Industrial-scale Applications Research Articles

Physicochemical Characteristics of Silicomanganese Slag as a Recycling Construction Material: An Overview

AbstractSilicomanganese (SiMn) slag is a by-product of ferromanganese and SiMn alloy production poses significant challenges in terms of environmentally sound disposal given its substantial volume. This brief review aims to assess the physicochemical attributes of SiMn slag and explore its potential applications in construction materials recycling. To accomplish this, we systematically evaluated 20 relevant articles, categorizing them into segments covering reutilization methods, key considerations, enhancement strategies, and the recent challenges and prospects associated with SiMn slag reutilization. Our analysis encompassed SiMn slags from five countries, revealing consistent chemical compositions characterized by SiO2, Al2O3, CaO, MnO, MgO, FeO + Fe2O3, and K2O + Na2O at similar proportions. We identified two distinct types of SiMn slag, i.e., air-cooled and water-quenched, each possessing unique physical properties influencing their suitability for reutilization. SiMn slag has been successfully repurposed into various construction materials, including cement paste, mortar, concrete, alkali-activated matrices, bricks, backfill materials, Mn extracts, and binder/cement. Several critical factors must be considered when reutilizing SiMn slag in construction materials, including cooling methods, moisture content, particle size (fineness), equipment, energy requirements, and cost considerations. To enhance the reutilization process, we propose a structured approach consisting of four key steps, i.e., incoming waste assessment, pre-treatment, physical/chemical treatment, and product development. Furthermore, this review suggests several avenues for future research, including the development of industrial-scale recycling applications, exploring environmentally friendly landfilling methods for SiMn slag, and assessing the practicality and feasibility of SiMn-slag-based products in real-world construction projects.

Hydrogen Sulfide Oxidizing Microbiome in Biogas-Stream Fed Biofilter in Palm Oil Factory

Hydrogen sulfide (H2S) is highly corrosive to electric generators, which is the main problem of biogas utilization. The industrial scale of the biofilter system relies on the performance of sulfide-oxidizing bacteria (SOB) via the activity of sulfur oxidation (soxABXYZ) and flavocytochrome sulfide dehydrogenase (fccAB) enzymes to reduce to a concentration below 100 ppm before using in industrial machinery. The main purpose of this research is to investigate the SOB community in full-scale H2S removal and their gene expression (fccAB and soxABXYZ) associated with H2S elimination efficiency. In this study, SOB communities were obtained from 2 sampling sites of the full-scale biofilter of palm oil factory (PPG), comprising starting sludge (PPG1) and recirculating sludge (PPG2). The abundance of SOB strains was examined by next-generation sequencing analysis (NGS) based on the 16S rRNA gene. The changes in the expression of genes involved in sulfur oxidation, namely soxABXYZ, and fccAB, between the 2 sampling sites were evaluated by using a comparative genomic hybridization (CGH) microarray. The results indicate that the high abundance of SOB genera that could play a vital role in biofilters belonged mainly to Sulfurovum, Paracoccus, Acidihalobacter, Acidithiobacillus, Thioalkalispira, Thiofaba, Caldisericum, Bacillus, were rapidly increased in the biofilter tank. Interestingly, expressions of soxAXYZ gene cluster at PPG2 were increased in Paracoccus pantotrophus J40 and Paracoccus alkenifer DSM 11593 for 1.1188 and 1.0518-fold, respectively, while in Acidihalobacter prosperus F5, the expression of fccAB genes was up to 1.3704 fold in comparison with PPG1. Increasing both relative abundance and gene expressions at PPG2 were correlated with 95% H2S removal efficiency. Hence, stabilization of the SOB microbiome is vital to H2S removal in industrial-scale biogas applications.

Surface Oxygen Defect Engineering of A2B2O7 Pyrochlore Semiconductors Boosts the Electrocatalytic Reduction of CO2-to-HCOOH.

The electrocatalytic conversion of inert CO2 to value-added chemical fuels powered by renewable energy is one of the benchmark approaches to address excessive carbon emissions and achieve carbon-neutral energy restructuring. However, the adsorption/activation of supersymmetric CO2 is facing insurmountable challenges that constrain its industrial-scale applications. Here, this theory-guided study confronts these challenges by leveraging the synergies of bimetallic sites and defect engineering, where pyrochlore-type semiconductor A2B2O7 is employed as research platform and the conversion of CO2-to-HCOOH as the model reaction. Specifically, defect engineering intensified greatly the chemisorption-induced CO2 polarization via the bimetallic coordination, thermodynamically beneficial to the HCOOH production via the *HCO2 intermediate. The optimal V-BSO-430 electrocatalyst with abundant surface oxygen vacancies achieved a superior HCOOH yield of 116.7mmol h-1 cm-2 at -1.2 VRHE, rivalling the incumbent similar reaction systems. Furthermore, the unique catalytic unit featured with a Bi1-Sn-Bi2 triangular structure, which is reconstructed by defect engineering, and altered the pathway of CO2 adsorption and activation to allow the preferential affinity of the suspended O atom in *HCO2 to H. As a result, V-BSO-430 gave an impressive FEHCOOH of 93% at -1.0 VRHE. This study held promises for inspiring the exploration of bimetallic materials from the massive semiconductor database.

Environmentally Friendly Coloration of Polyamide Fabrics with the Use of Natural Dyes: A Study Including Results of Industrial Scale Applications

In recent years, it is seen that there have been many publications on natural dyes in literature. In the studies carried out, one or more plants were taken and the color and fastness obtained with them in the presence of different mordants were examined. Beyond that, functionalities such as odor, antibacterial activity, and UV protection that natural dyes impart to the fabric were examined. However, the important thing that the literature needs is to represent also the results related to the industrial scale production since industry shows high interest to be able to use natural dyes. In this study, seven plant dyes have been used for the coloration of polyamide fabric. The studies have been conducted both on an industrial scale and at the laboratory scale. Based on the statistical analyses, four dyes with the highest color strength and fastness properties including catechu, madder, mulberry leaf, and pomegranate peel were selected for more studies on industrial scale. The results confirmed the good color strength and satisfactory fastness properties against repeated washing, rubbing, water, and perspiration for all selected dyes. The samples dyed with those dyes exhibited excellent protection against UV radiation. The results obtained in this study showed the potential of the selected natural dyes in eco-friendly industrial dyeing of nylon fabric with acceptable fastness properties.

Eight In. Wafer-Scale Epitaxial Monolayer MoS2.

Large-scale, high-quality, and uniform monolayer molybdenum disulfide(MoS2) films are crucial for their applications in next-generation electronics and optoelectronics. Epitaxy is a mainstream technique for achieving high-quality MoS2 films and is demonstrated at a wafer scale up to 4-in. In this study, the epitaxial growth of 8-in. wafer-scale highly oriented monolayer MoS2 on sapphire is reported as with excellent spatial homogeneity, using a specially designed vertical chemical vapor deposition (VCVD) system. Field effect transistors (FETs) based on the as-grown 8-in. wafer-scale monolayer MoS2 film are fabricated and exhibit high performances, with an average mobility and an on/off ratio of 53.5 cm2 V-1 s-1 and 107, respectively. In addition, batch fabrication of logic devices and 11-stage ring oscillators are also demonstrated, showcasing excellent electrical functions. This work may pave the way of MoS2 in practical industry-scale applications.

Pure-Water-Fed Forward-Bias Bipolar Membrane CO2 Electrolyzer.

Coupling renewable electricity to reduce carbon dioxide (CO2) electrochemically into carbon feedstocks offers a promising pathway to produce chemical fuels sustainably. While there has been success in developing materials and theory for CO2 reduction, the widespread deployment of CO2 electrolyzers has been hindered by challenges in the reactor design and operational stability due to CO2 crossover and (bi)carbonate salt precipitation. Herein, we design asymmetrical bipolar membranes assembled into a zero-gap CO2 electrolyzer fed with pure water, solving both challenges. By investigating and optimizing the anion-exchange-layer thickness, cathode differential pressure, and cell temperature, the forward-bias bipolar membrane CO2 electrolyzer achieves a CO faradic efficiency over 80% with a partial current density over 200 mA cm-2 at less than 3.0 V with negligible CO2 crossover. In addition, this electrolyzer achieves 0.61 and 2.1 mV h-1 decay rates at 150 and 300 mA cm-2 for 200 and 100 h, respectively. Postmortem analysis indicates that the deterioration of catalyst/polymer-electrolyte interfaces resulted from catalyst structural change, and ionomer degradation at reductive potential shows the decay mechanism. All these results point to the future research direction and show a promising pathway to deploy CO2 electrolyzers at scale for industrial applications.

Integral multi-valorization of agro-industrial wastes: A review

Agriculture and industries related to the agriculture sector generate a large amount of waste each year. These wastes are usually burned or dumped, causing damage to the environment, the economy and society. Due to their composition, they have great potential for obtaining high value-added products in biorefineries. This fact, added to the growing demand for energy and chemicals from fossil resources, is driving the interest of the scientific community in them.Biorefinery processes are hardly profitable when applied individually, so a better alternative is to develop integrated multi-feedstock and multi-product biorefinery schemes using all biomass fractions in a zero-waste approach. However, for industrial scale application, extensive research, scale-up studies, and techno-economic and environmental feasibility analyses are needed. This review compiles information on integrated multi-biorefinery processes from agro-industrial wastes to shed light on the path towards sustainable development and circular bioeconomy.

Unveiling the catalytic performance of unique core-fibrous shell silica-lanthanum oxide with different nickel loadings for dry reforming of methane

The dry reforming of methane (DRM) stands as a remarkable process for the conversion of methane and carbon dioxide into syngas (H2/CO). In this study, mesoporous fibrous silica lanthanum oxide-supported nickel catalysts (NSLF-x) with various nickel loadings (3 to 15 wt%) were efficiently fabricated using the microemulsion and impregnation approaches, respectively, to conduct DRM. The results obtained from FESEM and TEM revealed the presence of a unique core-fibrous shell-structured morphology of silica lanthanum oxide support (SLF). Furthermore, XRD and SEM-EDS analyses indicated that the structural integrity of SLF remained consistent regardless of the amount of Ni loading, while the size of NiO nanocrystalline varied with the quantity of Ni loading. Notably, H2-TPR analysis emphasized that the NSLF-15 catalyst exhibited the strongest metal-support interaction among the catalysts. Due to this reason, it exhibited outstanding catalytic activity and stability in terms of CO2 conversion (86.7 %), CH4 conversion (87 %), and a high H2/CO ratio at 750 °C, demonstrating high thermal stability after 28 h without any signs of deactivation. The superior catalytic performance of NSLF-15 catalysts, along with their ability to activate CH4 and CO2, can be attributed to the synergistic effects resulting from the enhanced physicochemical properties and the unique morphology. Additionally, the results from TEM, Raman, and TGA analyses also indicated the presence of non-filamentous carbon and filamentous carbons with accumulation of Ni species due to the elevated temperature of the reaction. Overall, the NSLF-15 catalysts hold significant potential for industrial-scale application for syngas formation.

Improved performance of Pseudomonas fluorescens lipase immobilized on a magnetic mesoporous solvothermal hybrid-nanocarrier and its application in ultrasonication assisted estolide synthesis

The exponential growth of the biotechnological market necessitates the exploring novel, economically viable materials for enzyme immobilization to enhance the biocatalyst performance. This study involves preparing a hybrid carrier with a magnetic mesoporous nature, using milled rice husk (MRH) and multi-walled carbon nanotubes (MWCNTs) via a one-pot solvothermal process at 200 °C for 6 h. The carrier, rich in-NH2 groups, was chemically bonded to Pseudomonas fluorescens lipase (PFL) using EDC/NHS cross-linkers. The synthesized support achieved a maximum PFL loading of 94.92 mg of protein per gram of support. Moreover, the maximum activity recovery was achieved at 1196 %, under the optimal conditions: immobilization temperature 25℃, pH 9.0, immobilization time 2 h and PFL mass concentration 4 mg/mL. Subsequently, the derived enzyme was used to catalyze ricinoleic acid esterification to synthesize estolide under ultrasound-assisted conditions. The optimized principal parameters for reaction temperature, reaction time, and immobilized lipase loading were respectively determined to be 48.99 °C, 1.60 h, and 3.09 % via response surface methodology. Ricinoleic acid conversion reached 65.23 % under the optimal conditions with the assistance of 40 % power and 40 kHz ultrasonic frequency. Furthermore, remarkable operational stability was also observed, with a retention rate of 49.28 %, even after 10 consecutive batches. This study demonstrates promising prospects for industrial-scale application using ultrasound as a fast and ecologically friendly procedure.

Large-Scale and Simple Synthesis of NiFe(OH)x Electrode Derived from Raney Ni Precursor for Efficient Alkaline Water Electrolyzer

Water electrolysis is a crucial technology in the production of hydrogen energy. Due to the escalating industrial demand for green hydrogen, the required electrode size for a traditional alkaline water electrolyzer has been increasing. Numerous studies have focused on developing highly active oxygen evolution reaction (OER) catalysts for water electrolysis. However, there remains a significant gap between the microscale synthesis of catalysts in laboratory settings and the macroscale preparation required for industrial scenarios. This challenge is particularly pronounced in the synthesis of sizable self-supported electrodes. In this work, we employed a commercially available Raney Ni-coated Ni mesh as a precursor material to fabricate a self-supported NiFe(OH)x@Raney Ni anode with a substantial dimension exceeding 300 mm through a straightforward immersion technique. The as-prepared electrode exhibited remarkable electrocatalytic OER activity, as an overpotential of only 240 mV is required to achieve 10 mA cm−2. This performance is comparable to that of NiFe-LDHs synthesized via a hydrothermal method, which is difficult to scale up for industrial applications. Furthermore, the electrode demonstrated exceptional durability, maintaining stable operation for over 100 h at a current density of 500 mA cm−2. The large-scale electrode displayed consistent overpotentials across various areas, indicating uniform catalytic activity. When integrated into an alkaline water electrolysis device, it delivered an average cell voltage of 1.80 V at 200 mA cm−2 and achieved a direct current hydrogen production energy consumption as low as 4.3 kWh/Nm3. These findings underline the suitability of electrodes for industrial scale applications, offering a promising alternative for energy-efficient hydrogen production.

Insight into Low-Temperature One-Step Biopreparation and Natural Dyeing of Cotton as an Environmentally Benign Route

The goal of this study is to present an environmentally benign route for cotton fabric and investigate the effect of different pretreatments in natural dyeing. In this context, conventional alkaline scouring, conventional hydrogen peroxide bleaching, low-temperature one-step biopreparation processes, namely enzymatic scouring (alkaline pectinase and alkaline pectinase-neutral cellulase combination) at 55 °C and enzyme-bleaching agent (hydrogen peroxide/sodium percarbonate/sodium perborate)-activator agent (TAED) combinations at 65 °C were applied to 100% cotton knitted fabric. The use of agricultural waste and eco-friendly mordants was preferred in natural dyeing. For this purpose, pretreated fabrics were dyed with the outer green shell of almond fruit extracts and a low amount of 0.4 g/L metal mordants (alum and iron(II) sulfate) in accordance with the simultaneous mordanting method. The dyeing properties of bio- and conventionally prepared cotton fabrics were examined in terms of colorimetric data (K/S, CIELa*b*C*h°) and wash fastness compared with water absorbency, whiteness, weight loss, pectin removal, and type of mordant. Excellent wash fastness values were achieved regardless of the type of pretreatment. Low-temperature one-step biopreparation can be a good substitute for conventional scouring and bleaching processes. Since different results can be achieved, it is essential to determine and evaluate all bioprocess conditions depending on the end-use characteristics of the textile (e.g. whether it will be white or dyed/printed, its color and lightness/darkness) at the laboratory and industrial scale applications.

Enhancing butanol separation efficiency in pervaporation with ZIF-8 porous liquid infused mixed matrix membranes

Separating butanol/water mixtures via distillation is notably energy-intensive and costly, highlighting the urgent need for more efficient alternatives. This study introduces a novel approach using mixed matrix membranes (MMMs) infused with Zeolitic Imidazolate Framework-8 (ZIF-8) transformed into its porous liquid (PL) form, aimed at enhancing the separation efficiency of butanol/water mixtures through pervaporation (PV). We selected ZIF-8 for its hydrophobic nature and high surface area, which are critical for improving both flux and selectivity in membrane-based separation processes. The study details the synthesis of ZIF-8-PL, its characterization through techniques such as Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM), and the fabrication of the MMMs. Our results demonstrate that ZIF-8-PL-based membranes at 55°C with a 30 wt% PL loading significantly enhance biobutanol-selective PV efficiency. Specifically, these membranes show an improvement in flux of approximately 102% and an increase in separation factor by 64% when compared to unmodified polydimethylsiloxane (PDMS) membranes. This significant enhancement highlights the effectiveness of PL-based fillers in advancing MMM performance for biofuel separation, providing a promising route to optimize energy efficiency and cost-effectiveness in industrial scale applications.

Decolorization and degradation of crystal violet dye by electron beam radiation: Performance, degradation pathways, and synergetic effect with peroxymonosulfate

Ionizing radiation (mainly including gamma ray and electron beam) technology provides a more efficient and ecological option for dye-containing wastewater treatment, which is supported by its successful achievements in industrial-scale applications. However, the degradation pathway of triphenylmethane dyes by radiation technology is still unclear. In this study, crystal violet (CV) was selected as representative cationic triphenylmethane dye, the decolorization and degradation performance by electron beam radiation technology was systematically evaluated. The results showed that CV can be efficiently decolorized and mineralized by radiation, and its degradation kinetics followed the first-order kinetic model. The effect of inorganic anions and chelating agents commonly existed in dye-containing wastewater on CV decolorization and total organic carbon (TOC) removal was explored. Quenching experiments, density functional theory (DFT) calculation and high performance liquid chromatography mass spectrometry (HPLC-MS) analysis were employed to reveal CV decolorization and degradation mechanism and pathway, which mainly included N-demethylation, triphenylmethane chromophore cleavage, ring-opening of aromatic products and further oxidation to carboxylic acid, and mineralization to CO2 and H2O. Additionally, electron beam radiation/PMS process was explored to decrease the absorbed dose required for decolorization and degradation, and the synergetic effect of radiation with PMS was elucidated. More importantly, the findings of this study would provide the support for treating actual dyeing wastewater by electron beam radiation technology.

Pilot-scale investigation of high-temperature thermochemical energy storage based on the material system CaO/Ca(OH)2 in a bubbling fluidized bed

Utilizing fluidized bed technology for thermochemical energy storage with CaO/Ca(OH)2 is promising for temperatures from 400 °C to 600 °C in industrial-scale applications. Much progress has been made on laboratory scale to develop this technology in recent years. Continuously changing material properties throughout storage cycles, mainly due to particle breakage, are identified to be challenging for scale-up. Transferability to large-scale systems needs to be examined.Investigations on a pilot scale (di = 257 mm, h = 600 mm, steam for fluidization, 700 °C, 6 barg) are done. A temperature-induced (456 °C discharging and 586 °C charging) and a pressure-induced (1.5 barg discharging and 3.5 barg charging) cyclization is performed. The applicability of standard scaling rules (scaling factor of 17) is possible. Fluidization regimes and breakage rates are transferrable. A detailed experimental characterization of the storage materials fluidization properties that are crucial for scale-up is done using a fluidization test rig (di = 140 mm, h = 658 mm, nitrogen for fluidization, ambient temperature and pressure).

Large-Scale Synthesis of Highly Porous CuO/Cu2O/Cu/Carbon Derived from Aerogels for Lithium-Ion Battery Anodes.

In this work, an effective strategy for the large-scale fabrication of highly porous CuO/Cu2O/Cu/carbon (P-Cu-C) has been established. Cu-cross-linked aerogels were first continuously prepared using a continuous flow mode to form uniform beads, which were transformed into P-Cu-C with a subsequent pyrolysis process. Various pyrolysis temperatures were used to form a series of P-Cu-C including P-Cu-C-250, P-Cu-C-200, P-Cu-C-350, and P-Cu-C-450 to investigate suitable pyrolysis conversion processes. The obtained P-Cu-C series were utilized as anodes of lithium-ion batteries, in which P-Cu-C-250 exhibited a higher reversible gravimetric capacity, excellent rate capability, and superior cycle stability. The enhanced behavior of P-Cu-C-250 was benefitted from the synergistic interaction between uniformly dispersed CuO, Cu2O, Cu nanoparticles, and highly graphitized carbon with a large surface area and highly porous structure. More importantly, the preparation of P-Cu-C-250 could be scaled up by taking advantage of the continuous flow synthesis mode, which may provide pilot- or industrial-scale applications. The large-scale fabrication proposed here may give a universal method to fabricate highly porous metal oxide-carbon anode materials for electrochemical energy conversion and storage applications. Porous CuO/Cu2O/Cu/carbon derived from Cu-crosslinked aerogels was used as Li-ion battery anode materials, exhibiting a high reversible areal capacity, large gravimetric capacity, superior cycling performance, and excellent rate capacity. A continuous preparation method is established to ensure the product scaled up.

On the use of WO42− as a third component to Co–Mo ionic activator for HER in alkaline water electrolysis

This study investigates the impact of Co–Mo–W ionic activators on the hydrogen evolution reaction (HER) in alkaline electrolysis, comparing their performance to Co–Mo and Co–W systems. The research focuses on analyzing the catalytic efficiency of these activators under varying conditions, including temperature and current density variations. Key findings reveal that the Co–Mo–W activator enhances HER performance, with a significant 17% reduction in energy consumption compared to plain electrolyte, mirroring the efficiency of Co–Mo. Tafel analysis gave the insight of the reaction mechanism for HER for all activators, with Co–Mo–W exhibiting a lower Tafel slope, suggesting improved catalytic activity. Structural and morphological analysis of electrode coatings shows a highly developed surface for Co–Mo–W, with a roughness factor similar to or slightly lower than the most developed Co–Mo coating. The study concludes that the synergistic combination of Co, Mo, and W in a tri-component ionic activator offers a promising catalytic activity for HER, outperforming bi-component systems and presenting significant potential for industrial-scale alkaline water electrolysis applications.

Enhancing soy protein isolate gels: Combined control of pH and surface charge for improved structural integrity and gel strength

The application of sophisticated technologies to enhance soy protein isolate (SPI) gelation in the industry faces limitations due to high costs and technical intricacies. This investigation examined how different combinations of pH pretreatment and NaCl concentration affect the gel properties of SPI. Decreasing pH and increasing NaCl concentration caused soy protein particle sizes to increase in the solution due to reduced electrostatic repulsion. Additionally, decreasing pH and increasing NaCl concentration reduced the absolute zeta potential, promoting particle collisions and aggregation in SPI solutions and influencing gel strength. Rheological studies showed that lowering pH levels decreased gelation temperatures and increased gel strength. However, extreme pH levels compromised gel integrity, impacting water-holding capacity and microstructure. Supplementing SPI pretreated at pH 6.0 with 100 mM NaCl notably boosted the gel strength compared to other pretreatment methods. Further solvent analyses revealed that interactions governing gel strength-hydrogen bonding and hydrophobic interactions emerged as crucial contributors. This comprehensive investigation sheds light on the intricate interplay of factors influencing SPI gel formation, providing crucial insights for future industrial-scale applications.

Investigating the impact of alkaline activator on the sustainability potential of geopolymer and alternative hybrid materials

Geopolymer binders are considered highly sustainable due to their utilization of industrial wastes. However, previous studies highlight the limited industrial-scale applications of geopolymers. Therefore, this study critically investigates the strength, cost, and environmental impact of geopolymers and alternative hybrid cement mixes to provide a complete picture for the sustainability analysis. Geopolymers and hybrid cement mixes are designed with varying proportions of alkaline activator (sodium hydroxide 5–25 wt%) and ordinary Portland cement (OPC) (15–35 wt%) respectively for the comparative analysis. The strength characteristics of designed mixes have been assessed by analyzing their compressive strength and microstructure. A comparative economic assessment has been made by contemplating the manufacturing and production costs of different materials used in geopolymer and hybrid cement mixes. ReCiPe Midpoint Life cycle assessment (LCA) has been performed to examine the environmental performance by considering the manufacturing and production processes of various binder and aggregate materials used in geopolymer and hybrid cement mixes. Mechanical and microstructural analysis shows that hybrid cement mix with 35 wt% of OPC yields the highest strength due to the formation of excess calcium aluminum silicate hydrate (C-A-S-H) and calcium silicate hydrate (C–S–H) gels than geopolymer mix containing 25 wt% of NaOH. Economic and life cycle assessment reveals that the geopolymer mix with 5 wt% NaOH offers the lowest cost and environmental impact as compared to others containing higher proportions of alkaline activator and OPC. Owing to the conflicting nature of the results, multi-criteria decision making approach has been used which presents the hybrid cement mix (with 35 wt% OPC) as the optimal and sustainable solution for the construction applications. The study's findings offer a sustainable direction for the construction industry by suggesting the application of hybrid concretes.

Numerical simulation of cavitation-vortex interaction mechanism in an advanced rotational hydrodynamic cavitation reactor

Hydrodynamic cavitation (HC), a promising technology for enhancing processes, has shown distinct effectiveness and versatility in various chemical and environmental applications. The recently developed advanced rotational hydrodynamic cavitation reactors (ARHCRs), employing cavitation generation units (CGUs) to induce cavitation, have demonstrated greater suitability for industrial-scale applications than conventional devices. However, the intricate interplay between vortex and cavitation, along with its spatial-temporal evolution in the complex flow field of ARHCRs, remains inadequately elucidated. This study investigated the interaction mechanism between cavitation and vortex in a representative interaction-type ARHCR for the first time using the “simplified flow field strategy” and the Q-criterion. The findings reveal that the flow instability caused by CGUs leads to intricate helical and vortex flows, subsequently giving rise to both sheet and vortex cavitation. Subsequently, utilizing the Q-criterion, the vortex structures are identified to be concentrated inside and at CGU edges with evolution process of mergence and separation. These vortex structures directly influence the shape and dimensions of cavities, establishing a complex interaction with cavitation. Lastly, the vorticity transport equation analysis uncovered that the stretching and dilatation terms dominate the vorticity transport process. Simultaneously, the baroclinic term focuses on the vapor-liquid interface, characterized by significant alterations in density and pressure gradients. These findings contribute to a better comprehension of the cavitation-vortex interaction in ARHCRs.

Rare Earth Extraction from Phosphogypsum by Aspergillus niger Culture Broth.

The extraction of rare earth elements (REEs) from phosphogypsum (PG) is of great significance for the effective utilization of rare earth resources and enhancing the resource value of PG waste residues. This study used Aspergillus niger (A. niger) fungal culture filtrate as a leaching agent to investigate the behavior of extracting REEs from PG through direct and indirect contact methods. According to the ICP-MS results, direct leaching at a temperature of 30 °C, shaking speed of 150 rpm, and a solid-liquid ratio of 2:1, achieved an extraction rate of 74% for REEs, with the main elements being yttrium (Y), lanthanum (La), cerium (Ce), and neodymium (Nd). Under the same conditions, the extraction rate of REEs from phosphogypsum using an A. niger culture filtrate was 63.3% higher than that using the simulated organic acid-mixed solution prepared with the main organic acid components in the A. niger leachate. Moreover, the morphological changes observed in A. niger before and after leaching further suggest the direct involvement of A. niger's metabolic process in the extraction of REEs. When compared to using organic acids, A. niger culture filtrate exhibits higher leaching efficiency for extracting REEs from PG. Additionally, using A. niger culture filtrate is a more environmentally friendly method with the potential for industrial-scale applications than using inorganic acids for the leaching of REEs from PG.