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Hydrothermal carbonization (HTC) of wetland plant could achieve the recovery of phosphorus (P) via the production of P-enriched hydrochar to alleviate the crisis of phosphate resources, while the migration and transformation of P should be determined. In this study, Canna indica was derived into hydrochar through HTC at different temperatures (200°C-260°C) and liquid mediums (H2O, CaCl2, and NaOH). The P forms were systematically characterized using P K-edge X-ray absorption near edge structure (XANES), 31P liquid nuclear magnetic resonance (NMR), and sequential extraction. The total P content in hydrochar was up to 23 mg g−1 with mainly inorganic P (> 97.8%), and the recovery rate was almost 100% during NaOH-mediated HTC. The P species, monoester-P and soluble orthophosphate (ortho-P), in biomass were transformed to more stable ortho-P in hydrochars, which was highly dependent on temperature and liquid medium. With increasing temperature, Al/Mg-P was gradually replaced by Ca/Fe-P. The CaCl2 solution facilitated the transformation of Ca(H2PO4)2 into CaHPO4 by elevating the Ca/P ratio. While for the NaOH-mediated HTC, the CaHPO4 and Ca(H2PO4)2 were transformed to hydroxyapatite (74.3%-81.5%), and the proportion of MgHPO4 elevated with increasing temperature. The diffusive gradients in thin films (DGT) results implied that the addition of hydrochar greatly elevated the soil available P content, which was further promoted by high temperature and NaOH medium. These results indicate that the species and availability of P in hydrochar could be adjusted through varying liquid medium and reaction temperature, which provide guidance for the target design of P-enriched hydrochar and P reclamation. Highlight: • P-enriched hydrochar was prepared from the wetland plant by the modified HTC. • Liquid medium and reaction temperature affected the speciation dynamics of P. • P was stabilized with high temperature, Ca2+ addition, and alkaline liquid medium. • Hydrochar addition greatly elevated the soil available P content via DGT analysis. [ABSTRACT FROM AUTHOR]

Graphite carbon nitride (g-C3N4) has been employed as an emerging metal-free catalyst in heterogeneous catalysis. However, the catalyst has a poor activation property for peroxymonosulfate (PMS). In this study, Bi-Fe oxide co-doped g-C3N4 (Bi@Fe/CN) was synthesized for PMS activation to degrade sulfamethoxazole (SMX). In particular, Bi@Fe/CN-3 presented remarkable catalytic performance with 99.7% removal of SMX within 60 min in the PMS system. Additionally, Bi@Fe/CN-3 presented good stability and recyclability through the cycling experiments. Moreover, it was shown that free radicals (O2•−, •OH, and SO4•−) and non-free radicals (1O2) were the primary active species in the Bi@Fe/CN-3/PMS system. Bi, Fe, and surface lattice oxygen were confirmed to be the main contributors to the active species. This work elucidates the mechanism of activation of PMS by Bi@Fe/CN-3, which is beneficial to promote the application of bimetallic oxide-modified g-C3N4/PMS systems in wastewater treatment. [ABSTRACT FROM AUTHOR]

Plastic waste management has emerged as an urgent global challenge, that has attracted significant attention from researchers, policymakers, and stakeholders. Conducting a bibliometric study on this issue aims to provide a holistic and in-depth bibliometric mapping and analysis of plastic waste management, carefully traced through the Web of Science. Expansive data comprising scientific production by researchers, country/region contributions, affiliations, author references, and topical trends were meticulously scrutinized using the VOSviewer software (version 1.6.15). The exploration of bibliometric studies in plastic waste management is still limited, and this forms the basis of our commitment to explore this field in more depth. The findings in this study showed a progressive increase in the number of published works from 1992 to 2022, using the main keyword "plastic waste management" and 13,103 documents were found that were further analyzed. This demonstrates the profound impact of Chinese scientists on plastic waste management research, as evidenced by their prevalence as top affiliated authors. Given the increasing concern and heightened government and societal attention towards plastic pollution and water contamination, effective waste management, with a particular focus on plastic waste, emerged as the most influential keyword. This comprehensive analysis contributes to the existing literature by highlighting key trends and the urgent need for concerted efforts to address the challenges posed by plastic waste. [ABSTRACT FROM AUTHOR]

Semipermeable membrane-covered composting is one of the most commonly used composting technologies in northeast China, but its humification process is not yet well understood. This study employed a semipermeable membrane-covered composting system to detect the organic matter humification and bacterial community evolution patterns over the course of agricultural waste composting. Variations in physicochemical properties, humus composition, and bacterial communities were studied. The results suggested that membrane covering improved humic acid (HA) content and degree of polymerization (DP) by 9.28% and 21.57%, respectively. Bacterial analysis indicated that membrane covering reduced bacterial richness and increased bacterial diversity. Membrane covering mainly affected the bacterial community structure during thermophilic period of composting. RDA analysis revealed that membrane covering may affect the bacterial community by altering the physicochemical properties such as moisture content. Correlation analysis showed that membrane covering activated the dominant genera Saccharomonospora and Planktosalinus to participate in the formation of HS and HA in composting, thus promoting HS formation and its structural complexity. Membrane covering significantly reduced microbial metabolism during the cooling phase of composting. [ABSTRACT FROM AUTHOR]

In order to improve the calorific value and reducibility of the syngas produced by traditional coal gasification technology, and to solve the problem of high cost of heat source in coal gasification, this paper proposes to use high-temperature copper slag as the heat carriers and catalyst for coal gasification, and CaO as the CO2 adsorbent during the coal gasification reaction. In this way, the proportion of H2 in the syngas gas can be increased, and the coal gasification reaction can be improved. In the experiment, the samples with different ratios were fully mixed, and then thermogravimetric experiment and gasification experiment were carried out. Through research, the following rules were found. The use of high-temperature copper slag as the heat source and catalyst in coal gasification can lead to a 20% increase in the final weight loss rate. Additionally, when CaO is used as the CO2 adsorbent during the coal gasification reaction, a noticeable secondary weight loss occurs at around 600°C and can reach a maximum speed of 0.19%/min. The use of the C/S/CaO = 1/1/2 ratio can result in a maximum weight loss rate of 23%. Meanwhile, the C/S/CaO = 1/2/1 group has been shown to achieve a maximum weight loss speed of 0.5%/min, and the C/S/CaO = 1/1/1 group exhibits a maximum secondary weight loss speed of 0.32%/min. The samples after gasification experiment were analyzed by SEM, CaO produced clustered iron-based and porous structure on the surface of copper slag in gasification reaction. Based on the Coats-Redfern method, kinetics of gasification reaction is obtained, and the optimum fitting function is C2, mechanism functions didn't change with the variation of C/S/CaO. The research results suggest that CaO and copper slag can both enhance the coal gasification reaction. In addition, CaO is proven to be a more affordable and accessible CO2 adsorbent compared to other alternatives. [ABSTRACT FROM AUTHOR]

Pyrolysis is considered an attractive option and a promising way to dispose waste plastics. The thermogravimetric experiments of high-density polyethylene (HDPE) were conducted from 105 °C to 900 °C at different heating rates (10 °C/min, 20 °C/min, and 30 °C/min) to investigate their thermal pyrolysis behavior. We investigated four methods including three model-free methods and one model-fitting method to estimate dynamic parameters. Additionally, an artificial neural network model was developed by providing the heating rates and temperatures to predict the weight loss (wt.%) of HDPE, and optimized via assessing mean squared error and determination coefficient on the test set. The optimal MSE (2.6297 × 10−2) and R2 value (R2 > 0.999) were obtained. Activation energy and pre-exponential factor obtained from four different models achieves the acceptable value between experimental and predicted results. The relative error of the model increased from 2.4 % to 6.8 % when the sampling frequency changed from 50 s to 60 s, but showed no significant difference when the sampling frequency was below 50 s. This result provides a promising approach to simplify the further modelling work and to reduce the required data storage space. This study revealed the possibility of simulating the HDPE pyrolysis process via machine learning with no significant accuracy loss of the kinetic parameters. It is hoped that this work could potentially benefit to the development of pyrolysis process modelling of HDPE and the other plastics. [ABSTRACT FROM AUTHOR]

Simple Summary: Accumulating studies have revealed that the gut microbiota had intimate relations with the animal gastrointestinal tract diseases. Through regulating the development of the host's intestinal immune system, the gut microbiota could directly influence the host's intestinal function. In the current study, the gut microbiota of Ragdoll cats and Felinae cats were investigated and compared. Results demonstrated the diversity and richness of the gut microbiota in the Felinae cats were much higher than in the Ragdoll cats. However, the relative abundances of beneficial microbes in the Ragdoll cats were much higher than those in the Felinae cats. In all, different genetic portraits determined the different microbial communities in the feline gut. The candidate probiotics isolated in the growing cat's gut might be applied to treat the gastrointestinal tract diseases. Today, domestic cats are important human companion animals for their appearance and favorable personalities. During the history of their domestication, the morphological and genetic portraits of domestic cats changed significantly from their wild ancestors, and the gut microbial communities of different breeds of cats also apparently differ. In the current study, the gut microbiota of Ragdoll cats and Felinae cats were analyzed and compared. Our data indicated that the diversity and richness of the gut microbiota in the Felinae cats were much higher than in the Ragdoll cats. The taxonomic analyses revealed that the most predominant phyla of the feline gut microbiota were Firmicutes, Bacteroidota, Fusobacteriota, Proteobacteria, Actinobacteriota, Campilobacterota, and others, while the most predominant genera were Anaerococcus, Fusobacterium, Bacteroides, Escherichia-Shigella, Finegoldia, Porphyromonas, Collinsella, Lactobacillus, Ruminococcus_gnavus_group, Prevotella, and others. Different microbial communities between the Ragdoll group and the Felinae group were observed, and the compared results demonstrated that the relative abundances of beneficial microbes (such as Lactobacillus, Enterococcus, Streptococcus, Blautia, Roseburia, and so on) in the Ragdoll group were much higher than in the Felinae group. The co-occurrence network revealed that the number of nodes and links in the Felinae group was significantly higher than the Ragdoll group, which meant that the network of the Felinae group was larger and more complex than that of the Ragdoll group. PICRUSt function analyses indicated that the differences in microbial genes might influence the energy metabolism and immune functions of the host. In all, our data demonstrated that the richness and diversity of beneficial microbes in the Ragdoll group were much higher than the Felinae group. Therefore, it is possible to isolate and identify more candidate probiotics in the gut microbiota of growing Ragdoll cats. [ABSTRACT FROM AUTHOR]

Traditional treatments of Chinese herb medicine residue (CHMR) inevitably cause secondary pollution and hardly remove the pesticide in it. Therefore, high-temperature treatment might be promising to achieve the reduction and resource utilization of CHMR. Based on this, the effects of essential parameters including temperature, equivalent ratio (ER), oxygen concentration and steam to biomass ratio (S/B ratio) were systematically and synthetically analyzed to explore the method and mechanism of improving gasification characteristics. Increasing temperature would promote endothermic reactions thus enhancing the gasification process. The optimal ER of air, oxygen-enriched air and oxygen-enriched air steam gasification are the same, 0.26. Higher O2 concentration would promote oxidation reaction thus increasing the temperature in gasifier and being conducive to the generation of CO and H2, while excess O2 would react with CO and H2. The optimal O2 concentration in oxygen-enriched air and oxygen-enriched air steam gasification were 40 vol% and 50 vol%, respectively. It might be caused by that more O2 was needed to offset the temperature reduction caused by steam addition. Supplying proper steam (S/B = 1.0 and 1.6 for oxygen-enriched air and oxygen-enriched air steam gasification, respectively) could promote the Primary water–gas ad Steam reforming reaction thus increasing the CO and H2 yields. However, excessive steam could reduce reaction temperature and be not conducive to gasification. Moreover, grey relational analysis was introduced to solve multi-attribute decision making issues and determine the influence levels of these parameters thus guiding CHMR gasification technology. These parameters followed the order of S/B ratio > O2 concentration > temperature > ER. [ABSTRACT FROM AUTHOR]

Temperature affects the emission behavior of formaldehyde from coatings. Initial emittable concentration (C0), diffusion coefficient (Dm) and partition coefficient (K) are three key parameters for characterizing the formaldehyde emission from coatings. However, recent research concerning temperature effect on volatile organic compound (VOC) emission from coatings mainly focused on the influence on gas-phase concentration or emission rate, and few studies were conducted on the correlation between temperature and key emission factors (C0, Dm and K). In this work, formaldehyde emission from a solvent-based coating was measured at 10, 15, 20 and 25°C in a 30 L environmental chamber. From 10 to 25°C, C0 increased by 2.35-fold, and positive linear correlation was observed between ln(C0*T0.5) and 1/T. An empirical equation characterizing temperature effect on K was derived. Temperature effects on Dm were negligible. Through the obtained equations that can characterize the correlation between temperature and the key parameters, C0 and K at different temperatures from this work can be easily calculated. This study would be useful for predicting emission behavior of formaldehyde from solvent-based coatings and better understanding the influence of temperature. [ABSTRACT FROM AUTHOR]

Limited availability of fossil energy and serious environmental pollution have caused the emergence of bio‐oil, which can serve as an alternative and promising green energy source. However, bio‐oil generated from the rapid pyrolysis of biomass cannot be utilized immediately owing to its corrosivity, instability, and low heating value. Herein, the electrocatalytic hydrogenation (ECH) process towards bio‐oil upgrading is reviewed. Specifically, the ECH integrates the advantages of mild operating conditions, no petrochemically derived hydrogen and good controllability. The influence of different factors on the conversion of bio‐oil components and product selectivity in the ECH process are presented comprehensively. In addition, various reaction mechanisms are discussed in the designed ECH systems. Finally, some challenges need to be further overcome for real bio‐oil reduction in the ECH process: exploration of efficient multifunctional electrocatalysts for specific bio‐oil components and determination of the dominant steps in the complicated reaction path network. [ABSTRACT FROM AUTHOR]

Tar is a major bottleneck for advancing biomass gasification in industrial applications, and therefore it is necessary to develop a clean and efficient tar elimination technology. Experiments of ex-situ real tar catalytic cracking to produce syngas under low temperature condition were proposed in this study with Ni supported by HZSM-5 as catalyst. The effects of various reaction conditions on catalytic performance were investigated, and the mechanisms of tar cracking and coke formation were also discussed by XRD, ICP-MS and BET analysis. Results showed that tar conversion and heat value of gaseous products were 91.52 wt% and 6.40 MJ/Nm3, respectively, when temperature was 500 °C, WHSV was 0.65 h−1 and Ni loading content was 6 wt%. However, coking rate of catalyst was higher than 19.20 wt%. HZSM-5 supported Ni exhibited remarkable tar cracking ability and it could also improve heating value of gaseous products, but coke deactivation of catalyst should be further investigated. [ABSTRACT FROM AUTHOR]

An investigation of hydrocarbon (HC) and aldehyde emissions from the combustion of 2-methylfuran (MF) was conducted, with samples taken from the exhaust of a single cylinder direct-injection spark ignition (SI) research engine. This article validates the mechanism of MF combustion, and assesses its toxic emissions. Aldehyde emissions from MF were quantitatively measured using high performance liquid chromatography, and the results were compared with those of gasoline, 2,5-dimethylfuran (DMF), ethanol, methanol, and n-butanol. The detected aldehydes were mainly formaldehyde and acetaldehyde. Reaction pathway analyses of the combustion of MF and DMF were performed using a closed homogeneous constant volume reactor model in the Chemkin package. The formaldehyde emission was related to the side chain of MF. It was only half that of DMF and it was much lower than those of other fuels. The acetaldehyde emission from MF was also one of the lowest among all tested fuels. HCs from MF combustion were qualitatively investigated using gas chromatography mass spectrometry. The exhaust spectrum detected signals from propylene, benzene, toluene, ethyl benzene, xylenes, carbonyl compounds, and furan series derivatives (furan, DMF, and furfural). [ABSTRACT FROM AUTHOR]