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1.
Artigo em Inglês | MEDLINE | ID: mdl-38954332

RESUMO

In the context of China's green development and "dual carbon" goal, urbanization, as a way to achieve Chinese modernization, has a particularly important effect on green and low-carbon economic development. Firstly, this paper empirically analyzed the influence of urbanization on per capita carbon emissions using Chinese city data and a panel fixed-effects model. Then, the impact mechanisms of urbanization on carbon emissions were examined from both the demand and supply sides. Finally, we analyzed the differences in the transmission mechanisms of urbanization affecting carbon emissions in the eastern, central, and western regions. The results show that (1) urbanization increases per capita carbon emissions. However, this effect shows inter-regional differences, with more significant promotion effects in the eastern and central regions; (2) on the demand side, the residents' consumption intensity can drive carbon emissions, while the rise of human capital agglomeration suppresses carbon emissions; on the supply side, industrial structure can drive carbon emissions, while the increase of green technological innovation suppresses carbon emissions; (3) the consumption effect and the industry effect play a major role in the eastern and central regions, while the intermediary effect is not obvious in the western region. This study can provide important insights for synergizing urbanization and achieving carbon reduction commitments.

2.
J Environ Manage ; 365: 121650, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38968881

RESUMO

Enhancing the coal-based fulvic acid (FA) yield through the effect of oxidation methods was of great importance. However, the realization of an efficient and environmentally friendly method for the preparation of FA, along with understanding of its formation mechanism, remains imperative. Herein, coal-based FA was prepared by oxidizing lignite with H2O2 and NaOH/KOH. The experimental data showed that ML lignite was pickled with HCl, metal ions such as iron, aluminum, and calcium can be removed, and this lignite is used as raw material, the reaction time was 150 min, the reaction temperature was 50 °C, and the volume ratio of H2O2 (30%) to KOH (3 mol/L) was 1:1, the effect of H2O2 and KOH on FA extraction was the best. The coal-based FA yield could reach 60.49%. The addition of silicone defoaming agent during the experiment resulted in a significant diminished the presence of bubbles and prevent the production of CO2. A decrease in N2 content was detected by GC. The FTIR, XPS, Py-GC/MS and other characterization results showed that FA has more polar functional groups (-COOH, -OH), and it contains more O-CO structure. Consequently, a greater quantity of FA molecules is generated during the reaction process. Moreover, the partial Gibbs free energies during the formation process of coal-based FA were calculated by density-functional theory (DFT). The highest energy required for free radicals was found to be between 1.3 and 1.7 eV. This study would provide theoretical support for exploring the FA formation process and the promotion of lignite humification by adding H2O2 or alkali to lignite.

3.
J Environ Manage ; 365: 121600, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38963957

RESUMO

Electrolytic manganese residue (EMR) is known for high concentrations of Mn2+, NH4+, and heavy metals. Failure to undergo benign treatment and landfill disposal would undeniably lead to negative impacts on the quality of the surrounding ecological environment. This study sought to mitigate the latent environmental risks associated with EMR using a cooperative solidification/stabilization (S/S) method involving coal fly ash (CFA). Leveraging leaching toxicity tests, the leaching behavior of pollutants in electrolytic manganese residue-based geopolymer materials (EMRGM) was determined. At the same time, mechanistic insights into S/S processes were explored utilizing characterization techniques such as XRF, XRD, FT-IR, SEM-EDS, and XPS. Those results confirmed significant reductions in the leaching toxicities of Mn2+ and NH4+ to 4.64 µg/L and 0.99 mg/L, respectively, with all other heavy metal ions falling within the permissible limits set by relevant standards. Further analysis shows that most of NH4+ volatilizes into the air as NH3, and a small part is fixed in the EMRGM in the form of struvite; in addition to being oxidized to MnOOH and MnO2, Mn2+ will also be adsorbed and wrapped by silicon-aluminum gel together with other heavy metal elements in the form of ions or precipitation. This research undeniably provides a solid theoretical foundation for the benign treatment and resourceful utilization of EMR and CFA, two prominent industrial solid wastes.

4.
Materials (Basel) ; 17(11)2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38893935

RESUMO

The inferior mechanical performance and freeze-thaw (FT) resistance of recycled concrete are mostly due to the significant water absorption and porosity of recycled coarse particles. In this study, different dosages of zeolite powder were used in recycled concrete. A series of macroscopic tests were used to evaluate the workability and FT durability of zeolite powder-modified recycled concrete (ZPRC). X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to reveal the micro-mechanisms of FT resistance in ZPRC. The results show that the increase in zeolite powder content leads to a decrease in the slump and water absorption of ZPRC. Additionally, ZPRC with 10% zeolite powder has superior mechanical characteristics and tolerance to FT conditions. The higher strength and FT resistance of the ZPRC can be attributed to the particle-filling effect, water storage function, and pozzolanic reaction of zeolite powder, which results in a denser microstructure. The particle-filling effect of zeolite powder promotes the reduction of surface pores in recycled coarse aggregates (RCAs). The water storage function of zeolite powder can provide water for the secondary hydration of cement particles while reducing the free water content in ZPRC. The pozzolanic reaction of zeolite powder can also promote the generation of hydrated calcium silicate and anorthite, thereby making the microstructure of ZPRC more compact. These results provide theoretical guidance for the engineering application of recycled concrete in cold regions.

5.
J Environ Manage ; 365: 121550, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38908154

RESUMO

In light of the escalating global climate risks threatening human survival, there is a global consensus on the necessity for collaborative reduction of pollutant and carbon emissions (CRPC). Within this context, digital inclusive finance (DIF) is recognized for its unique inclusiveness and digital characteristics as a critical factor in promoting environmentally friendly and sustainable development. DIF provides advantageous channels for environmental governance, thereby making the achievement of CRPC objectives feasible. However, the impact of DIF on CRPC has not been fully explored. This study employs a spatial econometric model to investigate the impact of DIF on CRPC in 278 prefecture-level cities in China from 2011 to 2020. The findings indicate that DIF has a positive impact on CRPC, with significant spatial spillover effects. The analysis highlights the pivotal mediating roles played by technology effect and electrified effect of the energy mix, while environmental regulation effect plays a moderating role. Notably, disparities in the impact of DIF on CRPC are evident, particularly in non-resource-based cities, cities with low carbon intensity, and eastern regions where spatial spillover effects are more pronounced. These experiences enrich the relevant thesis in terms of DIF on CRPC, providing a theoretical basis for formulating CRPC schemes.

6.
Sci Rep ; 14(1): 14072, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890504

RESUMO

The balance between the low and high temperature performance of asphalt materials is important to avoid either rutting deformation or low temperature cracking resistance of asphalt pavement. This is beneficial for improving the asphalt pavement comprehensive performance. Considering the excellent high temperature performance of Ethylene-vinyl acetate (EVA) modified asphalt, this study first modified it with Waste Biological Oil (WBO) to prepare WBO/EVA composite modified asphalt (WEMA) with different dosages. Then the samples were evaluated by the traditional physical properties, low and high temperature rheological properties. Finally, the micro mechanism of WBO on EVA modified asphalt were explored by gel permeation chromatography (GPC) test and atomic force microscope (AFM) experiments. The experimental results reveal that WBO has a softening effect on EVA modified asphalt, reducing its stiffness and improving its stretching performance and flowability. In addition, WBO can reduce the high-temperature deformation resistance of EMA modified asphalt, but it significantly enhances the low-temperature property of EVA modified asphalt. When the WBO content ranges from 1.5 to 2.5%, the high-temperature performance of WEMA is inferior to that of EVA-modified asphalt, however, its low-temperature performance is significantly better than that of EVA-modified asphalt. Importantly, within this WBO content range, the comprehensive performance of WEMA is superior to that of pure asphalt. Mechanism investigation showed that WBO reduces the content of macromolecular micelles and average molecular weight in EVA modified asphalt, and it also diluts the asphaltene components in the asphalt system, resulting in a slight weakening of the performance of WEMA at high temperatures and a significant performance enhancement at low temperatures. Ultimately, the utilization of WBO/EVA composite modified asphalt has a better comprehensive performance.

7.
Water Res ; 260: 121936, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38917504

RESUMO

Without light at night, the system for photocatalytic degradation of refractory organic pollutants in aquatic environments based on free radicals will fall into a dormant state. Hence, a round-the-clock photocatalyst (CCN@SMSED) was prepared by in situ growth of cyanide-deficient g-C3N4 on the surface of Sr2MgSi2O7:Eu2+,Dy3+ through a simple calcination method. The CCN@SMSED exhibits an outstanding oxidative degradation ability for refractory tetracycline (TC) in water under both light and dark conditions, which is attributed to the synergistic effect of free radical (•O2- and •OH) and non-radical (h+ and 1O2). Electrochemical analyses further indicate that direct electron transfer (DET) is also one of the reasons for the efficient degradation of TC. Remarkably, the continuous working time of the round-the-clock photocatalyst in a dark environment was estimated for the first time (about 2.5 h in this system). The degradation pathways of TC mainly include demethylation, ring opening, deamination and dehydration, and the growth of Staphylococcus aureus shows that the process is biosafe. More importantly, CCN@SMSED holds significant promise for practical application due to its low energy consumption and suitability for removing TC from a variety of complex water bodies. This work provides an energy consumption reference for the practical application of round-the-clock photocatalytic degradation of organic pollutants.

8.
Angew Chem Int Ed Engl ; : e202406585, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38863281

RESUMO

Polymer electrolytes play a crucial role in advancing rechargeable magnesium batteries (RMBs) owing to their exceptional characteristics, including high flexibility, superior interface compatibility, broad electrochemical stability window, and enhanced safety features. Despite these advantages, research in this domain remains nascent, plagued by single preparation approaches and challenges associated with the compatibility between polymer electrolytes and Mg metal anode. In this study, we present a novel synthesis strategy to fabricate a glycerol α,α'-diallyl ether-3,6-dioxa-1,8-octanedithiol-based polymer electrolyte supported by glass fiber substrate (GDT@GF) through anion modification and thiol-ene click chemistry polymerization. The developed route exhibits novelty and high efficiency, leading to the production of GDT@GF membranes featuring exceptional mechanical properties, heightened ionic conductivity, elevated Mg2+ transference number, and commendable compatibility with Mg anode. The assembled modified Mo6S8||GDT@GF||Mg cells exhibit outstanding performance across a wide temperature range and address critical safety concerns, showcasing the potential for applications under extreme conditions. Our innovative preparation strategy offers a promising avenue for the advancement of polymer electrolytes in high-performance rechargeable magnesium batteries, while also opens up possibilities for future large-scale applications and the development of flexible electronic devices.

9.
J Environ Manage ; 362: 121205, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38823299

RESUMO

Environmental provisions in Preferential Trade Agreements (PTAs) have increased in recent years, however, their impact on green total factor energy efficiency (GTFEE) remains underexplored. Utilizing comprehensive data on countries' engagement with PTAs' environmental provisions, along with environmental legislative information and green trade data, this study employs various quantitative and qualitative research methods to investigate heterogeneity influence, mechanism, nonlinear relationship, and combined effect of PTAs' environmental provisions on GTFEE. The empirical results indicate that: (1) Environmental provisions within PTAs significantly enhance the GTFEE of participating countries, which is more pronounced in North-South PTAs, particularly when these provisions are closely tied to trade issues. (2) Environmental provisions in PTAs improve the GTFEE by promoting environmental legislation, facilitating green goods trade, and fostering cleaner energy structures in participating countries. (3) As the number of PTAs' environmental provisions increases in participating countries, their effect on GTFEE follows a pattern of initial inhibition, followed by promotion, and ultimately insignificance. (4) The combined effect of different types of environmental provisions in PTAs reveals three primary pathways contributing to improved GTFEE: the "environment", the "environment-trade synergy", and the "trade-safeguard synergy".


Assuntos
Comércio , Conservação dos Recursos Naturais , Meio Ambiente
10.
Heliyon ; 10(11): e31941, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38933940

RESUMO

Agriculture is a significant source of carbon emissions, which have a substantial environmental impact. The digital economy plays a vital role in mitigating these emissions through innovative digital solutions. As a leading agricultural nation, China faces substantial pressure to reduce its agricultural carbon emissions(ACE). This paper aims to thoroughly examine the relationship between the growth of the rural digital economy and ACE. To achieve this, we utilize an extensive panel dataset covering China's provinces from 2011 to 2020, analyzing the dynamic and spatial effects of digital economy development on ACE. The key findings of this research are as follows: (1) The rapid expansion of the digital economy significantly reduces ACE. (2) The impact of digital economic development on lowering ACE varies spatially, with a clear progression from eastern to western regions. (3) The digital economy helps reduce ACE through three specific channels: fostering technological innovation, enhancing scale efficiency management, and providing agricultural financial incentives. Based on these findings, this study proposes policy recommendations to improve digital infrastructure, promote balanced regional development in the digital economy, and optimize the management of agricultural science and technology. These policy insights aim to transform agriculture and achieve the goal of reducing ACE, thereby contributing to broader environmental sustainability.

11.
J Environ Manage ; 365: 121579, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38936018

RESUMO

Digital technology advancement provides a significant impetus to achieve China's "dual-carbon" goals, yet it also gives rise to a series of challenges. Therefore, studying the relationship between digital technology innovation and carbon emission efficiency is of paramount importance. This study theoretically analyzes and empirically tests the influence of digital technology innovation (DTI) on total factor carbon emission efficiency (TFCE) using panel data from 268 Chinese cities between 2006 and 2021. The results indicate that: (1) DTI exhibits a "U-shaped" pattern on urban TFCE, with a decrease followed by an increase. (2) Conventional technological innovation (TI) also displays a "U-shaped" relationship with TFCE, with the turning point occurring earlier than that of DTI. DTI surpasses TI in bringing about later-stage improvements in carbon emission efficiency. (3) Mechanism tests reveal that digital technology innovation indirectly affects TFCE through energy effects, technological effects, structural effects, and regulatory effects. (4) The impact of DTI on urban TFCE varies significantly due to differences in geographical location and resource endowments. (5) The development of urban polycentricity advances the turning point at which DTI enhances TFCE while amplifying both the initial "pro-carbon" effect and the subsequent "carbon reduction" effect of DTI. (6) DTI has a spatial spillover effect on urban TFCE. This study provides empirical evidence and policy recommendations for policymakers to advance the digitalization, greening, and decarbonization transformation of cities.

12.
Nanotechnology ; 35(36)2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38749414

RESUMO

Multi-photon reduction (MPR) based on femtosecond laser makes rapid prototyping and molding in micro-nano scale feasible, but is limited in material selectivity due to lack of the understanding of the reaction mechanism in MPR process. In this paper, additively manufacturing of complex silver-based patterns through MPR is demonstrated. The effects of laser parameters, including laser pulse energies and scanning speeds, on the structural and chemical characteristics of the printed structures are systematically investigated. The results show that the geometric size of printed cubes deviates from the designed size further by increasing laser pulse energy or decreasing scanning speed. The reaction mechanism of MPR is revealed by studying the elemental composition and chemical structures of printed cubes. The evolution of Raman spectra upon the laser processing parameters suggests that the MPR process mainly includes two processes: reduction and decomposition. In the MPR process, silver ions are reduced and grow into particles by accepting the electrons from ethonal molecules; meanwhile carboxyl groups in polyvinylpyrrolidone are decomposed and form amorphous carbon that is attached on the surface of silver particles. The conductivity of silver wires fabricated by MPR reaches 2 × 105S m-1and stays relatively constant as varying their cross section area, suggesting excellent electrical conduction. The understanding of the MPR process would accelerate the development of MPR technology and the implementation of MPR in micro-electromechanical systems could therefore be envisioned.

13.
Environ Res ; 255: 119108, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38762004

RESUMO

Addressing natural resource dependence is integral to achieving the Sustainable Development Goals by promoting economic diversification, environmental sustainability, and climate resilience. This study explores the effect of natural resource dependence on green development by adopting the balanced panel dataset from the "Belt and Road" countries from 2005 to 2019. Notably, the novelty of our analysis lies in the empirical analysis using instrument-based techniques that consolidate the "green development curse hypothesis" in the Belt and Road countries. The mechanism analysis reveals that natural resource dependence curbs green development by weakening innovative capability, disturbing institutional quality, reducing population density, and crowding out human capital. Further, the dynamic panel threshold model handling endogeneity verifies the nonlinear relationship between natural resource dependence and green development. Interestingly, digital trade offers greater "resilience" than traditional trade, correcting the resource curse dilemma. Finally, heterogeneity analyses indicate that the green development curse hypothesis only exists in countries with high-level environmental regulations and resource-based countries.


Assuntos
Conservação dos Recursos Naturais , Recursos Naturais , Desenvolvimento Sustentável , Humanos
14.
J Hazard Mater ; 473: 134639, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38772113

RESUMO

In this study, cobalt molybdate (CoMoO4) activated peracetic acid (PAA) was developed for water purification. CoMoO4/PAA system could remove 95% SMX with pseudo-first-order reaction rate constant of 0.15410 min-1, which was much higher than CoFe2O4/PAA, FeMoO4/PAA, and CoMoO4/persulfate systems. CoMoO4/PAA system follows a non-radical species pathway dominated by the high-valent cobalt (Co(IV)), and CH3C(O)OO• shows a minor contribution to decontamination. Density functional theory (DFT) calculation indicates that the generation of Co(IV) is thermodynamically more favorable than CH3C(O)OO• generation. The abundant Co(IV) generation was attributed to the special structure of CoMoO4 and effect of molybdenum on redox cycle of Co(II)/Co(III). DFT calculation showed that the atoms of SMX with higher ƒ0 and ƒ- values are the main attack sites, which are in accordance with the results of degradation byproducts. CoMoO4/PAA system can effectively reduce biological toxicity after the reaction. Benefiting from the selective of Co(IV) and CH3C(O)OO•, the established CoMoO4/PAA system exhibits excellent anti-interference capacity and satisfactory decontamination performance under actual water conditions. Furthermore, the system was capable of good potential practical application for efficient removal of various organics and favorable reuse. Overall, this study provides a new strategy by CoMoO4 activated PAA for decontamination with high efficiency, high selectivity and favorable anti-interference.

15.
Environ Technol ; : 1-20, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38753523

RESUMO

The present study focused on the degradation of sulfamethoxazole (SMX) aqueous solution and the toxicity of processing aqueous by the dielectric barrier discharge (DBD) activated persulfate (PS). The effects of input voltage, input frequency, duty cycle, and PS dosage ratio on the SMX degradation efficiency were measured. Based on the results of the Response Surface Methodology (RSM), SMX degradation efficiency reached 83.21% which is 10.54% higher than that without PS, and the kinetic constant was 0.067 min-1 in 30 min when the input voltage at 204 V (input power at 110.6 W), the input frequency at 186 Hz, the duty cycle at 63%, and the PS dosage ratio at 5.1:1. The addition of PS can produce more active particles reached 1.756 mg/L (O3), 0.118 mg/L (H2O2), 0.154 mmol/L (·OH) in 30 min. Furthermore, the DBD plasma system effectively activated an optimal amount of PS, leading to improved removal efficiency of COD, and TOC to 30.21% and 47.21%, respectively. Subsequently, eight primary by-products were pinpointed, alongside the observation of three distinct pathways of transformation. Predictions from the ECOSAR software indicated that most of the degradation intermediates were less toxic than SMX. The biological toxicity experiments elucidated that the treatment with the DBD/PS system effectively reduced the mortality of zebrafish larvae caused by SMX from 100% to 20.13% and improved the hatching rate from 55.69% to 80.86%. In particular, it is important to note that the degradation intermediates exhibit teratogenic effects on zebrafish larvae.

16.
J Environ Manage ; 359: 121006, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38692028

RESUMO

Education expenditure is essential in mitigating air pollution, but the relationship between education expenditure and air pollution lacks in-depth discussion. Utilizing data at the county level in China during 2007-2021, this study estimates the effect of education expenditure from local governments on air pollution. Our findings demonstrate that education expenditure significantly and negatively affects air pollution, which remains robust after addressing endogeneity. The mechanism analysis presents that education expenditure reduces air pollution through the composition, technique, and income effects. The heterogeneity analysis indicates that the impact of education expenditure exhibits marked regional heterogeneity. Specifically, the role of education expenditure is significant in strong regulation, key, eastern, and central regions. By considering interaction terms, we identify the moderating effects of human capital, economic development, infrastructure construction, and public service for education expenditure. The cost-benefit analysis emphasizes that education expenditure improves social welfare. Our findings can inspire local governments to place more emphasis on air quality and public education expenditure.


Assuntos
Poluição do Ar , China , Humanos , Educação , Análise Custo-Benefício
17.
Environ Sci Pollut Res Int ; 31(24): 34981-34994, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38720124

RESUMO

As an innovative financial instrument, green credit is a new driving force for environmental governance. To study the impact of green credit on environmental quality, this paper uses the provincial panel data from 2007 to 2020 to construct a panel model for analysis based on the comprehensive environmental quality index. At the same time, it discusses the mechanism and regional heterogeneity of green credit affecting environmental quality. The results show that green credit significantly improves the overall quality of the environment, which has a significant effect on air quality and green quality but has no significant impact on water quality and soil quality. Green credit improves environmental quality by improving green technology innovation and promoting industrial structure upgrading. At the same time, there is obvious heterogeneity in the environmental effect of green credit. Among them, the environmental quality improvement effect of the eastern region and the carbon emission pilot area is more evident than that of the central and western regions and the non-carbon emission pilot area. This paper has important implications for promoting the development of green credit and giving full play to the environmental effects of green credit to achieve sustainable goals.


Assuntos
Conservação dos Recursos Naturais , China , Solo/química , Meio Ambiente , Monitoramento Ambiental/métodos
18.
Sci Total Environ ; 929: 172600, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38653416

RESUMO

Fungi-microalgae consortium (FMC) has emerged as a promising system for advanced wastewater treatment due to its high biomass yield and environmental sustainability. This study aimed to investigate the nutrients removal, bacterial community shift, emerging contaminants elimination, and treatment mechanism of a FMC composed of Cordyceps militaris and Navicula seminulum for aquaculture pond water treatment. The fungi and microalgae were cultured and employed either alone or in combination to evaluate the treatment performance. The results demonstrated that the FMC could improve water quality more significantly by reducing nutrient pollutants and optimizing the bacterial community structures. Furthermore, it exhibited stronger positive correlation between the enrichment of functional bacteria for water quality improvement and pollutants removal performance than the single-species treatments. Moreover, the FMC outperformed other groups in eliminating emerging contaminants such as heavy metals, antibiotics, and pathogenic Vibrios. Superiorly, the FMC also showed excellent symbiotic interactions and cooperative mechanisms for pollutants removal. The results collectively corroborated the feasibility and sustainability of using C. militaris and N. seminulum for treating aquaculture water, and the FMC would produce more mutualistic benefits and synergistic effects than single-species treatments.


Assuntos
Aquicultura , Microalgas , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água , Aquicultura/métodos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Águas Residuárias/microbiologia , Fungos , Purificação da Água/métodos , Bactérias
19.
Front Bioeng Biotechnol ; 12: 1332113, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38567082

RESUMO

Tobacco, a vital economic crop, had its quality post-curing significantly influenced by starch content. Nonetheless, the existing process parameters during curing were inadequate to satisfy the starch degradation requirements. Microorganisms exhibit inherent advantages in starch degradation, offering significant potential in the tobacco curing process. Our study concentrated on the microbial populations on the surface of tobacco leaves and in the rhizosphere soil. A strain capable of starch degradation, designated as BS3, was successfully isolated and identified as Bacillus subtilis by phylogenetic tree analysis based on 16SrDNA sequence. The application of BS3 on tobacco significantly enhanced enzyme activity and accelerated starch degradation during the curing process. Furthermore, analyses of the metagenome, transcriptome, and metabolome indicated that the BS3 strain facilitated starch degradation by regulating surface microbiota composition and affecting genes related to starch hydrolyzed protein and key metabolites in tobacco leaves. This study offered new strategies for efficiently improving the quality of tobacco leaves.

20.
J Hazard Mater ; 471: 134376, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38657503

RESUMO

Pig manure (PM) is a high concentration organic waste rich in sulfur, and its biofuel contains various sulfur-containing pollutants, which reduces the safety of the products. Supercritical water (SCW) can dissolve most organic matter, which is a technology worthy of further study. In order to reduce sulfur pollution in the process of PM resource utilization and better control the conversion path of sulfur, it is necessary to explore the migration mechanism of sulfur in the whole PM-SCW gasification process. The experimental results indicated that H2S was the only gaseous product. Only inorganic compounds (S2-, S2O32- and SO42-) were detected in the liquid. Sulfur in the solid mainly included thiol/thioether, thiophene and sulfone. The influence of different reaction conditions (temperature, residence time, PM concentration and catalysts) on sulfur migration was studied in a batch reactor. It was worth noting that the catalysts had a significant effect on H2S absorption. The lowest H2S yield was 3.2 * 10-4 mol/kg and more than 70% of the sulfur was distributed in the liquid under the condition of addition of K2CO3. While, the RTH2110 fixed most of the sulfur of PM (the maximum value reached 50.94%) in the solid. Thus, adding the catalysts flexibly can choose composition of the products. Furthermore, six possible pathways of sulfur migration in the solid were designed and the kinetic parameters were calculated by density functional theory (DFT). The results provided a basis for controlling sulfur in PM. Subsequently, the sulfur migration pathways during PM-SCW gasification process were comprehensively summarized through the combination of experiment and DFT. It provided a method for sulfur treatment in PM, which had guiding significance for the realization of pollution-free treatment of PM.

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