Extraction Of Residues Research Articles

Evaluation of Different Pectic Materials Coming from Citrus Residues in the Production of Films.

This article explores the use of citrus residues as a source of different pectic materials for packaging film production: a water-soluble orange residue extract (WSE) (~5% pectin), semi-pure pectins extracted in citric acid (SP) (~50% pectin), and commercial pure citrus pectins (CP). First, these materials were characterized in terms of chemical composition. Then, films were produced using them pure or mixed with chitosan or glycerol through solvent-casting. Finally, antioxidant activity, functional properties (e.g., mechanical and gas barrier properties), and visual appearance of the films were assessed. WSE films showed the highest antioxidant activity but the lowest mechanical strength with the highest elongation at break (EB) (54%); incorporating chitosan increased the films' strength (Young's modulus 35.5 times higher). SP films showed intermediate mechanical properties, reinforced by chitosan addition (Young's modulus 4.7 times higher); they showed an outstanding dry O2 barrier. CP films showed a similar O2 barrier to SP films and had the highest Young's modulus (~29 MPa), but their brittleness required glycerol for improved pliability, and chitosan addition compromised their surface regularity. Overall, the type of pectic material determined the film's properties, with less-refined pectins offering just as many benefits as pure commercial ones.

Enhanced anaerobic digestion of prairie biomass through alkaline-based hydroxycinnamic acid extraction

This study explores the hydroxycinnamic acid extraction from prairie biomass as a potential value-added pretreatment for enhancing the performance of anaerobic digestion. Pretreatment increased the biomethane potential of prairie biomass by 33 %; when the extraction residue was left on the biomass, the biomethane potential increased by 100 %. When the treated biomass was co-digested with manure, a 134 % and 25 % increase in methane productivity and methane content was obtained, respectively, relative to raw biomass co-digested with manure. Hydroxycinnamic acid extraction also improved anaerobic digestion performance under biochar supplementation and liquid digestate recirculation conditions. Lastly, the extraction process was optimized for hydroxycinnamic acid yield. It was found that increases in treatment temperature and time could further increase yield by 5 %. Collectively, the results show hydroxycinnamic acid extraction can be used as a highly effective pretreatment for improving the anaerobic digestion of prairie biomass.

Glyphosate contamination: implications for honeybee Apis mellifera and consumers in Southeastern Mexico

In a study conducted from June 2021 to May 2022 in two apiaries in southeastern Mexico, levels of glyphosate residues in pollen collected by bee Apis mellifera were analyzed to assess potential risks to both bees and humans. The analysis used an immunoassay method after residue extraction using the QUECHERS method. The results revealed the presence of glyphosate in all samples, with concentrations ranging between 3.71 and 7.29 μg/kg. However, risk analysis, as indicated by the pollen hazard quotient, suggested that these quantities did not pose a serious threat to bees or humans. The levels were within acceptable limits of the acceptable daily intake (ADI), acute reference dose (ARfD) and acceptable operator exposure level (AOEL). In conclusion, although this study did not find any significant association between glyphosate and potential risks for both humans and bees, its persistence in the environment is demonstrated. Glyphosate levels at the study site were low, suggesting minimal risk to both species. However, the wide distribution of glyphosato in the region makes it necessary to emphasize long-term studies to understand the possible chronic effects of the pesticide on all species in the area.

Research on identification and generative mechanism of heteroatom-containing organic compounds from sequential thermal dissolution of extraction residue from Piliqing subbituminous coal

Sequential thermal dissolution (STD) was commonly used to convert coal into high yield of soluble portions, but the generative mechanism of heteroatom-containing organic compounds (HACOCs) from STD was rarely reported. In this work, extraction residue (ER) from Piliqing subbituminous coal (PSBC) was sequentially thermal dissolved in n-hexane, toluene, methanol, and ethanol at 320 °C, and the obtained soluble portions (SPs) of ER (denote as SP1–4) were analyzed by multiple analytical techniques. Gas chromatograph/mass spectrometer (GC/MS) analysis shows that arenes and arenols are the main group components (GCⅠs) in SP1–3, while the most abundant GCⅠ in SP4 is esters. Through a quadrupole exactive orbitrap MS (QEOTMS) with the atmospheric pressure chemical ion source, O0 and O2 species are mainly contained in SP4. The RC of CH species detected in O0 species is the highest, followed by N3 species. However, according to a QEOTMS with electrospray ion source, the RC of O0 species is predominant in SP4, followed by the O3 species. N1 species are the most abundant in O0 species, followed by CH species. By further comparing with the effect of two ion sources on distribution of DBE of O0–6 species in SP4, thiophenes are connected to the large skeleton structure in coal through >C*-O-, and CH3CH2O attacks the >C*-O-, causing it to fracture, then the ethyl transfers to the O atom in >C*-O-, generating alkyl substituted thiophenes.

Characterization of Functional Ingredients Extracted with Ethanol Solvents from Ponkan (Citrus reticulata) By-Products Using the Microwave Vacuum Drying Method Combined with Ultrasound-Assisted Extraction.

For this study, microwave vacuum drying (MVD) was combined with ultrasound-assisted extraction to compare the effects of different ethanol volumes on ponkan extract and to evaluate the total phenolic content (TPC), total flavonoid content (TFC), and total ascorbic acid content (TAAC). High-performance liquid chromatography with photodiode array detection (HPLC-PDA) was used to analyze the flavanone contents and antioxidant activity of ponkan (Citrus reticulata) peels. The experimental results showed that the TPC and TFC increase with ethanol volume. Ethanol extraction (75%) showed significant advantages by increasing the TPC to 17.48 mg GAE/g (DW) and the TFC to 2.96 mg QE/g (DW) of ponkan extract and also exhibited the highest antioxidant activity. The TAAC improved along with increased water content. Water extraction showed the highest content (13.07 mg VitC/100 g, DW). The hesperidin content analyzed by HPLC-PDA was 102.95-622.57 mg/100 g (DW), which was the highest among the flavanones. Then, the ethanol insoluble residue extracts were taken from the pectin with four different solvents, evaluating TPC, TFC, and antioxidant activity. The TPC, TFC, and antioxidant capacity of pectin are significantly lower than those of the peels. Combining MVD and 75% ethanol with ultrasound-assisted extraction in the pre-treatment process can effectively eliminate polyphenols, flavonoids, and other compounds, thus enabling the extraction of high-methoxyl pectin. The total dietary fiber (TDF) content of MVD ponkan by-products was 25.83%. Ponkan by-products have the potential for the future development of functional foods and supplements.

RADDA-Net: Residual attention-based dual discriminator adversarial network for surface defect detection

Surface defect detection is a critical yet challenging task in the product production process, mainly because of the complex background texture on the material surface, the large intra-class defect differences, and the weak texture defect regions. To address this problem, a Residual Attention-based Dual Discriminator Adversarial Network (RADDA-Net) is developed to accurately detect various types of texture defect regions. Specifically, a residual network-based feature extraction module integrating multi-channel attention mechanism and multi-scale convolutional layers is designed to improve the detection ability of abnormal defects. Besides, to deeply excavate material surface texture information, the pixel attention-based up-sampling blocks are also incorporated into RADDA-Net to enhance the extraction of shallow features. To further improve the detection performance of RADDA-Net, a dual discriminant adversarial training strategy and a comprehensive measurement method are introduced to assist the developed network to identify defects from both macroscopic structure and microscopic edges. Finally, the six evaluation indexes of our proposed method outperformed other state-of-the-art methods on the four defect datasets, among which the highest detection precision, recall, and F-measure are 0.926, 0.916, 0.920, respectively. Therefore, the experimental results consistently verify the detection accuracy and effectiveness of RADDA-Net.

Machining quality prediction of multi-feature parts using integrated multi-source domain dynamic adaptive transfer learning

Machining quality prediction of multi-feature parts has been a challenging problem because of small dataset and inconsistent quality data distribution with respect to each machining feature. Transfer learning that leverages knowledge of one task and can be repurposed on another task seems a good solution for this purpose. However, traditional transfer learning typically has a single source domain and a target domain, which limits its applications in multi-source scenarios (e.g., multi-feature). To solve this issue, this paper proposes a novel integrated multi-source domain dynamic adaptive transfer learning (IMD-DATL) framework for machining quality prediction of multi-feature part machining systems. Specifically, a domain-sample similarity double matching multi-source domain integration method is designed to construct the integration knowledge transfer from multiple source domains to the target domain. A residual feature extraction network based on sample entropy-dynamic channel double-layer attention structure and a fine-grained transferable feature attention module are designed. These three attentions are used to improve the feature learning ability and the adaptation level to the predicted object in the three dimensions of sample, channel and data feature. Finally, multiple sets of comparative experiments in thin-walled part machining systems confirm the effectiveness and superiority of the proposed method for cross-domain quality prediction. Compared with other traditional transfer learning methods, the MAE, RMSE and Score on average of this method are increased by 5.47 %, 4.59 % and 4.84 %, respectively, compared with other multi-source domain adaptation methods, the MAE, RMSE and Score on average of this method are increased by 7.13 %, 7.37 % and 6.52 %, respectively.

The Role of Latent Heat Buffering in the Generation of High-Silica Rhyolites

Abstract The physical process of crystal-melt separation is responsible for the accumulation of small to very large volumes (>100 km3) of eruptible rhyolitic melt in the shallow crust. Granitic intrusions, although providing a terminal, time-integrated image of melt segregation processes, host an unmatched record of the physical properties controlling mechanisms and rates of interstitial melt extraction from a crystal-rich source. We applied mass balance calculations and thermodynamic modeling simulations to an extensive bulk rock geochemistry dataset (>150 samples) collected in a Permian upper-crustal granitoid intrusion of the Italian Southern Alps. Textural and geochemical evidence indicate that this intrusion constituted a single, zoned magma body, with a crystal-rich base and a thick (~2 km), high-silica cap (75–77 wt% SiO₂). The large compositional variability of the crystal-rich materials suggests variable degrees of melt extraction efficiency and corresponding terminal porosities. Specifically, the loosely bimodal distribution of porosity values (φ) indicates that at least two distinct melt segregation mechanisms were operating in this system, which produced both high (0.65–0.45) and low terminal porosities (0.45–0.25) in the crystal-rich, cumulate materials. Modeling of latent heat budget shows that coexistence of cumulate products with differing terminal porosity signature can be explained by melt segregation processes taking place at different depths across a thick, interconnected magmatic reservoir with an initial homogenous water content (~4 wt% H2O). Deep in the mush column, low water activities (aH₂O < 0.5) promoted thermal buffering of cooling magma at high crystallinities, enabling residual melt extraction by percolation through a crystalline framework accompanied by compaction. Instead, at shallower depths, high water activities (aH₂O > 0.5) ensured prolonged magma residence at porosities that promoted crystal melt separation via hindered settling. Distinct melt extraction processes, acting synchronously but at different depths in vertically extensive silicic mush columns, can account for the large volumes of residual, haplogranitic melt mobilized during the relatively short lifespan of upper crustal magma reservoirs (~105 years).

Unraveling the structural aspects of microwave-assisted OrganoCat-based coconut shell lignins: An eco-friendly route for obtaining bio-based antioxidants

New routes for biomass valorization have been developing by the scientific community. The aim of this work was developing a novel OrganoCat-based protocol and deeply understand the structure of the obtained lignins. Microwave-assisted OrganoCat-based process was performed using a biphasic system (ethyl acetate and oxalic acid or HCl) at mild conditions. OrganoCat-based lignins (OCLs) were characterized by compositional analysis, FTIR, 1H, 13C, 1H13C HSQC, 31P NMR, TGA and GPC. The solubility of OCLs in different organic solvents and their antioxidant capacity against DPPH were investigated. The spectroscopic analyses showed that OCLs have high residual extractives and the lignin motifs were preserved. OCLs have presented lower thermal stability than MWL, but showed great antioxidant activities and high solubility in a wide range of organic solvents. A novel biorefinery protocol yielded coconut shell lignins with peculiar structural and compositional features and several technological applications through an eco-friendly, sustainable and relatively low-cost biphasic pulping process.

Characteristics and mechanism of Ni2+ and Cd2+ adsorption by recovered perlite from agar extraction residue

Ni2+ and Cd2+ in wastewater accumulated through the ecological chain and could jeopardize human health. Adsorption of Ni2+ and Cd2+ from wastewater using recovered perlite was an important way to solve the problem of resource utilization of solid waste from agar production. Our previous study confirmed that recovered perlite from agar extraction residue had better pore size and specific surface area than commercial perlite. However, the adsorption efficiency and adsorption mechanism of recovered perlite were the main factors limiting its adsorption application. The adsorption process of Ni2+ and Cd2+ by recovered perlite in aqueous solution was described by the pseudo-second-order kinetic equation, and the relevant adsorption mechanism was mainly chemisorption. Compared with commercial perlite, the adsorption removal rate of Ni2+ and Cd2+ by enzymatic recovered perlite could reach 92.9% and 89.2%, respectively, and were improved by 12.63% and 13.03%. Langmuir isothermal adsorption model could better describe isothermal adsorption process of recovered perlite on heavy metal Ni2+ and Cd2+, and the relevant adsorption mechanism was mainly monolayer adsorption. The XPS results indicated that the decrease of Si-O Si2+ hydroxyl coordination bond and the increase of C-Si bond might make the binding effect of recovered perlite with heavy metals stronger. The competitive adsorption of Ni2+ and Cd2+ by recovered perlite was still dominated by chemisorption and monolayer adsorption. This study was expected to provide theoretical basis and technical support for the removal of Ni2+ and Cd2+ from wastewater using recovered perlite from seaweed residue.

Re-processing of pharmaceutical herb residues using isolated probiotics from plant sources and their beneficial effects on diarrhea

This study aims to use hot aqueous extract of herbal residue (HRE) to enhance bacterial growth and possess anti-diarrheal effects. In this study, lactobacillus species L. brevis (SAM-1), Lactobacillus plantarum (SAM-2), and Lactobacillus herbinensis (SAM-3) were isolated from date palm sap (collected in winter season). Square Pharmaceuticals PLC, Bangladesh provided herbal residues ‘Adovas’ which is non-sedating herbal cough syrup with sixteen common herbs including Adhatoda vasica. In our observation, HRE increased the number of colonies in MRS media. In the anti-diarrheal study by castor oil and magnesium sulphate-induced diarrheal mouse model, SAM-1 and 2 with or without HRE showed almost similar results. After initial morphological characterization, tests such as resistance to low pH, bile salt and survival capability in gastric simulated fluid (GSF) were performed to confirm them as a probiotic candidate. All three isolates were gram-positive bacteria and could grow in a mesophilic range of temperatures. The isolates were catalase-negative and were able to coagulate milk after overnight incubation. As the isolates exhibited resistance to low pH and could tolerate bile salts, they may survive in the stomach and intestine, thus making them a promising probiotic candidate. The isolated probiotics and HRE inhibited diarrheal and restored the body's electrolytes. Interestingly, SAM-2 showed higher efficacy than the standard drug (Loperamide), while SAM-1 showed a similar effect and SAM-3, had less effect than Loperamide. The findings suggest that probiotics and herbal residue could contribute to diarrhoeal disease prevention, which might be an alternative to a synthetic standard drug (Loperamide).

Comprehensive reutilization of Glycyrrhiza uralensis residue by extrusion-biological pretreatment for coproduction of flavonoids, cellulase, and ethanol

A continuous chemical-free green approach was investigated for the comprehensive reutilization of all components in herbal extraction residues (HERs), taking Glycyrrhiza uralensis residue (GUR) as an example. The GUR structural changes induced by mechanical extrusion which improve the specific surface area and enzyme accessibility of GUR. With 3 % pretreated GUR loading of high-tolerance Penicillium oxalicum G2. The reducing sugar yield of 11.45 g/L was achieved, along with an 81.06 % in situ enzymatic hydrolysis. Finally, 8.23 g/L bioethanol (0.40 g/g total sugar) was produced from GUR hydrolysates after 24 h fermentation of Pichia stipitis G32. The amount of functional medicinal ingredients extracted from GUR after hydrolysis (39.63 mg/g) was 37.69 % greater than that of un-pretreated GUR. In total, 1.49 g flavonoids, 294.36 U cellulase, and 14.13 g ethanol could be produced from 100 g GUR using this process, illustrating that this green and efficient process has the potential for industrial production.

Antibiotics in eggs: An analytical approach based on low- and high-resolution mass spectrometry techniques

Residues of antibiotics applied in chicken husbandry can be found in eggs for human consumption. To prevent this issue and avoid adverse effects on consumers' health, such as allergies and antimicrobial resistance (AMR), maximum residue limits (LMR) have been established by the European Commission. The aim of this study was to develop a method to extract, detect and quantify antibiotics in eggs, using UHPLC-TOF-MS for semi-quantitative screening and UHPLC-QTRAP-MS/MS for quantitative confirmation, following the performance criteria established by Commission Regulation (EU) Nº 2021/808 for analytical method validation. Different extraction methods were analyzed, with liquid-liquid extraction (LLE) based on acetonitrile (ACN) and ethylenediaminetetraacetic acid (EDTA), proving to be the most efficient method for extraction of antibiotic residues from eggs. UHPLC-TOF-MS and UHPLC-QTRAP-MS/MS were validated for 46 compounds, including penicillin, cephalosporins, tetracyclines, quinolones, macrolides, sulfonamides, and other antibiotics. After validation, robustness of both methods was evaluated by analyzing ten egg samples from backyard production and supermarkets. Erythromycin residues were detected in two eggs from backyard production; residues of up to seven antibiotics were detected in two samples of supermarket eggs. Nonetheless, all positive samples were below the established MRL. The developed methods will be a useful tool to monitor possible contamination in eggs, as they allow the simultaneous detection of several molecules. Furthermore, this methodology can be optimized to reduce the relative matrix effect, extended to a larger group of molecules, include other types of drugs, and be validated for other matrices of animal origin.

Ultrasonic-assisted extraction of total flavonoids from Zanthoxylum bungeanum residue and their allelopathic mechanism on Microcystis aeruginosa

Water eutrophication has emerged as a pressing concern for massive algal blooms, and these harmful blooms can potentially generate harmful toxins, which can detrimentally impact the aquatic environment and human health. Consequently, it is imperative to identify a safe and efficient approach to combat algal blooms to safeguard the ecological safety of water. This study aimed to investigate the procedure for extracting total flavonoids from Z. bungeanum residue and assess its antioxidant properties. The most favorable parameters for extracting total flavonoids from Z. bungeanum residue were a liquid–solid ratio (LSR) of 20 mL/g, a solvent concentration of 60%, an extraction period of 55 min, and an ultrasonic temperature of 80 °C. Meanwhile, the photosynthetic inhibitory mechanism of Z. bungeanum residue extracts against M. aeruginosa was assessed with a particular focus on the concentration-dependent toxicity effect. Z. bungeanum residue extracts damaged the oxygen-evolving complex structure, influenced energy capture and distribution, and inhibited the electron transport of PSII in M. aeruginosa. Furthermore, the enhanced capacity for ROS detoxification enables treated cells to sustain their photosynthetic activity. The findings of this study hold considerable relevance for the ecological management community and offer potential avenues for the practical utilization of resources in controlling algal blooms.

Antibacterial Activitiy of Triterpeniod Compounds

The goal of the study was to ascertain whether particular pathogenic bacteria could be inhibited by triterpeniod substances obtained from Rosmarinus officinalis (rosemary) extracts. The time frame for completing this construction was July 2023–April 2024. At the beginning, 100 specimens were taken from patients who were undergoing treatment at the Burn Cure Center in Nineveh Governorate, Iraq Routine biochemical testing were used to determine burn infections caused by bacteria, and the Vitek2 compact system was used to confirm the diagnosis. Acinetobacter baumani and Pseudomonas auroginosa were the most common isolates. In order to extract the substance, rosemary (R. officinalis) leaves were air-dried in the shade and then processed into a fine powder using a grinding machine. A soxhlet device was used to extract 50 g of powdered leaves for six hours at 40–60 °C using 250 ml of 75% petroleum ether. Afterwards, the mixture was dried out at 40°C in a rotating evaporator. After being weighed, the extract residue was stored until needed. Using gas chromatography/mass spectrometry (GC/MS), the crude extract was examined. Ursolic acid (1.38), oleanolic acid (3.27), and other triterpeniod substances with varying ratios were identified by GC-MS analysis. The antibacterial activity of triterpeniod compounds was assessed at concentrations of 12.5%, 25%, 50%, and 100% using the well-diffusion Kirby-Bauer method. The test was evaluated in comparison to six bacterial strains. The results indicated that staphylococcus aureus (50%:22mm – 100%: 26mm), staphylococcus haemolyticus (100%: 17mm), and Acinetobacter baumani (50%:18mm – 100%: 22mm) had the highest inhibitory.

COVID19-ResCapsNet: A Novel Residual Capsule Network for COVID-19 Detection from Chest X-Ray Scans Images

In response to the urgent need for swift and accurate diagnosis of COVID-19 during the global pandemic, there has been a growing interest in leveraging advanced technology like deep learning for detection purposes. This project introduces a novel approach termed COVID19-ResCapsNet, which integrates deep neural networks with X-ray imaging data to predict the likelihood of COVID-19 onset in patients. The methodology comprises two key steps. Initially, features are extracted using an enhanced Residual feature extraction network, aimed at capturing crucial information from the X-ray images. Subsequently, multiple Capsule Networks are employed to discern between COVID-19 and non-COVID-19 cases. This hybrid model is assessed using two separate datasets of chest X-ray images: Dataset-1 containing 50 images and Dataset-2 containing 20 images. Remarkably, the proposed method achieves high classification accuracy rates of 0.9988 on Dataset-1 and 0.9933 on Dataset-2 for binary classification tasks. To validate its efficacy, the performance of the COVID19-ResCapsNet model is compared against various state-of-the-art pre-trained classification models. Additionally, the study investigates the impact of two crucial hyper parameters: optimizer selection and batch size. The findings underscore the effectiveness of the proposed COVID-19 detection model, suggesting its potential as a complementary tool in clinical settings for expedited and accurate diagnosis. Keywords: Deep learning, Capsule network, Residual network, COVID-19 detection.

Biorefinery approach with green solvents for the valorization of Citrus reticulata leaves to obtain antioxidant and anticholinergic extracts

Citrus reticulata L leaves are one of the main post-harvest byproduct, containing bioactive compounds, that are usually undervalued. This work describes the development of a biorefinery process based on the application of supercritical CO2 (SC-CO2) followed by ultrasonic-assisted extraction (UAE) combined with Natural Deep Eutectic Solvents (NaDES) to extract bioactive terpenoids and phenolic compounds from these leaves. Extraction temperature and pressure of SC-CO2 were optimized, obtaining the highest bioactive terpenoids content using 200 bar at 60 °C. A Box-Behnken experimental design showed that 57% of water in NaDES composed of Choline Chloride and Glycerol (1:2) as extraction solvent at 25 °C for 50 min were the optimal UAE-NaDES extraction conditions to obtain the highest bioactive phenolic content from the residue of the optimal SC-CO2 extraction. The optimum extract presented the highest bioactivity and polyphenol content determined by LC-DAD-MS compared with extracts obtained using only water or NaDES as solvent.

Design of eco‐synthesized nanocomposites (PVA/TiO2) for promising agents in germicidal and photodecomposition behaviors

AbstractIn recent decades, there has been a significant surge in enthusiasm surrounding the topic of nanotechnology due to the rapid progress of innovation. The enhanced benefits exhibited by nanoparticles (NPs) in comparison to micro‐materials provide a diverse array of applications. Sustainable synthesis is a very efficient technique for producing nanomaterials using a simple, rapid, and eco‐friendly approach. In this investigation, titanium dioxide (TiO2) NPs were produced by combining the residue of coffee extract with PVA/TiO2 as an anchor material. The use of PVA/TiO2 substrates was employed to enhance the surface area of TiO2 NPs to enhance their characteristics. The TiO2 NPs/PVA nanocomposites (NCs) were characterized using procedures. The TiO2/PVA NCs exhibited an absorbance peak at 319 nm in the ultraviolet–visible spectrum, and the particle size was calculated to be 19.2 nm based on the data obtained from FE‐SEM and x‐ray diffraction analysis. Furthermore, an investigation was conducted to examine the photodecomposition and germicidal properties of the TiO2/PVA NCs. The TiO2/PVA NCs showed remarkable germicidal efficacy against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. The investigation focused on examining the photodecomposition performance of the TiO2/PVA NCs in the presence of methylene blue (MB). The MB dye exhibited the greatest photocatalytic activity, reaching 89% within 70 min. Hence, the findings of this study indicate that the TiO2/PVA NCs have promising characteristics for use as both germicidal and photodecomposition properties.

A mild and efficient closed-loop recycling strategy for spent lithium-ion battery

As lithium metal resource supply and demand stabilize and prices decrease, the efficient recovery of valuable metals other than lithium from spent lithium-ion batteries is receiving increasing attention. Currently, challenges remain in the selective lithium recovery efficiency and the high cost of regenerating valuable metal slag after lithium extraction, particularly for spent ternary cathode materials. To address these challenges, this study introduces a closed-loop recovery process for spent ternary cathode materials, employing sulfur-assisted roasting to achieve efficient lithium extraction and high-value direct regeneration of ternary leaching residues. At moderate temperatures (500 ℃), LiNixCoyMn1−x-yO2 (NCM) materials undergo a directional transformation of lithium to Li2SO4 in synergy with sulfur and oxygen, achieving a lithium leaching extraction rate of 98.91 %. Additionally, the relatively mild reaction conditions preserve the secondary spherical morphology and uniform distribution of NiCoMn-based oxide residue without introducing adverse impurities, ensuring the successful regeneration of high-value NCM cathode materials (R-NCM). The R-NCM material exhibits good discharge capacity (144.3 mA·h/g at 1 C) and relatively stable cycling performance, with a capacity retention rate of 80 % after 150 cycles. This work provides a viable pathway for the efficient and environmental-friendly pyrometallurgical closed-loop recovery of spent lithium-ion batteries.

Image reconstruction of electrostatic tomography based on the improved residual network.

The core of electrostatic tomography (EST) is to solve the inverse problem, but the EST independent measurement data are much smaller than the value that needs to be reconstructed, resulting in a more serious inverse problem. This paper presents an improved ResNet-34 network (P-ResNet), which consists of an input layer, a residual feature extraction layer, and an output layer. The number of residual blocks is 3, 4, 4, and 3. After the second convolution in the main path of each residual block, a ReLU activation function is added to enhance the nonlinear expression ability of the network, and the generalization ability of the model is improved by introducing the L2 regularization loss function. A total of 15 930 sets of samples were simulated for the simulation test. After 200 rounds of iteration, the reconstruction results show that the network achieves high accuracy in EST image reconstruction tasks. In addition, the model is tested under different degrees of Gaussian white noise to verify its anti-noise ability. Compared with the traditional algorithms, the image correlation coefficients of this proposed model network are higher. In addition, this paper designs a small sensor to obtain the induced charge values through the principle of electrostatic induction. The reconstructed results obtained from the experimental data are consistent with the simulation results, which verifies the effectiveness and generalization ability of the proposed model.