Biochar最新文献

Abstract

This study has introduced a pioneering methodology by employing biochars as a basic carbocatalyst in the context of multicomponent reactions. Biochars were produced from different manures and organic wastes using the pyrolysis-carbonization process under limited oxygen conditions. The prepared biochars were well characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET) analysis, and powder X-ray diffraction (XRD). The chemical characteristics and potentiometric titration analysis provide compelling evidence of the intriguing basicity properties exhibited by the prepared biochars. The pH values, ash content, and potentiometric titration results confirmed the exceptional basicity characteristics of cow manure biochar formed at 600 ^oC (CB600), establishing it as the most basic carbocatalyst in this study. Encouraged by these initial results, the activity of the biochars as basic carbocatalysts was evaluated in multicomponent synthesis of 4H-benzo[h]chromene and pyranopyrazoles and 600 °C exhibited the most pronounced catalytic performance owing to its superior total basicity. By these findings, it can be asserted that this work introduces the groundbreaking application of biochars as potent basic carbocatalysts for the multicomponent synthesis of structurally diverse heterocycles. Unveiling the vital basic role of biochars will definitely open up new opportunities in organic chemistry and provide salient features for environmentally-friendly chemistry, including easy retrieval, non-toxicity, and widespread accessibility.

Iron-carbon micro-electrolysis system is a promising method for promoting electron transfer in nitrate removal. However, many traditional approaches involving simple physical mixing inevitably suffered from the confined iron-carbon contact area and short validity period, leading to the overuse of iron. Here, a ceramsite-loaded microscale zero-valent iron (mZVI) and acidified carbon (AC) coupled-galvanic cell (CMC) was designed to support chemical, autotrophic and heterotrophic denitrification. Long-term experiments were conducted to monitor the nitrogen removal performance of denitrification reactors filled with CMC and thus optimized the denitrification performance by improving fabrication parameters and various operating conditions. The denitrification contributions test showed that the chemical denitrification pathway contributed most to nitrate removal (57.3%), followed by autotrophic (24.6%) and heterotrophic denitrification pathways (18.1%). The microbial analysis confirmed the significant aggregation of related denitrifying bacteria in the reactors, while AC promoted the expression of relevant nitrogen metabolism genes because of accelerated uptake and utilization of iron complexes. Meanwhile, the electrochemical analysis revealed a significantly improved electron transfer capacity of AC compared to pristine carbon. Overall, our study demonstrated the application of a novel mZVI-AC coupled material for effective nitrate removal and revealed the potential impact of CMC in the multipathway denitrification process.

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The significant volatilization of NH₃ during aerobic composting causes nitrogen (N) losses and environmental risks. Both iron (Fe) and biochar (BC) can influence the N conversion process in composting. Fe application can delay the maturation of materials, while biochar can enhance the quality of organic fertilizer. The combination of these two conditioners may help decrease NH₃ emissions and improve organic fertilizer quality. Therefore, this study investigates the effects of different doses of FeCl₃ and BC on NH₃ emissions and organic fertilizer quality during composting. The results demonstrated that Fe/BC co-conditioners reduced the accumulation of NH₃ emissions during composting by 11.1–48.2%, increased the total nutrient content by 0.6–15.3%, and enhanced economic and environmental benefits by 0.1–23.6 $ t⁻¹. At the high-temperature stage of composting, Fe/BC co-conditioners decreased the pH by 0.3–1.2, but there was no significant difference compared to the control at the end of composting, and they did not affect compost maturation. The structural equation model analysis suggested that the reduction in NH₃ emissions was related to ammonia-oxidizing bacteria (AOB), NH₄⁺–N, and total nitrogen (TN). As a result, the Fe/BC co-conditioners reduced NH₃ emissions by lowering the pH at the beginning of composting and increasing the content of NH₄⁺–N. This study concludes that Fe/BC co-conditioners could complement each other to significantly reduce NH₃ emissions and improve the quality of organic fertilizers.

Biochar and organic fertilizer are widely supported to maintain crop production and sustainable development of agroecosystems. However, it is unclear how biochar and organic fertilizer alone or in combination regulate soil functional microbiomes and their relationships to ecosystem multifunctionality (EMF). Herein, a long-term (started in 2013) field experiment, containing five fertilization treatments, was employed to explore the effects of biochar and organic fertilizer applications on the EMF (based on 18 functional indicators of crop productivity, soil nutrient supply, element cycling, and microbial biomass) and the functional microbiomes of bulk soil and rhizosphere soil [normalizing the abundances of 64 genes related to carbon (C), nitrogen (N), phosphorus (P), and sulphur (S) cycles]. Compared with single-chemical fertilization, biochar and organic fertilizer inputs significantly enhanced most ecosystem-single functions and, in particular, the EMF significantly increased by 18.7–30.1%; biochar and organic fertilizer applications significantly increased the abundances of soil microbial functional taxa related to C-N-P-S cycles to varying degree. The combined application of biochar and organic fertilizer showed a better improvement in these indicators compared to using them individually. Most functional microbial populations in the soil, especially the taxa involved in C degradation, nitrification, nitrate-reduction, organic P mineralization, and S cycling showed significantly positive associations with the EMF at different threshold levels, which ultimately was regulated by soil pH and nutrient availability. These results highlight the strong links between soil microbiomes and agroecosystem functions, as well as providing scientific support for inclusion of biochar in agricultural production and services with organic amendments.

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Biochar production from woody biomass generated during forest management (slash) offers significant benefits for soil health and carbon emissions, yet its adoption remains limited in the western United States (U.S.). To address this challenge, the U.S. Department of Agriculture (U.S.D.A.) Forest Service Rocky Mountain Research Station organized two workshops focused on forest management-centric biochar production. These workshops convened a diverse group of stakeholders, including investors, land management practitioners, industry professionals, and research scientists, each with unique roles in slash-based biochar production. This article presents a synthesis of the insights and perspectives gathered from these workshops, aiming to identify barriers and propose viable pathways for overcoming them. The barriers encompass governance issues such as policy and permitting, economic challenges related to costs, funding, and market stability, technological hurdles concerning methods and equipment, and a need for further research and improved science dissemination. In response to these challenges, workshop attendees collaboratively outlined specific strategies to reduce these barriers. These strategies emphasize the expansion of operational initiatives, the development of proactive policies, the stabilization of biochar markets, and the generation of additional case studies showcasing the effects of biochar amendments across various soils and environments. Collectively, the insights gleaned from this workshop series provide a comprehensive roadmap outlining both the struggles and the necessary actions and investments required to enhance the scale of slash-based biochar production and application in the western U.S.

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The increase in antimicrobial resistance (AMR) poses a massive threat to world health, necessitating the urgent development of alternative antimicrobial growth control techniques. Due to their specific physical and chemical properties, nanomaterials, particularly carbon-based nanomaterials, have emerged as attractive candidates for antimicrobial applications, however, reviews are lacking. This comprehensive review aims to bridge the existing knowledge gaps surrounding the mechanism and significance of nanobiochar (NBC) and carbon nanostructures in the field of antimicrobial applications. Notably, NBC, which is derived from biochar, exhibits promising potential as an environmentally-friendly substance with antimicrobial properties. Its strong adsorption capabilities enable the removal and immobilization of pathogens and pollutants from soil and water and also exhibit antimicrobial properties to combat harmful pathogens. In addition to NBC, carbon dots (CDs) and graphene oxide (GO) have also shown excellent antimicrobial properties. These carbon-based nanomaterials find applications in agriculture for phytopathogen control and post-harvest disease management, as well as in medicine for nanotheranostics and in the food industry for extending shelf life as an eco-friendly alternative to chemicals and antibiotics. However, the long-term toxicity of these nanoparticles to humans and the environment needs further investigation, considering the influence of different physiochemical characteristics on antimicrobial properties and nanotoxicity. Therefore, continued exploration in this area will pave the way for future research and safe deployment strategies of carbon-based nanomaterials in combating microbial threats.

Abstract

Bio-tar extra-produced from biomass pyrolysis is prone to pose a threat to environment and human health. A novel N-doped porous electrode from bio-tar was produced under dual-activation of urea and KOH in this study. One-pot dual-activation played significant roles in N-functional group and micro-mesoporous structure, which resulted in the carbon material with the highest of nitrogen content (4.08%) and the special surface area (1298.26 m²·g⁻¹). Specifically, the potential mechanisms of pore formation and N-doping in the one-pot dual-activation strategy were also proposed as a consequence, the one-pot dual-activated carbon material displayed excellent electrochemical performance with the highest capacitance of 309.5 F·g⁻¹ at 0.5 A·g⁻¹, and the unipolar specific capacitance remained with cyclic characteristics of 80.1% after 10,000 cycles in two-electrode symmetric system. Furthermore, the one-pot dual-activation strategy could create a profit of $1.64–$2.38 per kilogram of bio-tar processed without considering the initial investment and labor costs, which provides new perspectives for the utilization of waste bio-tar.

Due to the rising need for clean and renewable energy, green materials including biochar are becoming increasingly popular in the field of energy storage and conversion. However, the lack of highly active and stable electrode materials hinders the development of stable energy supplies and efficient hydrogen production devices. Herein, we fabricated stable, conductive, and multifunctional chitosan microspheres by a facile emulsion crosslinking solution growth and hydrothermal sulphuration methods as multifunctional electrodes for overall water splitting driven by supercapacitors. This material possessed three-dimensional layered conductors with favorable heterojunction interface, ample hollow and porous structures. It presented remarkably enhanced electrochemical and catalytic activity for both supercapacitors and overall water electrolysis. The asymmetric supercapacitors based on chitosan biochar microsphere achieved high specific capacitance (260.9 F g⁻¹ at 1 A g⁻¹) and high energy density (81.5W h kg⁻¹) at a power density of 978.4 W kg⁻¹. The chitosan biochar microsphere as an electrode for electrolyze only required a low cell voltage of 1.49 V to reach a current density of 10 mA cm⁻², and achieved excellent stability with 30 h continuous test at 20 mA cm⁻². Then, we assembled a coupled energy storage device and hydrogen production system, the SCs as a backup power source availably guaranteed the continuous operation of overall water electrolysis. Our study provides valuable perspectives into the practical design of both integrated biochar-based electrode materials and coupled energy storage devices with energy conversion and storage in practical.

Graphical Abstract

In the last few decades, sulfonated carbon materials have garnered significant attention as Brønsted solid acid catalysts. The sulfonation process and catalytic activity of sulfonated biochar can be influenced by the aromaticity and degree of condensation exhibited by biochar. However, the relationships between the aromaticity, sulfonating ability, and resultant catalytic activity are not fully understood. In this study, biochar samples pyrolyzed at 300–650 °C exhibiting different aromaticity and degrees of condensation were sulfonated and employed as sulfonate-bearing solid catalysts for hydrolytically removing tylosin. They exhibited excellent hydrolytic performance and their kinetic constants were positively correlated with the total acidity and negatively correlated with their aromaticity. This study has uncovered the relationship between the structure, properties, sulfonating ability, and subsequent hydrolytic performance of biochar samples. It was observed that the aromaticity of biochar decreased as the pyrolysis temperature increased. Lower pyrolysis temperatures resulted in a reduced degree of condensation, smaller ring size, and an increased number of ring edge sites available for sulfonation, ultimately leading to enhanced catalytic performance. These findings provide valuable insights into the fundamental chemistry behind sulfonation upgrading of biochar, with the aim of developing functional catalysts for mitigating antibiotics in contaminated water.

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