Absorbing oxygen carriers promotes phosphorus recovery from sludge via the microwave thermal conversion process.

This study aims to apply the Absorbing oxygen carriers (AOCs) to induce the migration and transformation of phosphorus compounds during the microwave thermal conversion of sludge so the hard-to-extract organic phosphorus (OP) can be converted to easy-to-extract inorganic phosphorus (IP) and be enriched onto the sludge char. The AOCs were recycled by screen separation from the IP-rich sludge char, with the latter being a renewable phosphorus source from sludge. The AOCs in this novel process enhanced the conversion efficiency of OP into non-apatite inorganic phosphorus (NAlP), which was further converted to apatite inorganic phosphorus (AP). Most phosphorus in the sludge char is presented in the form of orthophosphate.

Corrigendum: The oxidative aging model integrated various risk factors in type 2 diabetes mellitus at system level.

[This corrects the article DOI: 10.3389/fendo.2023.1196293.].

Photocatalytic Degradation and Toxicity Analysis of Sulfamethoxazole using TiO2/BC.

Sulfonamide antibiotics in the environment not only disrupt the ecological balance but can also enter the human or animal body in various forms and cause harm. Therefore, exploring efficient methods to degrade sulfonamide antibiotics is crucial. In this study, we prepared biochar (BC) using corn straw, and TiO2/BC was obtained by doping different proportions of TiO2 into biochar with varying carbonization temperatures using the sol-gel method. Next, we investigated the degradation of sulfamethoxazole (SMX) in solution using the generated TiO2/BC under ultraviolet irradiation and studied the effects of various experimental parameters, such as the type of composite material, composite material addition, solution pH, and initial antibiotic concentration on SMX degradation. Under an initial SMX concentration of 30 mg/L, the composite with the best photocatalytic degradation performance was TiO2/BC-5-300 (i.e., 5 mL of TiO2 doping; 300 °C calcination temperature), with an addition amount of 0.02 g and a solution pH of 3. The degradation efficiency increased from 22.3% to 89%, and the most significant degradation effect occurred during the initial stage of photocatalytic degradation. In the TiO2/BC-5-300 treated SMX solution, the average rhizome length of bean sprouts was significantly higher than that of the untreated SMX solution and slightly lower than that of the deionized aqueous solution (3.05 cm < 3.85 cm < 4.05 cm). This confirmed that the photocatalytic degradation of SMX by the composite was effective and could efficiently reduce its impact on the growth of bean sprouts. This study provides essential data and theoretical support for using TiO2/BC in the treatment of antibiotic-contaminated wastewater.

Fractionation of poplar wood with different acid hydrotropes: Lignin dissolution behavior and mechanism evaluation.

Acid hydrotropes was considered a green medium for efficient wood fractionation at mild conditions. This study reported a comparative study on the dissolution of lignin in different acid hydrotropes, including p-toluenesulfonic acid (p-TsOH), 4-hydroxybenzenesulfonic acid (4-HSA), 5-sulfosalicylic acid (5-SSA), and maleic acid (MA). Under identical treatment conditions (80 °C, 60 min, and 70 % acid concentration), the removal of wood lignin varied significantly among four acid hydrotropes, 4-HSA exhibited the highest removal rate at 88.0 %, followed by p-TsOH at 81.2 %, 5-SSA at 51.1 %, and MA at 26.2 %. The molecular mechanism of the lignin dissolution was analyzed by quantum chemistry (QC) calculation and molecular dynamics (MD) simulation. The higher absorb free energy (E(absorb)) of the 4-HSA and veratrylglycerol-ß-guaiacyl ether (VG) complex (E(absorb) = 17.97 kcal/mol), and the p-TsOH and VG complex (E(absorb) = 17.16 kcal/mol) contributed to a higher efficiency of lignin dissolution. Under the same level of lignin removal (~ 60 %), the four acid hydrotropes showed variations in the ß-O-4 content of the extracted lignin: 4-HSA (3.1 %) < 5-SSA (10.4 %) < p-TsOH (15.9 %) < MA (63.7 %). The acidity and critical aggregation concentrations of acid hydrotropes were found to influence the content of ß-O-4 bonds in the extracted lignin.

The oxidative aging model integrated various risk factors in type 2 diabetes mellitus at system level.

Background: Type 2 diabetes mellitus (T2DM) is a chronic endocrine metabolic disease caused by insulin dysregulation. Studies have shown that aging-related oxidative stress (as "oxidative aging") play a critical role in the onset and progression of T2DM, by leading to an energy metabolism imbalance. However, the precise mechanisms through which oxidative aging lead to T2DM are yet to be fully comprehended. Thus, it is urgent to integrate the underlying mechanisms between oxidative aging and T2DM, where meaningful prediction models based on relative profiles are needed. Methods: First, machine learning was used to build the aging model and disease model. Next, an integrated oxidative aging model was employed to identify crucial oxidative aging risk factors. Finally, a series of bioinformatic analyses (including network, enrichment, sensitivity, and pan-cancer analyses) were used to explore potential mechanisms underlying oxidative aging and T2DM. Results: The study revealed a close relationship between oxidative aging and T2DM. Our results indicate that nutritional metabolism, inflammation response, mitochondrial function, and protein homeostasis are key factors involved in the interplay between oxidative aging and T2DM, even indicating key indices across different cancer types. Therefore, various risk factors in T2DM were integrated, and the theories of oxi-inflamm-aging and cellular senescence were also confirmed. Conclusion: In sum, our study successfully integrated the underlying mechanisms linking oxidative aging and T2DM through a series of computational methodologies.

Activated char supported Fe-Ni catalyst for syngas production from catalytic gasification of pine wood.

Char-based catalyst has a promising application for biomass thermal conversion technology. In this work, Fe-Ni/Activated Char (AC) catalyst was prepared by impregnation method and used for the catalytic gasification of pine wood to obtain syngas. Further, the catalytic performance of Fe-Ni/AC was established by doing a comparative study of catalytic gasification of different biomass feedstocks. The results showed that under the catalysis of Fe-Ni/AC, the increase of gasification temperature was beneficial to increase gas yield, but not conducive to regulate the H2/CO ratio of syngas. The steam flow rate was directly related to the catalytic effect of Fe-Ni. The H2/CO ratio of syngas could reach 1.97 under the optimal conditions. Fe-Ni/AC had different catalytic effects on different biomass feedstocks, with the best for pine wood and the worst for cotton stalk, indicating that gasification intermediates of pine wood were difficult to decompose and depended more on catalyst.

Synergistic effect of the cotton stalk and high-ash coal on gas production during co-pyrolysis/gasification.

The synergistic effect of the cotton stalk (CS) and the high-ash coal (HAC) on the gas production in the co-pyrolysis/gasification processes was studied using the newly designed quartz boat in this work. The gas yield and the concentrations of main gas components were quantitatively compared between the co-pyrolysis/gasification and the individual pyrolysis/gasification. The results showed that the gas yield during the co-pyrolysis was promoted at 950℃. There was almost no interaction between CS and HAC, since the co-pyrolytic gas yield exhibited a linear relationship with CS mixing ratio of 20% to 60%. The catalytic effect of alkali metals and alkaline earth metals that existed in CS, was enhanced by the addition of steam, and the synergistic effect was reduced while gas yield was enhanced with CS blending ratio increasing during co-gasification. The results provided a method to enhance synergistic effect between biomass and coal during co-pyrolysis/gasification in this study.

Optimal extraction, purification and antioxidant activity of total flavonoids from endophytic fungi of Conyza blinii H. Lév.

BACKGROUND: Flavonoids are widely used in the market because of their antibacterial, antiviral, and antioxidant activities. But the production speed of flavonoids is limited by the growth of plants. CBL9 (Chaetomium cruentum) is a flavonoid-producing endophytic fungi from Conyza blinii H. Lév, which has potential to produce flavonoids. METHODS: In this study, we isolated total flavonoids from endophytic fungus CBL9 of Conyza blinii H. Lév using macroporous resin D101. The process was optimized by response surface and the best extraction process was obtained. The antioxidant activities of total flavonoids were analyzed in vitro. RESULTS: It was found that the best parameters were 25 °C pH 2.80, 1.85 h, and the adsorption ratio reached (64.14 ± 0.04)%. A total of 60% ethanol was the best elution solvent. The elution ratio of total flavonoid reached to (81.54 ± 0.03)%, and the purity was 7.13%, which was increased by 14.55 times compared with the original fermentation broth. Moreover its purity could rise to 13.69% after precipitated by ethanol, which is very close to 14.10% prepared by ethyl acetate extraction. In the antioxidant research, the clearance ratio of L9F-M on DPPH, ABTS, •OH, •O2-, (96.44 ± 0.04)% and (75.33 ± 0.03)%, (73.79 ± 0.02)%, (31.14 ± 0.01)% at maximum mass concentration, was higher than L9F. CONCLUSION: The result indicated using macroporous resin in the extraction of total flavonoid from endophytic fungus is better than organic solvents with higher extraction ratio, safety and lower cost. In vitro testing indicated that the flavonoid extracted by macroporous resin have good antioxidant activity, providing more evidence for the production of flavonoid by biological fermentation method.

Application of calcium oxide/ferric oxide composite oxygen carrier for corn straw chemical looping gasification.

Biomass chemical looping gasification (CLG) technology is an important utilization form of renewable energy. In order to obtain high-quality syngas, CaO/Fe2O3 was used as a composite oxygen carrier for biomass CLG in this study. The CLG experiment of corn straw and the study of oxygen carrier recycling were carried out, simultaneously, the reaction mechanism was further discussed. Results shown adding CaO to oxygen carrier could significantly improve the quality of syngas through increasing the H2 and reduce Greenhouse gas (CO2 and CH4, about 14% reduction). Besides, the ratio of Fe2O3 to CaO, steam to biomass, and oxygen carrier to biomass all affected the syngas composition (the H2/CO variation from 1.82 to 2.19), while the temperature had obvious influence on the gas yield of CLG. The most possible reaction mechanism shown that the variation of Ca might be the main factor of gas composition fluctuation.

Synergistic effect of mixing wheat straw and lignite in co-pyrolysis and steam co-gasification.

Co-pyrolysis and steam co-gasification of wheat straw (WS) and lignite coal (LC) were studied in a tube furnace between 700 °C and 900 °C. Synergistic effect in co-pyrolysis is not always apparent. However, with the introduction of H2O vapor, synergetic effect is more obvious. Gas volume generated by co-gasification was higher than the prediction in all cases. Meanwhile, temperature played an important role and had a linear relationship with the excess gas volume when it exceeded 800 °C. These findings can be explained by that sufficient H2O vapor could enhance synergy according raising catalytic effect of alkali and alkaline earth metals (AAEMs), promoting free radical generated and increasing reactivity of half-chars. Moreover, co-gasification of WS and LC with several blending ratios were studied at 850 °C. It found H2O vapor could promote free radical formation stronger with higher ratio of WS during co-gasification, thus showing an enhancing effect on the reactivity of WS-derived chars.

Chemical-looping gasification of corn straw with Fe-based oxygen carrier: Thermogravimetric analysis.

The chemical-looping gasification kinetics of corn straw with iron-based oxygen carrier to produce syngas were studied using thermogravimetric analysis. The main reactions of corn straw based on iron-based composite oxygen carrier is divided into three stages: the pyrolysis stage (200-500 °C), the gas-solid reaction stage (500-700 °C), and the solid-solid reaction stage (700-1100 °C). The Coats-Redfern method and the Malek method were used to screen the thirty reactions. The activation energies for the most likely main reactions were estimated to be 81.6 kJ/mol (Mample single-line rule), 117.5 kJ/mol (reaction order function), and 140.9 kJ/mol (Ginstling-Brounshtein equation). The chemical-looping gasification of corn straw with Fe-based oxygen carrier involved multi-step reaction mechanisms.

Integrated gasification and catalytic reforming syngas production from corn straw with mitigated greenhouse gas emission potential.

The syngas that is produced from waste biomass often has high levels of CH4 and CO2, which are greenhouse gases. This investigation presents an integrated gasification and catalytic reforming process with a closed gas loop that can improve quality of syngas from corn straw and mitigate CH4 and CO2 emission. The effects of the support type, reforming temperature, steam-to-biomass (S/B) ratio, and catalyst-to-biomass ratio (C/B) ratio on gas yield and composition were experimentally examined with waste corn straw as the feedstock gasified at 850 °C in the proposed closed-loop apparatus. Reformation of syngas using Ni/γ-Al2O3 at 850 °C, S/B = 1 and C/B = 0.5 yielded 1.16 m3/kg of syngas, which contained 48.5% H2, 33.9% CO, 12.2% CO2 and 5.3% CH4, corresponding to 71.0% and 81.5% enhancements of the first two and -77.8% and -58.1% reductions of the last two components.

Syngas production from biomass using Fe-based oxygen carrier: Optimization.

Chemical looping gasification is a promising technology to convert biomass into syngas with low adverse effects by heat loss and production dilution. This study utilized 60% loading Fe2O3/Al2O3 oxygen carrier (OC) for gasification tests on four biomass samples: rice straw, corn stalk, peanut shell and wheat straw under OC/biomass (OC/B) ratio of 1.0, steam/biomass (S/B) ratio of 2.8, reaction time of 20 min, and reaction temperature of 850 °C. All biomass samples yielded similar gasification performances: CO content 19.2-23.1%, H2 content 36.5-41.1%, carbon conversion rate 72.3-82.2% and gas yield 0.78-1.04 L/g. The gasification performance using rice straw was optimized on maximum H2/CO ratio using three levels Box-Behnken experimental design: 899.6 °C, 20.3 min, OC/B = 1.02 and S/B = 2.89, leading to maximum H2/CO value of 2.20. Verification tests confirmed this prediction. The adopted Fe-based OC can be applied to generate syngas from the tested biomass with promising outcomes.

Indoor Visual Positioning Aided by CNN-Based Image Retrieval: Training-Free, 3D Modeling-Free.

Indoor localization is one of the fundamentals of location-based services (LBS) such as seamless indoor and outdoor navigation, location-based precision marketing, spatial cognition of robotics, etc. Visual features take up a dominant part of the information that helps human and robotics understand the environment, and many visual localization systems have been proposed. However, the problem of indoor visual localization has not been well settled due to the tough trade-off of accuracy and cost. To better address this problem, a localization method based on image retrieval is proposed in this paper, which mainly consists of two parts. The first one is CNN-based image retrieval phase, CNN features extracted by pre-trained deep convolutional neural networks (DCNNs) from images are utilized to compare the similarity, and the output of this part are the matched images of the target image. The second one is pose estimation phase that computes accurate localization result. Owing to the robust CNN feature extractor, our scheme is applicable to complex indoor environments and easily transplanted to outdoor environments. The pose estimation scheme was inspired by monocular visual odometer, therefore, only RGB images and poses of reference images are needed for accurate image geo-localization. Furthermore, our method attempts to use lightweight datum to present the scene. To evaluate the performance, experiments are conducted, and the result demonstrates that our scheme can efficiently result in high location accuracy as well as orientation estimation. Currently the positioning accuracy and usability enhanced compared with similar solutions. Furthermore, our idea has a good application foreground, because the algorithms of data acquisition and pose estimation are compatible with the current state of data expansion.