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1.
Artículo en Inglés | MEDLINE | ID: mdl-38522626

RESUMEN

BACKGROUND: A substantial proportion of sensitized individuals tolerate suspected foods without developing allergic symptoms; this phenomenon is known as sensitized tolerance. The immunogenic and metabolic features underlying the sensitized-tolerant phenotype remain largely unknown. OBJECTIVE: We aimed to uncover the metabolic signatures associated with clinical milk allergy (MA) and sensitized tolerance using metabolomics. METHODS: We characterized the serum metabolic and immunologic profiles of children with clinical IgE-mediated MA (n = 30) or milk-sensitized tolerance (n = 20) and healthy controls (n = 21). A comparative analysis was performed to identify dysregulated pathways associated with the clinical manifestations of food allergy. We also analyzed specific biomarkers indicative of different sensitization phenotypes in children with MA. The candidate metabolites were validated in an independent quantification cohort (n = 41). RESULTS: Metabolomic profiling confirmed the presence of a distinct metabolic signature that discriminated children with MA from those with milk-sensitized tolerance. Amino acid metabolites generated via arginine, proline, and glutathione metabolism were uniquely altered in children with sensitized tolerance. Arginine depletion and metabolism through the polyamine pathway to fuel glutamate synthesis were closely associated with suppression of clinical symptoms in the presence of allergen-specific IgE. In children with MA, the polysensitized state was characterized by disturbances in tryptophan metabolism. CONCLUSIONS: By combining untargeted metabolomics with targeted validation in an independent quantification cohort, we identified candidate metabolites as phenotypic and diagnostic biomarkers of food allergy. Our results provide insights into the pathologic mechanisms underlying childhood allergy and suggest potential therapeutic targets.

2.
Bioresour Technol ; 399: 130634, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38548033

RESUMEN

Food waste anaerobic digestion requires proper utilization of solid digestate, and pyrolysis emerges as an effective method to produce nutrient-rich biochar. This study investigated the leaching characteristics and speciation changes of nutrients in food waste digestate (FWD)-derived biochar pyrolyzed at 350 °C (BC350), 450 °C (BC450), and 550 °C (BC550). BC350 featured inorganic nitrogen, while BC450 and BC550 contained elevated organic nitrogen. Nitrogen, potassium, and dissolved organic carbon were released via a quick surface wash-off process. Polyphosphates prevailed in BC350 and leached through a fast diffusion-controlled process. BC450 and BC550 were dominated by Ca/Mg orthophosphates and released via a slow dissolution-controlled process. Leachates from BC450 and BC550 stimulated the shoot length of wheat seeds. After 5 leaching cycles, there were more aromatic dissolved organics, and BC450 and BC550 exhibited higher abundance of C-N and O-P-O. Overall, pyrolysis of FWD at 450 °C and 550 °C shows potential in producing slow-release biochar fertilizers for resource recycling.


Asunto(s)
Alimento Perdido y Desperdiciado , Eliminación de Residuos , Alimentos , Carbón Orgánico , Nutrientes , Semillas/química , Nitrógeno/análisis , Suelo
3.
Bioresour Technol ; 393: 130085, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37993065

RESUMEN

To customize biochar suitable for efficient adsorption of benzene derivatives, this study presents programmed microwave pyrolysis to produce hydrophobic porous biochar with low-dose ferric chloride. Designated control of the ramping rates in the carbonization stage and the temperatures in the activation stage were conducive to enlarging the specific surface area. Iron species, including amorphous iron minerals, could create small-scale hotspots during microwave pyrolysis to promote microporous structure development. Compared with conventional pyrolysis, programmed microwave pyrolysis could increase the specific surface area from 288.6 m2 g-1 to 455.9 m2 g-1 with a short heating time (15 min vs. 2 h) under 650 °C. Engineered biochar exhibited higher adsorption capacity for benzene and toluene (136.6 and 94.6 mg g-1), and lower adsorption capacity for water vapour (6.2 mg g-1). These findings provide an innovative design of engineered biochar for the adsorption of volatile organic compounds in the environment.


Asunto(s)
Microondas , Pirólisis , Adsorción , Porosidad , Carbón Orgánico/química , Hierro
4.
J Hazard Mater ; 465: 133258, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38113734

RESUMEN

Copper plays a crucial role in the low-carbon transformation of global communities with prevalent use of electric vehicles. This study proposed an environmentally friendly approach that utilizes a deep eutectic solvent (DES), choline chloride-ethylene glycol (ChCl-EG), as green solvent for the selective extraction of copper from scrap materials. With hydrogen peroxide as an oxidizing agent, the copper species from the printed circuit boards (PCBs) scraps were efficiently leached by the DES through oxidation-complexation reactions (conditions: 25 min, 20 °C, and 5 wt% H2O2). Molecular dynamics and density functional theory were performed to simulate the intricate cascade of interactions between copper species and hydrogen bond donors/acceptors of DES, providing insights into the mechanistic processes involved. Copper was selectively recovered from the DES leachate containing impurities (e.g., Pb2+, Sn2+, and Al3+) through electrodeposition via a diffusion-controlled reaction under a constant potential mode. A comprehensive life cycle assessment of the process demonstrated that the utilisation of DES in the extraction of copper from waste PCBs could result in significant reduction in carbon dioxide emissions (-93.6 kg CO2 eq of 1000 kg waste PCBs), thus mitigating the carbon footprint of global copper use through the proposed solvometallurgical recycling process of secondary resources.

5.
Bioresour Technol ; 394: 130211, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38113950

RESUMEN

This study investigated the feasibility of a high-loading process with less water consumption for the valorization of wet biomass waste through hydrothermal carbonization (HTC) with and without N2 pressurization from the views of water saving, carbon utilization, and energy recovery. The results revealed that reducing the liquid-to-solid ratio from 10 to 2.5 significantly improved carbon storage in hydrochar due to preferential carbon sequestration as the solid phase (59.9%) instead of being lost in the liquid phase (∼10%). The pressurized HTC process resulted in a higher stability hydrochar through the devolatilization of secondary char that was less stable, yet resulted in âˆ¼10% 15% more carbon transformation to the gas phase. A cost-benefit analysis further demonstrated the potential of the high-loading HTC process for enhancing energy recovery while minimizing energy consumption during hydrochar production from high-moisture yard waste.


Asunto(s)
Carbono , Agua , Temperatura , Fenómenos Físicos , Biomasa
6.
Compr Rev Food Sci Food Saf ; 22(6): 4355-4377, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37679957

RESUMEN

There appears a steep increase in the prevalence of food allergy worldwide in the past few decades. It is believed that, rather than genetic factors, the recently altered dietary and environmental factors are the driving forces behind the rapid increase of this disease. Accumulating evidence has implied that external exposures that occurred in prenatal and postnatal periods could affect the development of oral tolerance in later life. Understanding the potential risk factors for food allergy would greatly benefit the progress of intervention and therapy. In this review, we present updated knowledge on the dietary and environmental risk factors in early life that have been shown to impact the development of food allergy. These predominantly include dietary habits, microbial exposures, allergen exposure routes, environmental pollutants, and so on. The key evidence, conflicts, and potential research topics of each theory are discussed, and associated interventional strategies to prevent the disease development and ameliorate treatment burden are included. Accumulating evidence has supported the causative role of certain dietary and environmental factors in the establishment of oral tolerance in early life, especially the time of introducing allergenic foods, skin barrier function, and microbial exposures. In addition to certain immunomodulatory factors, increasing interest is raised toward modern dietary patterns, where adequately powered studies are required to identify contributions of those modifiable risk factors. This review broadens our understanding of the connections between diet, environment, and early-life immunity, thus benefiting the progress of intervention and therapy of food allergy.


Asunto(s)
Contaminantes Ambientales , Hipersensibilidad a los Alimentos , Femenino , Embarazo , Humanos , Hipersensibilidad a los Alimentos/prevención & control , Hipersensibilidad a los Alimentos/epidemiología , Hipersensibilidad a los Alimentos/etiología , Dieta , Factores de Riesgo , Conducta Alimentaria
7.
Front Nutr ; 10: 1276929, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37680896
8.
Bioresour Technol ; 386: 129543, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37482202

RESUMEN

Pyrolysis vapor is an important byproduct in the production of biochar from biomass waste, and its emission may pose potential environmental risks. To achieve green production of biochar and efficient utilization of pyrolysis vapors, a novel strategy is proposed in this study to use pristine biochar as an adsorbent to adsorb the pyrolysis vapors. According to thermogravimetry-Fourier infrared spectroscopy-mass spectrometry evaluation, the evolved vapors mainly consisted of oxygenated compounds, hydrocarbons, CO2, CO, and H2O. With pyrolysis temperature increasing, ethers, phenols, hydrocarbons, acids/ketones, and CO2 were changed in the same direction based on two-dimensional correlation spectroscopy analysis. Moreover, butene, propargyl alcohol, and butane were the most abundant ionic fragments. After adsorbing pyrolysis vapors, the heating value of the biochar increased by a maximum of 3.2 MJ kg-1 with changes of physicochemical properties. This strategy provides a theoretical basis for green preparation of biochar while recovering energy from pyrolysis vapors.


Asunto(s)
Dióxido de Carbono , Pirólisis , Adsorción , Dióxido de Carbono/química , Biomasa , Carbón Orgánico/química , Gases
9.
Chemosphere ; 336: 139089, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37285985

RESUMEN

Arsenic (As) is a potentially toxic element with variable valence states. Due to high toxicity and bioaccumulation, As can pose a severe threat to the quality of the ecology as well as human health. In this work, As(III) in water was effectively removed by biochar-supported copper ferrite magnetic composite with persulfate. The copper ferrite@biochar composite exhibited higher catalytic activity than copper ferrite and biochar. The removal of As(III) could reach 99.8% within 1 h under the conditions of initial As(III) concentration at 10 mg/L, initial pH at 2-6, and equilibrium pH at 10. The maximum adsorption capacity of As(III) by copper ferrite@biochar-persulfate was 88.9 mg/g, achieving superior performance than mostly reported the metal oxide adsorbents. By means of a variety of characterization techniques, it was found that ∙OH acted as the main free radical for removing As(III) in the copper ferrite@biochar-persulfate system and the major mechanisms were oxidation and complexation. As a natural fibre biomass waste-derived adsorbent, ferrite@biochar presented a high catalytic efficiency and easy magnetic separation for As(III) removal. This study highlights the great potential of copper ferrite@biochar-persulfate application in As(III) wastewater treatment.


Asunto(s)
Arsénico , Contaminantes Químicos del Agua , Humanos , Aguas Residuales , Cobre , Carbón Orgánico/química , Contaminantes Químicos del Agua/análisis , Adsorción
10.
Food Res Int ; 169: 112842, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37254415

RESUMEN

Currently, the biological consequences of advanced glycation end-products (AGEs) and their link to the antigenicity of food allergens are largely unknown due to the uncertainty in their digestive fates within the body. In this study, the influence of glycation derived from α-dicarbonyl compounds (α-DCs), precursors of AGEs, on digestive behaviors of ovalbumin (OVA) was investigated in a two-step simulated gastrointestinal (GI) model. Methylglyoxal (MGO), glyoxal (GO), and 3-deoxyglucosone were selected as typical α-DCs to obtain glycated OVA with different AGE-modifications (AGE-Ms). It was unveiled that α-DC-glycation reduced the digestibility of OVA via blocking tryptic cleavage sites and inducing steric hindrance, especially seen in the GO- and MGO-OVA groups. The formed AGE-Ms, depending on the precursor type, showed masking effects on the epitopes of OVA, which counteracted the negative effects of reduced digestibility on its antigenicity. Substantial changes in the peptide release patterns were also noted in glycated OVA, including alterations in the sequences and structures of several known protease-resistant epitopes of OVA. This study provides new insights into the nutritional and healthy effects of MRPs in heat-processed foods, as well as their potential connection to the modulation of egg allergy.


Asunto(s)
Productos Finales de Glicación Avanzada , Reacción de Maillard , Ovalbúmina/química , Productos Finales de Glicación Avanzada/química , Óxido de Magnesio , Péptidos , Glioxal/química , Piruvaldehído
11.
Food Funct ; 14(11): 5342-5354, 2023 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-37211863

RESUMEN

Advanced glycation end-products (AGEs) are a group of heterogeneous compounds formed during the Maillard Reaction (MR) and have been proven to be detrimental to human health. In addition to thermally processed foods, the digestive tract may be an additional site for exogenous AGE formation since the MR would possibly occur between (oligo-)peptides, free amino acids, and reactive MR products (MRPs) such as α-dicarbonyl compounds (α-DCs) along the digestion. In this study, through establishing a simulated gastrointestinal (GI) model consisting of whey protein isolate (WPI) and two typical α-DCs, i.e., methylglyoxal (MGO) or glyoxal (GO), we first validated that co-digestion of WPI with α-DCs generated extra amounts of AGEs in a precursor-dependent manner, especially seen in the intestinal stage. At the end of GI digestion, the contents of total AGEs in WPI-MGO and WPI-GO systems were 4.3-242 and 2.5-73.6 times higher than those formed in the control system, respectively. Evaluation of the protein digestibility further showed that AGE formation along the digestion process slightly affected the digestibility of whey protein fractions. However, as sequenced and identified by high-resolution mass spectrometry, different types of AGE modifications were identified in peptides released from ß-lactoglobulin and α-lactalbumin in the final digests, as well as changes in peptide sequence motifs. This suggested that the glycated structures formed during co-digestion affected the action of digestive proteases toward whey proteins. Overall, these results highlight the GI tract as an additional source of exogenous AGEs and provide new insights into the biochemical consequences of MRPs in heat-processed foods.


Asunto(s)
Óxido de Magnesio , Reacción de Maillard , Humanos , Proteína de Suero de Leche/metabolismo , Óxido de Magnesio/metabolismo , Glioxal/química , Piruvaldehído/metabolismo , Péptidos/metabolismo , Productos Finales de Glicación Avanzada/metabolismo , Tracto Gastrointestinal/metabolismo , Digestión
12.
Water Res ; 238: 120006, 2023 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-37121197

RESUMEN

Microplastics and biochar, as particulate matter that is prevalent in the water environment, will inevitably encounter and interact with each other during environmental aging. The potential interaction of microplastics and biochar, and the associated impact on their environmental behavior remains largely unknown. In this study, we exposed microplastics and biochar concurrently to ultraviolet light to mimic the aging process, investigated the release and fluorescence characteristics of dissolved organic matter (DOM) in water, and analyzed the effects of co-existing microplastics and biochar on their sorption of organic contaminants. We demonstrate that early-stage interactions of microplastics and biochar could entangle to promote the release of DOM from biochar, while their long-term interactions after light irradiation resulted in the sorption of hydrophobic and small molecules of microbial byproduct-like DOM. Simultaneously, early-stage interactions of microplastics and biochar showed a promotion for sorption of organic contaminants with an increase of 5.3-17.7%. After aging, however, long-term interactions between microplastics and biochar made it no longer promote the sorption of organic contaminants due to the influence of heterogeneous aggregation. Our results provide new insights into the time-dependent interactions between microplastics and biochar and highlight the need to incorporate their interactions into future environmental risk assessments for microplastics in the water environment.


Asunto(s)
Microplásticos , Plásticos , Plásticos/química , Agua , Carbón Orgánico/química , Materia Orgánica Disuelta
13.
Glob Chall ; 7(3): 2200237, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36910467

RESUMEN

In the recycling of retired lithium-ion batteries (LIBs), the cathode materials containing valuable metals should be first separated from the current collector aluminum foil to decrease the difficulty and complexity in the subsequent metal extraction. However, strong the binding force of organic binder polyvinylidene fluoride (PVDF) prevents effective separation of cathode materials and Al foil, thus affecting metal recycling. This paper reviews the composition, property, function, and binding mechanism of PVDF, and elaborates on the separation technologies of cathode material and Al foil (e.g., physical separation, solid-phase thermochemistry, solution chemistry, and solvent chemistry) as well as the corresponding reaction behavior and transformation mechanisms of PVDF. Due to the characteristic variation of the reaction systems, the dissolution, swelling, melting, and degradation processes and mechanisms of PVDF exhibit considerable differences, posing new challenges to efficient recycling of spent LIBs worldwide. It is critical to separate cathode materials and Al foil and recycle PVDF to reduce environmental risks from the recovery of retired LIBs resources. Developing fluorine-free alternative materials and solid-state electrolytes is a potential way to mitigate PVDF pollution in the recycling of spent LIBs in the EV era.

14.
Bioresour Technol ; 372: 128698, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36731614

RESUMEN

Microwave (MW)-assisted catalytic degradation of organic pollutants draws increasing attention owing to its high efficiency in wastewater treatment. This work developed Cu-loaded biochar (CuBC) catalysts for time-efficient mineralization of refractory and high-concentration oxytetracycline (OTC). With only 1 min at 80 °C, Na2S2O8 achieved 100% total organic carbon (TOC) removal over the Cu5BC, while NaClO mineralized 73.3% TOC over the metal-free BC, in contrast to a relatively low mineralization efficiency (< 35%) achieved by H2O2. The high efficiency in MW-assisted oxidation systems could be ascribed to reactive oxidizing species (•SO4- or •ClO), which otherwise were barely detectable in a conventional heating system. The interactions between CuBC and MW were revealed by correlating the physiochemical characteristics to the MW absorption ability. The proposed catalytic systems can contribute to the development of a high-throughput and low-carbon wastewater treatment technology.


Asunto(s)
Oxitetraciclina , Contaminantes Químicos del Agua , Aguas Residuales , Ácido Hipocloroso , Peróxido de Hidrógeno , Microondas , Oxidación-Reducción , Carbono , Contaminantes Químicos del Agua/análisis
15.
J Hazard Mater ; 445: 130502, 2023 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-36493647

RESUMEN

Oxidative extraction has become an economically viable option for recycling lithium (Li) from spent lithium iron phosphate (LiFePO4) batteries. In this study, the releases behaviour of Li from spent LiFePO4 batteries under different oxidizing conditions was investigated with sodium hypochlorite (NaClO) as the solid oxidant. We revealed that, due to the intervention of graphitic carbon, the generated species of Li in mechanochemical oxidation (NaClO:LiFePO4 at a molar ratio of 2:1, 5 min, and 600 rpm) was lithium carbonate (Li2CO3). The graphite layer provided a channel for the conversion of Li species released by mechanochemical oxidation. While in hydrometallurgical oxidation (NaClO:LiFePO4 at a molar ratio of 2:1 and 12.5 min), the presence of hydrogen species led to the formation of lithium chloride (LiCl). Moreover, life cycle assessment (LCA) demonstrated that for recycling 1.0 kg of spent LiFePO4 batteries, mechanochemical and hydrometallurgical oxidation could reduce carbon footprints by 2.81 kg CO2 eq and 2.88 kg CO2 eq, respectively. Our results indicate that the oxidative environment determines the release pathway of Li from the spent LiFePO4 cathode material, thereby regulating the product forms of Li and environmental impacts. This study can provide key technical guidance for Li recycling from spent LiFePO4 batteries.

16.
Mol Nutr Food Res ; 67(5): e2200221, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36550625

RESUMEN

SCOPE: Epidemiologic studies suggest a link between the incidence of food allergy and the consumption of dietary advanced glycation end-products (AGEs). However, the pathogenic role of dietary AGEs in food allergy is largely unknown. This study aims to investigate the effect of allergen-specific and non-specific AGEs on the allergenic manifestation of ovalbumin (OVA), a typical food allergen in vivo. METHODS AND RESULTS: OVA is glycated by methylglyoxal to prepare allergen-specific AGEs (i.e., OVA-AGE), and a standard AIN-93G diet is heated to obtain allergen-non-specific AGEs. A BALB/c mouse model orally sensitizes to OVA with different forms of AGEs is established and the outcomes are measured as clinical signs, specific antibodies, type-2/type-2 cytokines, immune cell subpopulations, intestinal barrier function, and gut microbiota (GM) composition. The OVA-AGE which has a lower immunoglobulin E (IgE)-binding level in vitro does not reduce the allergenicity of OVA but promotes a stronger T helper 2 cells (Th2)-response than native OVA in vivo. Both forms of AGEs up-regulate the expression of splenic RAGE and aggravate the destruction of gut barrier and GM dysbiosis, especially when exposes to non-relevant AGEs. CONCLUSION: This study highlights the role of dietary AGEs in food allergy and helps to understand the biological consequences of immune-toxic compounds in modern diet.


Asunto(s)
Alérgenos , Hipersensibilidad a los Alimentos , Ratones , Animales , Ovalbúmina , Citocinas/metabolismo , Productos Finales de Glicación Avanzada , Ratones Endogámicos BALB C , Modelos Animales de Enfermedad
17.
Bioresour Technol ; 369: 128423, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36462767

RESUMEN

Worldwide surge in crop residue generation has necessitated developing strategies for their sustainable disposal. Pyrolysis has been widely adopted to convert crop residue into biochar with bio-oil and gas being two co-products. The review adopts a whole system philosophy and systematically summarises up-to-date knowledge of crop residue pyrolysis processes, influential factors, and biochar applications. Essential process design tools for biochar production e.g., cost-benefit analysis, life cycle assessment, and machine learning methods are also reviewed, which has often been overlooked in prior reviews. Important aspects include (a) correlating techno-economics of biochar production with crop residue compositions, (b) process operating conditions and management strategies, (c) biochar applications including soil amendment, fuel displacement, catalytic usage, etc., (d) data-driven modelling techniques, (e) properties of biochar, and (f) climate change mitigation. Overall, the review will support the development of application-oriented process pipelines for crop residue-based biochar.


Asunto(s)
Carbón Orgánico , Pirólisis , Carbón Orgánico/química , Suelo/química , Cambio Climático
18.
J Sci Food Agric ; 103(6): 3006-3016, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36397264

RESUMEN

BACKGROUND: As potent antioxidants, anthocyanins can protect the body from free radicals. However, the traditional solvent extraction method has the disadvantages of requiring a high extraction temperature and long extraction time, so it is necessary to develop an efficient extraction method for anthocyanins. RESULTS: In this study, the technique of natural deep eutectic solvents (DESs) was applied to extract anthocyanins from purple perilla leaves with the aid of microwave-ultrasonic assisted extraction (MUAE). The response surface methodology (RSM), based on the Box-Behnken design (BBD), predicted the maximum extraction yield of anthocyanins to be 619.62 mg (100 g)-1 under the following conditions: x1 (ultrasonic extraction power) = 357.25 W, x2 (time) = 25.62 min, and x3 (temperature) = 57.80 °C. The biological activity of the extract obtained was evaluated by examining its radical-scavenging effect on 1,1-diphenyl-2-picrylhydrazyl, hydroxyl radical, and superoxide anion radicals. Its bacteriostatic impact was investigated on four typical bacteria: Shewanella putrefaciens (S. putrefaciens), Pseudomonas fluorescens (P. fluorescens), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus). CONCLUSION: The integrated extraction method of DESs with MUAE was efficient, energy-saving, green, and sustainable. © 2022 Society of Chemical Industry.


Asunto(s)
Perilla frutescens , Perilla , Perilla frutescens/química , Disolventes Eutécticos Profundos , Antocianinas , Extractos Vegetales/química , Microondas , Ultrasonido , Staphylococcus aureus , Escherichia coli , Solventes/química
19.
Bioresour Technol ; 362: 127838, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36031124

RESUMEN

This study innovated the concept in designing an efficient and reusable microwave (MW) absorbent through concurrent exploitation of carbon graphitization, oxygen functionalization, and carbothermal iron reduction underpinned by an endothermic co-pyrolysis of wood waste and low-dosage iron. A powerful MW assimilation was accomplished from nanoscale amorphous magnetic particles as well as graphitized microporous carbon-iron skeleton in the biochar composites. Relative to a weak magnetic loss derived from the iron phase, the graphitic carbon architecture with abundant surface functionalities (i.e., CO and CO) exhibited a strong dielectric loss, which was thus prioritized as major active sites during MW reuse. The MW-absorbing biochar demonstrated a fast, robust, and durable removal of a refractory herbicide (2,4-dichlorophenoxy acetic acid) under mild MW irradiation with zero chemical input, low electricity consumption, and negligible Fe dissolution. Overall, this study will foster carbon-neutral industrial wastewater treatment and wood waste valorization.


Asunto(s)
Contaminantes Ambientales , Contaminantes Químicos del Agua , Adsorción , Carbono , Carbón Orgánico/química , Hierro/química , Microondas , Contaminantes Químicos del Agua/química , Madera
20.
Bioresour Technol ; 357: 127376, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35623603

RESUMEN

Lignocellulosic paper waste constitutes a major waste stream globally, which should be valorised for chemical production. However, paper properties (e.g., feedstock composition, cellulosic crystallinity, and thermal stability/degradability) vary with raw materials and pulping processes. This study investigated levulinic acid (LA), hydroxymethylfurfural (HMF), and furfural production by H2SO4 and FeCl3 catalysed conversion of nine types of paper wastes in a green solvent system (1:1 γ-valerolactone/water). At 160-180 °C for 1-20 min, ∼23-27 wt% LA yield was achieved from sanitary papers, tracing/parchment paper, and paper food box mainly containing crystalline cellulose, while a lower LA yield (∼10-20 wt%) was obtained from other paper wastes with high contents of ash and lignin. A higher selectivity towards HMF (∼12 mol%) was achieved in the presence of FeCl3. A furfural yield of âˆ¼ 4-7.5 wt% was also obtained from the hemicellulose content. This study elucidates crucial factors and desirable characteristics of paper waste for catalytic valorisation.


Asunto(s)
Furaldehído , Ácidos Levulínicos , Cloruros , Compuestos Férricos , Furaldehído/análogos & derivados , Furaldehído/química , Lignina/química
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