Waste management最新文献

Identifying plastic materials in post-consumer food containers and packaging waste using terahertz spectroscopy and machine learning

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

Waste management

Pub Date : 2025-02-18 DOI: 10.1016/j.wasman.2025.02.018

Kazuaki Okubo , Gaku Manago , Tadao Tanabe , Jeongsoo Yu , Xiaoyue Liu , Tetsuo Sasaki

Accurate identification of plastic materials from post-consumer food container and packaging waste is crucial for enhancing the purity and added value of recycled materials, thereby promoting recycling and addressing the issue of plastic pollution. However, the diverse characteristics of post-consumer plastics—such as variations in shape and additives—cause variations in spectral features like transmittance, even within the same material type. In this study, we combined near-infrared (NIR) and terahertz (THz) spectroscopies with machine learning (ML) techniques, specifically XGBoost and Bayesian optimization, to accurately identify transparent polyethylene terephthalate (PET), transparent polystyrene (PS), and black PS. We achieved a precision score exceeding 90%. Furthermore, using explainable AI (XAI) techniques, we evaluated the roles of NIR and THz waves in distinguishing between these plastics. We found that transmittance measured at a frequency of 0.140 THz was effective for identifying transparent PS, while the transmittance at 0.075 THz was crucial for identifying transparent PET. Additionally, NIR spectroscopy proved to be highly effective in distinguishing black PS from transparent plastics. Our findings indicate that the significance of THz frequencies varies depending on the material, highlighting that the identification technology developed in this study not only complements widely used NIR spectroscopy but also offers valuable insights into selecting effective frequencies for high-precision identification systems. Additionally, we discuss potential directions for further research to advance identification systems utilizing THz spectroscopy and ML techniques based on these findings.

{"title":"Identifying plastic materials in post-consumer food containers and packaging waste using terahertz spectroscopy and machine learning","authors":"Kazuaki Okubo , Gaku Manago , Tadao Tanabe , Jeongsoo Yu , Xiaoyue Liu , Tetsuo Sasaki","doi":"10.1016/j.wasman.2025.02.018","DOIUrl":"10.1016/j.wasman.2025.02.018","url":null,"abstract":"<div><div>Accurate identification of plastic materials from post-consumer food container and packaging waste is crucial for enhancing the purity and added value of recycled materials, thereby promoting recycling and addressing the issue of plastic pollution. However, the diverse characteristics of post-consumer plastics—such as variations in shape and additives—cause variations in spectral features like transmittance, even within the same material type. In this study, we combined near-infrared (NIR) and terahertz (THz) spectroscopies with machine learning (ML) techniques, specifically XGBoost and Bayesian optimization, to accurately identify transparent polyethylene terephthalate (PET), transparent polystyrene (PS), and black PS. We achieved a precision score exceeding 90%. Furthermore, using explainable AI (XAI) techniques, we evaluated the roles of NIR and THz waves in distinguishing between these plastics. We found that transmittance measured at a frequency of 0.140 THz was effective for identifying transparent PS, while the transmittance at 0.075 THz was crucial for identifying transparent PET. Additionally, NIR spectroscopy proved to be highly effective in distinguishing black PS from transparent plastics. Our findings indicate that the significance of THz frequencies varies depending on the material, highlighting that the identification technology developed in this study not only complements widely used NIR spectroscopy but also offers valuable insights into selecting effective frequencies for high-precision identification systems. Additionally, we discuss potential directions for further research to advance identification systems utilizing THz spectroscopy and ML techniques based on these findings.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"196 ","pages":"Pages 32-41"},"PeriodicalIF":7.1,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143427802","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}

引用次数: 0

Hydrothermally-targeted synthesis of Al-substituted tobermorite using MSWI fly ash with industrial SiO2 for potentially high-quality utilization

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

Waste management

Pub Date : 2025-02-16 DOI: 10.1016/j.wasman.2025.02.026

Xinlong Chen , Deli Wu , Bo Yang , Xiaofeng Gao , Xunchang Fei , Hongping He

Al-substituted tobermorite (TOB) can be synthesized as a value-added product through hydrothermal treatment (HT) using incineration fly ash (IFA) with an exogenous additive. However, extreme conditions and low purity limit its further use. To solve these issues, we explored the potential of industrial SiO₂ (i-SiO₂) in synthesizing Al-substituted TOB using IFA from two megacities: Shanghai (IFA-H) and Shenzhen (IFA-Z). Results showed that vast majority of Ca, Si, and Al in IFA and i-SiO₂ can be converted into Al-substituted TOB, allowing for targeted synthesis with low i-SiO₂ mass. Besides, the experimental condition, e.g., 0.4 mol/L of NaOH concentration, 160 °C of reaction temperature, and 24 h of reaction time, appears to be milder than the previous relevant studies. Both Al-substituted TOBs had Cl⁻ contents below 5.0 wt%, and total immobilization efficiencies for typical heavy metals exceeded 98.0 wt%. The cation exchange capacities (CECs) for Al-substituted TOBs from IFA-H and IFA-Z were 424.0 cmol/kg and 241.3 cmol/kg, respectively, comparable to commercial zeolite and indicating potential for high-quality use. The higher CEC of the Al-substituted TOB from IFA-H may be due to its higher Cl⁻ content. The HT solution, rich in Cl⁻, can be reused. The HT process utilizing i-SiO₂ can reduce economic cost by nearly half compared to current resource utilization approach. This study aims to enhance the resource utilization of IFA.

{"title":"Hydrothermally-targeted synthesis of Al-substituted tobermorite using MSWI fly ash with industrial SiO2 for potentially high-quality utilization","authors":"Xinlong Chen , Deli Wu , Bo Yang , Xiaofeng Gao , Xunchang Fei , Hongping He","doi":"10.1016/j.wasman.2025.02.026","DOIUrl":"10.1016/j.wasman.2025.02.026","url":null,"abstract":"<div><div>Al-substituted tobermorite (TOB) can be synthesized as a value-added product through hydrothermal treatment (HT) using incineration fly ash (IFA) with an exogenous additive. However, extreme conditions and low purity limit its further use. To solve these issues, we explored the potential of industrial SiO<sub>2</sub> (i-SiO<sub>2</sub>) in synthesizing Al-substituted TOB using IFA from two megacities: Shanghai (IFA-H) and Shenzhen (IFA-Z). Results showed that vast majority of Ca, Si, and Al in IFA and i-SiO<sub>2</sub> can be converted into Al-substituted TOB, allowing for targeted synthesis with low i-SiO<sub>2</sub> mass. Besides, the experimental condition, e.g., 0.4 mol/L of NaOH concentration, 160 °C of reaction temperature, and 24 h of reaction time, appears to be milder than the previous relevant studies. Both Al-substituted TOBs had Cl<sup>−</sup> contents below 5.0 wt%, and total immobilization efficiencies for typical heavy metals exceeded 98.0 wt%. The cation exchange capacities (CECs) for Al-substituted TOBs from IFA-H and IFA-Z were 424.0 cmol/kg and 241.3 cmol/kg, respectively, comparable to commercial zeolite and indicating potential for high-quality use. The higher CEC of the Al-substituted TOB from IFA-H may be due to its higher Cl<sup>−</sup> content. The HT solution, rich in Cl<sup>−</sup>, can be reused. The HT process utilizing i-SiO<sub>2</sub> can reduce economic cost by nearly half compared to current resource utilization approach. This study aims to enhance the resource utilization of IFA.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"196 ","pages":"Pages 22-31"},"PeriodicalIF":7.1,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The effect of desiccation cracks on water infiltration in landfill cover under extreme climate scenarios

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

Waste management

Pub Date : 2025-02-16 DOI: 10.1016/j.wasman.2025.02.021

Arwan Apriyono , Yuliana Yuliana , Viroon Kamchoom , Anthony Kwan Leung , Apiniti Jotisankasa , Zhan Liangtong

Predicting water infiltration in clay poses a significant challenge, primarily due to the presence of desiccation cracks, which are amplified by extreme climate. Accurate methods for calculating water infiltration, considering crack variations under extreme climates are essential especially for landfill covers. The objective of this study is to explore the relationship between crack intensity factor (CIF) and water infiltration in high-plasticity clay, focusing on seasonal changes and extreme climate conditions. A series of double-ring infiltration tests was conducted in the field to observe the impact of desiccation cracks on water infiltration. Subsequently, a modified Green–Ampt method incorporating CIF was developed and validated against these field test results to improve water infiltration predictions. This study revealed that the maximum CIF was notably higher in the second dry season (11.4 %) than that in the first one (8.1 %), indicating soil structural degradation. An exponential correlation was observed between increased CIF and infiltration rates, attributed to cracks creating preferential pathways. In extreme climate scenarios, CIF increases could surpass 15 %, potentially elevating soil’s saturated hydraulic conductivity (K_s) by over 85 % relative to current climate conditions.

{"title":"The effect of desiccation cracks on water infiltration in landfill cover under extreme climate scenarios","authors":"Arwan Apriyono , Yuliana Yuliana , Viroon Kamchoom , Anthony Kwan Leung , Apiniti Jotisankasa , Zhan Liangtong","doi":"10.1016/j.wasman.2025.02.021","DOIUrl":"10.1016/j.wasman.2025.02.021","url":null,"abstract":"<div><div>Predicting water infiltration in clay poses a significant challenge, primarily due to the presence of desiccation cracks, which are amplified by extreme climate. Accurate methods for calculating water infiltration, considering crack variations under extreme climates are essential especially for landfill covers. The objective of this study is to explore the relationship between crack intensity factor (CIF) and water infiltration in high-plasticity clay, focusing on seasonal changes and extreme climate conditions. A series of double-ring infiltration tests was conducted in the field to observe the impact of desiccation cracks on water infiltration. Subsequently, a modified Green–Ampt method incorporating CIF was developed and validated against these field test results to improve water infiltration predictions. This study revealed that the maximum CIF was notably higher in the second dry season (11.4 %) than that in the first one (8.1 %), indicating soil structural degradation. An exponential correlation was observed between increased CIF and infiltration rates, attributed to cracks creating preferential pathways. In extreme climate scenarios, CIF increases could surpass 15 %, potentially elevating soil’s saturated hydraulic conductivity (K<sub>s</sub>) by over 85 % relative to current climate conditions.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"196 ","pages":"Pages 10-21"},"PeriodicalIF":7.1,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enabling the twin transition of the textile industry: A systematic literature review

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

Waste management

Pub Date : 2025-02-15 DOI: 10.1016/j.wasman.2025.02.025

Rabia Hassan, Federica Acerbi, Sergio Terzi, Paolo Rosa

The textile industry, a significant resource consumer and polluter, ranks as the fourth-largest sector in raw material consumption and the fifth-largest emitter of greenhouse gases. To address these significant environmental challenges, there is an urgent need for a transformative shift toward sustainable production paradigms. However, circular strategies specific to various textile materials still need to be explored in existing research. This manuscript examines the adoption of circular strategies in the textile industry, focusing on key materials such as cotton, polyester, wool, silk, linen, polyamide, viscose, flax, and azlons. A comprehensive systematic literature review of 82 eligible papers from the Scopus database identified critical research streams: circular strategies, digital technologies, and evaluation methods. Findings reveal that cotton and polyester have received the most attention in circular practices, particularly in areas such as closed-loop supply chains, textile waste management, reuse, recycling, etc. In contrast, materials like wool, silk, linen, polyamide, viscose, flax, and azlons have been insufficiently studied, highlighting a critical gap in the literature that needs to be addressed. The authors developed a conceptual framework based on these findings to enhance understanding of the current research landscape. This review emphasizes the need for further investigation into circular strategies for a broader range of textile materials and suggests potential pathways for future research, providing valuable insights for advancing sustainability in the textile sector.

{"title":"Enabling the twin transition of the textile industry: A systematic literature review","authors":"Rabia Hassan, Federica Acerbi, Sergio Terzi, Paolo Rosa","doi":"10.1016/j.wasman.2025.02.025","DOIUrl":"10.1016/j.wasman.2025.02.025","url":null,"abstract":"<div><div>The textile industry, a significant resource consumer and polluter, ranks as the fourth-largest sector in raw material consumption and the fifth-largest emitter of greenhouse gases. To address these significant environmental challenges, there is an urgent need for a transformative shift toward sustainable production paradigms. However, circular strategies specific to various textile materials still need to be explored in existing research. This manuscript examines the adoption of circular strategies in the textile industry, focusing on key materials such as cotton, polyester, wool, silk, linen, polyamide, viscose, flax, and azlons. A comprehensive systematic literature review of 82 eligible papers from the Scopus database identified critical research streams: circular strategies, digital technologies, and evaluation methods. Findings reveal that cotton and polyester have received the most attention in circular practices, particularly in areas such as closed-loop supply chains, textile waste management, reuse, recycling, etc. In contrast, materials like wool, silk, linen, polyamide, viscose, flax, and azlons have been insufficiently studied, highlighting a critical gap in the literature that needs to be addressed. The authors developed a conceptual framework based on these findings to enhance understanding of the current research landscape. This review emphasizes the need for further investigation into circular strategies for a broader range of textile materials and suggests potential pathways for future research, providing valuable insights for advancing sustainability in the textile sector.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"195 ","pages":"Pages 294-307"},"PeriodicalIF":7.1,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422267","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}

引用次数: 0

Centrifuge model test studies on mechanically-biologically treated waste under seismic loading

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

Waste management

Pub Date : 2025-02-14 DOI: 10.1016/j.wasman.2025.02.020

Wenjie Chen , Zhenying Zhang , Hui Zhu , Zheheng Ma , Youwen Zhang , Bingke Lu , Kaifu Liu , Bo Huang

Early earthquakes often trigger landfill slope failures and damage to cover and liner systems, resulting in gas leakage, environmental contamination, and significant risks to landfill safety. Accurately assessing the static and dynamic characteristics of mechanically biologically treated (MBT) waste is crucial. Centrifuge shaking table tests offer a robust method to address the limitations of conventional shaking table tests by effectively simulating the static and dynamic stress–strain fields of prototype soils, fulfilling the requirements for comprehensive static and dynamic analysis. Accordingly, this study conducted experimental research on MBT waste using a centrifuge shaking table. Key findings are as follows: (1) The Poisson’s ratio of MBT waste is 0.483, and its small-strain shear modulus increases with depth, with a derived equation representing the relationship between small-strain shear modulus and depth. (2) MBT waste demonstrated a significant dynamic amplification effect, with an amplification factor ranging from 1.122 to 1.332. (3) The equivalent shear modulus of MBT waste decreases with increasing strain but increases with depth, with a surface equation established between the equivalent shear modulus, strain, and depth. (4) The equivalent damping ratio of MBT waste varies with strain and depth, and a surface equation was established to capture this relationship. (5) A comparison of the normalized equivalent shear modulus and equivalent damping ratio between MBT waste and municipal solid waste (MSW) shows that both parameters are higher in MBT waste than in MSW. These findings provide valuable insights for seismic stability analysis of MBT landfills.

{"title":"Centrifuge model test studies on mechanically-biologically treated waste under seismic loading","authors":"Wenjie Chen , Zhenying Zhang , Hui Zhu , Zheheng Ma , Youwen Zhang , Bingke Lu , Kaifu Liu , Bo Huang","doi":"10.1016/j.wasman.2025.02.020","DOIUrl":"10.1016/j.wasman.2025.02.020","url":null,"abstract":"<div><div>Early earthquakes often trigger landfill slope failures and damage to cover and liner systems, resulting in gas leakage, environmental contamination, and significant risks to landfill safety. Accurately assessing the static and dynamic characteristics of mechanically biologically treated (MBT) waste is crucial. Centrifuge shaking table tests offer a robust method to address the limitations of conventional shaking table tests by effectively simulating the static and dynamic stress–strain fields of prototype soils, fulfilling the requirements for comprehensive static and dynamic analysis. Accordingly, this study conducted experimental research on MBT waste using a centrifuge shaking table. Key findings are as follows: (1) The Poisson’s ratio of MBT waste is 0.483, and its small-strain shear modulus increases with depth, with a derived equation representing the relationship between small-strain shear modulus and depth. (2) MBT waste demonstrated a significant dynamic amplification effect, with an amplification factor ranging from 1.122 to 1.332. (3) The equivalent shear modulus of MBT waste decreases with increasing strain but increases with depth, with a surface equation established between the equivalent shear modulus, strain, and depth. (4) The equivalent damping ratio of MBT waste varies with strain and depth, and a surface equation was established to capture this relationship. (5) A comparison of the normalized equivalent shear modulus and equivalent damping ratio between MBT waste and municipal solid waste (MSW) shows that both parameters are higher in MBT waste than in MSW. These findings provide valuable insights for seismic stability analysis of MBT landfills.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"195 ","pages":"Pages 284-293"},"PeriodicalIF":7.1,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Does exposure enhance interest? An analysis of composting exposure on interest in household waste management

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

Waste management

Pub Date : 2025-02-13 DOI: 10.1016/j.wasman.2025.02.019

Mohammad Mashiur Rahman , Niraj Khatiwada , Alok K. Bohara

With the increasing amount of household waste produced in developing countries’ municipalities, composting can be a crucial alternative to ease the burden of disposal. This study utilizes primary survey data to investigate the association between households’ exposure to public composting campaigns and the interest in composting in Siddharthanagar Municipality, Nepal. We also use household attitudes, knowledge, barriers, and policy variables. Further, using our geo-referenced data as a novel approach, we probe the spatial connections between exposure and interest and investigate any inter-regional differences by constructing spatial maps. The dichotomous model results indicate a significant positive impact of exposure to composting campaigns on interest in composting, and the results remain consistent after the robustness check. Further, spatial autocorrelation is evident for composting exposure and interest. The spatial maps indicate inter-regional similarity for these variables. These results indicate the urge for policies that extensively promote public information regarding composting at the household level.

{"title":"Does exposure enhance interest? An analysis of composting exposure on interest in household waste management","authors":"Mohammad Mashiur Rahman , Niraj Khatiwada , Alok K. Bohara","doi":"10.1016/j.wasman.2025.02.019","DOIUrl":"10.1016/j.wasman.2025.02.019","url":null,"abstract":"<div><div>With the increasing amount of household waste produced in developing countries’ municipalities, composting can be a crucial alternative to ease the burden of disposal. This study utilizes primary survey data to investigate the association between households’ exposure to public composting campaigns and the interest in composting in Siddharthanagar Municipality, Nepal. We also use household attitudes, knowledge, barriers, and policy variables. Further, using our geo-referenced data as a novel approach, we probe the spatial connections between exposure and interest and investigate any inter-regional differences by constructing spatial maps. The dichotomous model results indicate a significant positive impact of exposure to composting campaigns on interest in composting, and the results remain consistent after the robustness check. Further, spatial autocorrelation is evident for composting exposure and interest. The spatial maps indicate inter-regional similarity for these variables. These results indicate the urge for policies that extensively promote public information regarding composting at the household level.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"196 ","pages":"Pages 1-9"},"PeriodicalIF":7.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Detailed estimation of generated woody biomass ash for use as fertilizer material

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

Waste management

Pub Date : 2025-02-12 DOI: 10.1016/j.wasman.2025.02.009

Minori Ike , Hiroyuki Kawagoe , Kazuyuki Oshita , Masaki Takaoka

The physical and chemical characteristics of woody biomass ash (WBA) are highly dependent on the ash type, fuel, and furnace type. WBA recycling requires knowledge of its amount and characteristics. In this study, the amount of WBA recoverable as fertilizer in Japan was estimated considering the ash type, furnace type, and fuel type, using data obtained in a questionnaire-based survey of 105 of the 220 biomass power plants in Japan. The results showed that the amount of ash was > 1.5 times larger than that calculated according to fuel type. The discharged ash contained moisture, sand, and impurities. The slopes of the estimation model of the actual versus calculated amount were larger for gasification power generation, followed by stoker furnaces and fluidized bed furnaces. The bottom ash ratio in WBA from all furnace types was 0.37. With an estimated biomass combustion by the 220 biomass power plants in Japan of 3.4 × 10⁷ t in 2026, the amount of generated ash would be 6.9–12 × 10⁵ t. Bottom ash accounted for 2.7–4.7 × 10⁵ t, with circulated fluidized bed furnace-derived ash comprising > 60 % of the total. The estimated annual amount of ash suitable for fertilizer use was 6.2–11 × 10⁵ t. The K content of WBA in 2026 was estimated to be 1.8 times larger than that in annually imported fertilizer. This K resource should be fully exploited and the efficient use of K extraction residue should be pursued to achieve an effective circular economy.

{"title":"Detailed estimation of generated woody biomass ash for use as fertilizer material","authors":"Minori Ike , Hiroyuki Kawagoe , Kazuyuki Oshita , Masaki Takaoka","doi":"10.1016/j.wasman.2025.02.009","DOIUrl":"10.1016/j.wasman.2025.02.009","url":null,"abstract":"<div><div>The physical and chemical characteristics of woody biomass ash (WBA) are highly dependent on the ash type, fuel, and furnace type. WBA recycling requires knowledge of its amount and characteristics. In this study, the amount of WBA recoverable as fertilizer in Japan was estimated considering the ash type, furnace type, and fuel type, using data obtained in a questionnaire-based survey of 105 of the 220 biomass power plants in Japan. The results showed that the amount of ash was > 1.5 times larger than that calculated according to fuel type. The discharged ash contained moisture, sand, and impurities. The slopes of the estimation model of the actual versus calculated amount were larger for gasification power generation, followed by stoker furnaces and fluidized bed furnaces. The bottom ash ratio in WBA from all furnace types was 0.37. With an estimated biomass combustion by the 220 biomass power plants in Japan of 3.4 × 10<sup>7</sup> t in 2026, the amount of generated ash would be 6.9–12 × 10<sup>5</sup> t. Bottom ash accounted for 2.7–4.7 × 10<sup>5</sup> t, with circulated fluidized bed furnace-derived ash comprising > 60 % of the total. The estimated annual amount of ash suitable for fertilizer use was 6.2–11 × 10<sup>5</sup> t. The K content of WBA in 2026 was estimated to be 1.8 times larger than that in annually imported fertilizer. This K resource should be fully exploited and the efficient use of K extraction residue should be pursued to achieve an effective circular economy.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"195 ","pages":"Pages 275-283"},"PeriodicalIF":7.1,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387200","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}

引用次数: 0

Effect of time delay after alkaline cleaning treatment on the properties of polyelectrolyte-coated end-of-life polyamide membranes

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

Waste management

Pub Date : 2025-02-10 DOI: 10.1016/j.wasman.2025.02.015

Luis A. Soto-Salcido, Joona Nieminen, Arto Pihlajamäki, Mika Mänttäri

End-of-life (EoL) reverse osmosis (RO) membranes were regenerated by an extended alkaline cleaning treatment (ACT) followed by polyelectrolyte (PE) deposition (coating). The effect of time delay between the ACT and PE coating on the membranes’ stability and filtration properties was investigated. The permeance of the membranes increased more than twofold compared to the value exhibited by the EoL membrane before the ACT. Additionally, the surface charge decreased from −45 mV to −99 mV at pH 7.7, due to the ACT. However, the ACT-induced effects were predominantly time-dependent and were partially reversed over time. When the membrane was coated with one layer of polydiallyldimethylammonium chloride (PDADMAC) immediately after the ACT, the resulting membrane had approximately 800 g/mol molecular weight cut-off (MWCO) value and 30 L/(m² h bar) pressure-corrected flux (PCF). In comparison, if the membrane was stored in deionized (DI) water for five hours between the ACT and coating, the resulting membrane had again approximately 30 L/(m² h bar) PCF but a much higher 2,900 g/mol MWCO. Furthermore, the promptly coated membranes showcased better replicability and stability during storage, in comparison to the samples that were kept in water prior to coating.

{"title":"Effect of time delay after alkaline cleaning treatment on the properties of polyelectrolyte-coated end-of-life polyamide membranes","authors":"Luis A. Soto-Salcido, Joona Nieminen, Arto Pihlajamäki, Mika Mänttäri","doi":"10.1016/j.wasman.2025.02.015","DOIUrl":"10.1016/j.wasman.2025.02.015","url":null,"abstract":"<div><div>End-of-life (EoL) reverse osmosis (RO) membranes were regenerated by an extended alkaline cleaning treatment (ACT) followed by polyelectrolyte (PE) deposition (coating). The effect of time delay between the ACT and PE coating on the membranes’ stability and filtration properties was investigated. The permeance of the membranes increased more than twofold compared to the value exhibited by the EoL membrane before the ACT. Additionally, the surface charge decreased from −45 mV to −99 mV at pH 7.7, due to the ACT. However, the ACT-induced effects were predominantly time-dependent and were partially reversed over time. When the membrane was coated with one layer of polydiallyldimethylammonium chloride (PDADMAC) immediately after the ACT, the resulting membrane had approximately 800 g/mol molecular weight cut-off (MWCO) value and 30 L/(m<sup>2</sup> h bar) pressure-corrected flux (PCF). In comparison, if the membrane was stored in deionized (DI) water for five hours between the ACT and coating, the resulting membrane had again approximately 30 L/(m<sup>2</sup> h bar) PCF but a much higher 2,900 g/mol MWCO. Furthermore, the promptly coated membranes showcased better replicability and stability during storage, in comparison to the samples that were kept in water prior to coating.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"195 ","pages":"Pages 253-263"},"PeriodicalIF":7.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143376817","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}

引用次数: 0

Contaminant detection in flexible polypropylene packaging waste using hyperspectral imaging and machine learning

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

Waste management

Pub Date : 2025-02-10 DOI: 10.1016/j.wasman.2025.02.010

Giuseppe Bonifazi, Giuseppe Capobianco, Paola Cucuzza, Silvia Serranti

Flexible plastic packaging (FPP) constitutes one of the largest post-consumer plastic streams processed in recycling facilities. To address the key challenges of its sorting and quality control, this study developed and tested a classification procedure based on hyperspectral imaging (HSI), combined with machine learning. The aim was to automatically detect contaminants (i.e., other polymers and materials) within a polypropylene (PP) stream of FPP waste (FPPW). Hyperspectral images of representative FPPW samples of PP and contaminants were acquired in the short-wave infrared range (SWIR: 1000–2500 nm) and preprocessed using different combinations of algorithms to emphasize their spectral characteristics. Principal component analysis (PCA) was applied as exploratory analysis of the spectral data followed by the application of a hierarchical classification model, based on partial least squares-discriminant analysis (Hi-PLS-DA), to differentiate between PP and other materials considered as contaminants, including polyethylene, polyester, polyethylene terephthalate, polystyrene, cellulose, polyurethane, aluminum and multilayer films. The results showed a classification accuracy of 87.5 %, with 147 out of 168 flakes correctly identified, as verified by Fourier transform-infrared (FT-IR) spectroscopy, demonstrating the model robust performance in distinguishing PP from other materials. Assuming all correctly identified particles are properly sorted, the model is predicted to achieve a Recovery of 98.2 % by weight for PP, indicating minimal material losses, with a Grade of 94.4 % by weight, representing a significant improvement compared to 77.2 % in the initial feed FPPW stream. This work demonstrated the effectiveness of HSI combined with Hi-PLS-DA in developing an automatic and efficient sorting and/or quality control process for FPPW, with minor classification errors occurring in filaments and multilayer flakes.

{"title":"Contaminant detection in flexible polypropylene packaging waste using hyperspectral imaging and machine learning","authors":"Giuseppe Bonifazi, Giuseppe Capobianco, Paola Cucuzza, Silvia Serranti","doi":"10.1016/j.wasman.2025.02.010","DOIUrl":"10.1016/j.wasman.2025.02.010","url":null,"abstract":"<div><div>Flexible plastic packaging (FPP) constitutes one of the largest post-consumer plastic streams processed in recycling facilities. To address the key challenges of its sorting and quality control, this study developed and tested a classification procedure based on hyperspectral imaging (HSI), combined with machine learning. The aim was to automatically detect contaminants (i.e., other polymers and materials) within a polypropylene (PP) stream of FPP waste (FPPW). Hyperspectral images of representative FPPW samples of PP and contaminants were acquired in the short-wave infrared range (SWIR: 1000–2500 nm) and preprocessed using different combinations of algorithms to emphasize their spectral characteristics. Principal component analysis (PCA) was applied as exploratory analysis of the spectral data followed by the application of a hierarchical classification model, based on partial least squares-discriminant analysis (Hi-PLS-DA), to differentiate between PP and other materials considered as contaminants, including polyethylene, polyester, polyethylene terephthalate, polystyrene, cellulose, polyurethane, aluminum and multilayer films. The results showed a classification accuracy of 87.5 %, with 147 out of 168 flakes correctly identified, as verified by Fourier transform-infrared (FT-IR) spectroscopy, demonstrating the model robust performance in distinguishing PP from other materials. Assuming all correctly identified particles are properly sorted, the model is predicted to achieve a Recovery of 98.2 % by weight for PP, indicating minimal material losses, with a Grade of 94.4 % by weight, representing a significant improvement compared to 77.2 % in the initial feed FPPW stream. This work demonstrated the effectiveness of HSI combined with Hi-PLS-DA in developing an automatic and efficient sorting and/or quality control process for FPPW, with minor classification errors occurring in filaments and multilayer flakes.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"195 ","pages":"Pages 264-274"},"PeriodicalIF":7.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143376818","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}

引用次数: 0

Substance flows of heavy metals in industrial-scale municipal solid waste incineration bottom ash treatment: A case study from Austria

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

Waste management

Pub Date : 2025-02-09 DOI: 10.1016/j.wasman.2025.02.011

Simon Mika , Julia Mühl , Stefan Skutan , Philipp Aschenbrenner , Andreas Limbeck , Jakob Lederer

While standard municipal solid waste incineration bottom ash (IBA) treatment aims to recover only ferrous and non-ferrous metals, enhanced treatment of IBA also promotes a recovery of glass and the mineral fraction. In this study, an enhanced dry-wet IBA treatment plant consisting of commonly applied dry process units, including several screens, a crusher, magnetic and eddy current separators and rarely applied wet process units, including a wet jigger, falcon concentrators and a wet shaking table, was evaluated for its ability to treat IBA from grate (G) and fluidized bed (FB) incineration. The process was examined on a material and substance flow level with regard to Ag, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb and Zn. It was found that the wet process units separated 52% of the total substance load of the aforementioned substances from G-IBA, while only 28% were separated from FB-IBA. The dry process units separated 57% from FB-IBA, while only 21% from G-IBA. The balance was found to remain in the mineral fraction of G-IBA (27%) or to be split between glass (7%) and mineral fraction (7%) of FB-IBA. While FB-IBA treatment was described for the first time on a substance flow level, transfer coefficients of 57–73% into the mineral fraction were reported for other G-IBA treatment plants for the substances investigated. Gravity separation was found to be able to promote the conservation of metallic resources and to deplete the total contents of heavy metals in the mineral fraction, which is favorable in terms of utilization.

{"title":"Substance flows of heavy metals in industrial-scale municipal solid waste incineration bottom ash treatment: A case study from Austria","authors":"Simon Mika , Julia Mühl , Stefan Skutan , Philipp Aschenbrenner , Andreas Limbeck , Jakob Lederer","doi":"10.1016/j.wasman.2025.02.011","DOIUrl":"10.1016/j.wasman.2025.02.011","url":null,"abstract":"<div><div>While standard municipal solid waste incineration bottom ash (IBA) treatment aims to recover only ferrous and non-ferrous metals, enhanced treatment of IBA also promotes a recovery of glass and the mineral fraction. In this study, an enhanced dry-wet IBA treatment plant consisting of commonly applied dry process units, including several screens, a crusher, magnetic and eddy current separators and rarely applied wet process units, including a wet jigger, falcon concentrators and a wet shaking table, was evaluated for its ability to treat IBA from grate (G) and fluidized bed (FB) incineration. The process was examined on a material and substance flow level with regard to Ag, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb and Zn. It was found that the wet process units separated 52% of the total substance load of the aforementioned substances from G-IBA, while only 28% were separated from FB-IBA. The dry process units separated 57% from FB-IBA, while only 21% from G-IBA. The balance was found to remain in the mineral fraction of G-IBA (27%) or to be split between glass (7%) and mineral fraction (7%) of FB-IBA. While FB-IBA treatment was described for the first time on a substance flow level, transfer coefficients of 57–73% into the mineral fraction were reported for other G-IBA treatment plants for the substances investigated. Gravity separation was found to be able to promote the conservation of metallic resources and to deplete the total contents of heavy metals in the mineral fraction, which is favorable in terms of utilization.</div></div>","PeriodicalId":23969,"journal":{"name":"Waste management","volume":"195 ","pages":"Pages 240-252"},"PeriodicalIF":7.1,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143369732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0