Waste management最新文献_第3页

Prediction of landfill gases concentration based on Grey Wolf Optimization – Support Vector Regression during landfill excavation process 垃圾填埋场挖掘过程中基于灰狼优化-支持向量回归的垃圾填埋场气体浓度预测

IF 7.1 2区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Waste management

Pub Date : 2025-03-04 DOI: 10.1016/j.wasman.2025.02.040

Zhansheng Liu , Zehua Zhang , Qingwen Zhang , Linlin Zhao

In some areas, there is a phenomenon that the landfill is full or even over-capacity with the extension of the service period. With the aging and damage of the protective facilities, this phenomenon may have a more serious impact on the surrounding environment. It is necessary to excavate and transport the waste beyond the part to control it. This process will inevitably produce many landfill gas emissions, which will pollute the air. Therefore, it is necessary to predict and control the landfill gas. This study utilizes the Grey Wolf Optimization (GWO) algorithm to optimize Support Vector Regression (SVR). It establishes prediction models for various LFG concentrations based on previous LFG concentration data and real-time environmental monitoring data. The models are compared with traditional Support Vector Regression and Random Forest (RF) algorithms, predicting the concentrations of odor, ammonia, hydrogen sulfide, methane, and nitrogen oxides. The results indicate that GWO-SVR demonstrates more stable and accurate predictions across various LFG, with the coefficient of determination R² approximately 10% higher than that of SVR and RF, and most other error metrics significantly lower. In contrast, SVR and RF show substantial errors in predicting odor, hydrogen sulfide, and nitrogen oxides. Thus, the GWO-SVR algorithm substantially improves the performance in predicting LFG concentrations, meeting the needs of on-site management.

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引用次数: 0

Effect of triethanolamine on the properties and hydration of fly ash-based geopolymer foam 三乙醇胺对粉煤灰基土工聚合物泡沫性能和水化的影响

IF 7.1 2区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Waste management

Pub Date : 2025-03-03 DOI: 10.1016/j.wasman.2025.02.045

Mingkang Gao , Zhongtao Luo , Meixiang Zhang , Xiaohai Liu , Lei Liu , Jiayuan Ye , Xinsheng Zhang , Yifan Yang , Mengxiao Ge , Haitao Yang , Siyu Rong , Ziwen Wang

Low compressive strength of fly ash-based geopolymer foam (FGF) severely limits its application in areas such as building thermal insulation, partition walls, and foundation backfill. In this study, triethanolamine (TEA) was examined as an additive with dual functions: acting as a foam stabilizer in the foam solution and enhancing the strength of FGF samples. The effects of TEA on the stability of preformed foam and the workability, bulk density, and compressive strength of FGF samples at room temperature were evaluated. The hydration products were examined by XRD, TGA, FTIR and SEM, and the pore structure was evaluated by image analysis method. Results showed that TEA was effective in enhancing stability of preformed foam. When 0.70 wt% of TEA was incorporated into foam solution, the drainage half-life of preformed foam increased by 50.5 % to 45.3 min. FGF samples prepared with TEA-modified preformed foam exhibited good workability and bulk density of 660 ± 20 kg/m³. The 3-day and 28-day compressive strengths of the FGF sample added with 0.70 wt% TEA increased by 50.0 % and 30.7 % to 1.17 MPa and 3.32 MPa, respectively. The enhancement was attributed to the effects of TEA on facilitating the hydration of geopolymer matrix and optimizing the pore structure of the FGF system.

{"title":"Effect of triethanolamine on the properties and hydration of fly ash-based geopolymer foam","authors":"Mingkang Gao , Zhongtao Luo , Meixiang Zhang , Xiaohai Liu , Lei Liu , Jiayuan Ye , Xinsheng Zhang , Yifan Yang , Mengxiao Ge , Haitao Yang , Siyu Rong , Ziwen Wang","doi":"10.1016/j.wasman.2025.02.045","DOIUrl":"10.1016/j.wasman.2025.02.045","url":null,"abstract":"<div><div>Low compressive strength of fly ash-based geopolymer foam (FGF) severely limits its application in areas such as building thermal insulation, partition walls, and foundation backfill. In this study, triethanolamine (TEA) was examined as an additive with dual functions: acting as a foam stabilizer in the foam solution and enhancing the strength of FGF samples. The effects of TEA on the stability of preformed foam and the workability, bulk density, and compressive strength of FGF samples at room temperature were evaluated. The hydration products were examined by XRD, TGA, FTIR and SEM, and the pore structure was evaluated by image analysis method. Results showed that TEA was effective in enhancing stability of preformed foam. When 0.70 wt% of TEA was incorporated into foam solution, the drainage half-life of preformed foam increased by 50.5 % to 45.3 min. FGF samples prepared with TEA-modified preformed foam exhibited good workability and bulk density of 660 ± 20 kg/m<sup>3</sup>. The 3-day and 28-day compressive strengths of the FGF sample added with 0.70 wt% TEA increased by 50.0 % and 30.7 % to 1.17 MPa and 3.32 MPa, respectively. The enhancement was attributed to the effects of TEA on facilitating the hydration of geopolymer matrix and optimizing the pore structure of the FGF system.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"198 ","pages":"Pages 106-116"},"PeriodicalIF":7.1,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Treatment of fine and medium fractions of MSWI bottom ash for use in concrete: A German case study

IF 7.1 2区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Waste management

Pub Date : 2025-03-03 DOI: 10.1016/j.wasman.2025.02.050

Iveta Vateva , Marcel Laabs , Bernhard Middendorf , David Laner

Incineration bottom ash (IBA) is the main solid residue from municipal solid waste incineration. IBA mostly contains minerals that can be used as secondary construction materials in unbound applications as well as concrete after appropriate treatment. Major challenges, in particular for its utilization in concrete, are residual metal contents, soluble salts, as well as the high porosity of the material. The goal of this study was to investigate the processing of the fine (0–2 mm) and medium (2–8 mm) IBA fractions with respect to their utilization as a partial substitute for binder and aggregates in concrete. Therefore, the IBA was treated in a two-stage process and the material fractions produced were utilized as secondary aggregates and partial cement replacement in concrete paving stones. The processing led to a reduction in residual metal concentrations, e.g. the metallic aluminum was reduced by 67 % and 60 % in the processed fine and medium fractions, respectively. Soluble metals and salts could be reduced to some extent, but remaining salts (up to 1800 mg/l and 2300 mg/l for chloride and sulfate, respectively) hinder the use of the IBA in reinforced concrete. The results demonstrate that IBA has promising potential for use in concrete paving stones, but further optimization is needed to meet requirements such as tensile splitting strength and weathering resistance (the tensile splitting strength was approx. 20 % lower and the frost resistance was about 4 times higher). Overall, partial replacement of binder and aggregates can effectively contribute to reducing the environmental footprint of concrete products.

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引用次数: 0

Efficient and high-selective lithium extraction from waste LiMn2O4 batteries by synergetic pyrolysis with polyvinyl chloride 通过与聚氯乙烯协同热解，从废弃锰酸锂电池中高效、高选择性地提取锂

IF 7.1 2区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Waste management

Pub Date : 2025-03-02 DOI: 10.1016/j.wasman.2025.02.049

Yuxue Zhang , Zhaoyong Liu , Jiahui Wang , Hui Du , Qi Sun , Ruitong Gao , Zhenming Xu

Recycling Li from spent lithium ion batteries (SLIBs) in an efficient and highly selective manner could protect the environment and introduce the circular economy principle to society. Simultaneously, the urgent need to address plastic waste, particularly polyvinyl chloride (PVC), has become a global concern. In this work, a strategy for Li extraction through synergetic pyrolysis of LiMn₂O₄ cathode materials (LMO) and PVC is proposed. Under optimal conditions, the recovery rates of lithium and manganese reached 99.89 % and 0.02 %, respectively, demonstrating efficient separation of these elements. Temperature was found to play a critical role in the leaching rates of lithium and manganese by promoting the decomposition and reduction of LMO. Additionally, kinetic analysis shows that the activation energy (E_a) of the synergetic pyrolysis is 139.60 KJ/mol, and the pyrolysis mechanism satisfies third-order reaction process. Eventually, the proposed mechanism involves the synergistic effects of chlorination and reduction reactions. First, HCl is generated by PVC pyrolysis under the catalytic effect of LMO. Then, the chlorination of HCl with LMO occurs by capturing structural oxygen and generating LiCl and MnCl₂. Simultaneously, the reduction reaction between the reducing species generated by PVC pyrolysis and LMO occurs to form Li₂O and MnO, ultimately enabling the separation of lithium and manganese. Overall, this paper presents a novel approach for future applications by providing a theoretical basis for selective Li extraction.

{"title":"Efficient and high-selective lithium extraction from waste LiMn2O4 batteries by synergetic pyrolysis with polyvinyl chloride","authors":"Yuxue Zhang , Zhaoyong Liu , Jiahui Wang , Hui Du , Qi Sun , Ruitong Gao , Zhenming Xu","doi":"10.1016/j.wasman.2025.02.049","DOIUrl":"10.1016/j.wasman.2025.02.049","url":null,"abstract":"<div><div>Recycling Li from spent lithium ion batteries (SLIBs) in an efficient and highly selective manner could protect the environment and introduce the circular economy principle to society. Simultaneously, the urgent need to address plastic waste, particularly polyvinyl chloride (PVC), has become a global concern. In this work, a strategy for Li extraction through synergetic pyrolysis of LiMn<sub>2</sub>O<sub>4</sub> cathode materials (LMO) and PVC is proposed. Under optimal conditions, the recovery rates of lithium and manganese reached 99.89 % and 0.02 %, respectively, demonstrating efficient separation of these elements. Temperature was found to play a critical role in the leaching rates of lithium and manganese by promoting the decomposition and reduction of LMO. Additionally, kinetic analysis shows that the activation energy (<em>E<sub>a</sub></em>) of the synergetic pyrolysis is 139.60 KJ/mol, and the pyrolysis mechanism satisfies third-order reaction process. Eventually, the proposed mechanism involves the synergistic effects of chlorination and reduction reactions. First, HCl is generated by PVC pyrolysis under the catalytic effect of LMO. Then, the chlorination of HCl with LMO occurs by capturing structural oxygen and generating LiCl and MnCl<sub>2</sub>. Simultaneously, the reduction reaction between the reducing species generated by PVC pyrolysis and LMO occurs to form Li<sub>2</sub>O and MnO, ultimately enabling the separation of lithium and manganese. Overall, this paper presents a novel approach for future applications by providing a theoretical basis for selective Li extraction.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"198 ","pages":"Pages 95-105"},"PeriodicalIF":7.1,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An attempt to study the photoreduction rate of divalent mercury in landfill cover soils using experimental control systems

IF 7.1 2区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Waste management

Pub Date : 2025-03-01 DOI: 10.1016/j.wasman.2025.02.041

Zhengkai Tao , Yiqing Fan , Qingyun Zhang , Dayong Xu

Mercury (Hg) emissions from landfill cover soils are an important source of atmospheric Hg affecting local and regional atmospheric Hg budget. To date, soil Hg emissions have been extensively studied, whereas the photoreduction rate of cover soil Hg(II) under various conditions is rarely studied. Herein, two experimental control systems were built to investigate the effect of varying soil Hg(II) concentrations, moistures, and temperature on soil Hg emission in order to obtain the photoreduction rate of soil Hg(II) under varying environmental conditions. The results showed that high soil Hg(II) concentration and high soil temperature can facilitate Hg emission; however, high moisture inhibited Hg emission. In addition, solar radiation is an extremely critical factor for Hg emission and solar radiation-driven photoreduction is an important contribution process for Hg emission; moreover, soil Hg emission is controlled by multiple environmental factors and varies with environmental factors. Through the data fitting and formula calculation, the photoreduction rates under varying conditions are in the range of 1.49–8.54 × 10⁻¹⁰ m² s⁻¹ W⁻¹, which can be helpful for the construction of a process-based model of soil Hg emission and Hg management in landfills.

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引用次数: 0

Hydrochars of mixed marine biomass and plastic wastes: Carbonization scenarios and the performance as ketoprofen adsorbents

IF 7.1 2区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Waste management

Pub Date : 2025-03-01 DOI: 10.1016/j.wasman.2025.02.038

Khonekeo Kingkhambang, Kayee Chan, Anatoly Zinchenko

The hydrothermal (HT) conversion of mixed biomass and plastic waste to hydrochar adsorbents has attracted significant attention; however, factors controlling the structure and adsorption properties of hydrochar remain still poorly understood. Herein, HT treatment of the marine biomass waste (crab shells (CR) and fishery waste-derived chitin (CT) and chitosan (CS)) mixed with plastic waste (polyethylene (PE) and polyethylene terephthalate (PET)) at temperatures of 200–250 °C and residence times of 4–12 h was conducted to prepare hydrochars for screening their adsorption characteristics towards ketoprofen, a pharmaceutical pollutant. PET underwent efficient degradation when processed with marine biomass, particularly in mixtures with CS, which facilitated PET depolymerization through an aminolysis reaction. Hydrochars derived from PET mixed with CS demonstrated adsorption capacities for ketoprofen of ca. 25 mg/g due to the presence of the amine, amido, and aromatic groups providing sites for electrostatic interactions, hydrogen bonding, and π-π interactions with ketoprofen. The ketoprofen adsorption was best described by the pseudo-second-order kinetic model and Freundlich-type isotherm. On the other hand, no significant decomposition of PE was observed during the HT treatment of PE and biomass mixtures even in the presence of H₂O₂ oxidizer. However, the hydrochars of CS and CR prepared in the presence of PE exhibited markedly improved ketoprofen adsorption capacity compared to hydrochars of CR and CS. The results of this study demonstrate the benefits of combining plastic and biomass in the waste streams to control waste degradation along with the structure and adsorption properties of the hydrochars.

{"title":"Hydrochars of mixed marine biomass and plastic wastes: Carbonization scenarios and the performance as ketoprofen adsorbents","authors":"Khonekeo Kingkhambang, Kayee Chan, Anatoly Zinchenko","doi":"10.1016/j.wasman.2025.02.038","DOIUrl":"10.1016/j.wasman.2025.02.038","url":null,"abstract":"<div><div>The hydrothermal (HT) conversion of mixed biomass and plastic waste to hydrochar adsorbents has attracted significant attention; however, factors controlling the structure and adsorption properties of hydrochar remain still poorly understood. Herein, HT treatment of the marine biomass waste (crab shells (CR) and fishery waste-derived chitin (CT) and chitosan (CS)) mixed with plastic waste (polyethylene (PE) and polyethylene terephthalate (PET)) at temperatures of 200–250 °C and residence times of 4–12 h was conducted to prepare hydrochars for screening their adsorption characteristics towards ketoprofen, a pharmaceutical pollutant. PET underwent efficient degradation when processed with marine biomass, particularly in mixtures with CS, which facilitated PET depolymerization through an aminolysis reaction. Hydrochars derived from PET mixed with CS demonstrated adsorption capacities for ketoprofen of <em>ca.</em> 25 mg/g due to the presence of the amine, amido, and aromatic groups providing sites for electrostatic interactions, hydrogen bonding, and π-π interactions with ketoprofen. The ketoprofen adsorption was best described by the pseudo-second-order kinetic model and Freundlich-type isotherm. On the other hand, no significant decomposition of PE was observed during the HT treatment of PE and biomass mixtures even in the presence of H<sub>2</sub>O<sub>2</sub> oxidizer. However, the hydrochars of CS and CR prepared in the presence of PE exhibited markedly improved ketoprofen adsorption capacity compared to hydrochars of CR and CS. The results of this study demonstrate the benefits of combining plastic and biomass in the waste streams to control waste degradation along with the structure and adsorption properties of the hydrochars.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"198 ","pages":"Pages 66-76"},"PeriodicalIF":7.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Techno-economic and scalability analysis of nitrogen plasma gasification of medical waste

IF 7.1 2区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Waste management

Pub Date : 2025-03-01 DOI: 10.1016/j.wasman.2025.02.028

Shu Wang , Haoyang Shi , Pingyang Wang

Plasma gasification by which high-temperature plasma jets can be used to rapidly kill various pathogens and produce syngas and other valuable products, is among the most promising technologies for medical waste treatment. Due to the oxidizing and ablative effect of oxidizing gases on plasma torches, this study uses nitrogen as the working gas for plasma torches. This work introduces a hybrid model implemented in Aspen to assess the impact of temperature and gasifying agent flow rate ratios on the molar fractions of constituents in the syngas generated from four types of medical waste: plastic, rubber, fiber, and biomass. Thereafter, the optimal gasification temperatures and flow ratio of gasifying agent were determined. Furthermore, two scalable systems based on nitrogen plasma gasification of medical waste were proposed, one is syngas to power system and the other is syngas to hydrogen system, which realize profitability while harmlessly treating medical waste. Energy and economic analyses were carried out to promote nitrogen plasma technology as a viable and sustainable waste-to-energy technology. Economic analysis shows that considerable returns can be achieved in a relatively short period of time for both systems (2.57 years of waste-to-hydrogen), which demonstrated the economic viability of nitrogen plasma gasification of medical waste system. A comparison of the two scalable systems reveals that both systems have their own appropriate application scenarios.

{"title":"Techno-economic and scalability analysis of nitrogen plasma gasification of medical waste","authors":"Shu Wang , Haoyang Shi , Pingyang Wang","doi":"10.1016/j.wasman.2025.02.028","DOIUrl":"10.1016/j.wasman.2025.02.028","url":null,"abstract":"<div><div>Plasma gasification by which high-temperature plasma jets can be used to rapidly kill various pathogens and produce syngas and other valuable products, is among the most promising technologies for medical waste treatment. Due to the oxidizing and ablative effect of oxidizing gases on plasma torches, this study uses nitrogen as the working gas for plasma torches. This work introduces a hybrid model implemented in Aspen to assess the impact of temperature and gasifying agent flow rate ratios on the molar fractions of constituents in the syngas generated from four types of medical waste: plastic, rubber, fiber, and biomass. Thereafter, the optimal gasification temperatures and flow ratio of gasifying agent were determined. Furthermore, two scalable systems based on nitrogen plasma gasification of medical waste were proposed, one is syngas to power system and the other is syngas to hydrogen system, which realize profitability while harmlessly treating medical waste. Energy and economic analyses were carried out to promote nitrogen plasma technology as a viable and sustainable waste-to-energy technology. Economic analysis shows that considerable returns can be achieved in a relatively short period of time for both systems (2.57 years of waste-to-hydrogen), which demonstrated the economic viability of nitrogen plasma gasification of medical waste system. A comparison of the two scalable systems reveals that both systems have their own appropriate application scenarios.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"198 ","pages":"Pages 55-65"},"PeriodicalIF":7.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Reducing food waste in the HORECA sector using AI-based waste-tracking devices

IF 7.1 2区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Waste management

Pub Date : 2025-03-01 DOI: 10.1016/j.wasman.2025.02.044

Evangelia G. Sigala , Paula Gerwin , Christina Chroni , Konstadinos Abeliotis , Christina Strotmann , Katia Lasaridi

This study assesses the effectiveness of an intervention employing an AI-based, fully automatic waste-tracking system for food waste reduction in HORECA establishments. Waste-tracking devices were installed in a restaurant within a holiday resort and a business caterer in Germany, a hotel in Switzerland, and two hotels in Greece. The devices utilize computer vision and advanced deep learning algorithms to automatically weigh and optically segregate food waste in real time. At baseline, total food waste was 76.2–121.0 g/meal for the hotels, 99.4 g/meal for the business caterer, and 151.9 g/meal for the restaurant. Avoidable food waste constituted 45 % to73% of the total, attributable to overproduction (20–92 %) and consumers’ leftovers (8–80 %). The remaining waste was unavoidable, stemming from preparation procedures (47–99 %) and consumers’ leftovers (1–53 %). Vegetables and prepared foods contributed the most to total amounts. This data-driven intervention raised staff awareness towards food waste, facilitating the implementation of corrective actions. Therefore, except for the Swiss hotel that exhibited an increase of 13 %, the intervention was effective in achieving a 23–51 % reduction in food waste, especially in food preparation and overproduction, demonstrating the intervention’s transferability across different settings. Additional evidence supported its long-term sustainability. The cost of wasted food per meal was reduced by up to 39 % compared to the baseline. Future studies should explore combining waste-tracking devices with consumer-level interventions to enhance food waste reduction.

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引用次数: 0

Separation and recovery of the active material from Cu foils in lithium-ion battery anodes by electrohydraulic fragmentation using pulsed discharge

IF 7.1 2区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Waste management

Pub Date : 2025-02-28 DOI: 10.1016/j.wasman.2025.02.039

Taketoshi Koita , Yuto Imaizumi , Asako Narita , Yutaro Takaya , Yosuke Kita , Hiroyuki Akashi , Takao Namihira , Chiharu Tokoro

The increasing demand for lithium-ion batteries (LIBs) has led to a significant rise in the amount of spent LIBs, necessitating efficient recycling methods to recover valuable materials from the cathodes and anodes. Furthermore, the efficient recycling of graphite anodes (GA) from LIBs has become an important economic and environmental concern because GAs account for nearly 10% of the total production cost. This paper reports on the separation and recovery of GA material and copper (Cu) foil from LIB anode sheets made from in-process end materials that have not been immersed in electrolyte, which mimics in-process scrapped anodes, by performing electrohydraulic fragmentation (EHF) using the pulsed discharge. The previous study of life cycle assessment indicated that the separation method conducted by the discharge involves lower energy consumption and environmental impact. The objective of this study is to experimentally determine the optimal voltage and number of discharge shots for high separation rates of GA particles with low Cu contamination. The results indicate that 5–7 discharge shots at 14–20 kV are useful for separation and satisfy the required conditions for anode recycling, providing a material recovery rate of more than 95% and a Cu concentration of less than 1.0 wt%. The size of the recovered GA particles was smaller, and the size distribution was narrower as the discharge voltage of EHF increased. This study suggests that EHF is a useful and novel method for the separation from the LIB cathode, which is required in the recycling process.

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引用次数: 0

Alkaline catalytic liquefaction of pig manure fermentation residue in ethanol solvent for the production of high-quality biocrude oil

IF 7.1 2区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Waste management

Pub Date : 2025-02-27 DOI: 10.1016/j.wasman.2025.02.035

Jialong Tang , Jingchen Zou , Qianlan Li , Qingdan Wu , Xiaochen Zheng , Jun Fang , Zhihua Xiao

The widespread application of biogas projects generates substantial amounts of waste fermentation residue. Further treatment of fermentation residues facilitates resource utilization, ensures safe disposal, and is anticipated to enhance the economic returns of biogas projects. Herein, catalytic liquefaction of pig manure fermentation residue to produce biocrude oil was investigated using various alkaline catalysts at 340 ℃ with ethanol as the solvent. Biocrude oils were analyzed by elemental analysis, gas chromatography-mass spectrometry (GC–MS), thermogravimetric analysis, and kinetic analysis. The maximum biocrude oil yield (45.24 wt%) was obtained with the KOH catalyst. Additionally, the biocrude oil produced by the catalysis of CaO exhibited the maximum higher heating value at 44.18 MJ/kg. GC–MS results showed that KOH and K₂CO₃ considerably increased the content of phenols and hydrocarbons in the biocrude while reducing nitrogenous compounds. All alkaline catalysts effectively reduced the activation energy of biocrude oil compared to biocrude oil without catalyst. The maximum reduction in activation energy (18.73 %) was achieved with the addition of Na₂CO₃. More importantly, adding CaO not only increased the yield and higher heating value of biocrude oil but also reduced nitrogenous compounds and activation energy, improving the overall yield and quality. Overall, this work provides an effective and promising method to convert pig manure fermentation residue into green high-quality biocrude oil, simultaneously providing an economical and environmentally friendly waste management strategy for the fermentation industry.

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引用次数: 0