High Temperature Pretreatment Research Articles

Analytical Pyrolysis of Soluble Bio-Tar from Steam Pretreatment of Bamboo by Using TG-FTIR and Py-GC/MS.

Steam pretreatment at high temperatures enables fresh bamboo to possess antifungal and antiseptic properties. The process produces a large amount of wastewater that urgently needs to be recycled. Soluble bio-tars derived from wastewater under low-temperature (LTS-tar) and high-temperature (HTS-tar) steam pretreatments of moso bamboo were studied with a thermogravimetric analyzer coupled with Fourier transform infrared spectroscopy (TG-FTIR) and pyrolysis-gas-chromatography/mass spectrometry (Py-GC/MS). Thermogravimetric analysis showed that in the three stages of the thermal decomposition process, the final residue of the bamboo and HTS-tar had two main peaks of 0.88 wt% and 6.85 wt%. The LTS-tar had much more complicated thermal decomposition behavior, with six steps and a high residue yield of 23.86 wt%. A large quantity of CH4 was observed at the maximum mass loss rates of the bamboo and bio-tars. Acids, aldehydes, ketones, esters, and phenolic compounds were found in the pyrolysis products of the bamboo and soluble bio-tars. Both bio-tars contained carbohydrates and lignin fragments, but the LTS-tar under mild steam conditions had more saccharides and was much more sensitive to temperature. The lignin in the bamboo degraded under harsh steam conditions, resulting in high aromatic and polymeric features for the HTS-tar. The significant differences between LTS-tar and HTS-tar require different techniques to achieve the resource utilization of wastewater in the bamboo industry.

High-Temperature Hydrothermal Extraction of Phenolic Compounds from Brewer's Spent Grain and Malt Dust Biomass Using Natural Deep Eutectic Solvents.

Aligned with the EU Sustainable Development Goals 2030 (EU SDG2030), extensive research is dedicated to enhancing the sustainable use of biomass waste for the extraction of pharmaceutical and nutritional compounds, such as (poly-)phenolic compounds (PC). This study proposes an innovative one-step hydrothermal extraction (HTE) at a high temperature (120 °C), utilizing environmentally friendly acidic natural deep eutectic solvents (NADESs) to replace conventional harmful pre-treatment chemicals and organic solvents. Brewer's spent grain (BSG) and novel malt dust (MD) biomass sources, both obtained from beer production, were characterized and studied for their potential as PC sources. HTE, paired with mild acidic malic acid/choline chloride (MA) NADES, was compared against conventional (heated and stirred maceration) and modern (microwave-assisted extraction; MAE) state-of-the-art extraction methods. The quantification of key PC in BSG and MD using liquid chromatography (HPLC) indicated that the combination of elevated temperatures and acidic NADES could provide significant improvements in PC extraction yields ranging from 251% (MD-MAC-MA: 29.3 µg/g; MD-HTE-MA: 103 µg/g) to 381% (BSG-MAC-MA: 78 µg/g; BSG-HTE-MA: 375 µg/g). The superior extraction capacity of MA NADES over non-acidic NADES (glycerol/choline chloride) and a traditional organic solvent mixture (acetone/H2O) could be attributed to in situ acid-catalysed pre-treatment facilitating the release of bound PC from lignin-hemicellulose structures. Qualitative 13C-NMR and pyro-GC-MS analysis was used to verify lignin-hemicellulose breakdown during extraction and the impact of high-temperature MA NADES extraction on the lignin-hemicellulose structure. This in situ acid NADES-catalysed high-temperature pre-treatment during PC extraction offers a potential green pre-treatment for use in cascade valorisation strategies (e.g., lignin valorisation), enabling more intensive usage of available biomass waste stream resources.

Short-term high-temperature pretreated compost increases its application value by altering key bacteria phenotypes

Short-term high-temperature pretreatment can effectively shorten the maturity period of organic waste composting and improve the fertilizer efficiency and humification degree of products. To investigate the effect and mechanism of the end products on the saline–alkali soil improvement and plant growth, the short-term high-temperature pretreatment composting (SHC) and traditional composting (STC) were separately blended with saline–alkali soil in a ratio of 0–40 % to establish a soil–fertilizer blended matrix for cultivating Lolium perenne L. The pot experiments combined with principal component analysis showed Lolium perenne L. planted in 20 % SHC-blended saline–alkali soil had the best growth effect, and its biomass, chlorophyll content, and plant height were 109–113 % higher than STC. The soil physicochemical property analysis showed that SHC and STC increased the soil nutrient content, humification degree, and enzyme activity at any blending ratio. The microbial analysis showed that 20 % SHC in the saline–alkali soil stimulated the growth of functional microorganisms and the addition of SHC promoted the sulfur cycle, nitrogen fixation, and carbon metabolism in the soil–plant system. The correlation analysis showed that pH; nutrient contents; and urease, catalase, sucrase, and phosphatase activities in the saline–alkali soil were significantly correlated with plant growth indexes (p < 0.05). Georgenia and norank_f__Fodinicurvataceae had a stronger correlation with four types of enzyme activities (p < 0.01). SHC improved the saline–alkali soil and promoted plant growth by adjusting soil pH, increasing soil nutrients, and influencing soil enzyme activity and dominant flora. This study provides a theoretical basis for applying SHC products in soil improvement.

Highly efficient activation of peroxymonosulfate by calcinated construction & demolition waste powder with free radical generation for organic pollutant degradation

BackgroundA simple, efficient and cost-efficiency peroxymonosulfate (PMS) oxidation process for organic pollutant removal is expected. This research aims to investigate the feasibility of construction & demolition waste (C&D waste) as recycled material for organic pollutant degradation. MethodsC&D waste was novelty introduced into the advanced oxidation process for organic pollutant removal. Taking phenol as the target pollutant, the effects of C&D waste loading, PMS concentration, particle diameter and solution pH were all investigated in this study by a series of batch tests and spectrometry measurements. Significant findingsBoth the intrinsic oxidation power of PMS and the adsorption of the pretreated C&D waste were negligible under this CDW/PMS system. However, calcinated C&D waste, with calcium silicate generation, enhanced the degradation efficiency of target organic pollutant by promoting the decomposition of PMS to generate •OH and SO4•−. Both •OH and SO4•− had been detected through the free radicals quenching tests and electron paramagnetic resonance (EPR) spectrometry. Except for high temperature pretreatment, the micro C&D waste after mechanical treatment could also improve the organic pollutant degradation efficiency with a high kinetic rate as a bonus especially for the introduced powder at low doses.

Heat Treatments at Varying Ambient Temperatures and Durations Differentially Affect Plant Defense to Blumeria hordei in a Resistant and a Susceptible Hordeum vulgare Line.

Our previous research showed that a powdery mildew resistant barley line (MvHV07-17) maintains its resistance to Blumeria hordei (Bh) even if plants are exposed to a long-term high temperature of 35°C for 120 h before Bh inoculation, whereas such high temperature pretreatment further increases susceptibility to infection in the susceptible barley line MvHV118-17. In the present study, we extended this approach using short-term high-temperature water treatment (49°C for 30 s) to determine how it affects powdery mildew resistance in these barley lines. We found that this short-term heat shock (HS) impaired plant defense responses, as reflected by development of Bh colonies and visible necrotic spots on leaves of MvHV07-17, which does not develop visible symptoms upon Bh inoculation under optimal growth conditions. In contrast, both HS and long-term heat stress enhanced susceptibility to Bh in MvHV118-17 plants. These results were supported by the measurement of Bh biomass using a qPCR method. Furthermore, microscopic examinations showed that HS elevated the rate of successful Bh penetration events and the spread of cell death in the surrounding mesophyll area and allowed for colony formation and sporulation in resistant barley, whereas early and effective plant defense responses, such as papilla formation and single-cell epidermal hypersensitive response, were significantly reduced. Furthermore, we found that the accumulation of hydrogen peroxide in both resistant and susceptible barley was correlated with susceptibility induced by HS and long-term heat-stress. This study may contribute to a better understanding of plant defense responses to Bh in barley exposed to heat. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Utilization of short-term high temperature pretreatment for food waste composting: Effects of end-products on soil properties and plant growth

Short-term high-temperature pretreatment helps accelerate the composting process and improve compost product quality. The aim of this research was to clarify the role of high-temperature pretreatment compost (PHC) on soil and plant growth. We conducted an experiment in which PHC, traditional compost (PTC), and high-temperature pretreatment food waste (PFW) were used as organic amendments (OA). Each type of compost was mixed into purple soil at mass ratios of 3, 5, 10, and 20% to establish a soil-compost mixture; they were then used in pot experiments with Lolium perenne L. Plant growth-promoting effects were stronger in the three experimental groups with 10% OA than in groups with other mixing ratios (p < 0.05). Plant growth-promoting effects were strongest in the experimental group with 10% PHC, and Lolium perenne L. biomass, the chlorophyll content, and plant height were 1.1–1.3 times higher in this group than in the PTC and PFW groups. Soil physicochemical analyses revealed that OA at various mixing ratios could enhance soil nutrient levels, the humification degree, and enzyme activity, and the strength of the positive effects increased with the mixing ratio. The most pronounced soil amendment effects were observed in the PHC group at all mixing ratios (p < 0.05). Microbial analysis revealed that both the microbial diversity and relative abundances of unclassified_f_Rhizobiaceae and Terrimonas were significantly higher in the 10% PHC group than in the 10% PTC and PFW groups (p < 0.01). Correlation analyses indicated that urease, peroxidase, and sucrase activities were positively correlated with plant growth indexes. The correlation coefficients of unclassified_f_Rhizobiaceae with urease and Terrimonas with peroxidase and sucrase were 0.997, 0.878, and 0.863, respectively. PHC can promote plant growth by altering the dominant microbial communities and enzyme activity in the soil. This study provides a theoretical basis for the application of high-temperature pretreated compost products.

Potential for using tropical solid wood waste from the Amazon for the production of edge glued panels

The objective of this study was to evaluate the potential use of solid wood waste of the following species Cedrela odorata, Enterolobium schomburgkii, Erisma uncinatum, and Qualea paraensis for the manufacture of edge glued panels. The quality of the finger joint and edge bonding with PVA and EPI adhesives, respectively, with spreading rates of 180 g.m-2, was evaluated through static bending, parallel tensile, and shear tests, using ASTM D 5572, EN 13353, and EN 13354 standards. A total of 1,460 test specimens exposed to dry, high temperature, triple cycle, and wet pre-treatments were tested for glue line resistance. The results of all tests for all pre-treatments of finger joints and edge bonding demonstrated the potential of wood waste for the manufacture of edge glued panels for interior use in dry environments. There was a tendency for resistance values to be balanced in splices and joints combined with mixtures of species, possibly due to the densities of the wood pieces. Wet pre-treatment delivered excellent lower 5th percentile results, highlighting the potential of Amazonian tropical solid wood waste for the production of edge glued panels.

Preparation and characterization of novel low-cost sensible heat storage materials with steel slag

Heat storage temperature, heat storage density, heat storage stability and the cost of heat storage are the breakthroughs for further development of heat storage materials. In this study, a new type of sensible heat storage material was prepared by using low-cost steel slag as the main component, and at the same time, an effective way of recycling steel slag was provided. The stabilizable shaped steel slag powder was obtained by high temperature pretreatment, and the optimal high temperature pretreatment temperature was found to be 850 °C. Through the analysis of the effects of different pretreatment steel slag content and different sintering temperatures on the organization and properties of heat storage materials, it was found that a large number of elemental migration and oxide solid solution phenomena occur during the sintering process, and the melting of low melting point solid solution occurs during the high temperature treatment process. The steel slag heat storage material has the best performance when the content of pretreated steel slag is 60 wt% and the sintering temperature is 1200 °C. Its compressive strength is stabilized at about 80 MPa, thermal conductivity is 1.13 W/(m·K), and thermal density is 1222.168 J/g in the range of 50–1000 °C. More importantly, it has excellent thermal cycle stability. After 300 thermal cycles, the shape of the samples remains unchanged, and the samples retained 94.4 % of the compressive strength, 98.8 % of the thermal conductivity and the thermal density was almost unchanged. In addition, the cost of the sample was only $0.58/kWh. The results indicate that this study provides a novel low-cost method for the preparation of steel slag sensible heat storage materials, which has high potential for application in heat storage systems.

Optimization of the process of decreasing the filtration resistance of sewage sludge by thermal pretreatment: a case study for the Lviv WWTP.

The article presents the results of an experimental study of the effect of high-temperature thermal pretreatment on the specific resistance to filtration (SRF) of the sewage sludge (SS) from the Lviv wastewater treatment plant (WWTP), which is a combination of primary sludge and excess-activated sludge collected in primary sedimentation tanks. The kinetics of SRF reduction over time at temperatures of 140 - 150 °С are described by simple exponents, while at temperatures of 160 - 170 °С, they are described by modified two-parameter exponents. The study analyzed the dimensionless optimization function, which is the product of the final relative SRF of the sludge and the dimensionless time of thermal pretreatment. An optimal dimensionless thermal pretreatment time of 4.1 tr.0/2 was determined, and an empirical exponential equation for the time of SRF reduction by twice tr.0/2 was derived. Based on the analysis, it was found that the highest efficiency in reducing the SRF of Lviv WWTP SS occurs at a temperature of 170 °C and an optimal duration of thermal pretreatment of 55 min.

Mechanistic study of heterogeneous propene metathesis on WOx/SiO2 catalysts

Silica-supported tungsten oxides are widely used industrial catalysts for olefin metathesis due to their low cost and robustness, yet the mechanisms for heterogeneously catalyzed metathesis reactions remain comparatively less understood. In this work, density-functional theory (DFT) calculations were used to study the model reactions of propene metathesis. Our calculations confirm that the metathesis reactions catalyzed by WOx/SiO2 largely follow the Chauvin cycle, with an overall energetic barrier of 142 kJ/mol. To understand how the initial alkylidene active sites are generated, three mechanisms were examined: The pseudo-Wittig mechanism was found to be most favorable and proceeds with a metallacycle intermediate, while the allylic and vinylic CH activations are much more difficult and require the reduction of surface sites to W(+4). Relative to the adsorbed reactant state, the overall intrinsic barriers for three mechanisms were computed to be 193, 261, and 355 kJ/mol, respectively. The higher barriers for active-site formation than for the metathesis cycle are consistent with the difficult, high-temperature pretreatment required in experiments to activate WOx/SiO2 catalysts.

CuO–TiO2 pilot-plant system performance for solar photocatalytic hydrogen production

The main goal of the present study was to explore photocatalytic performance of the TiO2–CuO mixture, for solar to hydrogen conversion at pilot plant scale under two different irradiation conditions (sunny and partly cloudy), focusing on high-temperature pretreatment of the catalyst mixture to try to improve TiO2 doping with copper. P25–TiO2 and commercial CuO were used with different amounts of Cu (2 wt% or 7 wt% Cu) calcined at 200–400 °C during several hours. Catalysts were tested at pilot plant scale using solar compound parabolic collectors, with glycerol as the sacrificial agent. The photocatalyst prepared after heating at 200 °C for 3 h and with 7 wt% Cu, resulted in higher hydrogen production than under the other heating conditions, and results were slightly better (5–10%) than the reference values with the untreated catalysts. Photocatalytic efficiency was slightly lower at the higher calcination temperature (400 °C). CO2 production and formation of formate and glycolate clearly demonstrated glycerol photoreforming. The Cu from the calcined catalyst remaining on the solid was significantly less (2.5%) than on the non-calcined catalyst (4.2%), with an important fraction of lixiviated copper and copper deposition on the reactor walls. This is a critical drawback that must be considered for large-scale applications.

Promotion of bio-oil production from the microwave pyrolysis of cow dung using pretreated red mud as a bifunctional additive: Parameter optimization, energy efficiency evaluation, and mechanism analysis

To address the issues of high oxygen content and energy consumption in the microwave-assisted pyrolysis of biomass for biofuel production, this study used high-temperature pretreated red mud (RM) as an additive. The pretreated RM exhibited dual functionalities, namely microwave absorption and catalytic properties, during the microwave-assisted pyrolysis of cow dung (CD). This study also evaluated the optimization potential of energy recovery efficiency. The results showed that the addition of pretreated RM significantly increased the oil yield during the microwave-assisted pyrolysis of CD. The highest oil yield (59.63%) was obtained via the microwave-assisted pyrolysis of CD over catalysis with RM pretreated at 750 °C (RM750). Through the optimization of the RM750-to-CD mixing ratio, optimal oil quality and energy recovery efficiency were achieved. At a mixing ratio of 1:1, the pyrolysis oil featured the highest aromatic hydrocarbon content and lowest acid content. The high-temperature pretreatment of RM increased the Fe2O3 content, which enhanced the dielectric properties and magnetic loss ability of the reactants. This resulted in localized high temperatures and the formation of “hot spots,” which can promote the deoxygenation and hydrogenation reactions of oil. Consequently, the lower heating rate of oil increased from 35.12 to 40.11 MJ kg−1. The released oxygen escaped in the form of CO. In addition, pyrolytic char was used as an in situ microwave absorbing material owing to its increased Fe2O3 content and graphitization degree, leading to an increase in energy recovery efficiency from 4.71% to 9.98%. This study provides valuable guidance for the efficient utilization of diversified solid wastes and demonstrates the potential application of microwave-assisted pyrolysis technology in the resource utilization of solid wastes.

Alkali-Induced Phase Transition to β-Spodumene along the LiAlSi2O6-LiAlSi4O10 Join

Due to the refractory nature of α-spodumene (LiAlSi2O6) and petalite (LiAlSi4O10), two major lithium minerals, conventional lithium recovery processes involve a high-temperature pre-treatment (&gt;1000 °C) to induce a phase transition to tetragonal β-spodumene, an open structure allowing easier access to lithium through ion exchange. Considering that these high temperatures are not dictated by thermodynamics but rather sluggish kinetics, the study investigates the mechanisms enhancing the rate of transformation to β-spodumene at lower temperatures while minimizing the growth of metastable hexagonal β-quartz typically observed at the onset of the conversion. The heat treatment of natural α-spodumene revealed that rapid growth of β-spodumene veinlets is achieved at ≤600 °C by activation of alkali-rich fluid inclusions, through a dissolution–recrystallization process. For petalite, the mechanism of the phase transition, initiated at ≈750 °C is a solid-state transformation keeping crystallographic coincidence with the mineral host. Synthetic growth experiments along the LiAlSi2O6-LiAlSi4O10 join indicate a compositional dependence on the resulting β-phase structure, where minor sodium doping strongly favors β-spodumene, as the tetrahedral framework of β-quartz does not allow the extent of deformation to accommodate the larger alkali. These findings open opportunities for energy-efficient lithium recovery pathways where the phase transition and ion exchange can be achieved simultaneously without a high-temperature pre-treatment.

Rapid heat hardening in embryos of the lizard Anolis sagrei.

Adaptive thermal tolerance plasticity can dampen the negative effects of warming. However, our knowledge of tolerance plasticity is lacking for embryonic stages that are relatively immobile and may benefit the most from an adaptive plastic response. We tested for heat hardening capacity (a rapid increase in thermal tolerance that manifests in minutes to hours) in embryos of the lizard Anolis sagrei. We compared the survival of a lethal temperature exposure between embryos that either did (hardened) or did not (not hardened) receive a high but non-lethal temperature pre-treatment. We also measured heart rates (HRs) at common garden temperatures before and after heat exposures to assess metabolic consequences. 'Hardened' embryos had significantly greater survival after lethal heat exposure relative to 'not hardened' embryos. That said, heat pre-treatment led to a subsequent increase in embryo HR that did not occur in embryos that did not receive pre-treatment, indicative of an energetic cost of mounting the heat hardening response. Our results are not only consistent with adaptive thermal tolerance plasticity in these embryos (greater heat survival after heat exposure), but also highlight associated costs. Thermal tolerance plasticity may be an important mechanism by which embryos respond to warming that warrants greater consideration.

Effective Suppression of Amorphous Ga2O and Related Deep Levels on the GaN Surface by High-Temperature Remote Plasma Pretreatments in GaN-Based Metal-Insulator-Semiconductor Electronic Devices.

Gallium nitride (GaN) has been considered one of the most promising materials for the next-generation power and radio-frequency electronic devices, as they can operate at higher voltage, higher frequency, and higher temperature, compared with their silicon (Si) counterparts. However, the fresh GaN surface is susceptible to the natural oxidation composed of Ga2O3, Ga2O, and other intermediate oxidation states. Moreover, the oxidized GaN surface no longer features the distinct atomic step-terrace morphology, resulting in a degraded interface when gate or passivation dielectrics are deposited without appropriate pretreatment. It is responsible for the degraded performance of GaN-based devices such as current collapse and threshold voltage instability. In this study, the proposed high-temperature (500 °C) remote plasma pretreatments (RPPs) can play a significant role in addressing the issue of the deteriorated GaN surface exposed to air. Atomic step-terrace morphology was recovered after 500 °C-RPP due to the removal of oxides and suboxides. First-principles calculations verified that Ga2O at the GaN surface leads to interface states at ∼2.9 eV (EC-E ∼ 0.4 eV) in the bandgap, which is consistent with the increase of interface states at the EC-E range of 0.4-0.9 eV measured through constant-capacitance deep-level transient spectroscopy. Meanwhile, deep interface states and surface-related current collapse are well suppressed in GaN metal-insulator-semiconductor devices. These improved properties by 500 °C-RPP are generalizable to a broader range, including pre-gate and pre-passivation treatment, of which a decent surface/interface is desirable for high-performance GaN-based devices.

A comprehensive study on flocculation of anionic dyes using the bioflocculant produced by Bacillus thuringiensis: Kinetics, affecting factors, and perspectives.

Bioflocculants have received more and more attention as alternatives to chemical flocculants because of their innocuousness, environmental friendliness, and high effectiveness. This study aims to investigate various factors that influence the performance of the novel bioflocculant produced by Bacillus thuringiensis (BF-TWB10) and analyze its adsorption kinetics to optimize its flocculation performance for real applications. The best-fit kinetic model was pseudo-second order with R2 = 0.999. The effects of pretreatment temperature, pH, and the presence of cations on flocculation were assessed. Further investigations of flocculation, including zeta potential analysis and particle size analysis, were also conducted. Thermal pretreatment of BF-TWB10 or the presence of divalent cations could stimulate the decolorization efficiency of the bioflocculant. BF-TWB10 manifested outstanding dye removal performances with over 90% for all tested anionic dyes at pH2 and 3. Its decolorization efficiency on anionic dyes decreased with the increase of pH values. Zeta potential analysis revealed that the electrostatic repulsion between anionic dyes decreased after the addition of BT-TWB10 and further diminished by adjusting the reaction mixture to pH2 before flocculation, suggesting the occurrence of adsorption bridging and charge neutralization. These findings proposed that BF-TWB10 might be a promising bioflocculant for the removal of dyes in textile wastewater. PRACTITIONER POINTS: Bioflocculant BF-TWB10 shows outstanding performance in flocculation. Adsorption process follows pseudo-second-order kinetic model. Flocculation process is pH-responsive. High-temperature pretreatment or divalent cations enhance its flocculation performance. The analyses suggest the occurrence of charge neutralization and adsorption bridging.

The elastase and melanogenesis inhibitory and anti-inflammatory activities of phosvitin phosphopeptides produced using high-temperature and mild-pressure (HTMP) pretreatment and enzyme hydrolysis combinations

This study aimed to determine the skin protective effect of egg yolk phosvitin phosphopeptides (PPPs). Phosvitin was separated from the egg yolk, and PPPs were produced using high-temperature and mild-pressure (HTMP) pretreatment and enzyme-sterilization hydrolysis combinations. The elastase and melanogenesis inhibitory activities and anti-inflammatory effects of egg yolk PPPs were determined. All PPPs significantly inhibited elastase activity, but the PPPs prepared with HTMP pretreatment and trypsin-sterilization (HTMP-T-S) combination suppressed the tyrosinase activity the most. PPPs (3 mg/mL) inhibited the α-melanocyte-stimulating hormone-induced melanin production in B16F10 melanoma cells by 31.18 to 38.58%. In addition, PPPs effectively inhibited nitric oxide (NO) production in the LPS (lipopolysaccharide)-stimulated RAW 264.7 macrophages, and the PPPs from HTMP-T-S exhibited the highest inhibitory activity. The protein expressions of pro-inflammatory enzymes, inducible nitric oxide synthase, and cyclooxygenase-2 were down-regulated by the PPPs from the HTMP-T-S. Therefore, PPPs could be used as an anti-melanogenic, anti-elastase, and anti-inflammatory agent for humans and skin care products.

Effects of high temperature pretreatment and inoculation of Bacillus coagulans on promoting aerobic composting of chicken manure

Effects of high temperature pretreatment and inoculation of Bacillus coagulans were determined relative to the physicochemical properties and bacterial community of aerobic composting of chicken manure. Chicken manure was pretreated with high temperature for 0 h (CJ), 0.5 h (T-0.5h), 1.0 h (T-1.0h), 1.5 h (T-1.5h), and 2.0 h (T-2.0h) and then inoculated with B. coagulans. Chicken manure without high temperature pretreatment was included as control (CK). The results showed that the temperature of manure in CJ, T-0.5h, T-1.0h, T-1.5h, and T-2.0h groups was 2.2 to 8.4 °C higher than the chicken manure in CK within 1 day. On day 3, the chicken manure temperature reached a peak, which was 1.5 to 7.7 °C higher than that in the CK (56.8 °C). Both inoculation of B. coagulans and high temperature pretreatment increased the abundance and diversity of the bacterial community. The abundance of Firmicutes in T-1.5h was significantly higher than that in CJ. In the temperature decreasing period, the abundance of Bacillus in T-1.5h group was significantly higher than that in the CK and CJ. Overall, it was concluded that high temperature pretreatment and B. coagulans inoculation can accelerate the temperature elevation, increase the temperature of compost, and regulate the structure of bacterial community.

Seed germination requirements of Amaranthus retroflexus L. populations exposed to environmental factors

Seed germination studies are often used to predict the potential of plants to extend their global distribution. In this research, the effect of gibberellic acid (GA3) concentrations, pre-chilling, temperature, water and salt stresses, pH, high-temperature pretreatment, planting depth, and flooding on seed germination and seedling emergence of three Amaranthus retroflexus L. populations was investigated. GA3 concentration significantly affected seed germination of all three A. retroflexus populations grown under light/dark conditions. All three populations germinated under constant (10, 15, 20, 25, and 30 °C) and alternating (20/15, 25/18, and 35/25 °C (day/night)) temperatures. The optimum alternating temperature for germination of all three populations was 18/25 °C day/night. Seed germination was severely reduced under moisture and salt stresses. Seedling emergence was reduced on the soil surface by increasing the planting depth from 2.5 to 7.5 cm, and no seedlings emerged when the planting depth of seeds was more than 10 cm . The results of this research help us to understand the germination capacity and requirements of A. retroflexus in different environments and also provide information to help better control the weed.

Support Effect and Stability of Inverse Fe1(OH)x/Pt Single-Site Interfacial Structured Catalysts for Preferential CO Oxidation in H2

Preferential oxidation of CO in hydrogen (PROX) has been regarded as a promising method for removing a trace amount of CO to a parts-per-million (ppm) level to provide pure hydrogen fuel for polymer-electrolyte membrane fuel cells. Recently, we reported that SiO2-supported Pt nanoparticles with atomically dispersed Fe1(OH)x decoration exhibited exceptional CO removal in a very broad temperature window of −75–107 °C in the PROX reaction because of enriched interfaces and remarkably high reducibility of the iron species. Here, we further investigated the support effect on the catalytic performance of this inverse Fe1(OH)x/Pt single-site interfacial structure, as well as their stabilities under high-temperature redox atmospheres. We found that Fe1(OH)x/Pt on nonreducible supports such as SiO2 and Al2O3 is more favorable for efficient CO removal than those on reducible supports (e.g., Fe2O3 and TiO2) in the PROX reaction. The inferior performance of the latter case is attributed to the creation of additional active interfaces to initiate competing H2 oxidation. High-temperature redox pretreatments of the optimized SiO2-supported Fe1(OH)x/Pt catalyst up to 500 °C did not cause any noticeable changes of the temperature window of complete CO removal, indicating that the inverse Fe1(OH)x/Pt single-site interface structure has high thermal stability against sintering. Further increasing the H2 concentration did not change the temperature window either. The above results suggest that the inverse Fe1(OH)x/Pt catalyst is very robust with high potential for practical applications and other catalytic reactions.