


Assuntos
Poluentes Atmosféricos , Emissões de Veículos , Madeira , Madeira/química , Alaska , Radicais Livres , Material Particulado , Monitoramento Ambiental , Aerossóis , Hidrocarbonetos Policíclicos Aromáticos/análise
16.
Med J Aust ; 220(1): 29-34, 2024 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-38030130

RESUMO

OBJECTIVES: To estimate the number of deaths and the cost of deaths attributable to wood heater smoke in the Australian Capital Territory. STUDY DESIGN: Rapid health impact assessment, based on fine particulate matter (PM2.5 ) data from three outdoor air pollution monitors and published exposure-response functions for natural cause mortality attributed to PM2.5 exposure. SETTING: Australian Capital Territory (population, 2021: 454 000), 2016-2018, 2021, and 2022 (2019 and 2020 excluded because of the impact of extreme bushfires on air quality). MAIN OUTCOME MEASURES: Proportion of PM2.5 exposure attributable to wood heaters; numbers of deaths and associated cost of deaths (based on the value of statistical life: $5.3 million) attributable to wood heater smoke. RESULTS: Wood heater emissions contributed an estimated 1.16-1.73 µg/m3 to the annual mean PM2.5 concentration during the three colder years (2017, 2018, 2021), or 17-25% of annual mean exposure, and 0.72 µg/m3 (15%) or 0.89 µg/m3 (13%) during the two milder years (2016, 2022). Using the most conservative exposure-response function, the estimated annual number of deaths attributable to wood heater smoke was 17-26 during the colder three years and 11-15 deaths during the milder two years. Using the least conservative exposure-response function, an estimated 43-63 deaths per year (colder years) and 26-36 deaths per year (milder years) were attributable to wood heater smoke. The estimated annual equivalent cost of deaths was $57-136 million (most conservative exposure-response function) and $140-333 million (least conservative exposure-response function). CONCLUSIONS: The estimated annual number of deaths in the ACT attributable to wood heater PM2.5 pollution is similar to that attributed to the extreme smoke of the 2019-20 Black Summer bushfires. The number of wood heaters should be reduced by banning new installations and phasing out existing units in urban and suburban areas.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Humanos , Fumaça/efeitos adversos , Poluentes Atmosféricos/análise , Território da Capital Australiana , Madeira/efeitos adversos , Madeira/química , Avaliação do Impacto na Saúde , Austrália/epidemiologia , Poluição do Ar/efeitos adversos , Material Particulado/efeitos adversos , Exposição Ambiental/efeitos adversos
17.
J Nat Prod ; 87(4): 652-663, 2024 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-38359463

RESUMO

Castanea sativa wood is a rich source of hydrolyzable tannins, known for their diverse bioactivities. To investigate these bioactive properties further, it is crucial to isolate and characterize hydrophilic compounds effectively. To address this issue, we developed a centrifugal partition chromatography (CPC) method and applied it to an aqueous C. sativa wood extract. We determined the partition coefficients (KD) of the six major compounds using four butanol-/water-based biphasic solvent systems. Initially, we utilized the n-butanol/propanol/water (3:1:4, v/v/v) systems for the first fractionation step. Subsequently, we employed the water/methyl tert-butyl ether/butanol/acetone (8:5:3:4, v/v/v/v) system to fractionate moderately and highly hydrophilic fractions. We calculated the KD values for major compounds of the most hydrophilic fractions using the butanol/ethanol/water (4:1:5, v/v/v) and butanol/isopropanol/water (2:1:3, v/v/v) systems. In total, we isolated 23 compounds through a combination of CPC, size exclusion chromatography, and preparative HPLC. Among these compounds, six have never been previously described. We characterized them by 1D and 2D NMR experiments and high-resolution mass spectroscopy acquisitions.


Assuntos
Fagaceae , Taninos Hidrolisáveis , Taninos Hidrolisáveis/química , Taninos Hidrolisáveis/isolamento & purificação , Fagaceae/química , Estrutura Molecular , Madeira/química , Extratos Vegetais/química
18.
Nature ; 554(7691): 224-228, 2018 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-29420466

RESUMO

Synthetic structural materials with exceptional mechanical performance suffer from either large weight and adverse environmental impact (for example, steels and alloys) or complex manufacturing processes and thus high cost (for example, polymer-based and biomimetic composites). Natural wood is a low-cost and abundant material and has been used for millennia as a structural material for building and furniture construction. However, the mechanical performance of natural wood (its strength and toughness) is unsatisfactory for many advanced engineering structures and applications. Pre-treatment with steam, heat, ammonia or cold rolling followed by densification has led to the enhanced mechanical performance of natural wood. However, the existing methods result in incomplete densification and lack dimensional stability, particularly in response to humid environments, and wood treated in these ways can expand and weaken. Here we report a simple and effective strategy to transform bulk natural wood directly into a high-performance structural material with a more than tenfold increase in strength, toughness and ballistic resistance and with greater dimensional stability. Our two-step process involves the partial removal of lignin and hemicellulose from the natural wood via a boiling process in an aqueous mixture of NaOH and Na2SO3 followed by hot-pressing, leading to the total collapse of cell walls and the complete densification of the natural wood with highly aligned cellulose nanofibres. This strategy is shown to be universally effective for various species of wood. Our processed wood has a specific strength higher than that of most structural metals and alloys, making it a low-cost, high-performance, lightweight alternative.


Assuntos
Madeira/química , Ligas/química , Parede Celular/química , Celulose/química , Temperatura Alta , Lignina/química , Lignina/isolamento & purificação , Metais/química , Peso Molecular , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Hidróxido de Sódio/química , Sulfitos/química , Resistência à Tração , Madeira/classificação
19.
Environ Res ; 252(Pt 3): 118987, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38670212

RESUMO

Sludge incineration is the main strategy for sludge reduction in China. The combined conditioning of lime and chemical agents has been proven to achieve sludge dewatering by disrupting the extracellular polymeric substances (EPS) of sludge and reducing its compressibility. However, when incineration is the intended disposal purpose, this method poses challenges such as incomplete combustion, equipment corrosion, secondary pollution, and decreased calorific value of sludge cake. In contrast, freeze-thaw conditioning, coupled with sawdust as a high-calorific-value bio-waste, emerges as an efficient and clean alternative. The research investigates the synergistic effects of freeze-thaw and sawdust co-conditioning on various sludge properties, including dewaterability, compressibility, consolidation, permeability, microscopicity, and calorific value. The study reveals that the combined conditioning significantly reduces water content and compressibility while increasing void ratio, consolidation, permeability, and enhancing the calorific value of the sludge cake. Specifically, sludge cake conditioned with 60% dried solids (DS) sawdust and freeze-thaw achieved a water content (Wc) of 49.07% and a calorific value of 1422.3 kcal/kg, meeting standards for self-sustained incineration. With heat recovery, the combined conditioning generates an economic revenue of 25.1 $/t DS after deducting costs, thereby reducing the overall cost of sludge reduction treatment. This research offers a clean and practical solution for sludge incineration and reduction, demonstrating great economic value and application potential.


Assuntos
Congelamento , Incineração , Esgotos , Esgotos/química , Incineração/métodos , Madeira/química , Estudos de Viabilidade , Água
20.
Environ Res ; 241: 117609, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37949287

RESUMO

The research assessed waste-based briquettes consumption compared to conventional fuels in the Andes. Laboratory tests were conducted together with on-field analysis in Colquencha (Bolivia). The laboratory study shows that the performances of briquettes are better in terms of PM2.5 (933.4 ± 50.8 mg kg-1) and CO emissions (22.89 ± 2.40 g kg-1) compared to animal dung (6265.7 ± 1273.5 mgPM2.5 kg-1 and 48.10 ± 12.50 gCO kg-1), although the boiling time increased due to the lower fuel consumption rate and firepower compared to shrubs. The social survey organized with 150 Bolivian citizens suggested that low-income households are not able to pay for an alternative fuel: about 40% would pay less than 4 USD per month, while methane use for cooking is positively correlated with the income level (r = 0.244, p < 0.05). On field analysis suggested that local cookstoves are not appropriate for briquettes combustion since indoor air pollution overcomes 30 ppm of CO and 10 mgPM2.5 m-3. On balance, local small manufactures can be the main target for selling waste-based briquettes to reduce shrubs and wood consumption. However, briquettes production costs seem not yet competitive to natural easy-to-obtain fuels (i.e., animal dung). The research encourages the use of cellulosic and biomass waste-based briquettes in the Andean area for cooking, heating, or manufacturing and strongly advises policy-makers to introduce economic incentives for the recovery of secondary raw materials.


Assuntos
Poluição do Ar em Ambientes Fechados , Status Social , Poluição do Ar em Ambientes Fechados/análise , Madeira/química , Pobreza , Características da Família , Culinária , Material Particulado/análise
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