Pub Date : 2024-11-12DOI: 10.1016/j.wasman.2024.11.003
Özge Östürk Sömek , Fikret Yıldız , Orhan Sevimoğlu
Combustion chamber deposits adversely affect the operating performance of gas engines. In this study, the elemental composition of deposit samples collected from the inner surface of combustion chambers in gas engines across three different facilities was examined using various methods. The proportional changes in metal oxides along the internal cross-sectional surfaces of the deposits were examined to depict the deposit formation process from beginning to end. Additionally, the study investigated the identification of metals accumulated in the engine oil, their contribution to deposit formation, and the accumulation mechanisms of metal oxide nanoparticles on the engine’s interior metal surfaces. The main elements identified in the deposits from the Odayeri and Kömürcüoda facilities were Si, S, and Ca, whereas deposits from the Dilovası facility contained Si and Sb. These major elements, identified by SEM-EDS, were confirmed through XRF analysis. XRD analysis further confirmed the presence of Ca and S as CaSO4 crystals in the deposits. Ca originates from additives used to increase the total base number of engine oil and control the corrosive effects of landfill gas. It has been determined that silicon accumulates in engine oil over time. An important finding is that metal oxides in the combustion chamber primarily accumulate through impaction, sticking, and thermophoresis mechanisms.
燃烧室沉积物会对燃气发动机的运行性能产生不利影响。在这项研究中，我们使用各种方法检测了从三个不同设备的燃气发动机燃烧室内表面收集的沉积物样本的元素组成。研究了沉积物内部横截面上金属氧化物的比例变化，以描述沉积物自始至终的形成过程。此外，该研究还调查了发动机油中积累的金属的识别、它们对沉积物形成的作用以及金属氧化物纳米颗粒在发动机内部金属表面的积累机制。在 Odayeri 和 Kömürcüoda 工厂的沉积物中发现的主要元素为 Si、S 和 Ca，而在 Dilovası 工厂的沉积物中则含有 Si 和 Sb。通过扫描电子显微镜-电子显微镜 (SEM-EDS) 确定的这些主要元素通过 XRF 分析得到了确认。XRD 分析进一步证实，矿床中的 Ca 和 S 以 CaSO4 晶体的形式存在。钙来自于用于增加机油总碱值和控制垃圾填埋气腐蚀性的添加剂。已确定硅会随着时间的推移在发动机油中累积。一个重要的发现是，燃烧室中的金属氧化物主要是通过撞击、粘附和热泳机制积累起来的。
{"title":"Comparative analysis of metal oxide nanoparticle accumulation in landfill gas engine combustion chambers: Insights from three sites","authors":"Özge Östürk Sömek , Fikret Yıldız , Orhan Sevimoğlu","doi":"10.1016/j.wasman.2024.11.003","DOIUrl":"10.1016/j.wasman.2024.11.003","url":null,"abstract":"<div><div>Combustion chamber deposits adversely affect the operating performance of gas engines. In this study, the elemental composition of deposit samples collected from the inner surface of combustion chambers in gas engines across three different facilities was examined using various methods. The proportional changes in metal oxides along the internal cross-sectional surfaces of the deposits were examined to depict the deposit formation process from beginning to end. Additionally, the study investigated the identification of metals accumulated in the engine oil, their contribution to deposit formation, and the accumulation mechanisms of metal oxide nanoparticles on the engine’s interior metal surfaces. The main elements identified in the deposits from the Odayeri and Kömürcüoda facilities were Si, S, and Ca, whereas deposits from the Dilovası facility contained Si and Sb. These major elements, identified by SEM-EDS, were confirmed through XRF analysis. XRD analysis further confirmed the presence of Ca and S as CaSO<sub>4</sub> crystals in the deposits. Ca originates from additives used to increase the total base number of engine oil and control the corrosive effects of landfill gas. It has been determined that silicon accumulates in engine oil over time. An important finding is that metal oxides in the combustion chamber primarily accumulate through impaction, sticking, and thermophoresis mechanisms.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"191 ","pages":"Pages 147-159"},"PeriodicalIF":7.1,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142629293","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 : 2024-11-11DOI: 10.1016/j.wasman.2024.11.011
Rana Adel , Irene Samy Fahim , Emad S. Bakhoum , Ahmed M. Ahmed , Sherif S. AbdelSalam
Expanded polystyrene (EPS) geofoam blocks are gaining acceptance across industries due to their low density, insulation properties, strength, compressibility, and shock absorption under dynamic loads. The effective application of EPS is impeded by restrictions imposed by using conventional polymer-based synthetic geomembrane insulation ought for protection. Meanwhile, the production process of the geomembrane has detrimental environmental impacts, incurs high costs, and limits the utilization of EPS blocks in various applications. This research aims to create an innovative nanocoating substance using nanocellulose derived from agricultural residues to provide an eco-friendly alternative to geomembranes. The nanocellulose was extracted from four agricultural waste materials; sugarcane bagasse, banana fibers, rice straw, and spent-ground coffee; where each had a local percentage yield of 35 %, 25 %, 19 %, and 10 %, respectively. Based upon a technical criterion provided by the transmission electron microscopy (TEM) micrographs, the TOPSIS multi-criteria decision-making method was used to rank the sustainability of waste materials. It was found that sugarcane bagasse (SCB) is the most sustainable type with the smallest nano particle size. Nanocellulose extracted from SCB was characterized using X-ray diffraction (XRD), energy dispersive X-ray (EDX), nuclear magnetic resonance (NMR), and Fourier transform infrared spectroscopy (FTIR). The innovative nanocellulose coating primarily consisted of a nanocellulose mixture (SCB + water), polyvinyl acetate (PVA), and zinc oxide. Fourteen distinct formulas were obtained to identify the optimal proportions suitable for application on EPS surface with respect to the nano particle size, purity, and binding energy between the elements. It was found that the optimum formula consists of 42 % SCB, 50 % PVA, and 8 % zinc oxide.
{"title":"Sustainable nanocellulose coating for EPS geofoam extracted from agricultural waste","authors":"Rana Adel , Irene Samy Fahim , Emad S. Bakhoum , Ahmed M. Ahmed , Sherif S. AbdelSalam","doi":"10.1016/j.wasman.2024.11.011","DOIUrl":"10.1016/j.wasman.2024.11.011","url":null,"abstract":"<div><div>Expanded polystyrene (EPS) geofoam blocks are gaining acceptance across industries due to their low density, insulation properties, strength, compressibility, and shock absorption under dynamic loads. The effective application of EPS is impeded by restrictions imposed by using conventional polymer-based synthetic geomembrane insulation ought for protection. Meanwhile, the production process of the geomembrane has detrimental environmental impacts, incurs high costs, and limits the utilization of EPS blocks in various applications. This research aims to create an innovative nanocoating substance using nanocellulose derived from agricultural residues to provide an eco-friendly alternative to geomembranes. The nanocellulose was extracted from four agricultural waste materials; sugarcane bagasse, banana fibers, rice straw, and spent-ground coffee; where each had a local percentage yield of 35 %, 25 %, 19 %, and 10 %, respectively. Based upon a technical criterion provided by the transmission electron microscopy (TEM) micrographs, the TOPSIS multi-criteria decision-making method was used to rank the sustainability of waste materials. It was found that sugarcane bagasse (SCB) is the most sustainable type with the smallest nano particle size. Nanocellulose extracted from SCB was characterized using X-ray diffraction (XRD), energy dispersive X-ray (EDX), nuclear magnetic resonance (NMR), and Fourier transform infrared spectroscopy (FTIR). The innovative nanocellulose coating primarily consisted of a nanocellulose mixture (SCB + water), polyvinyl acetate (PVA), and zinc oxide. Fourteen distinct formulas were obtained to identify the optimal proportions suitable for application on EPS surface with respect to the nano particle size, purity, and binding energy between the elements. It was found that the optimum formula consists of 42 % SCB, 50 % PVA, and 8 % zinc oxide.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"191 ","pages":"Pages 135-146"},"PeriodicalIF":7.1,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142629309","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 : 2024-11-11DOI: 10.1016/j.wasman.2024.10.030
Daniele Bruno , Marco Orlando , Edoardo Testa , Marco Carnevale Miino , Giulia Pesaro , Matteo Miceli , Loredano Pollegioni , Vincenzina Barbera , Elisa Fasoli , Lorenza Draghi , Alberto Pietro Damiano Baltrocchi , Navarro Ferronato , Raffaello Seri , Elena Maggi , Silvia Caccia , Morena Casartelli , Gianluca Molla , Maurizio Stefano Galimberti , Vincenzo Torretta , Andrea Vezzulli , Gianluca Tettamanti
The transition from a linear to a circular production system involves transforming waste into valuable resources. Insect-mediated bioconversion, particularly using black soldier fly (BSF) larvae, can offer a promising opportunity to convert the organic fraction of municipal solid waste (OFMSW) into protein-rich biomass. However, current regulatory restrictions do not allow the use of this substrate to obtain insect proteins for animal feed, prompting the exploration of other applications, such as the production of bioplastics. Here, we explored at laboratory scale an innovative and integrated circular supply chain which aims to valorize the OFMSW through BSF larvae for the production of biobased materials with high technological value. BSF larvae reared on this organic waste showed excellent growth performance and bioconversion rate of the substrate. The use of well-suited extraction methods allowed the isolation of high-purity lipids, proteins, and chitin fractions, which are building blocks to produce biobased materials. In particular, the protein fraction was used to develop biodegradable plastic films which showed potential for replacing traditional petroleum-based materials, with the possibility to be fully recycled back to amino acids. Socioeconomic analysis highlighted values generated along the entire supply chain, and life cycle assessment pointed out that lipid extraction was the most challenging step: implementation of more sustainable methods is thus needed to reduce the overall environmental impact of the proposed chain. In conclusion, this study represents a proof of concept gathering evidence to support the feasibility of an alternative supply chain that can promote circular economy while valorising organic waste.
{"title":"Valorization of organic waste through black soldier fly: On the way of a real circular bioeconomy process","authors":"Daniele Bruno , Marco Orlando , Edoardo Testa , Marco Carnevale Miino , Giulia Pesaro , Matteo Miceli , Loredano Pollegioni , Vincenzina Barbera , Elisa Fasoli , Lorenza Draghi , Alberto Pietro Damiano Baltrocchi , Navarro Ferronato , Raffaello Seri , Elena Maggi , Silvia Caccia , Morena Casartelli , Gianluca Molla , Maurizio Stefano Galimberti , Vincenzo Torretta , Andrea Vezzulli , Gianluca Tettamanti","doi":"10.1016/j.wasman.2024.10.030","DOIUrl":"10.1016/j.wasman.2024.10.030","url":null,"abstract":"<div><div>The transition from a linear to a circular production system involves transforming waste into valuable resources. Insect-mediated bioconversion, particularly using black soldier fly (BSF) larvae, can offer a promising opportunity to convert the organic fraction of municipal solid waste (OFMSW) into protein-rich biomass. However, current regulatory restrictions do not allow the use of this substrate to obtain insect proteins for animal feed, prompting the exploration of other applications, such as the production of bioplastics. Here, we explored at laboratory scale an innovative and integrated circular supply chain which aims to valorize the OFMSW through BSF larvae for the production of biobased materials with high technological value. BSF larvae reared on this organic waste showed excellent growth performance and bioconversion rate of the substrate. The use of well-suited extraction methods allowed the isolation of high-purity lipids, proteins, and chitin fractions, which are building blocks to produce biobased materials. In particular, the protein fraction was used to develop biodegradable plastic films which showed potential for replacing traditional petroleum-based materials, with the possibility to be fully recycled back to amino acids. Socioeconomic analysis highlighted values generated along the entire supply chain, and life cycle assessment pointed out that lipid extraction was the most challenging step: implementation of more sustainable methods is thus needed to reduce the overall environmental impact of the proposed chain. In conclusion, this study represents a proof of concept gathering evidence to support the feasibility of an alternative supply chain that can promote circular economy while valorising organic waste.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"191 ","pages":"Pages 123-134"},"PeriodicalIF":7.1,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142629311","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 : 2024-11-11DOI: 10.1016/j.wasman.2024.11.012
Frederik Dalgaard Kjaer , François-Xavier Joly
Plastic pollution has become a global environmental issue, with between 22 and 48 millions of tons of plastic waste accumulating in the environment annually. Transitioning from conventional plastics to biodegradable materials for single-use items could limit this accumulation, but the degradation advantage of biodegradable material over plastic lacks empirical evidence from in situ experiments. Here, we compared the short-term degradation of seven single-use items (e.g., shopping bags, take-away boxes), made from plastic and biodegradable materials, in both marine and terrestrial environments. Biodegradable items tended to degrade faster than their plastic counterparts, but this advantage occurred in less than half of the situations tested (6 out of 14 situations). Notably, biodegradable items degraded faster than plastic counterparts more often in the terrestrial (5 out of 7 items) compared to the marine (1 out of 7 items). Interestingly, biodegradable items made of plant-based materials, such as bagasse and cellulose, generally degraded more rapidly than plastic, while those made of polylactic acid rarely degraded faster than plastic. We conclude that biodegradable single-use items should not be disposed of in the environment and require adequate waste management, and we encourage future research on the long-term degradation of biodegradable items in a range of environments.
{"title":"Biodegradable waste does not always degrade faster than plastic","authors":"Frederik Dalgaard Kjaer , François-Xavier Joly","doi":"10.1016/j.wasman.2024.11.012","DOIUrl":"10.1016/j.wasman.2024.11.012","url":null,"abstract":"<div><div>Plastic pollution has become a global environmental issue, with between 22 and 48 millions of tons of plastic waste accumulating in the environment annually. Transitioning from conventional plastics to biodegradable materials for single-use items could limit this accumulation, but the degradation advantage of biodegradable material over plastic lacks empirical evidence from <em>in situ</em> experiments. Here, we compared the short-term degradation of seven single-use items (e.g., shopping bags, take-away boxes), made from plastic and biodegradable materials, in both marine and terrestrial environments. Biodegradable items tended to degrade faster than their plastic counterparts, but this advantage occurred in less than half of the situations tested (6 out of 14 situations). Notably, biodegradable items degraded faster than plastic counterparts more often in the terrestrial (5 out of 7 items) compared to the marine (1 out of 7 items). Interestingly, biodegradable items made of plant-based materials, such as bagasse and cellulose, generally degraded more rapidly than plastic, while those made of polylactic acid rarely degraded faster than plastic. We conclude that biodegradable single-use items should not be disposed of in the environment and require adequate waste management, and we encourage future research on the long-term degradation of biodegradable items in a range of environments.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"191 ","pages":"Pages 117-122"},"PeriodicalIF":7.1,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142629291","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}
Life cycle optimization (LCO) is an effective decision-making method combining life cycle assessment and optimization, which is capable of adjusting system configurations to meet specified sustainability goals. This study analyzed the status quo of LCO studies related to sustainable waste management and the circular economy. Most studies have focused on simultaneously optimizing environmental and economic objectives, whereas few have considered social impacts. Greenhouse gas emissions is the most commonly used environmental indicator in optimization, followed by the endpoint single-score indicator. A static deterministic model is often employed to formulate an LCO problem, while uncertainty and dynamic models are less frequently applied but cause concerns. To deal with multi-objective optimization, the ε-constraint method and non-dominated sorting genetic algorithm are popular. Waste LCO has been mainly applied to macro system planning, such as integrated municipal solid waste management systems, biowaste supply chains, waste-to-energy systems, and waste-to-resource networks, aiming to determine optimal waste allocation, facility capacity/location, technology choice, etc. It is occasionally used in optimizing process structure, operating conditions, blending ratio of feedstocks, and product development. Future research should focus on exploring the integration of more environmental and social indicators into multi-objective optimization, modeling under uncertainty, dynamic LCO, process and product optimization, and addressing the lack of multi-scale studies.
{"title":"Life cycle optimization oriented to sustainable waste management and circular economy: A review","authors":"Dandan Zhao , Yong Chen , Haoran Yuan , Dezhen Chen","doi":"10.1016/j.wasman.2024.11.001","DOIUrl":"10.1016/j.wasman.2024.11.001","url":null,"abstract":"<div><div>Life cycle optimization (LCO) is an effective decision-making method combining life cycle assessment and optimization, which is capable of adjusting system configurations to meet specified sustainability goals. This study analyzed the status quo of LCO studies related to sustainable waste management and the circular economy. Most studies have focused on simultaneously optimizing environmental and economic objectives, whereas few have considered social impacts. Greenhouse gas emissions is the most commonly used environmental indicator in optimization, followed by the endpoint single-score indicator. A static deterministic model is often employed to formulate an LCO problem, while uncertainty and dynamic models are less frequently applied but cause concerns. To deal with multi-objective optimization, the ε-constraint method and non-dominated sorting genetic algorithm are popular. Waste LCO has been mainly applied to macro system planning, such as integrated municipal solid waste management systems, biowaste supply chains, waste-to-energy systems, and waste-to-resource networks, aiming to determine optimal waste allocation, facility capacity/location, technology choice, etc. It is occasionally used in optimizing process structure, operating conditions, blending ratio of feedstocks, and product development. Future research should focus on exploring the integration of more environmental and social indicators into multi-objective optimization, modeling under uncertainty, dynamic LCO, process and product optimization, and addressing the lack of multi-scale studies.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"191 ","pages":"Pages 89-106"},"PeriodicalIF":7.1,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142629300","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}
The increasing disposal of waste tires is a growing environmental challenge requiring innovative recycling and reuse approaches. Crumb rubber, derived from end-of-life tires, has potential for various applications where resilience and elasticity are required. However, as highlighted by the upcoming ban on using crumb rubber granulate as infill for artificial turf in the EU, one of the most prominent issues, zinc leaching, urgently requires an effective solution. We studied a range of commercial polymer coatings as a zinc leaching barrier through batch and column leaching tests. This study demonstrates that coatings can reduce the leaching down to 1 % of that of uncoated rubber, reducing environmental risks while improving the prospects for continued use of crumb rubber in various applications. The physico-chemical relation between the coating structure and zinc leaching is elucidated for the most promising coatings by comparing the leaching results with FTIR, GPC and 1H NMR analyses. The use of certain additives shows a cumulative effect to further reduce zinc leaching, while improving UV- and moisture stability. Thermal stability is controlled by the stability of the polymer base. These findings allow us to tailor the mechanical properties to various applications requiring specific elasticity and durability, while retaining the versatility and adaptability of crumb rubber in a range of scenarios. Additionally, the use of additives, typically cheaper than the polymer matrix, enhances the economic viability. By effectively controlling zinc leaching and tailoring mechanical properties through coatings, this study offers a way to extend the life and utility of waste rubbers.
{"title":"Mitigation of zinc leaching from waste ground tire rubbers through polymer encapsulation","authors":"Muhammad Adeel , Yanou Fishel , Johan Blom , Freddy Dardenne , Bart Michielsen , Jef Bergmans , Lorenz Van Nueten , Cedric Vuye , Christophe M.L. Vande Velde , Pieter Billen","doi":"10.1016/j.wasman.2024.11.008","DOIUrl":"10.1016/j.wasman.2024.11.008","url":null,"abstract":"<div><div>The increasing disposal of waste tires is a growing environmental challenge requiring innovative recycling and reuse approaches. Crumb rubber, derived from end-of-life tires, has potential for various applications where resilience and elasticity are required. However, as highlighted by the upcoming ban on using crumb rubber granulate as infill for artificial turf in the EU, one of the most prominent issues, zinc leaching, urgently requires an effective solution. We studied a range of commercial polymer coatings as a zinc leaching barrier through batch and column leaching tests. This study demonstrates that coatings can reduce the leaching down to 1 % of that of uncoated rubber, reducing environmental risks while improving the prospects for continued use of crumb rubber in various applications. The physico-chemical relation between the coating structure and zinc leaching is elucidated for the most promising coatings by comparing the leaching results with FTIR, GPC and <sup>1</sup>H NMR analyses. The use of certain additives shows a cumulative effect to further reduce zinc leaching, while improving UV- and moisture stability. Thermal stability is controlled by the stability of the polymer base. These findings allow us to tailor the mechanical properties to various applications requiring specific elasticity and durability, while retaining the versatility and adaptability of crumb rubber in a range of scenarios. Additionally, the use of additives, typically cheaper than the polymer matrix, enhances the economic viability. By effectively controlling zinc leaching and tailoring mechanical properties through coatings, this study offers a way to extend the life and utility of waste rubbers.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"191 ","pages":"Pages 107-116"},"PeriodicalIF":7.1,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142629303","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 : 2024-11-08DOI: 10.1016/j.wasman.2024.11.005
Xiqing Cui, Xunan Ning, Jianyi Zhang, Dingyuan Zhang, Guoqiang Qiu, Yi Wang
Magnetization roasting of iron tailings (IT) is an effective method to recovery fine iron concentrate (IC) from refractory IT. However, the migration and transformation of sulfur during the roasting process remain unclear, impacting iron quality if sulfur content exceeds the allowable limit value. This study investigates the sulfur release and fixation during magnetization roasting of textile dyeing sludge (TDS) and IT, elucidating the sulfur migration and transformation processes. Results indicate that 31.7 % of sulfur migrates to the gas phase due to the thermal decomposition of organic-S and the reduction of high-valent sulfur to SO2 by H2 and CO. The total sulfur (TS) content in tailing slag (TSL) (1.96 %) is significantly higher than that in the roasted product (RP) (0.84 %), suggesting a tendency for sulfur migration into TSL. This migration is attributed to reactions between H2S/COS and Fe2O3/Fe3O4, resulting in the formation of non-magnetic byproduct FeS. Additionally, due to the symbiosis of hematite and sulfate, sulfur in the IC primarily exists as sulfate sulfur (76.98 %). This research is crucial for quality control in iron ore processing and provides theoretical guidance for sulfur regulation in practical production processes.
对铁尾矿（IT）进行磁化焙烧是一种从难选 IT 中回收精铁精矿（IC）的有效方法。然而，硫在焙烧过程中的迁移和转化仍不清楚，如果硫含量超过允许限值，就会影响铁的质量。本研究调查了纺织印染污泥（TDS）和 IT 在磁化焙烧过程中的硫释放和固定情况，阐明了硫的迁移和转化过程。结果表明，由于有机硫的热分解以及 H2 和 CO 将高价硫还原为 SO2，31.7% 的硫迁移到气相中。尾渣 (TSL) 中的总硫 (TS) 含量（1.96%）明显高于焙烧产品 (RP) 中的总硫 (0.84%)，这表明硫有向 TSL 中迁移的趋势。这种迁移可归因于 H2S/COS 与 Fe2O3/Fe3O4 之间的反应，从而形成非磁性副产品 FeS。此外，由于赤铁矿和硫酸盐的共生作用，集成电路中的硫主要以硫酸盐硫（76.98%）的形式存在。这项研究对铁矿石加工的质量控制至关重要，并为实际生产过程中的硫调节提供了理论指导。
{"title":"Insights into sulfur migration and transformation during the magnetization roasting of iron tailings and textile dyeing sludge","authors":"Xiqing Cui, Xunan Ning, Jianyi Zhang, Dingyuan Zhang, Guoqiang Qiu, Yi Wang","doi":"10.1016/j.wasman.2024.11.005","DOIUrl":"10.1016/j.wasman.2024.11.005","url":null,"abstract":"<div><div>Magnetization roasting of iron tailings (IT) is an effective method to recovery fine iron concentrate (IC) from refractory IT. However, the migration and transformation of sulfur during the roasting process remain unclear, impacting iron quality if sulfur content exceeds the allowable limit value. This study investigates the sulfur release and fixation during magnetization roasting of textile dyeing sludge (TDS) and IT, elucidating the sulfur migration and transformation processes. Results indicate that 31.7 % of sulfur migrates to the gas phase due to the thermal decomposition of organic-S and the reduction of high-valent sulfur to SO<sub>2</sub> by H<sub>2</sub> and CO. The total sulfur (TS) content in tailing slag (TSL) (1.96 %) is significantly higher than that in the roasted product (RP) (0.84 %), suggesting a tendency for sulfur migration into TSL. This migration is attributed to reactions between H<sub>2</sub>S/COS and Fe<sub>2</sub>O<sub>3</sub>/Fe<sub>3</sub>O<sub>4</sub>, resulting in the formation of non-magnetic byproduct FeS. Additionally, due to the symbiosis of hematite and sulfate, sulfur in the IC primarily exists as sulfate sulfur (76.98 %). This research is crucial for quality control in iron ore processing and provides theoretical guidance for sulfur regulation in practical production processes.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"191 ","pages":"Pages 81-88"},"PeriodicalIF":7.1,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142629298","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 : 2024-11-07DOI: 10.1016/j.wasman.2024.11.007
Ying Tian , Sichao Cai , Yuansen Li , Lin He , Hong Sui
The management of large volumes of hazardous organic waste poses remarkable challenges due to costs and environmental pollution in industrial processes. Developing a universal strategy for recycling such waste is crucial for environmental protection. Herein, a reaction-based strategy has been proposed to recover and recycle the heavy phenolic slag wastes (HPSW) in a high-valued way. After analyzing the chemical structure of HPSW, the polycondensation method has been used to convert HPSW into an activated carbon adhesive (ACA) through reaction between phenolic hydroxyl groups and formaldehyde. The newly prepared activated carbon sample (AC-12, at optimal conditions) exhibited a high iodine value of 1320.80 mg·g−1 and a specific surface area of 1368.8 m2·g−1. It demonstrates high efficiency in adsorbing organic pollutants from both gaseous (p-xylene vapor) and liquid phases (methylene blue), with an equilibration time under 15 min, achieving the standard of high-end commercial ACs. This environmentally friendly and cost-effective method offers innovative approaches for the resourceful recycling and treatment of various types of organic waste, facilitating the efficient utilization and disposal of hazardous organic solid wastes in industries.
{"title":"Low-carbon and high-value utilization of hazardous industrial organic waste: From molecular mechanism to application","authors":"Ying Tian , Sichao Cai , Yuansen Li , Lin He , Hong Sui","doi":"10.1016/j.wasman.2024.11.007","DOIUrl":"10.1016/j.wasman.2024.11.007","url":null,"abstract":"<div><div>The management of large volumes of hazardous organic waste poses remarkable challenges due to costs and environmental pollution in industrial processes. Developing a universal strategy for recycling such waste is crucial for environmental protection. Herein, a reaction-based strategy has been proposed to recover and recycle the heavy phenolic slag wastes (HPSW) in a high-valued way. After analyzing the chemical structure of HPSW, the polycondensation method has been used to convert HPSW into an activated carbon adhesive (ACA) through reaction between phenolic hydroxyl groups and formaldehyde. The newly prepared activated carbon sample (AC-12, at optimal conditions) exhibited a high iodine value of 1320.80 mg·g<sup>−1</sup> and a specific surface area of 1368.8 m<sup>2</sup>·g<sup>−1</sup>. It demonstrates high efficiency in adsorbing organic pollutants from both gaseous (<em>p</em>-xylene vapor) and liquid phases (methylene blue), with an equilibration time under 15 min, achieving the standard of high-end commercial ACs. This environmentally friendly and cost-effective method offers innovative approaches for the resourceful recycling and treatment of various types of organic waste, facilitating the efficient utilization and disposal of hazardous organic solid wastes in industries.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"191 ","pages":"Pages 56-69"},"PeriodicalIF":7.1,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142606128","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 : 2024-11-07DOI: 10.1016/j.wasman.2024.11.002
Anna Iliushina , Gleb Mazanov , Sergey Nesteruk , Andrey Pimenov , Anton Stepanov , Nadezhda Mikhaylova , Anna Baldycheva , Andrey Somov
Computer vision systems have been integrated into facilities dealing with the sorting of household waste. This solution allows for the sorting efficiency improvement and cost reduction. However, challenges associated with the poor annotation quality of existing waste segmentation datasets, unsuitable environment for recognition on a conveyor belt, or limited data for creating an effective and cost-efficient sorting system using visible range cameras significantly limit the application efficiency of computer vision systems. In this article, we report on the data-centric pipeline for enhancing the precision of predictions in multiclass household waste segmentation on a conveyor belt. In particular, we have demonstrated that by employing a pseudo-annotation approach combined with an object-based data augmentation algorithm, it is possible to train a model on a set of ’simple’ images and achieve satisfactory results when estimating the model on a set of ’complex’ images. We collected and prepared the dataset consisting of 5 k manually labeled data and additionally 10 k pseudo-labeled data by object-based augmentation. The proposed pipeline incorporates data balancing, transfer learning, and pseudo-labeling to improve the mean Average Precision (mAP) of the YOLOV8 segmentation model from 67 % to 83 % for ’simple’ use case scenarios and from 42 % to 59 % or ’complex’ industrial solutions.
{"title":"Data-centric approach for instance segmentation in optical waste sorting","authors":"Anna Iliushina , Gleb Mazanov , Sergey Nesteruk , Andrey Pimenov , Anton Stepanov , Nadezhda Mikhaylova , Anna Baldycheva , Andrey Somov","doi":"10.1016/j.wasman.2024.11.002","DOIUrl":"10.1016/j.wasman.2024.11.002","url":null,"abstract":"<div><div>Computer vision systems have been integrated into facilities dealing with the sorting of household waste. This solution allows for the sorting efficiency improvement and cost reduction. However, challenges associated with the poor annotation quality of existing waste segmentation datasets, unsuitable environment for recognition on a conveyor belt, or limited data for creating an effective and cost-efficient sorting system using visible range cameras significantly limit the application efficiency of computer vision systems. In this article, we report on the data-centric pipeline for enhancing the precision of predictions in multiclass household waste segmentation on a conveyor belt. In particular, we have demonstrated that by employing a pseudo-annotation approach combined with an object-based data augmentation algorithm, it is possible to train a model on a set of ’simple’ images and achieve satisfactory results when estimating the model on a set of ’complex’ images. We collected and prepared the dataset consisting of 5 k manually labeled data and additionally 10 k pseudo-labeled data by object-based augmentation. The proposed pipeline incorporates data balancing, transfer learning, and pseudo-labeling to improve the mean Average Precision (mAP) of the YOLOV8 segmentation model from 67 % to 83 % for ’simple’ use case scenarios and from 42 % to 59 % or ’complex’ industrial solutions.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"191 ","pages":"Pages 70-80"},"PeriodicalIF":7.1,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142606118","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 : 2024-11-06DOI: 10.1016/j.wasman.2024.11.004
Georgios Garbounis , Helen Karasali , Dimitrios Komilis
After pesticide application onto crops, waste plastic pesticide containers (WPPC) may still contain residual active substances (AS) that are typically hazardous. Specific limits exist per pesticide active substance to classify WPPC as hazardous or non-hazardous wastes. The most frequent limit is 0.1% w/w (mass of active substance per mass of as received container). Triple rinsing is a widely used management technique to decontaminate WPPC and determine their downstream management. However, its efficiency needs to be evaluated for new types of pesticides. The goal of the work was to measure the residual contents of 15 new pesticide AS, widely used all over the world, before and after triple rinsing using 56 WPPC. In addition, the contents of pesticide AS sorbed onto the plastic containers are analyzed for the first time. Results show that all unrinsed WPPC had residual AS contents above the hazard limits except for four AS. Triple rinsing removed from 68.3% (minimum) to 99.9% (maximum) of the liquid contents of 15 active substances. However, due to high variances of the AS contents after triple rinsing, mean values before and after rinsing were statistically equal for 8 out of 14 AS. The sorbed AS contents ranged from 3% to 97% of the total AS content. Only Azoxystrobin’s total content (i.e. the sum of liquid and sorbed phases) slightly exceeded the hazard limit of 0.1% w/w. Conclusively, triple rinsing may not always lead to AS content reductions below hazard limits. The sorbed contents should be considered to check legal compliances.
在农作物上施用农药后，废塑料农药容器（WPPC）仍可能含有残留的活性物质（AS），而这些物质通常是有害的。每种农药活性物质都有特定的限制，可将 WPPC 划分为危险废物或非危险废物。最常见的限值是 0.1% w/w（活性物质的质量/接收容器的质量）。三重漂洗是一种广泛使用的管理技术，用于净化 WPPC 并确定其下游管理。然而，需要对新型农药的效率进行评估。这项工作的目标是在使用 56 个 WPPC 进行三重漂洗之前和之后，测量在全球广泛使用的 15 种新农药 AS 的残留含量。此外，还首次分析了吸附在塑料容器上的农药 AS 的含量。结果表明，除四种 AS 外，所有未经漂洗的 WPPC 的残留 AS 含量都超过了危害限值。三重漂洗可去除 68.3%（最少）至 99.9%（最多）的 15 种活性物质的液体含量。不过，由于三重漂洗后的 AS 含量差异较大，在 14 种 AS 中，有 8 种在漂洗前后的平均值在统计上是相等的。吸附的 AS 含量占总 AS 含量的比例从 3% 到 97% 不等。只有唑啉草酯的总含量（即液相和吸附相的总和）略微超过了 0.1% w/w 的危害限值。总之，三重漂洗不一定能使 AS 含量降至危害限值以下。在检查是否符合法律规定时，应考虑吸附含量。
{"title":"Triple water rinsing does not always render waste plastic pesticide containers non-hazardous waste","authors":"Georgios Garbounis , Helen Karasali , Dimitrios Komilis","doi":"10.1016/j.wasman.2024.11.004","DOIUrl":"10.1016/j.wasman.2024.11.004","url":null,"abstract":"<div><div>After pesticide application onto crops, waste plastic pesticide containers (WPPC) may still contain residual active substances (AS) that are typically hazardous. Specific limits exist per pesticide active substance to classify WPPC as hazardous or non-hazardous wastes. The most frequent limit is 0.1% w/w (mass of active substance per mass of as received container). Triple rinsing is a widely used management technique to decontaminate WPPC and determine their downstream management. However, its efficiency needs to be evaluated for new types of pesticides. The goal of the work was to measure the residual contents of 15 new pesticide AS, widely used all over the world, before and after triple rinsing using 56 WPPC. In addition, the contents of pesticide AS sorbed onto the plastic containers are analyzed for the first time. Results show that all unrinsed WPPC had residual AS contents above the hazard limits except for four AS. Triple rinsing removed from 68.3% (minimum) to 99.9% (maximum) of the liquid contents of 15 active substances. However, due to high variances of the AS contents after triple rinsing, mean values before and after rinsing were statistically equal for 8 out of 14 AS. The sorbed AS contents ranged from 3% to 97% of the total AS content. Only Azoxystrobin’s total content (i.e. the sum of liquid and sorbed phases) slightly exceeded the hazard limit of 0.1% w/w. Conclusively, triple rinsing may not always lead to AS content reductions below hazard limits. The sorbed contents should be considered to check legal compliances.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"191 ","pages":"Pages 47-55"},"PeriodicalIF":7.1,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592671","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}
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