Volatile organic compounds (VOCs) are a class of organic compounds that are easily volatilized at room temperature, causing serious damage to the human body, soil, and water bodies, and affecting the balance of the ecosystem. Cobalt tetraoxide (Co3O4) has a very high catalytic degradation ability for VOCs and is considered to be one of the metal oxides with the greatest potential to replace precious metal catalysts. Relevant studies have shown that Co3O4 catalysts prepared under different conditions have excellent photocatalytic and thermocatalytic activities. This paper discusses the effects of precursors, precipitants, reaction temperatures, and subsequent heat treatment temperatures on the catalytic degradation activity of benzene by the prepared Co3O4 catalysts. The activity differences of the samples were determined by the degradation rate of 15 mu L benzene and the CO2 generation rate of the Co3O4 catalysts prepared under different conditions at 290 degrees C, and the optimized preparation scheme of the Co3O4 catalyst with high catalytic activity was obtained. The study found that the Co3O4 catalyst prepared with cobalt acetate as a precursor, urea as a precipitant, 90 degrees C reaction, and subsequent 300 degrees C calcination showed the best activity in photothermocatalytic degradation of VOCs. The optimal Co3O4 catalyst had a catalytic degradation rate of 95.3% for 15 mu L benzene in only 5 min, and maintained a catalytic degradation rate of more than 95% for 15 mu L benzene after 10 photothermocatalytic degradation stability tests, proving its good catalytic stability. Combined with the test characterization results of XRD, SEM, UV-Vis-IR, TG, etc., the reasons for the difference in catalytic degradation efficiency of Co3O4 catalysts were explored: Co3O4 catalysts prepared under different conditions have different absorption capacities for ultraviolet-visible-infrared light, and calcination at a too high temperature will increase the surface area of the Co3O4 catalyst, resulting in a reduction in its active attachment sites. The optimal Co3O4 catalyst was further analyzed for photocatalysis at room temperature, thermocatalysis at different temperatures, and photothermocatalytic activity. It was found that its photothermal synergistic catalytic efficiency at 200, 240, and 290 degrees C was always greater than the simple sum of photocatalysis and thermocatalysis. The activation energy of the photothermal catalytic reaction is lower than that of the thermal catalytic reaction. Due to the reduction of activation energy, photothermal synergistic catalysis can significantly accelerate the reaction rate. The electron or energy excitation caused by the participation of light can trigger more reactant molecules to cross the energy barrier and accelerate the reaction. The photogenerated holes generated by photocatalysis can promote the release of lattice oxygen, thereby accelerating the formation of oxygen vacancies. Photogenerated electrons can reduce the reduction energy barrier of oxygen molecules during the reaction, accelerate the adsorption and dissociation of oxygen, allow oxygen vacancies to be quickly refilled, and restore the activity of the catalyst. Therefore, the Co3O4 catalyst has a photothermal synergistic effect in the catalytic degradation of VOCs, that is, the active species O2-, OH and C6H6+ produced by photocatalysis are more active than O-2, H2O and C6H6 participating in the reaction in traditional thermocatalysis, which accelerates the thermocatalytic redox of Co3O4.

In order to reveal the effect mechanism of hydrothermal aging on jute fiber (JF)-reinforced waterborne acrylic resin (WAR) composites and broaden the application of JF in the field of composites, JF/WAR composites were prepared in this paper to explore the impact mechanism of hydrothermal aging on the flexural properties and volatile organic compound (VOC) release of composites. The results showed that the atomic kinetic energy increased with increasing temperature at 25 degrees C, 40 degrees C and 60 degrees C, and the diffusion coefficient increased by 476.88 % at 60 degrees C. The weight loss rates were 1.53 %, 2.71 %, and 5.07 %, respectively. The weakening of the CO peaks, O-H peaks as well as C--O proved the degradation of JF and WAR. The flexural strength of the samples decreased to 63.43 MPa, 59.87 MPa, and 42.88 MPa with increasing temperature at 25 degrees C, 40 degrees C and 60 degrees C, respectively, and the flexural modulus was more sensitive to hydrothermal aging. Under short-term hydrothermal aging conditions, the composites all complied with Fick law. Water molecules diffuse, adsorb and dissolve hydrophilic VOC molecules in the pores of the composite materials. Non-Fick diffusion behaviors occurred under long-term hydrothermal aging conditions, and serious damage occurred at the interface of the fiber matrix, with fiber breakage as the main damage mode, and the transmission resistance of VOC will decrease after 1440 mins hydrothermal aging, and the release of VOC will increase significantly.

BACKGROUNDTruffle cultivation is evolving rapidly and new agronomic practices such as 'truffle nests' (localized peat amendments of the orchard soil) are being developed. Truffle nests improve the shape of truffles and their depth in the soil and reduce the occurrence of insect damage but have also raised concerns about their impact on the ripeness and maturity of the harvested truffles. In this study, the effect of the nests on the volatile organic compounds profile and the aromatic profile of black truffles was evaluated, as well as the existence of perceptible sensorial differences in truffles. For this, truffles growing in nests were compared with truffles growing in the bulk soil of the same host tree.RESULTSGas chromatography showed that nest truffles had a less complex volatile organic compound profile than bulk-soil truffles. Olfactometry indicated that nest truffles were associated with higher modified frequency values of odorants corresponding to sulfur-containing compounds. Despite this, sensory evaluation with consumers could not clearly show that nest truffles can be distinguished sensorially from bulk-soil truffles.CONCLUSIONThe results prove that soil conditions can influence the aromatic profile of truffles and thus suggest the possibility of managing truffle aroma using agronomic practices. (c) 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Maize is highly susceptible to drought, which affects growth and yield. This study investigated how bacterial volatile organic compounds (BVOCs) affect maize drought tolerance. Drought reduced shoot size but increased root length, an adaptation for accessing deeper soil moisture. BVOCs from strain D12 significantly increased root length and shoot growth under drought conditions. Drought also altered root biochemistry, decreasing enzyme activity, and increased osmolyte levels. BVOCs from strains F11 and FS4-14 further increased osmolyte levels but did not protect membranes from oxidative damage, while BVOCs from strains D12 and D7 strains reduced osmolyte levels and cell damage. In shoots, drought increased the levels of osmolytes and oxidative stress markers. BVOCs from FS4-14 had minimal effects on shoot biochemistry. BVOCs from D12 and F11 partially restored metabolic activity but did not reduce cell damage. BVOCs from D7 reduced metabolic activity and cell damage. These results suggest that BVOCs can modulate the biochemical response of maize to drought, with some strains evidencing the potential to enhance drought tolerance.

Kerosene is widely used in various types of anthropogenic activities. Its environmental safety is mainly discussed in the context of aerospace activities. At all stages of its life cycle, aerospace activity impacts the environment. In aviation, the pollution of atmospheric air and terrestrial ecosystems is caused, first of all, by jet fuel and the products of its incomplete combustion and is technologically specified for a number of models in the case of fuel leak during an emergency landing. In the rocket and space activities, jet fuel enters terrestrial ecosystems as a result of fuel spills from engines and fuel tanks at the crash sites of the first stages of launch vehicles. The jet fuel from the second and third stages of launch vehicles does not enter terrestrial ecosystems. The fuel components have been studied in sufficient detail. However, the papers with representative data sets and their statistical processing not only for the kerosene content, but also for the total petroleum hydrocarbons in the soils affected by aerospace activity are almost absent. Nevertheless, the available data and results of mathematical modeling allow us to assert that an acceptable level of hydrocarbons, not exceeding the assimilation potential, enters terrestrial ecosystems during a regular aerospace activity. Thus, the incoming amount of jet fuel disappears rapidly enough without causing any irreversible damage.

Soil is an environment with numerous niches, where bacteria are exposed to diverse conditions. Some bacteria are exposed earlier than others to pressure, and the emission of signals that other bacteria can receive and perceive may allow a better response to an eminent stimulus. To shed light on how bacteria trigger their response and adapt to changes in the environment, the intra- and interspecific influences of volatiles on bacterial strains growing under non-stressed and cadmium-stressed conditions were assessed. Each strain was exposed to its volatiles emitted by cells growing under different conditions to test whether the environment in which a cell grows influences neighboring cells. The five genera tested showed different responses, with Rhizobium displaying the greatest influence. In a second experiment, 13 strains from different genera were grown under control conditions but exposed to volatiles released by Cd-stressed Rhizobium cells to ascertain whether Rhizobium's observed influence was strain-specific or broader. Our results showed that the volatiles emitted by some bacteria under stress are differentially perceived and translated into biochemical changes (growth, alteration of the antioxidant response, and oxidative damage) by other bacteria, which may increase the adaptability and resilience of bacterial communities to environmental changes, especially those with a prooxidant nature. Cadmium (Cd) contamination of soils constitutes a risk to the environment and human health. Here, we showed the effects of Cd exposure on bacteria and how volatile communication influences the biochemistry related to coping with oxidative stress. This knowledge can be important for remediation and risk assessment and highlights that new biological features, such as volatile communication, should be considered when studying and assessing the impact of contaminants on soil ecosystems.

Fusarium head blight (FHB), caused by Fusarium graminearum, is a predominant disease of wheat. Due to the lack of disease-resistant germplasm, chemical control is an important means to control wheat scab. Volatile substances produced in near-isogenic wheat lines were detected after inoculation with F. graminearum, and 4-propylphenol, which appears in FHB-resistant lines, was identified. In vitro and in vivo antifungal activity tests demonstrate that 4-propylphenol effectively inhibits the mycelial growth of F. graminearum. Metabolomics analysis showed changes in glutathione metabolism, indicating that 4-propylphenol triggered reactive oxygen species (ROS) stress. This was consistent with the increasing ROS levels in Fusarium cells treated with 4-propylphenol. Further results demonstrated that excessive accumulation of ROS induced DNA and cell membrane damage in the mycelium. Moreover, 4-propylphenol showed different degrees of inhibition against other soil-borne pathogens (fungi and oomycetes). These findings illustrated that 4-propylphenol has broad spectrum and high antifungal activity and should be considered for use as an ecological fungicide.

Volatile organic compounds (VOCs), as a primary pollutant in industrial-contaminated sites or polluted soils, cause severe damage to the soil. Therefore, a comprehensive understanding of the transport of VOCs in soil is imperative to develop effective detection means and removal methods. Among them, biochar possesses potential advantages in the adsorption of VOCs, serving as an effective method for removing VOCs from soil. This review provides an overview of the VOCs within soil, their transport mechanisms, monitoring technology, and removal approach. Firstly, the historical development of the VOC migration mechanism within the capping layer is described in detail. Secondly, the in situ monitoring techniques for VOCs are systematically summarized. Subsequently, one of the effective removal technologies, a capping layer for polluted sites, is simply introduced. Following this, the potential application of a biochar-modified capping layer for the removal of VOCs is comprehensively discussed. Finally, the major challenges in the field and present prospects are outlined. The objective of this study is to furnish researchers with a foundational understanding of VOCs, their relevant information, and their removal approach, inspiring environmental protection and soil pollution control.

Using microorganisms as biocontrol agents of phytopathogens has been an alternative to synthetic fungicides. Actinomycetes isolated from soil and plants have reduced diseases caused by phytopathogens; however, microorganisms from marine environments may be an option as biocontrol agents. The tomato crop possesses an important economic impact worldwide, being Mexico the main exporter. Several species of Fusarium cause damage to tomato crops and are controlled with synthetic fungicides. The objective of this work was to determine the effect of marine actinomycetes as biocontrol on Fusarium solani in tomato plants. Four strains of marine actinomycetes (A20, A19, A18, and A15) and one terrestrial actinomycete (ED48) were used. The actinomycetes strains used, produced siderophores. The greatest inhibition of mycelial growth of F. solani due to iron competition was obtained by strain A19 with 74.28%. Only two actinomycetes showed antifungal activity by VOCs (A19 and A18), strain A19 showed the highest antagonistic activity with PICR of 76.75%. Actinomycetes treatments showed significant differences with synthetic fungicide application in growth, disease severity (SE), and disease incidence (DI) variables. The application of marine actinomycete (A19) on plants infested with F. solani increased the levels of enzyme activity (SOD, POD, CAT, and PAL) versus plants in that only F. solani and distilled water (control) were applied. Actinomycetes of marine origin are an option as biocontrol agents for F. solani .

Volatile organic compounds (VOCs) play an essential role in climate change and air pollution by modulating tropospheric oxidation capacity and providing precursors for ozone and aerosol formation. Arctic permafrost buries large quantities of frozen soil carbon, which could be released as VOCs with permafrost thawing or collapsing as a consequence of global warming. However, due to the lack of reported studies in this field and the limited capability of the conventional measurement techniques, it is poorly understood how much VOCs could be emitted from thawing permafrost and the chemical speciation of the released VOCs. Here we apply a Vocus proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF) in laboratory incubations for the first time to examine the release of VOCs from thawing permafrost peatland soils sampled from Finnish Lapland. The warming-induced rapid VOC emissions from the thawing soils were mainly attributed to the direct release of old, trapped gases from the permafrost. The average VOC fluxes from thawing permafrost were four times as high as those from the active layer (the top layer of soil in permafrost terrain). The emissions of less volatile compounds, i.e. sesquiterpenes and diterpenes, increased substantially with rising temperatures. Results in this study demonstrate the potential for substantive VOC releases from thawing permafrost. We anticipate that future global warming could stimulate VOC emissions from the Arctic permafrost, which may significantly influence the Arctic atmospheric chemistry and climate change.