Pub Date : 2024-10-19DOI: 10.1016/j.wasman.2024.10.014
Minseob Lim, Youngjae Lee, Yongwoon Lee, Won Yang, Seongil Kim
The heating value and composition of waste are crucial operational variables for understanding waste incinerators behavior and optimizing their operation. However, because the heating value and composition of waste are highly variable, their prediction in waste incineration plants is difficult. To overcome this issue, this study developed a novel method to derive heating value and composition waste via a reverse calculation algorithm using operating data and physics-based model. In addition, a process simulation model was developed to predict the performance of waste incinerator systems. We derived heating values and compositions of waste in the target incinerator using the supposed method and proposed an operating strategy to improve the energy recovery efficiency of the waste incinerator through the process simulation model. The energy recovery efficiency increased by approximately 10 % relative to that of the existing incinerator operation. The methodology developed in this study can be applied to various incinerator systems. Our study findings contribute to establishing an optimal operation of a waste incinerator by calculating the heating value and composition of waste.
{"title":"Improving waste-incineration energy recovery efficiency using a reverse calculation algorithm to estimate waste composition and heating value","authors":"Minseob Lim, Youngjae Lee, Yongwoon Lee, Won Yang, Seongil Kim","doi":"10.1016/j.wasman.2024.10.014","DOIUrl":"10.1016/j.wasman.2024.10.014","url":null,"abstract":"<div><div>The heating value and composition of waste are crucial operational variables for understanding waste incinerators behavior and optimizing their operation. However, because the heating value and composition of waste are highly variable, their prediction in waste incineration plants is difficult. To overcome this issue, this study developed a novel method to derive heating value and composition waste via a reverse calculation algorithm using operating data and physics-based model. In addition, a process simulation model was developed to predict the performance of waste incinerator systems. We derived heating values and compositions of waste in the target incinerator using the supposed method and proposed an operating strategy to improve the energy recovery efficiency of the waste incinerator through the process simulation model. The energy recovery efficiency increased by approximately 10 % relative to that of the existing incinerator operation. The methodology developed in this study can be applied to various incinerator systems. Our study findings contribute to establishing an optimal operation of a waste incinerator by calculating the heating value and composition of waste.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"190 ","pages":"Pages 486-495"},"PeriodicalIF":7.1,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142476272","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}
Pub Date : 2024-10-19DOI: 10.1016/j.wasman.2024.10.015
Shaun T. Lancaster , Eskil Sahlin , Marcus Oelze , Markus Ostermann , Jochen Vogl , Valérie Laperche , Solène Touze , Jean-Philippe Ghestem , Claire Dalencourt , Régine Gendre , Jessica Stammeier , Ole Klein , Daniel Pröfrock , Gala Košarac , Aida Jotanovic , Luigi Bergamaschi , Marco Di Luzio , Giancarlo D’Agostino , Radojko Jaćimović , Melissa Eberhard , Johanna Irrgeher
As the drive towards recycling electronic waste increases, demand for rapid and reliable analytical methodology to analyse the metal content of the waste is increasing, e.g. to assess the value of the waste and to decide the correct recycling routes. Here, we comprehensively assess the suitability of different x-ray fluorescence spectroscopy (XRF)-based techniques as rapid analytical tools for the determination of critical raw materials, such as Al, Ti, Mn, Fe, Co, Ni, Cu, Zn, Nb, Pd and Au, in three electronic waste matrices: printed circuit boards (PCB), light emitting diodes (LED), and lithium (Li)-ion batteries. As validated reference methods and materials to establish metrological traceability are lacking, several laboratories measured test samples of each matrix using XRF as well as other independent complementary techniques (instrumental neutron activation analysis (INAA), inductively coupled plasma mass spectrometry (ICP-MS) and ICP optical emission spectrometry (OES)) as an inter-laboratory comparison (ILC). Results highlighted key aspects of sample preparation, limits of detection, and spectral interferences that affect the reliability of XRF, while additionally highlighting that XRF can provide more reliable data for certain elements compared to digestion-based approaches followed by ICP-MS analysis (e.g. group 4 and 5 metals). A clear distinction was observed in data processing methodologies for wavelength dispersive XRF, highlighting that considering the metals present as elements (rather than oxides) induces overestimations of the mass fractions when compared to other techniques. Eventually, the effect of sample particle size was studied and indicated that smaller particle size (<200 µm) is essential for reliable determinations.
{"title":"Evaluation of X-ray fluorescence for analysing critical elements in three electronic waste matrices: A comprehensive comparison of analytical techniques","authors":"Shaun T. Lancaster , Eskil Sahlin , Marcus Oelze , Markus Ostermann , Jochen Vogl , Valérie Laperche , Solène Touze , Jean-Philippe Ghestem , Claire Dalencourt , Régine Gendre , Jessica Stammeier , Ole Klein , Daniel Pröfrock , Gala Košarac , Aida Jotanovic , Luigi Bergamaschi , Marco Di Luzio , Giancarlo D’Agostino , Radojko Jaćimović , Melissa Eberhard , Johanna Irrgeher","doi":"10.1016/j.wasman.2024.10.015","DOIUrl":"10.1016/j.wasman.2024.10.015","url":null,"abstract":"<div><div>As the drive towards recycling electronic waste increases, demand for rapid and reliable analytical methodology to analyse the metal content of the waste is increasing, e.g. to assess the value of the waste and to decide the correct recycling routes. Here, we comprehensively assess the suitability of different x-ray fluorescence spectroscopy (XRF)-based techniques as rapid analytical tools for the determination of critical raw materials, such as Al, Ti, Mn, Fe, Co, Ni, Cu, Zn, Nb, Pd and Au, in three electronic waste matrices: printed circuit boards (PCB), light emitting diodes (LED), and lithium (Li)-ion batteries. As validated reference methods and materials to establish metrological traceability are lacking, several laboratories measured test samples of each matrix using XRF as well as other independent complementary techniques (instrumental neutron activation analysis (INAA), inductively coupled plasma mass spectrometry (ICP-MS) and ICP optical emission spectrometry (OES)) as an inter-laboratory comparison (ILC). Results highlighted key aspects of sample preparation, limits of detection, and spectral interferences that affect the reliability of XRF, while additionally highlighting that XRF can provide more reliable data for certain elements compared to digestion-based approaches followed by ICP-MS analysis (e.g. group 4 and 5 metals). A clear distinction was observed in data processing methodologies for wavelength dispersive XRF, highlighting that considering the metals present as elements (rather than oxides) induces overestimations of the mass fractions when compared to other techniques. Eventually, the effect of sample particle size was studied and indicated that smaller particle size (<200 µm) is essential for reliable determinations.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"190 ","pages":"Pages 496-505"},"PeriodicalIF":7.1,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142476271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Textiles are an integral part of daily life globally, but their widespread use leads to significant waste generation. Repurposing these discarded fabrics for energy harvesting offers a sustainable solution to both energy demand and textile waste management. In this study, Textile-based Triboelectric Nanogenerators (T-TENGs) were developed using recycled cloth as tribopositive layers and polyvinyl chloride (PVC) film as the tribonegative layer, with aluminum foil tape serving as electrodes. Five different recycled textiles were evaluated, and Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) analysis revealed a correlation between yarn structure and carbon content, leading to enhanced triboelectric performance. Silk-based TENG (S-TENG) demonstrated the highest output, with 320.76 V and 8.73 µA, while exhibiting stable performance over 10,000 cycles. Practical applications were explored by integrating T-TENGs into shoe insoles for energy harvesting during walking and jumping, with rayon-based TENG generating up to 208.52 V on a PVC coil mat. This work highlights the dual benefits of waste reduction and sustainable energy applications, making a compelling case for advanced technologies where recycled textiles function as frictional materials to harvest mechanical energy from human motion and convert it into electrical energy for use in flexible sensors and wearable devices.
纺织品是全球日常生活中不可或缺的一部分，但其广泛使用会产生大量废物。将这些废弃织物重新用于能源采集，为能源需求和纺织品废物管理提供了一种可持续的解决方案。本研究开发了基于纺织品的三电纳米发电机（T-TENGs），使用回收布料作为摩擦正极层，聚氯乙烯（PVC）薄膜作为摩擦负极层，铝箔胶带作为电极。对五种不同的回收纺织品进行了评估，扫描电子显微镜（SEM）和能量色散 X 射线光谱（EDS）分析表明，纱线结构与碳含量之间存在相关性，从而提高了三电性能。丝基 TENG（S-TENG）的输出功率最高，达到 320.76 V 和 8.73 µA，同时在 10,000 次循环中表现出稳定的性能。通过将 T-TENG 集成到鞋垫中，在行走和跳跃过程中进行能量收集，探索了实际应用，其中人造丝基 TENG 在 PVC 线圈垫上可产生高达 208.52 V 的电压。这项工作强调了减少废物和可持续能源应用的双重好处，为先进技术提供了令人信服的理由，即回收纺织品可作为摩擦材料，从人体运动中收集机械能，并将其转化为电能，用于柔性传感器和可穿戴设备。
{"title":"Electrifying waste textiles: Transforming fabric scraps into high-performance triboelectric nanogenerators for biomechanical energy harvesting","authors":"Sebghatullah Amini , Rumana Farheen Sagade Muktar Ahmed , Santosh Kumar , Sangamesha Madanahalli Ankanathappa , Krishnaveni Sannathammegowda","doi":"10.1016/j.wasman.2024.10.013","DOIUrl":"10.1016/j.wasman.2024.10.013","url":null,"abstract":"<div><div>Textiles are an integral part of daily life globally, but their widespread use leads to significant waste generation. Repurposing these discarded fabrics for energy harvesting offers a sustainable solution to both energy demand and textile waste management. In this study, Textile-based Triboelectric Nanogenerators (T-TENGs) were developed using recycled cloth as tribopositive layers and polyvinyl chloride (PVC) film as the tribonegative layer, with aluminum foil tape serving as electrodes. Five different recycled textiles were evaluated, and Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) analysis revealed a correlation between yarn structure and carbon content, leading to enhanced triboelectric performance. Silk-based TENG (S-TENG) demonstrated the highest output, with 320.76 V and 8.73 µA, while exhibiting stable performance over 10,000 cycles. Practical applications were explored by integrating T-TENGs into shoe insoles for energy harvesting during walking and jumping, with rayon-based TENG generating up to 208.52 V on a PVC coil mat. This work highlights the dual benefits of waste reduction and sustainable energy applications, making a compelling case for advanced technologies where recycled textiles function as frictional materials to harvest mechanical energy from human motion and convert it into electrical energy for use in flexible sensors and wearable devices.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"190 ","pages":"Pages 477-485"},"PeriodicalIF":7.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142476270","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}
Pub Date : 2024-10-18DOI: 10.1016/j.wasman.2024.10.011
Zixi Han , Xu Zhao , Bingxin Tong , Yongsong Mu , Xiangjun Yang , Yong Hou , Zhiping Zhu
With the development of modern breeding technology, the scale of dairy farming is becoming increasingly large, which leading to decoupling of planting and breeding. Hence, massive amounts of manure could not handled by traditional method in time, which caused serious environmental problems. Therefor, there is a urgent needs for industrialized treatment methods to treat cow manure for dairy farm industry. In order to expand the types of industrial treatment methods of cow manure, two types of industrialized cow manure based agriculture films were introduced in this research, manure slurry film (MSF) and manure paper film (MPF). Taking silage corn cultivation as an example, their feasibility were testified: the usage performances of the films were expanded by crop yield and soil physicochemical properties, and environmental impacts of the films was conducted by life cycle assessment (LCA). The results showed: (1) both MSF and MPF would decomposed in one growth period of silage maize, with MPF having better performance in temperature retention; (2) both MSF and MPF improved soil nutrients and agglomerate structures; (3) the yield of maize with MSF and MPF was increased from 62.6 t to 88.4 t and 84.6 t per hectare compared to control group; and (4) according to LCA, MPF had 39 % and 50 % lower average environment impact than PE film and MSF. In conclusion, manure based films could effectively promotes crop growth with lower environment impact compared with traditional methods, which thus might provide effective linkage strategies for coupling of planting and breeding.
{"title":"Preparation of agriculture film from cow manure for silage maize planting: Experimental study and life cycle assessment","authors":"Zixi Han , Xu Zhao , Bingxin Tong , Yongsong Mu , Xiangjun Yang , Yong Hou , Zhiping Zhu","doi":"10.1016/j.wasman.2024.10.011","DOIUrl":"10.1016/j.wasman.2024.10.011","url":null,"abstract":"<div><div>With the development of modern breeding technology, the scale of dairy farming is becoming increasingly large, which leading to decoupling of planting and breeding. Hence, massive amounts of manure could not handled by traditional method in time, which caused serious environmental problems. Therefor, there is a urgent needs for industrialized treatment methods to treat cow manure for dairy farm industry. In order to expand the types of industrial treatment methods of cow manure, two types of industrialized cow manure based agriculture films were introduced in this research, manure slurry film (MSF) and manure paper film (MPF). Taking silage corn cultivation as an example, their feasibility were testified: the usage performances of the films were expanded by crop yield and soil physicochemical properties, and environmental impacts of the films was conducted by life cycle assessment (LCA). The results showed: (1) both MSF and MPF would decomposed in one growth period of silage maize, with MPF having better performance in temperature retention; (2) both MSF and MPF improved soil nutrients and agglomerate structures; (3) the yield of maize with MSF and MPF was increased from 62.6 t to 88.4 t and 84.6 t per hectare compared to control group; and (4) according to LCA, MPF had 39 % and 50 % lower average environment impact than PE film and MSF. In conclusion, manure based films could effectively promotes crop growth with lower environment impact compared with traditional methods, which thus might provide effective linkage strategies for coupling of planting and breeding.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"190 ","pages":"Pages 465-476"},"PeriodicalIF":7.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446366","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}
Pub Date : 2024-10-17DOI: 10.1016/j.wasman.2024.10.007
Jessica Leindorf de Almeida , Joelle Dumouchel , Jeovana Jisla das Neves Santos , Yohan Dulac , Alexandre R. Cabral , Martin Héroux
The City of Montreal has committed to achieve carbon neutrality by 2050. To meet this commitment, the city has adopted the Climate Plan 2020–2030, which includes the treatment of landfill gas (LFG). Within this framework, this research aimed to investigate the efficiency of a biofilter designed to treat high volumes of low-concentration LFG collected from lateral trenches at the Complexe Environnemental de Saint-Michel (CESM) in Montreal. The methane oxidation layer (MOL) of this biofilter, employed a material composed of 50% compost and 50% wood chips. Over a 54-week monitoring period, the system effectively maintained temperature conditions favorable to bacterial activity and methane oxidation. To assess the accuracy of predicting the hydraulic behavior of a methane oxidation biosystem (MOB) using numerical modeling, the biofilter was designed and constructed with specific features. In particular, the pore voids at the interface between the MOL and the gas distribution layer (GDL) were intentionally blocked along the downstream quarter of the biofilter length. This design ensures that water reaches the occlusion point due to the capillary barrier effect. Moisture content values remained within the expected range for most of the monitoring phase but increased with time. Despite this issue, the biofilter achieved an average efficiency higher than 95%. The findings underscore the capability of biosystems to manage substantial volumes of lean LFG, but also highlight the importance of acclimatizing the compost before exposure to maximum landfill load.
{"title":"Construction, monitoring, and efficiency of a biofilter treating a high flow, lean, landfill gas","authors":"Jessica Leindorf de Almeida , Joelle Dumouchel , Jeovana Jisla das Neves Santos , Yohan Dulac , Alexandre R. Cabral , Martin Héroux","doi":"10.1016/j.wasman.2024.10.007","DOIUrl":"10.1016/j.wasman.2024.10.007","url":null,"abstract":"<div><div>The City of Montreal has committed to achieve carbon neutrality by 2050. To meet this commitment, the city has adopted the Climate Plan 2020–2030, which includes the treatment of landfill gas (LFG). Within this framework, this research aimed to investigate the efficiency of a biofilter designed to treat high volumes of low-concentration LFG collected from lateral trenches at the Complexe Environnemental de Saint-Michel (CESM) in Montreal. The methane oxidation layer (MOL) of this biofilter, employed a material composed of 50% compost and 50% wood chips. Over a 54-week monitoring period, the system effectively maintained temperature conditions favorable to bacterial activity and methane oxidation. To assess the accuracy of predicting the hydraulic behavior of a methane oxidation biosystem (MOB) using numerical modeling, the biofilter was designed and constructed with specific features. In particular, the pore voids at the interface between the MOL and the gas distribution layer (GDL) were intentionally blocked along the downstream quarter of the biofilter length. This design ensures that water reaches the occlusion point due to the capillary barrier effect. Moisture content values remained within the expected range for most of the monitoring phase but increased with time. Despite this issue, the biofilter achieved an average efficiency higher than 95%. The findings underscore the capability of biosystems to manage substantial volumes of lean LFG, but also highlight the importance of acclimatizing the compost before exposure to maximum landfill load.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"190 ","pages":"Pages 455-464"},"PeriodicalIF":7.1,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-17DOI: 10.1016/j.wasman.2024.10.008
Zongjing Lin , Huxiu Xu , Maoying Zhou , Ban Wang , Huawei Qin
Waste classification is an important measure to protect the environment. Existing waste classification methods mainly focus on scientific research, but lack attention to the challenges of waste classification in actual scenarios. For example, wastes with similar contours, similar textures, or contaminated appearance are difficult to be classified in actual scenarios. To address these issues, this paper proposes an innovative multi-scale feature fusion strategy (MFFS) to improve the classification accuracy of these wastes. MFFS combines local fine-grained features with global coarse-grained features to improve the feature expression ability of waste. However, how to effectively fuse these two features is a key challenge. This paper proposes a dual-scale feature fusion strategy, first fusing fine-grained features in the first dimension, then fusing coarse-grained features in the second dimension, and introducing spatial features to further enhance feature expression capabilities. In order to reduce the interference of background information, the model in this paper models global relationships based on convolutional features. The MFFS strategy achieved a classification accuracy of 95.5% on the self-built dataset and 94.1% on the public dataset TrashNet. The number of parameters of our model is reduced by 57.2% compared with the classic VGG16 and by 34.2% compared with the Vision Transformer. In addition, we designed an intelligent waste sorting device and deployed the MFFS model on the device to implement the application. Experiments show that our model has ideal accuracy and stability and can be promoted and applied.
{"title":"Waste classification strategy based on multi-scale feature fusion for intelligent waste recycling in office buildings","authors":"Zongjing Lin , Huxiu Xu , Maoying Zhou , Ban Wang , Huawei Qin","doi":"10.1016/j.wasman.2024.10.008","DOIUrl":"10.1016/j.wasman.2024.10.008","url":null,"abstract":"<div><div>Waste classification is an important measure to protect the environment. Existing waste classification methods mainly focus on scientific research, but lack attention to the challenges of waste classification in actual scenarios. For example, wastes with similar contours, similar textures, or contaminated appearance are difficult to be classified in actual scenarios. To address these issues, this paper proposes an innovative multi-scale feature fusion strategy (MFFS) to improve the classification accuracy of these wastes. MFFS combines local fine-grained features with global coarse-grained features to improve the feature expression ability of waste. However, how to effectively fuse these two features is a key challenge. This paper proposes a dual-scale feature fusion strategy, first fusing fine-grained features in the first dimension, then fusing coarse-grained features in the second dimension, and introducing spatial features to further enhance feature expression capabilities. In order to reduce the interference of background information, the model in this paper models global relationships based on convolutional features. The MFFS strategy achieved a classification accuracy of 95.5% on the self-built dataset and 94.1% on the public dataset TrashNet. The number of parameters of our model is reduced by 57.2% compared with the classic VGG16 and by 34.2% compared with the Vision Transformer. In addition, we designed an intelligent waste sorting device and deployed the MFFS model on the device to implement the application. Experiments show that our model has ideal accuracy and stability and can be promoted and applied.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"190 ","pages":"Pages 443-454"},"PeriodicalIF":7.1,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446187","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}
Pub Date : 2024-10-16DOI: 10.1016/j.wasman.2024.10.010
Jun Li , Menglan Wu , Zhen Wu , Weizhen Liu , Zhang Lin , Xiaoqin Li
Stainless steel dust (SSD) contains a high content of Cr and is listed as hazardous solid waste. However, SSD is mainly stockpiled in legacy waste sites due to its complexity and lack of investigation. Herein we comprehensively investigates the microscopic interaction between heavy metals and coexisting phases of SSD from the electric arc furnace (EAF). Furthermore, a new approach for extracting Cr from SSD was developed for the first time. It was found that SSD is enriched with Cr, Ni, Mn, and Zn. Most of these heavy metals are bound to stable spinel (e.g., FeCr2O4) and encapsulated by silicate. Using Na2S2O8 as the flux (1–24 mmol), under roasting at 350–750 °C in the air for 0.25–6 h, efficient heavy metal extraction can be achieved (Cr-80 %, Ni-86 %, Mn-93 %, Zn-94 %) at 650 °C for 1h. During the roasting processes, the silicate shell was broken, which facilitated the mass transfer of the oxidant. Fe(II) was oxidized to Fe(III) and collapsed the spinel structure, releasing the heavy metals during the following acid leaching. The total mass of SSD is reduced by 90–95 %, and detoxification of SSD is achieved after processing. In conclusion, efficient extraction refractory metals in SSD by Na2S2O8 roasting and the mechanism was elucidated for the first time. This method might also be applied for the treatment of other slags/ash waste that have a stable spinel structure and are encapsulated by silicate.
{"title":"Efficient extraction of refractory Cr from stainless steel dust by sodium persulfate oxidation roasting","authors":"Jun Li , Menglan Wu , Zhen Wu , Weizhen Liu , Zhang Lin , Xiaoqin Li","doi":"10.1016/j.wasman.2024.10.010","DOIUrl":"10.1016/j.wasman.2024.10.010","url":null,"abstract":"<div><div>Stainless steel dust (SSD) contains a high content of Cr and is listed as hazardous solid waste. However, SSD is mainly stockpiled in legacy waste sites due to its complexity and lack of investigation. Herein we comprehensively investigates the microscopic interaction between heavy metals and coexisting phases of SSD from the electric arc furnace (EAF). Furthermore, a new approach for extracting Cr from SSD was developed for the first time. It was found that SSD is enriched with Cr, Ni, Mn, and Zn. Most of these heavy metals are bound to stable spinel (e.g., FeCr<sub>2</sub>O<sub>4</sub>) and encapsulated by silicate. Using Na<sub>2</sub>S<sub>2</sub>O<sub>8</sub> as the flux (1–24 mmol), under roasting at 350–750 °C in the air for 0.25–6 h, efficient heavy metal extraction can be achieved (Cr-80 %, Ni-86 %, Mn-93 %, Zn-94 %) at 650 °C for 1h. During the roasting processes, the silicate shell was broken, which facilitated the mass transfer of the oxidant. Fe(II) was oxidized to Fe(III) and collapsed the spinel structure, releasing the heavy metals during the following acid leaching. The total mass of SSD is reduced by 90–95 %, and detoxification of SSD is achieved after processing. In conclusion, efficient extraction refractory metals in SSD by Na<sub>2</sub>S<sub>2</sub>O<sub>8</sub> roasting and the mechanism was elucidated for the first time. This method might also be applied for the treatment of other slags/ash waste that have a stable spinel structure and are encapsulated by silicate.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"190 ","pages":"Pages 423-431"},"PeriodicalIF":7.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441190","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}
Pub Date : 2024-10-16DOI: 10.1016/j.wasman.2024.10.006
A. Conversano , D. Sogni , G. Lombardelli , D. Di Bona , F. Viganò , S. Consonni
The increasing interest in Waste-to-Chemical (WtC) technologies operating with Solid Recovered Fuels (SRF) from non-recyclable plastic streams requires a quantitative analysis on the actual convenience of this alternative valorization pathway.
This study assesses SRF in selected WtC technologies for hydrogen and methanol production and compares it with the well-established practice of co-combustion in the cement industry. Two case studies are considered: the first one represents the current scenario where SRF is used in co-combustion for cement production meanwhile the chemical is produced by steam reforming; in the second scenario, the cement plant is fed with pet-coke only, leaving SRF as a feedstock for WtC.
WtC performance assessment has been carried out in Aspen Plus®, whereas cement production and steam reforming have been characterized based on literature information.
The two scenarios have been assessed for two SRF qualities (different LHV and biogenic content) calculating primary energy and fossil CO2 emissions.
The results show that SRF from plastic waste as a feedstock in WtC is less effective than its utilization in cement plant: when WtC technology for hydrogen production is adopted, additional 9.1% (SRF-1) and 8.6% (SRF-2) of energy consumption is estimated and 25.8% (SRF-1) and 24.1% (SRF-2) additional fossil CO2 is emitted with respect to the corresponding conventional cases (i.e., chemical from steam reforming and SRF burnt in the cement kiln). When considering methanol production, WtC technology requires 6.2% (SRF-1) and 5.6% (SRF-2) increase of primary energy and 30.2% (SRF-1) and 28.4% (SRF-2) additional fossil CO2 against the conventional cases.
{"title":"Energy and environmental assessment of solid recovered fuels valorisation: Waste-to-Chemicals options vs co-combustion in cement plants","authors":"A. Conversano , D. Sogni , G. Lombardelli , D. Di Bona , F. Viganò , S. Consonni","doi":"10.1016/j.wasman.2024.10.006","DOIUrl":"10.1016/j.wasman.2024.10.006","url":null,"abstract":"<div><div>The increasing interest in Waste-to-Chemical (WtC) technologies operating with Solid Recovered Fuels (SRF) from non-recyclable plastic streams requires a quantitative analysis on the actual convenience of this alternative valorization pathway.</div><div>This study assesses SRF in selected WtC technologies for hydrogen and methanol production and compares it with the well-established practice of co-combustion in the cement industry. Two case studies are considered: the first one represents the current scenario where SRF is used in co-combustion for cement production meanwhile the chemical is produced by steam reforming; in the second scenario, the cement plant is fed with pet-coke only, leaving SRF as a feedstock for WtC.</div><div>WtC performance assessment has been carried out in Aspen Plus®, whereas cement production and steam reforming have been characterized based on literature information.</div><div>The two scenarios have been assessed for two SRF qualities (different LHV and biogenic content) calculating primary energy and fossil CO<sub>2</sub> emissions.</div><div>The results show that SRF from plastic waste as a feedstock in WtC is less effective than its utilization in cement plant: when WtC technology for hydrogen production is adopted, additional 9.1% (SRF-1) and 8.6% (SRF-2) of energy consumption is estimated and 25.8% (SRF-1) and 24.1% (SRF-2) additional fossil CO<sub>2</sub> is emitted with respect to the corresponding conventional cases (i.e., chemical from steam reforming and SRF burnt in the cement kiln). When considering methanol production, WtC technology requires 6.2% (SRF-1) and 5.6% (SRF-2) increase of primary energy and 30.2% (SRF-1) and 28.4% (SRF-2) additional fossil CO<sub>2</sub> against the conventional cases.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"190 ","pages":"Pages 432-442"},"PeriodicalIF":7.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1016/j.wasman.2024.10.004
Wensi Zhang , Xiuyu Liu , Li Zhu , Wei Wang , Hongfang Song
With the continuous promotion of electric vehicle applications, the recycling of power battery is urgent. Some batteries, although not suitable for continued use in electric vehicles, can be recycled for echelon utilization or remanufacturing. Thus, this study considers an electric vehicle power battery closed-loop supply chain consisting of a manufacturer and a retailer. We develop three strategies: no production research and development effort strategy, production research and development effort strategy, and government subsidy for production research and development strategy. Optimal pricing and production research and development effort decisions are derived based on Stackelberg game. Results indicate that production research and development positively impact the recycling of waste electric vehicle power batteries, with government subsidy further amplifying this effect by offering higher buyback and recycling prices. Government subsidy encourages manufacturer to increase production research and development effort and lowers the market pricing of electric vehicle power batteries, making these batteries more accessible to consumers. A sizable consumer base can offset the increased costs of production research and development, enabling manufacturer and retailer to achieve greater profitability. Both manufacturer and retailer can benefit from production research and development and government subsidy, ultimately enhancing the profitability of the entire closed-loop supply chain.
{"title":"Pricing and production R&D decisions in power battery closed-loop supply chain considering government subsidy","authors":"Wensi Zhang , Xiuyu Liu , Li Zhu , Wei Wang , Hongfang Song","doi":"10.1016/j.wasman.2024.10.004","DOIUrl":"10.1016/j.wasman.2024.10.004","url":null,"abstract":"<div><div>With the continuous promotion of electric vehicle applications, the recycling of power battery is urgent. Some batteries, although not suitable for continued use in electric vehicles, can be recycled for echelon utilization or remanufacturing. Thus, this study considers an electric vehicle power battery closed-loop supply chain consisting of a manufacturer and a retailer. We develop three strategies: no production research and development effort strategy, production research and development effort strategy, and government subsidy for production research and development strategy. Optimal pricing and production research and development effort decisions are derived based on Stackelberg game. Results indicate that production research and development positively impact the recycling of waste electric vehicle power batteries, with government subsidy further amplifying this effect by offering higher buyback and recycling prices. Government subsidy encourages manufacturer to increase production research and development effort and lowers the market pricing of electric vehicle power batteries, making these batteries more accessible to consumers. A sizable consumer base can offset the increased costs of production research and development, enabling manufacturer and retailer to achieve greater profitability. Both manufacturer and retailer can benefit from production research and development and government subsidy, ultimately enhancing the profitability of the entire closed-loop supply chain.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"190 ","pages":"Pages 409-422"},"PeriodicalIF":7.1,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142438376","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}
Pub Date : 2024-10-14DOI: 10.1016/j.wasman.2024.10.005
Rui Zhao , Qihao Zeng , Liping Zhan , De Chen
The identification of waste composition based on target-detection is crucial in promoting sustainable solid waste management. However, discrimination of different solid waste categories in the presence of incomplete and insufficient feature information remains a challenge in multi-target detection. This paper proposes an improved You Only Look Once (YOLOX-S) model that enables the effective recognition of different waste components in complex environments, which enhances feature-information extraction ability regarding different dimensions by introducing a convolutional block attention module, an adaptive spatial feature fusion module, and an improved efficient intersection-over-union loss function. The improved model was trained on a self-constructed image dataset with multiple waste components and targets in various complex scenarios, including interference from similar color backgrounds, similar waste localization, and mutual waste occlusion. The experimental results showed that the improved model achieved a mean average precision (mAP) of 85.02 %, an increase of 5.32 % over the original YOLO model’s mAP, and that it reduced incidents related to inaccurate positioning and false and missed detection. Moreover, the improved model outperformed classical detection models including support vector machine, RestNet-18, and RestNet-50 on a public dataset, achieving a mAP of 94.85 %. The improved model is expected to be applied to intelligent monitoring for waste components in scenarios including indiscriminate waste disposal and illegal dumping, providing decision support for emergency management.
{"title":"Multi-target detection of waste composition in complex environments based on an improved YOLOX-S model","authors":"Rui Zhao , Qihao Zeng , Liping Zhan , De Chen","doi":"10.1016/j.wasman.2024.10.005","DOIUrl":"10.1016/j.wasman.2024.10.005","url":null,"abstract":"<div><div>The identification of waste composition based on target-detection is crucial in promoting sustainable solid waste management. However, discrimination of different solid waste categories in the presence of incomplete and insufficient feature information remains a challenge in multi-target detection. This paper proposes an improved You Only Look Once (YOLOX-S) model that enables the effective recognition of different waste components in complex environments, which enhances feature-information extraction ability regarding different dimensions by introducing a convolutional block attention module, an adaptive spatial feature fusion module, and an improved efficient intersection-over-union loss function. The improved model was trained on a self-constructed image dataset with multiple waste components and targets in various complex scenarios, including interference from similar color backgrounds, similar waste localization, and mutual waste occlusion. The experimental results showed that the improved model achieved a mean average precision (mAP) of 85.02 %, an increase of 5.32 % over the original YOLO model’s mAP, and that it reduced incidents related to inaccurate positioning and false and missed detection. Moreover, the improved model outperformed classical detection models including support vector machine, RestNet-18, and RestNet-50 on a public dataset, achieving a mAP of 94.85 %. The improved model is expected to be applied to intelligent monitoring for waste components in scenarios including indiscriminate waste disposal and illegal dumping, providing decision support for emergency management.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"190 ","pages":"Pages 398-408"},"PeriodicalIF":7.1,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434073","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号