Waste management最新文献_第9页

Kinetic investigation on the catalytic pyrolysis of plastic fractions of waste electrical and electronic equipment (WEEE): A mathematical deconvolution approach. 废弃电气和电子设备（WEEE）塑料部分催化热解的动力学研究：数学解卷积方法。

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

Waste management

Pub Date : 2024-10-01 Epub Date: 2024-07-22 DOI: 10.1016/j.wasman.2024.07.015

Samina Gulshan, Hoda Shafaghat, Shule Wang, Leilei Dai, Chuchu Tang, Wenming Fu, Yuming Wen, Chi-Hwa Wang, Panagiotis Evangelopoulos, Weihong Yang

Waste electrical and electronic equipment (WEEE) has become a critical environmental problem. Catalytic pyrolysis is an ideal technique to treat and convert the plastic fraction of WEEE into chemicals and fuels. Unfortunately, research using real WEEE remains relatively limited. Furthermore, the complexity of WEEE complicates the analysis of its pyrolytic kinetics. This study applied the Fraser-Suzuki mathematical deconvolution method to obtain the pseudo reactions of the thermal degradation of two types of WEEE, using four different catalysts (Al₂O₃, HBeta, HZSM-5, and TiO₂) or without a catalyst. The main contributor(s) to each pseudo reaction were identified by comparing them with the pyrolysis results of the pure plastics in WEEE. The n^th order model was then applied to estimate the kinetic parameters of the obtained pseudo reactions. In the low-grade electronics pyrolysis, the pseudo-1 reaction using TiO₂ as a catalyst achieved the lowest activation energy of 92.10 kJ/mol, while the pseudo-2 reaction using HZSM-5 resulted in the lowest activation energy of 101.35 kJ/mol among the four catalytic cases. For medium-grade electronics, pseudo-3 and pseudo-4 were the main reactions for thermal degradation, with HZSM-5 and TiO₂ yielding the lowest pyrolytic activation energies of 75.24 and 226.39 kJ/mol, respectively. This effort will play a crucial role in comprehending the pyrolysis kinetic mechanism of WEEE and propelling this technology toward a brighter future.

废弃电气和电子设备（WEEE）已成为一个严重的环境问题。催化热解是处理废弃电气和电子设备中的塑料部分并将其转化为化学品和燃料的理想技术。遗憾的是，利用实际废弃电子电气设备进行的研究仍然相对有限。此外，废弃电子电气设备的复杂性也使其热解动力学分析变得复杂。本研究采用 Fraser-Suzuki 数学解卷积法，获得了使用四种不同催化剂（Al2O3、HBeta、HZSM-5 和 TiO2）或不使用催化剂的两类废弃电子电气设备热降解的伪反应。通过与 WEEE 中纯塑料的热解结果进行比较，确定了每种假反应的主要促成因素。然后应用 nth 阶模型来估算所得伪反应的动力学参数。在低档电子产品热解过程中，以 TiO2 为催化剂的伪-1 反应的活化能最低，为 92.10 kJ/mol；而在四种催化情况下，以 HZSM-5 为催化剂的伪-2 反应的活化能最低，为 101.35 kJ/mol。对于中档电子产品，伪-3 和伪-4 是热降解的主要反应，HZSM-5 和 TiO2 产生的热解活化能最低，分别为 75.24 和 226.39 kJ/mol。这项研究对于理解废弃电子电气设备的热解动力学机制以及推动这项技术走向更光明的未来将起到至关重要的作用。

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引用次数: 0

Decarbonizing paper mill sludge waste into micro and nanofibrillated cellulose via enzyme hydrolysis and dual asymmetric centrifugation 通过酶水解和双不对称离心将造纸厂污泥废料脱碳为微纤维和纳米纤维素

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

Waste management

Pub Date : 2024-09-27 DOI: 10.1016/j.wasman.2024.09.013

Roman Sarder, Nick Starrett, Sachin Agate, Lokendra Pal

The production of micro- and nano-fibrillated cellulose (MNFC) from paper mill sludge (PS) using simple enzymatic and mechanical treatments has been evaluated for their performance as value-added materials in packaging and other applications. Sludge from a US paper mill was analyzed for the viability of this conversion process. The enzymatic treatment was conducted at variable concentrations using an enzyme cocktail of exoglucanase and endoglucanase, followed by mechanical dual asymmetric centrifugation (DAC) treatment. The presence of inorganics and lignin facilitated the mechanical defibrillation of the fibers, making the MNFC production more energy-efficient. The prepared MNFC was characterized for fibrillation, charge, crystallinity, and surface morphology. Scanning electron microscopic (SEM) images show the highly fibrillated MNFC and the distribution of inorganic nanoparticles on the fiber surface. The X-ray diffractometric (XRD) analysis shows 44–65 % crystallinity. Furthermore, MNFC-based films derived from PS demonstrated excellent strength and flexibility, making them suitable for packaging and other applications. Overall, this conversion approach can save the paper industry millions of dollars in disposal costs while upcycling waste and reducing greenhouse gas (GHG) emissions associated with waste streams.

通过简单的酶解和机械处理，从造纸厂污泥（PS）中生产出微纤维素和纳米纤维素（MNFC），并对其在包装和其他应用中作为增值材料的性能进行了评估。对美国一家造纸厂的污泥进行了分析，以确定这种转化工艺的可行性。在不同浓度下使用外切葡聚糖酶和内切葡聚糖酶的鸡尾酒酶进行酶处理，然后进行机械双不对称离心（DAC）处理。无机物和木质素的存在促进了纤维的机械脱纤，使 MNFC 的生产更具能效。对制备的 MNFC 进行了纤度、电荷、结晶度和表面形态表征。扫描电子显微镜（SEM）图像显示了高度纤维化的 MNFC 以及纤维表面无机纳米颗粒的分布。X 射线衍射（XRD）分析显示结晶度为 44-65%。此外，由 PS 制成的基于 MNFC 的薄膜具有出色的强度和柔韧性，因此适用于包装和其他应用。总之，这种转化方法可以为造纸业节省数百万美元的处理成本，同时还能实现废物的再循环利用，减少与废物流相关的温室气体（GHG）排放。

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引用次数: 0

Technical and environmental assessment of sludge-derived slag generated from high temperature slagging co-gasification process as a sustainable construction material 高温炉渣联合气化工艺产生的污泥衍生炉渣作为可持续建筑材料的技术和环境评估

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

Waste management

Pub Date : 2024-09-26 DOI: 10.1016/j.wasman.2024.09.021

Ya Zhao , Wei Ping Chan , Vernette Chin , Yinn Zhao Boon , Xiaoxu Fu , Yan Gu , James Oh , Grzegorz Lisak

Tremendous amount of sludge is generated annually from freshwater treatment or sewage. The high temperature slagging co-gasification converts the sludge to slag showing the potential application for construction material. In this study, the physico-chemical properties of 4 types of slags generated from the co-gasification of municipal solid waste (MSW) with sludge from freshwater treatment or sewage, and ashes from sludge incineration are comprehensively analyzed. Leaching performance of the sludge-derived slag and mortar (with slag as the fine aggregate), as determined based on Toxicity Characteristic Leaching Procedure (TCLP), batch leaching and column leaching tests, indicates the slag can be considered safe for reutilization. Compressive strength test demonstrates that the mortars perform excellently and have the potential to replace sand in concrete production. The consolidation coefficient of slag (1.6 – 39.1 m²/year) is lower than the sandy silt but higher than clay. Additionally, the coefficient of permeability (∼1.96 × 10^-3 m/s), angle of shearing resistance (∼39°), and undrained shear strength (375.5

\pm

54.8 kPa) of the slag are comparable to sand. The life cycle assessment (LCA) is also conducted to evaluate the environmental impacts and benefits of reutilizing sludge-derived slag as an alternative material for concrete production and land reclamation.

淡水处理或污水处理每年会产生大量污泥。高温炉渣共气化将污泥转化为炉渣，显示出其作为建筑材料应用的潜力。本研究全面分析了城市固体废弃物（MSW）与淡水处理或污水处理产生的污泥以及污泥焚烧产生的灰烬共同气化产生的 4 种炉渣的物理化学性质。根据毒性特征浸出程序 (TCLP)、批量浸出和柱浸出试验确定的污泥衍生炉渣和灰泥（以炉渣为细骨料）的浸出性能表明，炉渣可以安全地再利用。抗压强度测试表明，灰泥性能优异，有可能在混凝土生产中取代砂。矿渣的固结系数（1.6 - 39.1 平方米/年）低于砂质粉土，但高于粘土。此外，矿渣的渗透系数（∼1.96 × 10-3 m/s）、抗剪角（∼39°）和排水剪切强度（375.5 ± 54.8 kPa）与砂相当。此外，还进行了生命周期评估（LCA），以评价将污泥产生的炉渣作为混凝土生产和土地复垦的替代材料进行再利用的环境影响和效益。

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引用次数: 0

Co-hydrothermal carbonization of lignocellulosic biomass and swine manure: Optimal parameters for enhanced nutrient reclamation, carbon sequestration, and heavy metals passivation 木质纤维素生物质和猪粪的共水热碳化：增强养分回收、碳封存和重金属钝化的最佳参数

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

Waste management

Pub Date : 2024-09-25 DOI: 10.1016/j.wasman.2024.09.019

Weijie Xiong , Yuping Luo , Wengao Shangguan , Yue Deng , Ronghua Li , Dan Song , Muyuan Zhang , Zengyi Li , Ran Xiao

Hydrochar, the primary product of hydrothermal carbonization (HTC) of wet organic waste, is recognized as a versatile, carbon-abundant material with diverse applications. However, optimizing its performance for specific uses remains challenging. Therefore, this study introduced a co-HTC process involving carbon-rich lignocellulosic materials and ash-rich livestock manure [i.e., Zanthoxylum bungeanum branch residue (ZB) and swine manure (SM), respectively]. The impacts of HTC temperature (i.e., 180 °C, 220 °C, and 240 °C) and mass ratios (i.e., 1:0, 7:3, 5:5, 3:7, and 0:1) on hydrochar properties (e.g., pH, EC, nutrient contents, heavy metal content and availability, chemical stability, etc) and the characteristics of process water were evaluated. Results reveal that co-HTC dramatically improved the quality of hydrochars compared with that derived from a single feedstock. Notably, the ZB:SM ratio had a more substantial impact on total nutrient content, carbon stability, and heavy metal accumulation and mobility. Additionally, the synergistic effects of ZB and SM were greatly dependent on the HTC temperature. By adjusting the feedstock mass ratio and HTC temperature, a highly-functionalized hydrochar can be produced. For example, hydrochars produced at 240 °C with a 7:3 ZB to SM ratio (HC240-7) is optimal for degraded soil amendment, enhancing carbon sequestration and nutrient supplementation. Results from this study could provide valuable insights for improving waste management through HTC and expanding the environmental and agricultural application of hydrochar.

水碳是湿有机废物水热碳化（HTC）的主要产物，被认为是一种用途广泛的富碳材料，具有多种用途。然而，针对特定用途优化其性能仍具有挑战性。因此，本研究引入了一种涉及富碳木质纤维素材料和富灰牲畜粪便（分别为 Zanthoxylum bungeanum 枝状残渣（ZB）和猪粪（SM））的共 HTC 工艺。评估了 HTC 温度（即 180 °C、220 °C 和 240 °C）和质量比（即 1:0、7:3、5:5、3:7 和 0:1）对水炭特性（如 pH 值、EC 值、养分含量、重金属含量和可用性、化学稳定性等）和工艺用水特性的影响。结果表明，与单一原料相比，共 HTC 显著提高了水炭的质量。值得注意的是，ZB:SM 比率对总养分含量、碳稳定性、重金属积累和流动性的影响更大。此外，ZB 和 SM 的协同效应在很大程度上取决于 HTC 温度。通过调整原料质量比和 HTC 温度，可以生产出高功能化的水炭。例如，以 7:3 的 ZB 与 SM 比率（HC240-7）在 240 °C 下生产的水炭最适合用于降解土壤改良，提高碳固存和养分补充效果。这项研究的结果可为通过氢化碳技术改善废物管理以及扩大氢化炭在环境和农业方面的应用提供有价值的见解。

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引用次数: 0

Identify the impact of pyrolysis temperature on preparation of carbon nanotubes by catalytic reforming polypropylene 确定热解温度对通过催化重整聚丙烯制备碳纳米管的影响

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

Waste management

Pub Date : 2024-09-24 DOI: 10.1016/j.wasman.2024.09.016

Ning Cai , Qingyu Liu , Xiaoqiang Li , Shujiang Li , Haiping Yang , Hanping Chen

Catalytic reforming offers a promising method for converting waste plastics into valuable products such as carbon nanotubes (CNTs). The composition of the carbon source plays a crucial role in determining the growth of CNTs because pyrolysis temperature exerts a significant influence on volatilisation. This study investigated the impact of pyrolysis temperature on the formation of CNTs in the presence of an Fe/Al₂O₃ catalyst. A pyrolysis temperature of 500 ℃, generated a liquid product containing a high concentration of long-chain waxy hydrocarbons, while the gaseous products were dominated by C₃H₆ (47 vol%) and C₂H₆ (20 vol%). Increasing the pyrolysis temperature facilitated the formation of CH₄ and aromatic hydrocarbons at the expense of the waxy components. Following catalysis, carbon deposits of > 30 wt% (comprising approximately 80 % CNTs) were obtained at 500 ℃, compared to 20 wt% (with CNTs comprising 60 %) at 900 ℃. In summary, the results suggest that small molecular hydrocarbons, including C₃H₆ and waxy components, promote CNT formation, whereas aromatic hydrocarbons contribute to the formation of amorphous carbon or coke.

催化重整是将废塑料转化为有价值产品（如碳纳米管）的一种可行方法。由于热解温度对碳纳米管的挥发有重要影响，因此碳源成分对碳纳米管的生长起着至关重要的作用。本研究调查了热解温度对在 Fe/Al2O3 催化剂存在下形成 CNT 的影响。热解温度为 500 ℃ 时，生成的液态产物中含有高浓度的长链蜡状碳氢化合物，而气态产物则以 C3H6（47%）和 C2H6（20%）为主。提高热解温度可促进 CH4 和芳香烃的形成，但会牺牲蜡状成分。催化后，在 500 ℃ 时可获得 30% 的碳沉积物（其中约 80% 为碳纳米管），而在 900 ℃ 时则可获得 20% 的碳沉积物（其中 60% 为碳纳米管）。总之，研究结果表明，小分子碳氢化合物（包括 C3H6 和蜡状成分）可促进碳纳米管的形成，而芳香烃则有助于无定形碳或焦炭的形成。

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引用次数: 0

Occurrence and mass flow rate of PFAS in a Waste-to-Energy water treatment process 废物变能源水处理过程中全氟辛烷磺酸的发生率和质量流量

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

Waste management

Pub Date : 2024-09-24 DOI: 10.1016/j.wasman.2024.09.020

Sofie Björklund , Amanda Carlund , Eva Weidemann , Stina Jansson

This study investigated the fate of per- and polyfluoroalkyl substances (PFAS) in the in-house process-water treatment (PWT) of a 65 MW Waste-to-Energy (WtE) plant. PFAS are used in a wide variety of applications, but are persistent and will end up in waste streams when products reach the end of their lives. The study aimed to identify the pathway of PFAS from flue-gas treatment to the PWT, and to assess the efficiency of the PWT in removing PFAS.

Sampling was conducted over five days at five different locations in the PWT. Nine of the eleven target PFAS were detected in at least one sample. The total concentration of PFAS exhibited day-to-day variations, likely caused by fluctuations in the composition of the waste fuel. The highest average PFAS concentration was observed in foam, and was around 130 times that found in the treated water. However, the mass flow of PFAS in the foam was substantially lower, on average 20 times, than that in the treated water.

It was found that the condensate scrubber acts as a PFAS transfer step, carrying over certain PFAS from the flue gases into the condensate and PWT. The mass flow rate of PFAS in the PWT after the addition of condensate was six times that before the addition.

The study concludes that, while there are some key changes that could be made to enhance the PFAS removal capacity of the in-house PWT, in its current configuration the PWT is not able to efficiently remove PFAS from process-water.

本研究调查了 65 兆瓦废物变能源（WtE）工厂内部工艺水处理（PWT）中全氟和多氟烷基物质（PFAS）的去向。PFAS 用途广泛，但具有持久性，当产品寿命结束时会进入废物流。这项研究旨在确定 PFAS 从烟道气处理到污泥脱水装置的路径，并评估污泥脱水装置去除 PFAS 的效率。在 11 个目标 PFAS 中，有 9 个至少在一个样本中被检测到。PFAS 的总浓度每天都有变化，这可能是由于废燃料成分的波动造成的。泡沫中的 PFAS 平均浓度最高，约为处理水的 130 倍。然而，泡沫中 PFAS 的质量流量却大大低于处理水的质量流量，平均为处理水的 20 倍。研究得出的结论是，虽然可以通过一些关键的改变来提高内部污泥脱水装置对 PFAS 的去除能力，但在目前的配置下，污泥脱水装置无法有效去除工艺水中的 PFAS。

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引用次数: 0

Optimizing waste handling with interactive AI: Prompt-guided segmentation of construction and demolition waste using computer vision 利用交互式人工智能优化废物处理：利用计算机视觉对建筑和拆除废物进行提示性引导分割

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

Waste management

Pub Date : 2024-09-24 DOI: 10.1016/j.wasman.2024.09.018

Diani Sirimewan , Nilakshan Kunananthaseelan , Sudharshan Raman , Reyes Garcia , Mehrdad Arashpour

Optimized and automated methods for handling construction and demolition waste (CDW) are crucial for improving the resource recovery process in waste management. Automated waste recognition is a critical step in this process, and it relies on robust image segmentation techniques. Prompt-guided segmentation methods provide promising results for specific user needs in image recognition. However, the current state-of-the-art segmentation methods trained for generic images perform unsatisfactorily on CDW recognition tasks, indicating a domain gap. To address this gap, a user-guided segmentation pipeline is developed in this study that leverages prompts such as bounding boxes, points, and text to segment CDW in cluttered environments. The adopted approach achieves a class-wise performance of around 70 % in several waste categories, surpassing the state-of-the-art algorithms by 9 % on average. This method allows users to create accurate segmentations by drawing a bounding box, clicking, or providing a text prompt, minimizing the time spent on detailed annotations. Integrating this human–machine system as a user-friendly interface into material recovery facilities enhances the monitoring and processing of waste, leading to better resource recovery outcomes in waste management.

处理建筑和拆除废物（CDW）的优化和自动化方法对于改善废物管理中的资源回收过程至关重要。废物自动识别是这一过程中的关键步骤，它依赖于强大的图像分割技术。针对图像识别中的特定用户需求，提示引导分割方法提供了很好的结果。然而，目前最先进的、针对普通图像进行训练的分割方法在垃圾围堰识别任务中的表现并不令人满意，这表明存在领域差距。为了弥补这一差距，本研究开发了用户引导分割管道，利用边界框、点和文本等提示来分割杂乱环境中的 CDW。所采用的方法在多个废物类别中实现了约 70% 的分类性能，比最先进的算法平均高出 9%。这种方法允许用户通过绘制边界框、点击或提供文本提示来创建精确的分割，从而最大限度地减少了用于详细注释的时间。将这一人机系统作为用户友好界面集成到材料回收设施中，可加强对废物的监控和处理，从而在废物管理中实现更好的资源回收效果。

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引用次数: 0

Comparative assessment of solvent chemical delamination of end-of-life solar panels 报废太阳能电池板溶剂化学分层比较评估

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

Waste management

Pub Date : 2024-09-23 DOI: 10.1016/j.wasman.2024.09.014

Jackson Lee , Noel Duffy , James Petesic , Tom Witheridge , Jessica Allen

This work investigates the use of toluene, d-limonene and three deep eutectic solvents (based on choline chloride, urea and zinc chloride) for the delamination process of recovered and de-glassed end-of-life solar panels. The organic solvents that have been previously investigated for delamination such as toluene and trichloroethylene are generally hazardous and fossil fuel derived. To evaluate and compare the effectiveness of separation of alternative solvents to toluene, solar panel laminates recovered from end-of-life solar modules were exposed to the respective solvent at 30 °C, 90 °C and (for deep eutectic solvents) 160 °C for 30 – 60 min at each temperature. After chemical treatment the recovered photovoltaic material and encapsulant was sieved into the size fractions > 1.0 mm, 1.0 – 0.5 mm and < 0.5 mm before being oxidised at 550 °C to quantify the remaining encapsulant in each fraction by mass change. It was found that d-limonene has a similar degree of separation as toluene. Moreover, d-limonene showed an improved recovery of up to 4.5 times more photovoltaic cell material below the 1.0 mm size fraction making it a more effective alternative. No discernible effects were observed for either of the three deep eutectic solvent combinations tested. The experimental data obtained was used to model and compare a separation process based on toluene and d-limonene, with maximal solar photovoltaic cell recoveries of 10 % for toluene delamination and 39 % for d-limonene delamination in size fractions < 1.0 mm.

这项研究调查了甲苯、二柠檬烯和三种深共晶溶剂（基于氯化胆碱、尿素和氯化锌）在回收的报废太阳能电池板脱胶过程中的使用情况。以前研究过的用于分层的有机溶剂，如甲苯和三氯乙烯，一般都是危险的化石燃料。为了评估和比较甲苯替代溶剂的分离效果，将从报废太阳能电池组件中回收的太阳能电池板层压板分别置于 30 ℃、90 ℃ 和 160 ℃ 溶剂中（对于深共晶溶剂），每个温度下 30 - 60 分钟。经过化学处理后，回收的光伏材料和封装剂被筛分为 1.0 毫米、1.0 - 0.5 毫米和 0.5 毫米三个粒度等级，然后在 550 °C 下氧化，通过质量变化对每个等级中剩余的封装剂进行量化。研究发现，d-柠檬烯的分离程度与甲苯相似。此外，在 1.0 毫米以下的馏分中，d-柠檬烯的光电池材料回收率提高了 4.5 倍，使其成为更有效的替代品。在测试的三种深共晶溶剂组合中，没有观察到明显的影响。获得的实验数据被用来模拟和比较基于甲苯和二柠檬烯的分离过程，在尺寸分数为 1.0 毫米的情况下，甲苯分层的太阳能光伏电池最大回收率为 10%，二柠檬烯分层的最大回收率为 39%。

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引用次数: 0

Assessing the food recovery hierarchy concept from an eMergy accounting perspective: Validation and theoretical insights 从电子能量核算的角度评估食品回收等级概念：验证和理论见解

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

Waste management

Pub Date : 2024-09-23 DOI: 10.1016/j.wasman.2024.09.015

Federico Sulis, Feni Agostinho, Cecília M.V.B. Almeida, Biagio F. Giannetti

The food recovery hierarchy (FRH) is an important concept widely used worldwide as a guideline for food waste management policies. It consists of different options for food waste management hierarchically organized, in which source reduction is the most preferable option, followed by food donation, feeding animals, industrial use, composting, energy recovery, and landfilling. The most common approaches used in the literature to validate the FRH concept consider both, a user-side and donor-side perspectives. While the former are typical of methods such as life cycle assessment and ecological footprint that are extensively explored in the literature, the latter is typical of methods such as eMergy accounting (EMA), a perspective that remains unexplored. This study aims to overcome that literature gap by discussing: (i) The validity of FRH concept under an EMA perspective; (ii) The differences on saving natural resources depending on the adopted FRH option; (iii) Obtaining a mathematical model representing the saved emergy as a function of invested emergy. Results show that the FRH is confirmed under the EMA lens as expressed by the proposed emergy return index (ERI). The most preferable options within FRH are by far more efficient in saving emergy than the least preferable options (about 250 times better). The obtained model EMS=2.44E+22/EMI ^0.51 describes the relation between the invested and saved emergy along the FRH hierarchy. Insights are presented to promote discussions on existing ERIs cluster within the FRH.

食物回收等级制度（FRH）是全世界广泛使用的一个重要概念，是食物废物管理政策的指导原则。它由不同的厨余管理方案组成，按等级排列，源头减量是最可取的方案，其次是食物捐赠、喂养动物、工业利用、堆肥、能源回收和填埋。文献中用于验证 FRH 概念的最常见方法同时考虑了用户方和捐赠方的观点。前者是典型的生命周期评估和生态足迹等方法，在文献中得到了广泛的探讨，而后者则是典型的电子能量核算（EMA）等方法，是一种尚未被探讨的视角。本研究旨在通过讨论：(i) EMA 视角下 FRH 概念的有效性；(ii) 采用 FRH 方案在节约自然资源方面的差异；(iii) 获得一个数学模型，将节约的应急能量表示为投资应急能量的函数，从而克服文献空白。结果表明，在 EMA 的视角下，FRH 得到了证实，这体现在所提出的应急能源回报指数（ERI）上。在 FRH 中，最可取的方案在节约应急能源方面的效率远远高于最不可取的方案（约 250 倍）。所得模型 EMS=2.44E+22/EMI 0.51 描述了在 FRH 层次结构中投资和节约的应急能源之间的关系。所提出的见解可促进对 FRH 中现有 ERIs 群组的讨论。

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引用次数: 0

High-efficiency leaching process for selective leaching of lithium from spent lithium iron phosphate 从废磷酸铁锂中选择性萃取锂的高效萃取工艺

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

Waste management

Pub Date : 2024-09-23 DOI: 10.1016/j.wasman.2024.09.017

Guidong Li, Ye Chen, Mingkun Wu, Yuzhi Xu, Xiang Li, Mengkui Tian

With the arrival of the scrapping wave of lithium iron phosphate (LiFePO₄) batteries, a green and effective solution for recycling these waste batteries is urgently required. Reasonable recycling of spent LiFePO₄ (SLFP) batteries is critical for resource recovery and environmental preservation. In this study, mild and efficient, highly selective leaching of lithium from spent lithium iron phosphate was achieved using potassium pyrosulfate (K₂S₂O₇) and hydrogen peroxide (H₂O₂) as leaching agents. The leaching rates of lithium and iron were 99.83 % and 0.34 %, respectively, at the optimal leaching conditions of 4 vol% 30 wt% H₂O₂, 0.08 mol/L K₂S₂O₇, 25℃, 5 min, and a solid–liquid ratio of 20 g/L. Meanwhile, the mechanism of the leaching process was explored by thermodynamic, XRD, XPS, FTIR, and SEM analyses. The leaching solution was concentrated and purified, with the addition of potassium carbonate (K₂CO₃) to convert lithium into lithium carbonate (Li₂CO₃). A small amount of sulfuric acid (H₂SO₄) is added to the saline wastewater after precipitation, which can be converted into a leaching agent for recycling after heat treatment. This study provides a sustainable green process for the recovery of lithium iron phosphate and a new idea for resource recovery.

随着磷酸铁锂电池（LiFePO4）报废潮的到来，迫切需要一种绿色、有效的废电池回收解决方案。合理回收利用废旧磷酸铁锂电池对于资源回收和环境保护至关重要。本研究使用焦硫酸钾（K2S2O7）和过氧化氢（H2O2）作为浸出剂，实现了从废磷酸铁锂中温和、高效、高选择性地浸出锂。在 4 vol% 30 wt% H2O2、0.08 mol/L K2S2O7、25℃、5 min、固液比 20 g/L 的最佳浸出条件下，锂和铁的浸出率分别为 99.83 % 和 0.34 %。同时，通过热力学、XRD、XPS、傅立叶变换红外光谱和扫描电镜分析探索了浸出过程的机理。浸出液经过浓缩和净化，加入碳酸钾（K2CO3）将锂转化为碳酸锂（Li2CO3）。沉淀后的含盐废水中加入少量硫酸（H2SO4），经热处理后可转化为浸出剂循环使用。这项研究为磷酸铁锂的回收提供了一种可持续的绿色工艺，也为资源回收提供了一种新思路。

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