Search Results (1,079)

Wood vinegar (WV), a by-product of woody biomass pyrolysis, is increasingly used in agriculture as a sustainable biostimulant, although its effects on plant stress resistance and underlying mechanisms remain poorly understood. Recent studies propose that WV may act through a eustress-based mechanism, defined as a mild and controlled stress that activates adaptive physiological responses and enhances plant performance without causing structural or metabolic damage. This study investigated the physiological and biochemical effects of WV on strawberry plants grown under three water-deficit stress levels [no stress (NS), moderate stress (MS), and high stress (HS)] and treated with WV either via fertigation (0.5% v/v, WV₁) or foliar spray (0.2% v/v, WV₂). Gas exchange parameters (A, g_sw, E, Ci, WUE), total chlorophyll content, and nutrient balance ratios (Fe/Mn and K/Ca) were measured after a three-month growth period. PERMANOVA revealed significant effects of both WV and water-deficit stress, as well as their interaction, on most parameters. Under NS and MS conditions, WV reduced A, gsw, E, and Ci while increasing WUE, indicating enhanced water-use efficiency and improved physiological adjustment to water limitation. Chlorophyll content remained stable, demonstrating preserved photosynthetic integrity. Nutrient ratios further supported a controlled ion rebalancing associated with adaptive stress responses under NS and MS, whereas HS conditions indicated the onset of distress. Overall, the data demonstrate that WV enhances plant stress resistance primarily by inducing eustress-mediated physiological regulation rather than by directly stimulating growth. Full article

Changes in preservation conditions act as an important environmental filter driving shifts in microbial communities. However, the precise identities, functional traits, and ecological mechanisms of the dominant agents driving stage-specific deterioration remain insufficiently characterized. This study investigated microbial communities and dominant fungal degraders in waterlogged versus dried bamboo slips using amplicon sequencing, multivariate statistics, and microbial isolation. Results revealed compositionally distinct communities, with dried slips sharing only a small proportion of operational taxonomic units (OTUs) with waterlogged slips, while indicating the persistence of a subset of taxa across preservation states. A key discovery was the dominance of Fonsecaea minima (92% relative abundance) at the water-solid-air interface of partially submerged slips. Scanning electron microscopy (SEM) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) indicate that this fungus forms melanin-rich, biofilm-like surface structures, suggesting enhanced surface colonization and stress resistance. In contrast, the fungal community isolated from dried slips was characterized by Apiospora saccharicola associated with detectable xylanase activity. Meanwhile, the xerophilic species Xerogeomyces pulvereus dominated (99% relative abundance) the storage box environment. Together, these results demonstrate that preservation niches select for fungi with distinct functional traits, highlighting the importance of stage-specific preservation strategies that consider functional traits rather than taxonomic identity alone. Full article

The rapid expansion of China’s photovoltaic (PV) industry has led to a significant increase in decommissioned PV modules. To address the high energy consumption and environmental impact of traditional recycling techniques, this study proposes a novel method that integrates DMPU solvent recycling with pyrolysis for recovering PV cell sheets. DMPU, an organic solvent with low volatility, non-toxicity, and excellent recyclability, was used in this study. The effects of temperature and treatment duration on the structural integrity of silicon cell sheets were systematically evaluated, establishing optimal parameters: immersion in DMPU at 200 °C for 60 min, followed by pyrolysis at 480 °C for 60 min. A case study was conducted on a small-scale recycling facility with a daily processing capacity of 200 standard PV panels, encompassing system boundaries such as transportation, pretreatment, and pyrolysis. The recycling process consumed 2.14 × 10⁹ kJ of energy annually, reducing CO₂ emissions by 9357.2 tons. Compared to conventional methods such as pyrolysis, mechanical dismantling, and chemical dissolution, the proposed approach employing a green, recyclable solvent markedly reduces energy consumption and carbon emissions, offering notable environmental benefits. Full article

Chromium (Cr) toxicity poses a significant challenge to agricultural productivity, human health, and food security. Biochar (BC) is a versatile amendment employed to alleviate Cr toxicity. Chromium stress impairs growth by inducing membrane damage and cellular oxidation, as well as inhibiting chlorophyll synthesis, photosynthetic efficiency, water uptake, and nutrient absorption. This review consolidates information on the mechanisms through which BC mitigates Cr stress. Biochar facilitates Cr immobilization by reduction, adsorption, precipitation, and complexation processes. It enhances growth by improving photosynthetic efficiency, water and nutrient uptake, osmolyte synthesis, and hormonal balance. Additionally, biochar promotes resilient bacterial communities that reduce Cr and enhance nutrient cycling. The effectiveness of BC is not universal and largely depends on its feedstock properties and pyrolysis temperature. This review provides insights into soil quality, plant function, and human health, which contribute to providing a comprehensive assessment of the capacity of BC to mitigate Cr toxicity. This review highlights that BC application can reduce Cr entry into the food chain, thus decreasing its health risk. This review also identifies knowledge gaps and outlines future research directions to increase the efficiency of BC in mitigating Cr toxicity. This review also offers insights into the development of eco-friendly measures to remediate Cr-polluted soils. Full article

This manuscript reports the preparation, surface characterization, and modeling of chars and activated carbons obtained from avocado biomass for hydrogen storage. Activated carbons were prepared from avocado biomass via the following stages: (a) pyrolysis of avocado biomass, (b) impregnation of the avocado-based char using an aqueous lithium solution, and (c) thermal activation of lithium-loaded avocado char. The synthesis conditions of char and activated carbon samples were tailored to maximize their hydrogen adsorption properties at 77 K, where the impact of both pyrolysis and activation conditions was assessed. The hydrogen storage mechanism was discussed based on computational chemistry calculations and multilayer adsorption simulation. The modelling focuses on the analysis of the saturation of activated carbon active sites via the adsorption of multiple hydrogen molecules. The results showed that the activated carbon samples displayed adsorption capacities higher than their char counterparts by 71–91% because of the proposed activation protocol. The best activated carbon obtained from avocado residues showed a maximum hydrogen adsorption capacity of 142 cm³/g, and its storage performance can compete with other carbonaceous adsorbents reported in the literature. The hydrogen adsorption mechanism implied the formation of 2–4 layers on activated carbon surface, where physical interactions via oxygenated functionalities played a relevant role in the binding of hydrogen dimers and trimers. The results of this study contribute to the application of low-cost activated carbons from residual biomass as a storage medium in the green hydrogen supply chain. Full article

Sewage sludge (SS) management and wastewater (WW) treatment remain among the most critical environmental challenges. The pyrolysis of sewage sludge to produce biochar (BC) represents a sustainable and circular strategy for waste valorization and pollution mitigation. This scoping review provides a comprehensive overview of BC derived from SS (BCxSS), with particular emphasis on how pyrolysis conditions affect key physicochemical characteristics such as yield, ash content, pH, surface area, and functional groups. Although substantial research has focused on the removal of heavy metals and organic pollutants using BCxSS, far less attention has been directed toward its potential for pathogen adsorption and inactivation, revealing a notable research gap. Recent studies highlight BCxSS as a versatile material with considerable promise in adsorption and catalysis. However, its application in pathogen removal remains insufficiently investigated, underscoring the need for further investigation into sorption mechanisms and biochar–microbe interactions. Full article

In this study, the advanced oxidation system of peroxymonosulfate (PMS) was activated by molybdenite supported on biochar (Molybdenite@BC), and the degradation efficiency, influencing factors and degradation mechanism of sulfamethoxazole (SMX) were explored through experiments. Molybdenite@BC, a composite material used in the study, was prepared by pyrolysis at high temperature. The optimum pyrolysis temperature was 700 °C, and the mass ratio of molybdenite to biochar (BC) was 1:3. By changing dosage of Molybdenite@BC, pH value, initial concentration of PMS, and the types and concentration of inorganic anions, the effects of various factors on SMX degradation were systematically studied. The optimum reaction conditions of the Molybdenite@BC/PMS process were as follows: Molybdenite@BC dosage was 100 mg/L, PMS concentration was 0.2 mM, pH value was 6.9 ± 0.2, and initial SMX concentration was 6 mg/L. Under these conditions, the degradation rate of SMX was 97.87% after 60 min and 99.06% after 120 min. The material characterization analysis showed that Molybdenite@BC had a porous structure and rich active sites, which was beneficial to the degradation of pollutants. After the composite material was used, the peaks of MoO₂ and MoS₂ became weaker, which indicated that there was some loss of molybdenum from the material structure. Electron paramagnetic resonance (EPR) and radical quenching experiments revealed that Molybdenite@BC effectively catalyzed PMS to generate various reactive oxygen radicals and non-free radicals, including singlet oxygen (¹O₂), hydroxyl radical (^•OH), sulfate radical (SO₄^•−) and superoxide radical (^•O₂⁻). ¹O₂ played a leading role in the degradation of SMX, while ^•OH and SO₄^•− had little influence. The intermediate products of the degradation of SMX in Molybdenite@BC/PMS system were analyzed by liquid chromatography–tandem mass spectrometry (LC–MS). The results showed that there were nine main intermediate products in the process of degradation, and the overall toxicity tended to decrease during the degradation of SMX. The degradation path analysis showed that with the gradual ring opening and bond breaking of SMX, small molecular compounds were generated, which were finally mineralized into H₂O, CO₂, CO₃²⁻, H₂SO₄ and other substances. The research results confirmed that the Molybdenite@BC/PMS process provided a feasible new method for the degradation of SMX in water. Full article

Converting agricultural solid waste into porous biochar for HCHO adsorption is considered as a “two birds with one stone” strategy, which can achieve the environmental goal of “treating waste with waste”. Unfortunately, the HCHO adsorption performance of pristine biochar is generally unsatisfactory, which is derived from its poor surface activity and insufficient number of pores. In this study, a series of nitrogen-doped porous biochars with adjustable N-containing groups and porosity were synthesized by one-step pyrolysis of melamine and waste jujube pit in different mass ratios (NBC-x, x represented the mass ratio of melamine to waste jujube pit, x = 4–12) for HCHO adsorption. The HCHO adsorption tests indicated that the insertion of nitrogen-containing species improved the adsorption capacity of pristine biochar (BC). However, after the insertion of excessive nitrogen-containing species, the porosity of the samples significantly decreased due to the blockage of pores, which could be disadvantageous for HCHO adsorption. DFT calculation results showed that N doping (especially pyrrolic-N) significantly increased the maxima of absolute ESP values of the carbonaceous models and consequently enhanced the affinity between polar HCHO and carbonaceous models (varied from −20.65 kJ/mol to −33.26 kJ/mol). Thus, the NBC-8 possessing both substantial nitrogen content (19.81 wt. %) and developed porosity (specific surface area of 223 m²/g) exhibited the highest HCHO uptake of 6.30 mg/g. This was approximately 6.4 times larger than that of BC. This work not only deepens the understanding of the HCHO adsorption mechanism at molecular scale, but also concurrently offers a facile and eco-friendly route of N-doped porous biochar preparation, an efficient technology with high-value utilization of waste biomass resources, and a sustainable method of pollution remediation. Full article

Plastic streams dominated by polyethylene (PE) including PE HD/MD (High Density/Medium Density) and PE LD/LLD (Low Density/Linear Low Density), polypropylene (PP), and polyvinyl chloride (PVC) across Europe demand a design framework that links synthesis with end of life reactivity, supporting circular economic goals and European Union waste management targets. This work integrates polymerization derived chain architecture and depolymerization mechanisms to guide selective valorization of commercial plastic wastes in the European context. Catalytic topologies such as Bronsted or Lewis acidity, framework aluminum siting, micro and mesoporosity, initiators, and strategies for process termination are evaluated under relevant variables including temperature, heating rate, vapor residence time, and pressure as encountered in industrial practice throughout Europe. The analysis demonstrates that polymer chain architecture constrains reaction pathways and attainable product profiles, while additives, catalyst residues, and contaminants in real waste streams can shift radical populations and observed selectivity under otherwise similar operating windows. For example, strong Bronsted acidity and shape selective micropores favor the formation of C₂ to C₄ olefins and Benzene, Toluene, and Xylene (BTX) aromatics, while weaker acidity and hierarchical porosity help preserve chain length, resulting in paraffinic oils and waxes. Increasing mesopore content shortens contact times and limits undesired secondary cracking. The use of suitable initiators lowers the energy threshold and broadens processing options, whereas diffusion management and surface passivation help reduce catalyst deactivation. In the case of PVC, continuous hydrogen chloride removal and the use of basic or redox co catalysts or ionic liquids reduce the dehydrochlorination temperature and improve fraction purity. Staged dechlorination followed by subsequent residue cracking is essential to obtain high quality output and prevent the release of harmful by products within European Union approved processes. Framing process design as a sequence that connects chain architecture, degradation chemistry, and operating windows supports mechanistically informed selection of catalysts, severity, and residence time, while recognizing that reported selectivity varies strongly with reactor configuration and feed heterogeneity and that focused comparative studies are required to validate quantitative structure to selectivity links. In European post consumer sorting chains, PS and PC are frequently handled as separate fractions or appear in residues with distinct processing routes, therefore they are not included in the polymer set analyzed here. Polystyrene and polycarbonate are outside the scope of this review because they are commonly handled as separate fractions and are typically optimized toward different product slates than the gas, oil, and wax focused pathways emphasized here. Full article

Atrazine (ATZ), a typical triazine herbicide with a long half-life and recalcitrant biodegradation, contaminates water and soil, necessitating efficient removal technologies. Conventional adsorbents have limited capacity and stability, while sesame straw-derived biochar realizes agricultural waste recycling and provides an efficient, economical, and eco-friendly adsorbent. Sepiolite, a natural mineral with a unique fibrous structure and a high specific surface area, has attracted widespread attention. Therefore, in this work, the agricultural waste of sesame hulls and sepiolite were used as precursors to prepare a composite material of sesame hull biochar/sepiolite (KNPB) through co-mixing heat treatment, followed by sodium hydroxide activation and pyrolysis. The results showed that, under the conditions of an adsorbent dosage of 3 g/L, pH of 6.8, and an adsorption time of 360 min, the removal rate of 3 mg/L ATZ by KNPB was 89.14%. Reusability experiments further demonstrated that KNPB has the potential for practical application in water treatment. Additionally, by integrating adsorption kinetics and isotherm analysis with a suite of characterization results from BET, FTIR, and XPS, the adsorption mechanism of KNPB for ATZ was further clarified to be primarily based on pore-filling, π–π interactions, and hydrogen bonding. This study not only provides a new idea for the resource utilization of waste sesame straw, but also provides scientific guidance for the solution of atrazine pollution, which has important environmental and economic significance. Full article

Cross-linked polyethylene (PEX) is very stable, both chemically and mechanically. This makes its waste difficult to process. A very promising approach is slow pyrolysis catalyzed by hematite (α-Fe₂O₃). Such pyrolysis was carried out on a large scale (feedstock of 38 kg, catalyst amount of 2 wt.%, heating rate of 4 K min⁻¹, end temperature of 435 °C, delay at the end temperature several hours) and provided an oil containing both liquid (up to C₁₇) and solid hydrocarbons (>C₁₇). Thus, the oil obtained can be a source of valuable chemicals, solvents, and paraffin, and/or used as a clean liquid fuel and/or as a source of lubricants. Pyrolysis of PEX also yielded energy gas (12 wt.%) and solid carbonaceous residue (15 wt.%) for further use. The process mass balance and parameters (temperature, heating rate, dwell time, catalyst amount), composition, and chemical (elemental analysis, XRF, GC-MS, GC, distillation curve) and physical (viscosity, density, higher and lower heating value) properties of the oil, gas, and solid carbonaceous residue obtained are presented and discussed. The main product of the proposed technology is oil with a yield of almost 73 wt.%. The by-products are energy gas (12 wt.%) and solid carbonaceous residue (15 wt.%). The results obtained showed that the proposed technology successfully recycles difficult-to-process PEX with a process efficiency of 70%. Full article

The present studies focus on the analysis of the inherent differences between temperature- and pyrolysis-based models and foster a rational and comprehensive understanding of numerical models for lightning strike damage in laminated composites. A systematic methodology combining numerical simulation and pyrolysis kinetics analysis has been developed to examine the inherent differences in damage area and depth, damage threshold, electrical conductivity characteristics, and Joule energy between temperature- and pyrolysis-based models. The results indicate that the pyrolysis-based model demonstrates closer agreement with experimental data in terms of both damage area and damage depth predictions compared to the temperature-based model. The two damage thresholds (500 °C and pyrolysis degree of 0.1) yield equivalent predictions of overall damage, but the temperature-based criterion neglects localized heating rate effects. The pyrolysis-based model exhibits significantly delayed through-thickness conductivity development during initial current conduction compared to the temperature-based model due to the influence of heating rate. This lag results in the pyrolysis-based model predicting larger damage areas and shallower penetration depths. Joule heating analysis further confirms that the pyrolysis-based model exhibits higher overall electrical resistance than the temperature-based model. Through a systematic comparison of temperature- and pyrolysis-based models, this research holds the significance of enhancing the understanding of lightning strike damage mechanisms and advancing the development of high-fidelity numerical models for predicting lightning strike damage in laminated composite. Full article

Achieving efficient and clean use of low-volatile coal is of vital importance to China’s energy system. This study aims to elucidate how the high-concentration-CO₂ atmosphere influences the migration pathways of fuel-bound nitrogen during the pyrolysis of low-volatile coal, thereby providing critical insights for the prediction and control of NO_x emissions under oxy-fuel conditions. A high-temperature drop-tube furnace system capable of high heating rates (up to 10⁴–10⁵ °C/s) was employed to comparatively investigate the pyrolysis behavior of a typical low-volatile coal (volatile matter content of 7.44%) under Ar and pure CO₂ atmospheres at 1000–1400 °C. The outcomes show that the CO₂ atmosphere significantly promoted the release of volatiles, with the volatile release rate at 1400 °C reaching 2.1 times that under the Ar atmosphere. While volatile nitrogen primarily consists of HCN and NH₃ with HCN dominance at lower temperatures, NH₃ release exceeds HCN by more than tenfold at 1400 °C. CO₂ promotes nitrogen release through enhanced gasification reactions, reducing char nitrogen proportion while increasing volatile nitrogen yield approximately fourfold at elevated temperatures. The X-ray photoelectron spectroscopy analysis reveals the transformation pathway of nitrogen functionalities from quaternary nitrogen to pyridine nitrogen and subsequently to pyridine under oxy-fuel conditions. These findings provide fundamental insights into fuel nitrogen evolution mechanisms and offer theoretical support for optimizing oxy-fuel combustion processes toward efficient NO_x control. Full article

Biochar has emerged as a promising material for carbon storage, exhibiting properties analogous to those of activated carbon. Biochar has a particularly high absorbance due to its high porosity, surface area, and functional groups, although these parameters depend on the feedstock and pyrolysis conditions. The sorbent properties of biochar make it suitable for many applications, including the biological treatment of organic waste. In the context of composting, biochar addition seems to positively impact the process performance and the final compost characteristics. Furthermore, it reduces greenhouse gas and odor emissions, which is a crucial step in preventing the full implementation of composting. The objective of this review is to provide a comprehensive description of the effects of biochar on composting emissions and the reported mechanisms, highlighting the limitations of current research. In summary, the use of biochar in composting is still in its early stages and requires further research and consensus on fundamental issues, such as the optimal biochar dosage and mitigation mechanisms. Moreover, there is a significant lack of full-scale implementation. Accordingly, future work should focus on overcoming these critical challenges to take a step forward towards a consistent and complete picture of the environmental impacts and a rigorous economic analysis of the use of biochar in composting. Full article

This study examines the influence of physical biomass pretreatment on the pyrolysis behavior of woody pruning residues of Carya illinoinensis (pecan tree) processed in a stainless-steel batch reactor heated by concentrated radiative energy. Experiments were conducted with 25.5 g of biomass using a solar simulator equipped with a mirror concentrator, operating at three constant thermal power levels (234, 482, and 725 W). As a pretreatment strategy, the woody residues were deliberately processed without drying, while mechanical size reduction and sieving were applied to obtain a controlled particle size range of 1–4 mm. This approach enabled the isolated assessment of the effects of physical pretreatment, particularly particle size and bulk density, on heat transfer, thermal response, and pyrolysis behavior. The pyrolysis performance of the pretreated woody biomass was systematically compared with that of walnut shell biomass and inert volcanic stones subjected to the same particle size control. Two consecutive experimental cases were implemented: Case A (CA), comprising heating, pyrolysis of fresh biomass, and cooling; and Case B (CB), involving reheating of the resulting biochar under identical operating conditions. An improved analytical methodology integrating temperature–time profiles, their derivatives, and gas composition analysis was employed. The results demonstrated the apparently inert thermal behavior of biochar during reheating and enabled clear temporal identification of the main biomass conversion stages, including drying, active pyrolysis of hemicellulose and cellulose, and passive lignin degradation. However, relative to walnut shell biomass of equivalent volume, the woody pruning residues exhibited attenuated thermal and reaction signals, primarily attributed to their lower bulk density resulting from the selected pretreatment conditions. This reduced bulk density led to less distinct pyrolysis stages and a 4.66% underestimation of the maximum reaction temperature compared with thermogravimetric analysis, highlighting the critical role of physical pretreatment in governing heat transfer efficiency and temperature measurement accuracy during biomass pyrolysis. Full article