Effects of biomass co-pyrolysis and herbaceous plant colonization on the transformation of tailings into soil like substrate.

Enhancing soil organic matter characteristics, ameliorating physical structure, mitigating heavy metal toxicity, and hastening mineral weathering processes are crucial approaches to accomplish the transition of tailings substrate to a soil-like substrate. The incorporation of biomass co-pyrolysis and plant colonization has been established to be a significant factor in soil substrate formation and soil pollutant remediation. Despite this, there is presently an absence of research efforts aimed at synergistically utilizing these two technologies to expedite the process of mining tailings soil substrate formation. The current study aimed to investigate the underlying mechanism of geochemical changes and rapid mineral weathering during the process of transforming tailings substrate into a soil-like substrate, under the combined effects of biomass co-smoldering pyrolysis and plant colonization. The findings of this study suggest that the incorporation of smoldering pyrolysis and plant colonization induces a high-temperature effect and biological effects, which enhance the physical and chemical properties of tailings, while simultaneously accelerating the rate of mineral weathering. Notable improvements include the amelioration of extreme pH levels, nutrient enrichment, the formation of aggregates, and an increase in enzyme activity, all of which collectively demonstrate the successful attainment of tailings substrate reconstruction. Evidence of the accelerated weathering was verified by phase and surface morphology analysis using X-ray diffraction and scanning electron microscopy. Discovered corrosion and fragmentation on the surface of minerals. The weathering resulted in corrosion and fragmentation of the surface of the treated mineral. This study confirms that co-smoldering pyrolysis of biomass, combined with plant colonization, can effectively promote the transformation of tailings into soil-like substrates. This method has can effectively address the key challenges that have previously hindered sustainable development of the mining industry and provides a novel approach for ecological restoration of tailings deposits.

Oxygen atmosphere enhances ball milling remediation of petroleum-contaminated soil and reuse as adsorptive/catalytic materials for wastewater treatment.

Ball milling is an environmentally friendly technology for the remediation of petroleum-contaminated soil (PCS), but the cleanup of organic pollutants requires a long time, and the post-remediation soil needs an economically viable disposal/reuse strategy due to its vast volume. The present paper develops a ball milling process under oxygen atmosphere to enhance PCS remediation and reuse the obtained carbonized soil (BCS-O) as wastewater treatment materials. The total petroleum hydrocarbon removal rates by ball milling under vacuum, air, and oxygen atmospheres are 39.83%, 55.21%, and 93.84%, respectively. The Langmuir and pseudo second-order models satisfactorily describe the adsorption capacity and behavior of BCS-O for transition metals. The Cu2+, Ni2+, and Mn2+ adsorbed onto BCS-O were mainly bound to metal carbonates and metal oxides. Furthermore, BCS-O can effectively activate persulfate (PDS) oxidation to degrade aniline, while BCS-O loaded with transition metal (BCS-O-Me) shows better activation efficiency and reusability. BCS-O and BCS-O-Me activated PDS oxidation systems are dominated by 1O2 oxidation and electron transfer. The main active sites are oxygen-containing functional groups, vacancy defects, and graphitized carbon. The oxygen-containing functional groups and vacancy defects primarily activate PDS to generate 1O2 and attack aniline. Graphitized carbon promotes aniline degradation by accelerating electron transfer. The paper develops an innovative strategy to simultaneously realize efficient remediation of PCS and sequential reuse of the post-remediation soil.

Comparative analysis of additive decomposition using one-dimensional and two-dimensional gas chromatography: Part II - Irgafos 168 and zinc stearate.

Plastic production has experienced a significant increase in the last sixty years due to its cost-efficiency and adaptable characteristics, leading to the extensive use of additives to improve its performance and longevity. Due to the high demand for plastic, plastic waste production has increased, contaminating the environment and living beings by leaching additives, among other substances. Pyrolysis stands out among recycling techniques because it can handle mixed polymer waste feedstock. However, understanding the pyrolyzates distribution of additives is fundamental to assessing pyrolysis process of plastic waste. This study investigated the pyrolysis product distributions of two commonly used antioxidants, namely, Irgafos 168 and zinc stearate (ZnSt), using one-dimensional gas chromatography equipped with a quadruple mass spectrometer (GC-MS) and two-dimensional gas chromatography coupled to flame ionization detector and time-of-flight mass spectrometer (GC×GC-FID/TOF-MS). While GC separation technique provided limited information on product distribution, GC×GC offered enhanced resolution and identification of the decomposition products. In the pyrolysis of Irgafos 168 at 550 °C, GC identified 18 products, while GC×GC identified 198 products, representing an increase of approximately 11-fold. Similarly, for ZnSt, GC identified 67 products, while GC×GC identified 434 products, representing a 6-fold increase. GC×GC identified decomposition products from 15 different chemical classes for Irgafos 168 and 16 chemical classes for ZnSt, compared to 4 and 11 chemical classes identified by GC, respectively. Phenols and their derivatives were the major chemical class in the decomposition products of Irgafos 168 with a yield of 9.51 wt.%. In contrast, olefinic products were the dominant ones for ZnSt, with a yield of 9.73 wt.%. The major decomposition product of Irgafos 168 and ZnSt was 2­tert­butyl­methylphenol (C11H16O) and C6 olefin (C6H12) with yields of 3.88 wt.%, and 1.13 wt.%, respectively. Utilizing the GC×GC separation method improved the ability to identify decomposition products, which can ultimately lead to a better understanding of antioxidant degradation that occurs during the pyrolysis process. GC×GC also provided thorough characterization of minor and co-eluted products along with major antioxidant degradation products. Additionally, the decomposition product distribution of Irgafos 168 and ZnSt was also compared with the primary antioxidants, Irganox 1010, Irganox 1076, and BHT, studied in part 1. The analysis indicated that the olefinic chemical class was the predominant one in Irganox 1010, Irganox 1076, and ZnSt, while ketones were the major chemical class in the decomposition of BHT and phenolics had the highest yield in Irgafos 168.

Enhanced biofuel production from Sacha Inchi wastes: Optimizing pyrolysis for higher yield and improved fuel properties.

Sacha inchi waste consists of residues (SR) and shells (SS) that are processed into liquid fuel using a traditional pyrolysis process. Pyrolysis was performed at a constant heating rate of 20 °C/min and nitrogen flow rate of 100 mL/min. Before the process took place, a preliminary TGA analysis was performed and the results revealed that the appropriate pyrolysis temperature and time allowed a variation of 250-450 °C and 10-50 min, respectively. The results showed that the pyrolysis oil yields of both SR and SS increased with increasing pyrolysis temperature and time. However, the pyrolysis oil yield of SR was significantly higher than that of SS because the main component of SR contains abundant carbon from saturated fatty acids. The ANOVA method shows that the SS model is more complex and examines more terms and interactions, whereas the SR model is simpler and focuses on fewer components, but still shows significant effects, especially through temperature. The nonsignificant p-value for time in the SR model suggests that time may not have the same influence as temperature on the dependent variable. The SS pyrolysis oil was consistent and resulted in a constant calorific value and flash point between 31.10 and 32.14 MJ/kg and 120 and 124 °C, respectively. However, decreasing the O/C atomic ratio of SR pyrolysis oil from 0.92 to 0.38 influenced the increasing calorific value from 36.66 to 38.75 MJ/kg, while the H/C atomic ratio of SR pyrolysis oil was close to 2.00. This suggests that its effectiveness maintains an alkene structure that can improve fuel efficiency. The molecular formulae of the SS pyrolysis oil were CH16N0.04O7 and that of SR pyrolysis oil was CH2.2N0.08O0.45.

Preparation of high quality carbon nanotubes by catalytic pyrolysis of waste plastics using FeNi-based catalyst.

Plastic waste pollution is the serious environmental problem, and catalytic pyrolysis of waste plastics is an effective way to solve this problem. Carbon nanotubes (CNTs) are prepared by catalytic pyrolysis of low-density polyethylene (LDPE) waste plastics by one-stage method using iron nitrate and nickel nitrate as catalyst. The growth mechanism of CNTs is analyzed in detail. TPO, XRD, SEM and Raman analyses show that increasing Ni content contributes to the production of CNTs with good morphology and high graphitization degree. While the increasing Fe content contributes to improving the yield of CNTs. The outer and inner diameters of the FeNi12-CNTs-800 are about 21 nm and 8 nm with the length of 18.9 µm, respectively. LDPE pyrolysis gases are analyzed to determine that the primary carbon source required for CNTs growth is C2H4. The C2H4 adsorption and decomposition processes on FeNi alloys are performed to reveal the growth mechanism of CNTs, based on density functional theory calculation. Three kinds of the growth models are proposed to explain the difference of the CNTs tubular shape. FeNi12-CNTs-800 are used to remove microplastics from wastewater due to existence of magnetic. PVC can be quickly removed from wastewater with removal of 100 % at 20 min. This study provides an effective way for recycling and treatment of waste plastic.

Study on the effect of conditioner on NOx precursor control behavior from sewage sludge pyrolysis: Focusing on conditioner assessments and in-situ fixation mechanism.

The nitrogen transformation during sludge pyrolysis is affected by the dewater conditioner. However, the comparative analysis of the conditioner under identical pyrolysis conditions has been previously absent. In this study, Ca-, Fe- and Al-based conditioners were selected as the representatives. A comprehensive evaluation considering the cost of the conditioners and the product characteristics was conducted. Additionally, the in-situ fixation mechanism of the conditioner on nitrogen-containing gas was concurrently revealed. Among the six conditioners, CaO and AlCl3 were identified as the top performers, ranking first and second, respectively. Furthermore, Fe/Ca-based conditioners reduced NH3 and HCN release by 1.5 âˆ¼ 5.53 % and 0 âˆ¼ 1.55 %, respectively, by facilitating the conversion of amine-N to a more stable form in condensable fraction. Fe promoted volatile amine-N cyclization, while Ca encouraged its dehydrogenation. Both Fe/Ca-based conditioners increased 7.5 âˆ¼ 14.8 % nitrogen retention in char, by inhibiting the decomposition of protein-N. Al-based conditioners had little effect on NH3 and HCN, but contributed to 2.3 âˆ¼ 2.8 % production of stabilized nitrogen in char. The introduction of Cl in Fe/Ca/Al chloride conditioners would promote the decomposition of inorganic ammonium salts to produce NH3 at 30 âˆ¼ 185 °C. And Cl also reacted with volatiles through electrophilic substitution reaction, leading to the formation of halogenated hydrocarbons in condensable fraction and the release of more NH3, HCN, and HNCO at 30 âˆ¼ 465 °C. The findings of this study provide a detailed comparative analysis of various conditioners under uniform conditions and reveal the in-situ fixation mechanism of nitrogen-containing gas. This will provide guidance for the sludge conditioning-dewatering-drying integrated treatment and disposal.

Effective waste management through Co-pyrolysis of EFB and tire waste: Mechanistic and synergism analysis.

Driven by the need for solutions to address the global issue of waste accumulation from human activities and industries, this study investigates the thermal behaviors of empty fruit bunch (EFB), tyre waste (TW), and their blends during co-pyrolysis, exploring a potential method to convert waste into useable products. The kinetics mechanism and thermodynamics properties of EFB and TW co-pyrolysis were analysed through thermogravimetric analysis (TGA). The rate of mass loss for the blend of EFB:TW at a 1:3 mass ratio shows an increase of around 20% due to synergism. However, the blend's average activation energy is higher (298.64 kJ/mol) when compared with single feedstock pyrolysis (EFB = 257.29 kJ/mol and TW = 252.92 kJ/mol). The combination of EFB:TW at a 3:1 ratio does not result in synergistic effects on mass loss. However, a lower activation energy is reported, indicating the decomposition process can be initiated at a lower energy requirement. The reaction model that best describes the pyrolysis of EFB, TW and their blends can be categorised into the diffusion and power model categories. An equal mixture of EFB and TW was the preferred combination for co-management because of the synergistic effect, which significantly impacts the co-pyrolysis process. The mass loss rate experiences an inhibitive effect at an earlier stage (320 °C), followed by a promotional impact at the later stage (380 °C). The activation energy needed for a balanced mixture is the least compared to all tested feedstocks, even lower than the pyrolysis of a single feedstock. The study revealed the potential for increasing decomposition rates using lower energy input through the co-pyrolysis of both feedstocks. These findings evidenced that co-pyrolysis is a promising waste management and valorisation pathway to deal with overwhelming waste accumulation. Future works can be conducted at a larger scale to affirm the feasibility of EFB and TW co-management.

Rapid humification of cotton stalk catalyzed by coal fly ash and its excellent cadmium passivation performance.

Due to industrialization, soil heavy metal pollution is a growing concern, with humic substances (HS) playing a pivotal role in soil passivation. To address the long duration of the compost humification problem, coal fly ash (CFA) in situ catalyzes the rapid pyrolysis of the cotton stalk (CS) to produce HS to address Cd passivation. Results indicate that the highest yield of humic acid (HA) (8.42%) and fulvic acid (FA) (1.36%) is obtained when the CS to CFA mass ratio is 1:0.5, at 275 ℃ for 120 min. Further study reveals that CFA catalysis CS humification, through the creation of alkaline pyrolysis conditions, Fe2O3 can stimulate the protein and the decomposition of hemicellulose in CS, and then, through the Maillard and Sugar-amine condensation reaction synthesis HA and FA. Applying HS-CS&CFA in Cd-contaminated soil demonstrates a 26.69% reduction in exchangeable Cd within 30 days by chemical complexation. Excellent maize growth effects and environmental benefits of HS products are the prerequisites for subsequent engineering applications. Similar industrial solid wastes, such as steel slag and red mud, rich in Fe2O3, can be explored to identify their catalytic humification effect. It could provide a novel and effective way for industrial solid wastes to be recycled for biomass humification and widely applied in remediating Cd-contaminated agricultural soil.

Assessing thermal hazards and toxicity of raw biomass particles from prevalent agricultural crops in China.

Fire and explosion hazards pose significant safety concerns in the processing and storage of biomass particles, warranting the safe utilization of these particles. This study employed scanning electron microscopy, thermogravimetric analysis, and cone calorimetry to investigate the thermal hazards and toxicity of raw biomass particles from four prevalent agricultural crops in China: rice, sorghum, corn, and reed. Among the samples, corn exhibited the highest heat output of 8006.82 J/g throughout the thermal decomposition process. The quantitative evaluation of critical heat flux, heat release rate intensity, fire growth rate index (FIGRA), post-ignition fire acceleration (PIFA) and flashover potential (X) revealed a substantial fire risk inherent to all the examined straw samples. Notably, corn displayed the lowest FIGRA value of 8.30 kW/m2 s, while rice demonstrated the minimum PIFA value of 16.11 kW/m2 s. Moreover, the X values for all four biomass particle types exceeded 10 under varying external heat flux levels, indicating their high propensity for fire hazards. Analysis of CO and CO2 emissions during combustion showed all four biomass samples exhibited high concentrations throughout, from the initial stages to the end. The present study offers crucial insights for formulating comprehensive fire safety guidelines tailored to the storage and processing of biomass particles.

Revealing the Effect of Electronic Configuration in Cux Species on CO2 Photoreduction Characteristic Products.

As of the present time, the in-depth study of the structure-activity relationship between electronic configuration and CO2 photoreduction performance is often overlooked. Herein, a series of Cux species modified CeO2 nanodots are constructed in situ by flame spray pyrolysis (FSP) to achieve an efficient photocatalytic CO2-to-C2 conversion with an electron utilization of up to 142.5 µmol g-1. Through an in-depth study of the electronic behavior and catalytic pathways, it is found that the Cu0/Cu+ species in the coexistence state of Cu0/Cu+/Cu2+ can optimize the energy band structure, photocurrent stability, and provide a kinetic basis for the active surface catalytic reaction process that requires the conversion of multiple electrons into C2 products, which ultimately enhances the CO2-to-C2H6 photoreduction by 3.8-fold and that for CO2-to-C2H4 photoreduction by 5.2-fold. Besides, the Cu2+ species in the coexistence state of Cu0/Cu+/Cu2+ are able to regulate the electronic behavior and the choice of the catalytic pathway, enabling the transitions between CO2-to-C2H6 and CO2-to-C2H4. This work indicates that electronic configuration optimization is an effective strategy to significantly enhance the CO2 photoreduction performance and provides new ideas for the design and synthesis of high-performance heterostructure photocatalysts.

Combination of co-pyrolyzed biomass-sludge biochar and ultrasound for persulfate activation in antibiotic degradation: efficiency, synergistic effect, and reaction mechanism.

A carbon material Cu-corn straw-sludge biochar (Cu-CSBC) was prepared by hydrothermally modifying sewage sludge and corn stover. The composite coupled to ultrasound can effectively catalyze the activation of PS for organic pollutants degradation, and the removal rate of 20 mg/L TC reached 89.15% in 5 min in the presence of 0.5 g/L Cu-CSBC and 3 mM PS. The synergistic effect between the factors in the system, the reaction mechanism, and the efficient removal of TC in the aqueous environment were explored in a Cu-CSBC/US/PS system established for that purpose. Quenching experiments and electron paramagnetic resonance analysis both demonstrated the Cu-CSBC/US/PS system generated •OH, SO4-•, 1O2, and O2- •, which involved in the reaction. The Cu, carboxyl, and hydroxyl groups on the Cu-CSBC surface promoted the generation of radicals and non-radicals for the degradation process, which was dominated by both radical and non-radical pathways. The degradation pathway is proposed by measuring the intermediate products with LC-MS. Finally, the stability of the Cu-CSBC/US/PS system was tested under various reaction conditions. This study not only prepared a novel biochar composite material for the active degradation of organic pollutants by PS but also provided an effective method for the resource utilization of solid waste and sludge treatment.

Toxicology of anhydroecgonine methyl ester: A systematic review of a cocaine pyrolysis product.

Anhydroecgonine Methyl Ester (AEME), also known as methylecgonidine, is the main pyrolysis product of smoking cocaine (cocaine base paste or basuco, crack, or freebase). This review aims to synthesize the available scientific evidence on the toxicokinetic and toxicodynamic effects of AEME. A search of scientific articles published in Science Direct, SCOPUS, and MEDLINE up to May 2024 was conducted. Twenty-four articles, including 13 experimental animal studies, 2 clinical trials, and 3 observational studies, were reviewed. AEME is readily deposited in the alveoli; its absorption improves in combination with cocaine and has a broad tissue distribution. It is metabolized primarily in the liver, with a half-life of approximately one hour, and is mainly excreted through urine. Moreover, AEME acts as a partial agonist of M1 and M3 muscarinic cholinergic receptors, influences dopaminergic system neuroadaptation, increases the production of reactive oxygen species, imbalances the activity of glutathione-associated enzymes, and reduces melatonin levels, affecting its antioxidant regulatory properties. When combined with cocaine, AEME activates the non-apoptotic pathway of caspase-9 and then, the apoptotic pathway via caspase-8, reducing neuronal viability in half the time of cocaine. AEME plays a significant role in cocaine toxicity and AEME itself.

Pyrolysis of metal oxides treated Canarium schweinfurthii Shell: Investigation of thermogravimetric kinetics and thermodynamics.

Metal oxides as catalysts alter the properties of the pyrolysis vapor secondary reactions during the thermal decomposition of several biomass leading to high-value bio-oils. This study aimed to investigate the thermal decomposition characteristics of Canarium Schweinfurthii (CS) shells that were treated with various metal oxides (ZnO, CuO, Fe2O3/FeO, and Fe2O3) using pyrolysis. The study also sought to identify pyrolysis reaction parameters (kinetics and thermodynamics parameters) that are not widely documented. Thermogravimetric pyrolysis was carried out at different heating rates, and the undocumented pyrolysis kinetic parameters were determined using the Flynn-Wall Ozawa method (FWO) according to American Standard Testing and Materials (ASTM) 6441 guidelines for assessing biomass decomposition. The metal oxide-treated CS shells lost significant weight between 62 and 67 wt% during the thermogravimetric pyrolysis, lower than 75 wt% of the CS shell. The average activation energies (Eα) for pyrolysis of the ZnO, CuO, Fe2O3/FeO, and Fe2O3 treated CS shells were 203.04, 155.35, 338.85, and 219.92 kJ/mol, respectively in contrast to that of the untreated CS-shell. The Bayesian Information Criteria revealed that the diffusion kinetics of the Gistling-Brounshtein model best describes the pyrolysis of the shell mixed with metal oxides. The metal oxides affected the CS shells' pyrolysis kinetic parameter (Eα), which can promote pyrolysis vapor upgrading to encourage the widespread use of metal oxides in pyrolysis for bioenergy and chemical recovery.

Biofilm mitigation in hybrid chemical-biological upcycling of waste polymers.

Introduction: Accumulation of plastic waste in the environment is a serious global issue. To deal with this, there is a need for improved and more efficient methods for plastic waste recycling. One approach is to depolymerize plastic using pyrolysis or chemical deconstruction followed by microbial-upcycling of the monomers into more valuable products. Microbial consortia may be able to increase stability in response to process perturbations and adapt to diverse carbon sources, but may be more likely to form biofilms that foul process equipment, increasing the challenge of harvesting the cell biomass. Methods: To better understand the relationship between bioprocess conditions, biofilm formation, and ecology within the bioreactor, in this study a previously-enriched microbial consortium (LS1_Calumet) was grown on (1) ammonium hydroxide-depolymerized polyethylene terephthalate (PET) monomers and (2) the pyrolysis products of polyethylene (PE) and polypropylene (PP). Bioreactor temperature, pH, agitation speed, and aeration were varied to determine the conditions that led to the highest production of planktonic biomass and minimal formation of biofilm. The community makeup and diversity in the planktonic and biofilm states were evaluated using 16S rRNA gene amplicon sequencing. Results: Results showed that there was very little microbial growth on the liquid product from pyrolysis under all fermentation conditions. When grown on the chemically-deconstructed PET the highest cell density (0.69 g/L) with minimal biofilm formation was produced at 30°C, pH 7, 100 rpm agitation, and 10 sL/hr airflow. Results from 16S rRNAsequencing showed that the planktonic phase had higher observed diversity than the biofilm, and that Rhodococcus, Paracoccus, and Chelatococcus were the most abundant genera for all process conditions. Biofilm formation by Rhodococcus sp. And Paracoccus sp. Isolates was typically lower than the full microbial community and varied based on the carbon source. Discussion: Ultimately, the results indicate that biofilm formation within the bioreactor can be significantly reduced by optimizing process conditions and using pure cultures or a less diverse community, while maintaining high biomass productivity. The results of this study provide insight into methods for upcycling plastic waste and how process conditions can be used to control the formation of biofilm in bioreactors.

Engineering of LiTaO3 Nanoparticles by Flame Spray Pyrolysis: Understanding In Situ Li-Incorporation into the Ta2O5 Lattice.

Lithium tantalate (LiTaO3) perovskite finds wide use in pyroelectric detectors, optical waveguides and piezoelectric transducers, stemming from its good mechanical and chemical stability and optical transparency. Herein, we present a method for synthesis of LiTaO3 nanoparticles using a scalable Flame Spray Pyrolysis (FSP) technology, that allows the formation of LiTaO3 nanomaterials in a single step. Raman, XRD and TEM studies allow for comprehension of the formation mechanism of the LiTaO3 nanophases, with particular emphasis on the penetration of Li atoms into the Ta-oxide lattice. We show that, control of the High-Temperature Particle Residence Time (HTPRT) in the FSP flame, is the key-parameter that allows successful penetration of the -otherwise amorphous- Li phase into the Ta2O5 nanophase. In this way, via control of the HTPRT in the FSP process, we synthesized a series of nanostructured LiTaO3 particles of varying phase composition from {amorphous Li/Ta2O5/LiTaO3} to {pure LiTaO3, 15-25 nm}. Finally, the photophysical activity of the FSP-made LiTaO3 was validated for photocatalytic H2 production from H2O. These data are discussed in conjunction with the role of the phase composition of the LiTaO3 nanoparticles. More generally, the present work allows a better understanding of the mechanism of ABO3 perovskite formation that requires the incorporation of two cations, A and B, into the nanolattice.

Atomically dispersed ternary FeCoNb active sites anchored on N-doped honeycomb-like mesoporous carbon for highly catalytic degradation of 4-nitrophenol.

In the last decades, 4-nitrophenol is regarded as one of highly toxic organic pollutants in industrial wastewater, which attracts great concern to earth sustainability. Herein, atomically dispersed ternary FeCoNb active sites were incorporated into nitrogen-doped honeycomb-like mesoporous carbon (termed FeCoNb/NHC) by a two-step pyrolysis strategy, whose morphology, structure and size were characterized by a set of techniques. Further, the catalytic activity and reusability of the as-prepared FeCoNb/NHC were rigorously examined by using 4-NP catalytic hydrogenation as a proof-of-concept model. The influence of the secondary pyrolysis temperature on the catalytic performance was investigated, combined by illuminating the catalytic mechanism. The resultant catalyst exhibited significantly enhanced catalytic features with a normalized rate constant (kapp) of 1.2 × 104 min-1g-1 and superior stability, surpassing the home-made catalysts in the control groups and earlier research. This study provides some constructive insights for preparation of high-efficiency and cost-effectiveness single-atom nanocatalysts in organic pollutants environmental remediation.

On the Role of Anions in Solid Catalysts with Ionic Liquid Layer (SCILL) for the Selective Hydrogenation of Highly Concentrated Acetylene Streams.

Electric plasma assisted pyrolysis of methane represents a highly promising greener alternative to produce ethylene from biogas and renewable energies compared to  conventional steam cracking of naphtha. The mediocre performance of typical Pd-Ag catalysts for the downstream purification of the substantially higher concentrated acetylene impurities (≥ 15 vol.-%) in those ethylene streams via selective hydrogenation is yet limiting economic interest. Following the concept of solid catalysts with ionic liquid layer  (SCILL), we have modified an intrinsically non-selective palladium catalyst with imidazolium based ionic liquids varying among 10 different anions and investigated them in this  reaction. The best performing [C4C1IM][MeSO4]-SCILL reaches an outstanding average ethylene selectivity over 20 h on-stream of 82% at full acetylene conversion without any sign of deactivation, clearly outperforming conventional Pd-Ag catalysts. By varying parameters like ionic liquid (IL) loading, temperature, feed gas composition, cations, and by using XPS for surface analysis we could gain a very comprehensive understanding of the underlying mechanisms that reduce the competing over-hydrogenation and oligomerisation side-reactions.

Biochar from Co-Pyrolyzed Municipal Sewage Sludge (MSS): Part 2: Biochar Characterization and Application in the Remediation of Heavy Metal-Contaminated Soils.

The disposal of municipal sewage sludge (MSS) from wastewater treatment plants poses a major environmental challenge due to the presence of inorganic and organic pollutants. Co-pyrolysis, in which MSS is thermally decomposed in combination with biomass feedstocks, has proven to be a promising method to immobilize inorganic pollutants, reduce the content of organic pollutants, reduce the toxicity of biochar and improve biochar's physical and chemical properties. This part of the review systematically examines the effects of various co-substrates on the physical and chemical properties of MSS biochar. This review also addresses the effects of the pyrolysis conditions (temperature and mixing ratio) on the content and stability of the emerging pollutants in biochar. Finally, this review summarizes the results of recent studies to provide an overview of the current status of the application of MSS biochar from pyrolysis and co-pyrolysis for the remediation of HM-contaminated soils. This includes consideration of the soil and heavy metal types, experimental conditions, and the efficiency of HM immobilization. This review provides a comprehensive analysis of the potential of MSS biochar for environmental sustainability and offers insights into future research directions for optimizing biochar applications in soil remediation.

Study on the Pyrolysis and Fire Extinguishing Performance of High-Temperature-Resistant Ultrafine Dry Powder Fire Extinguishing Agents for Aviation Applications.

Ultrafine KAl(OH)2CO3 dry powder (UDWP), as a novel high-temperature-resistant ultrafine dry powder fire extinguishing agent, has garnered significant attention in the field of aviation fire protection. However, its development has been hindered by its hydrophilicity, which leads to hygroscopicity, and its tendency for re-ignition due to oil deposition. Therefore, this study employs perfluorodecyltrimethoxysilane (PFDTMS) to modify the surface of UDWP, resulting in hydrophobic and oleophobic M-UDWP. The thermal stability and hydrophobicity of M-UDWP ensure its long-term stable storage in aircraft equipment compartments, thereby reducing aircraft maintenance costs. Additionally, its oleophobicity provides excellent anti-re-ignition performance, protecting aircraft power compartments from secondary fire damage. Energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analyses indicate that the PFDTMS modifier was successfully grafted onto KAl(OH)2CO3. Furthermore, M-UDWP exhibits a three-stage thermal decomposition process. The first-stage decomposition can be regarded as a single-step reaction, and the calculated kinetic parameters provide accurate predictions. Thermogravimetric analysis-Fourier transform infrared spectroscopy-mass spectrometry (TG-FTIR-MS) results reveal that M-UDWP significantly produces H2O and CO2 during thermal decomposition, which is one of its core fire extinguishing mechanisms. For the combustion of #RP-3 and #RP-5 aviation kerosene, commonly found in aircraft engine nacelles, the extinguishing times required by M-UDWP are 243 ms and 224 ms, respectively, with minimum extinguishing concentrations (MEC) of 25.9 g/m3 and 23.4 g/m3, respectively. The study of M-UDWP's thermal stability aids in understanding its storage stability under high-temperature conditions and its fire extinguishing mechanisms in fire zones. Moreover, the research findings suggest that M-UDWP has the potential to replace Halon 1301 in aircraft engine nacelles.

Demystifying In Situ Pyrolysis Chemistry for High-Performance Polyanionic Cathodes in Sodium-Ion Batteries.

The carbon coating strategy has emerged as an indispensable approach to improve the conductivity of polyanionic cathodes. However, owing to the complex reaction process between precursors of carbon and cathode, establishing a unified screening principle for carbonaceous precursors remains a technical challenge. Herein, we reveal that carbonaceous precursor pyrolysis chemistry undeniably influences the formation process and performance of Na3V2(PO4)3 (NVP) cathodes from in situ insights. By investigating three types of carbonaceous precursors, it is found that O/H-containing functional groups can provide more bonding sites for cathode precursors and generate a reducing atmosphere by pyrolysis, which is beneficial to the formation of polyanionic materials and a uniform carbon coating layer. Conversely, excessive pyrolysis of functional groups leads to a significant amount of gas, which is detrimental to the compactness of the carbon layer. Furthermore, the substantial presence of residual heteroatoms diminishes graphitization. In this case, it is demonstrated that carbon dots (CDs) precursors with suitable functional groups can comprehensively enhance the Na+ migration rate, reversibility, and interface stability of the cathode material. As a result, the NVP/CDs cathode displays outstanding capacity retention, maintaining 92% after 10,000 cycles at a high rate of 50 C. Altogether, these findings provide a valuable benchmark for carbon source selection for polyanionic cathodes.