Pub Date : 2022-09-30DOI: 10.31025/2611-4135/2022.15224
Guadalupe Vianey Landeros Gonzalez, Gabriela Dominguez Cortinas, M. Hudson, Peter Shaw, I. Williams
Concerns regarding the impacts of microplastics in the global environment have brought into focus the need to understand better their origins, transport, and fate. Wastewaters (WW) are important in this regard: discharges from households, commercial and industrial premises, and surface run-off deliver microplastics to wastewater treatment plants (WWTPs) via sewerage systems, through which they are removed along with sewage sludge or destined for release into the environment in treated effluent. This review provides a contemporary and critical analysis of factors influencing the quantities and composition of microplastics (MPs) reaching wastewater treatment plants, including both primary and secondary sources. Three specific areas of concern were highlighted. First, current legislation, where present, needs to address regulation of microplastics in personal care and cosmetic products that cross international borders. Secondly, accurate estimation of microplastics arising from some sources and activities (e.g., mis-managed waste and hand washing of textiles) is challenging and estimated contributions of associated microplastics remain unsatisfactory as a basis for management decisions. Thirdly, information relating to microplastics in personal care and cosmetic products used by male consumers is lacking and contributions of such products to wastewater remain uncertain. We recommend that (1) voluntary practices and programmes should be replaced with formal regulation to achieve compliance, and (2) the role of consumers’ behaviour in generating microplastics that are destined for wastewater treatment plants remains largely unknown and that more research in this domain is needed.
{"title":"A Review of the Origins of Microplastics arriving at Wastewater Treatment Plants","authors":"Guadalupe Vianey Landeros Gonzalez, Gabriela Dominguez Cortinas, M. Hudson, Peter Shaw, I. Williams","doi":"10.31025/2611-4135/2022.15224","DOIUrl":"https://doi.org/10.31025/2611-4135/2022.15224","url":null,"abstract":"Concerns regarding the impacts of microplastics in the global environment have brought into focus the need to understand better their origins, transport, and fate. Wastewaters (WW) are important in this regard: discharges from households, commercial and industrial premises, and surface run-off deliver microplastics to wastewater treatment plants (WWTPs) via sewerage systems, through which they are removed along with sewage sludge or destined for release into the environment in treated effluent. This review provides a contemporary and critical analysis of factors influencing the quantities and composition of microplastics (MPs) reaching wastewater treatment plants, including both primary and secondary sources. Three specific areas of concern were highlighted. First, current legislation, where present, needs to address regulation of microplastics in personal care and cosmetic products that cross international borders. Secondly, accurate estimation of microplastics arising from some sources and activities (e.g., mis-managed waste and hand washing of textiles) is challenging and estimated contributions of associated microplastics remain unsatisfactory as a basis for management decisions. Thirdly, information relating to microplastics in personal care and cosmetic products used by male consumers is lacking and contributions of such products to wastewater remain uncertain. We recommend that (1) voluntary practices and programmes should be replaced with formal regulation to achieve compliance, and (2) the role of consumers’ behaviour in generating microplastics that are destined for wastewater treatment plants remains largely unknown and that more research in this domain is needed.","PeriodicalId":44191,"journal":{"name":"Detritus","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48378219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.31025/2611-4135/2022.15219
D. Cazzuffi, Piergiorgio Recalcati, L. S. Calvarano, S. Marelli
One of the crucial aspects in design of a landfill capping is the interface behavior between the different layers of the cover system, from levelling layer above waste up to the topsoil. Design guidelines and international codes require a geotechnical stability analysis to be performed along every interface. The critical interface is the one which gives the minimum shear resistance, in terms of friction angle and adhesion. Evaluation of the correct values to be used is then essential. Shear resistance at the interface between different geosynthetics or between a geosynthetic and a soil can be measured through laboratory tests. Testing methods are EN ISO 12957-1 and ASTM D5321 (for direct shear test) and EN ISO 12957-2 (for inclined plane). The paper briefly describes direct shear and inclined plane testing methods and enhances pros and cons. In the last 25 years the authors have coordinated a great number of the above tests with different types of geosynthetics and soils. The main results of these tests are reported in the paper, summarizing the values obtained with contact interface between different products belonging to the same families. The purpose of this work is to validate the already big database of interface strength measured with direct shear tests and to evaluate the differences with the results obtained for the different types of tests. This can give to designers the chance to have a critical approach toward the most suitable testing method to be used according to the specific needs of a project.
填埋场盖层设计的一个关键方面是覆盖系统的不同层之间的界面行为，从垃圾上方的找平层到表土。设计准则和国际规范要求沿每个界面进行岩土稳定性分析。从摩擦角和粘附力的角度来看，临界界面是具有最小剪切阻力的界面。对要使用的正确值进行评估是至关重要的。在不同的土工合成材料之间的界面或土工合成材料与土壤之间的剪切阻力可以通过实验室测试来测量。测试方法是EN ISO 12957-1和ASTM D5321(直接剪切试验)和EN ISO 12957-2(斜面试验)。本文简要介绍了直接剪切和斜面试验方法，并对其优缺点进行了比较。在过去的25年中，作者对不同类型的土工合成材料和土进行了大量的上述试验。本文报道了这些试验的主要结果，总结了同族不同产品之间接触界面的结果。这项工作的目的是验证已经通过直接剪切试验测量的界面强度数据库，并评估不同类型试验结果的差异。这可以让设计师有机会根据项目的具体需求，找到最合适的测试方法。
{"title":"A REVIEW OF DIRECT SHEAR AND INCLINED PLANE TESTS RESULTS FOR DIFFERENT INTERFACES IN LANDFILL CAPPING","authors":"D. Cazzuffi, Piergiorgio Recalcati, L. S. Calvarano, S. Marelli","doi":"10.31025/2611-4135/2022.15219","DOIUrl":"https://doi.org/10.31025/2611-4135/2022.15219","url":null,"abstract":"One of the crucial aspects in design of a landfill capping is the interface behavior between the different layers of the cover system, from levelling layer above waste up to the topsoil.\u0000Design guidelines and international codes require a geotechnical stability analysis to be performed along every interface. The critical interface is the one which gives the minimum shear resistance, in terms of friction angle and adhesion. Evaluation of the correct values to be used is then essential. Shear resistance at the interface between different geosynthetics or between a geosynthetic and a soil can be measured through laboratory tests. Testing methods are EN ISO 12957-1 and ASTM D5321 (for direct shear test) and EN ISO 12957-2 (for inclined plane).\u0000The paper briefly describes direct shear and inclined plane testing methods and enhances pros and cons. In the last 25 years the authors have coordinated a great number of the above tests with different types of geosynthetics and soils. The main results of these tests are reported in the paper, summarizing the values obtained with contact interface between different products belonging to the same families. The purpose of this work is to validate the already big database of interface strength measured with direct shear tests and to evaluate the differences with the results obtained for the different types of tests. This can give to designers the chance to have a critical approach toward the most suitable testing method to be used according to the specific needs of a project.\u0000\u0000","PeriodicalId":44191,"journal":{"name":"Detritus","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69398141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-20DOI: 10.31025/2611-4135/2022.15220
Oskar Johannson
{"title":"Did End of Waste bring the end of waste?","authors":"Oskar Johannson","doi":"10.31025/2611-4135/2022.15220","DOIUrl":"https://doi.org/10.31025/2611-4135/2022.15220","url":null,"abstract":"","PeriodicalId":44191,"journal":{"name":"Detritus","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42776243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-20DOI: 10.31025/2611-4135/2022.15218
Giulia Tameni, Francesco Cammelli, H. Elsayed, Francesco Stangherlin, E. Bernardo
The present Covid-19 emergency has dramatically increased the demand for pharmaceutical containers and the amounts of related waste. This paper aims at presenting the upcycling of discarded pharmaceutical glass into various porous ceramics, starting from the activation of fine powders suspended in weakly alkaline solutions (2.5 M NaOH/KOH). The alkaline attack determines the gelation of glass suspensions, according to hydration of glass surfaces, followed by condensation starting from 40 °C (‘cold consolidation’). Alkali are mostly expelled from the gel, according to the formation of water-soluble hydrated carbonates. The mutual binding of activated powders was exploited for the encapsulation of waste-derived glass (from the plasma processing of municipal solid waste) and quartz sand as coarse aggregate. Moreover, industrial mud could be used instead of water in the preparation of alkaline solutions. Depending on the formulations, products comparable to facing bricks can be obtained directly after cold consolidation or after application of low temperature (700 °C) firing. In addition, selected formulations led to highly porous glass foams, to be used for thermal and acoustic insulation.
{"title":"Upcycling of Boro-Alumino-Silicate Pharmaceutical Glass in Sustainable Construction Materials","authors":"Giulia Tameni, Francesco Cammelli, H. Elsayed, Francesco Stangherlin, E. Bernardo","doi":"10.31025/2611-4135/2022.15218","DOIUrl":"https://doi.org/10.31025/2611-4135/2022.15218","url":null,"abstract":"The present Covid-19 emergency has dramatically increased the demand for pharmaceutical containers and the amounts of related waste. This paper aims at presenting the upcycling of discarded pharmaceutical glass into various porous ceramics, starting from the activation of fine powders suspended in weakly alkaline solutions (2.5 M NaOH/KOH). The alkaline attack determines the gelation of glass suspensions, according to hydration of glass surfaces, followed by condensation starting from 40 °C (‘cold consolidation’). Alkali are mostly expelled from the gel, according to the formation of water-soluble hydrated carbonates. The mutual binding of activated powders was exploited for the encapsulation of waste-derived glass (from the plasma processing of municipal solid waste) and quartz sand as coarse aggregate. Moreover, industrial mud could be used instead of water in the preparation of alkaline solutions. Depending on the formulations, products comparable to facing bricks can be obtained directly after cold consolidation or after application of low temperature (700 °C) firing. In addition, selected formulations led to highly porous glass foams, to be used for thermal and acoustic insulation.","PeriodicalId":44191,"journal":{"name":"Detritus","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48026945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-20DOI: 10.31025/2611-4135/2022.15217
N. Mahdjoub, Yusuf Omartjee, C. Trois
In South-Africa, approximately 30% of all recycled paper is being disposed into landfill sites or incinerated. Using this type of hazardous and industrial waste as a resource is essential to reduce landfilling of organic waste. In this study, Pulp and Paper-Mill Sludge (PPMS) has been evaluated under two possible pathways contributing to landfill diversion and secondary use: compostability and the use of PPMS as a soil amendment. A short review of existing studies on PPMS using these two pathways as alternative for secondary use and within the South-African context have been undertaken. This investigation showed that the addition of PPMS to soil as an amendment does not negatively affect sol fertility. The potential of PPMS as a soil amendment or compost contribute to improving factors allowing for increased soil fertility resulting in a better soil structure. Such effects from either using PPMS as an amendment or compost will directly increase resistance of soils to degradation ultimately allowing for reduced erosion potential of soils.
{"title":"Pulp and Paper Mill Sludge; a Soil Amendment and Compost option for Landfill Diversion for South-Africa","authors":"N. Mahdjoub, Yusuf Omartjee, C. Trois","doi":"10.31025/2611-4135/2022.15217","DOIUrl":"https://doi.org/10.31025/2611-4135/2022.15217","url":null,"abstract":"In South-Africa, approximately 30% of all recycled paper is being disposed into landfill sites or incinerated. Using this type of hazardous and industrial waste as a resource is essential to reduce landfilling of organic waste. In this study, Pulp and Paper-Mill Sludge (PPMS) has been evaluated under two possible pathways contributing to landfill diversion and secondary use: compostability and the use of PPMS as a soil amendment. A short review of existing studies on PPMS using these two pathways as alternative for secondary use and within the South-African context have been undertaken. This investigation showed that the addition of PPMS to soil as an amendment does not negatively affect sol fertility. The potential of PPMS as a soil amendment or compost contribute to improving factors allowing for increased soil fertility resulting in a better soil structure. Such effects from either using PPMS as an amendment or compost will directly increase resistance of soils to degradation ultimately allowing for reduced erosion potential of soils.","PeriodicalId":44191,"journal":{"name":"Detritus","volume":"58 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69398132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-14DOI: 10.31025/2611-4135/2022.15216
Namrata Mhaddolkar, G. Koinig, D. Vollprecht
Biobased plastics are often seen to be an environmentally friendly alternative to conventional plastics, with their share, though being less now, is gradually increasing. This necessitates that the waste management of these possibly eco-friendly materials is also at par with their growth. Near-infrared (NIR) sorting is an effective waste sorting technology and is already widely used for conventional plastics. Thus, it would be imperative to analyse whether this effective existing infrastructure could also be successfully used to sort bioplastic. In the present study, the lab-scale NIR sensor-based sorting system in Montanuniversität Leoben was used to analyse polylactic acid (PLA) in three sets of experiments. First, the spectra of 7 conventional plastics were compared to that of virgin PLA and it was found that PLA has a distinct spectrum and should ideally be detected from a mixed plastic fraction. Second, it was assessed whether different grades and thicknesses of virgin PLA samples produced different spectra and it was found that there is a slight difference in the intensities without any wavelength shift of the recognizable peaks. Lastly, the detection of 10 PLA product samples was tested using the NIR recipe of a virgin PLA. It was observed that the samples were successfully detected and blown out as PLA for all the conducted trials. Additionally, it was also seen that an appropriate backlight setting is important to be able to correctly sort the transparent PLA products in the used chute-type sorter.
{"title":"NEAR-INFRARED IDENTIFICATION AND SORTING OF POLYLACTIC ACID","authors":"Namrata Mhaddolkar, G. Koinig, D. Vollprecht","doi":"10.31025/2611-4135/2022.15216","DOIUrl":"https://doi.org/10.31025/2611-4135/2022.15216","url":null,"abstract":"Biobased plastics are often seen to be an environmentally friendly alternative to conventional plastics, with their share, though being less now, is gradually increasing. This necessitates that the waste management of these possibly eco-friendly materials is also at par with their growth. Near-infrared (NIR) sorting is an effective waste sorting technology and is already widely used for conventional plastics. Thus, it would be imperative to analyse whether this effective existing infrastructure could also be successfully used to sort bioplastic. In the present study, the lab-scale NIR sensor-based sorting system in Montanuniversität Leoben was used to analyse polylactic acid (PLA) in three sets of experiments. First, the spectra of 7 conventional plastics were compared to that of virgin PLA and it was found that PLA has a distinct spectrum and should ideally be detected from a mixed plastic fraction. Second, it was assessed whether different grades and thicknesses of virgin PLA samples produced different spectra and it was found that there is a slight difference in the intensities without any wavelength shift of the recognizable peaks. Lastly, the detection of 10 PLA product samples was tested using the NIR recipe of a virgin PLA. It was observed that the samples were successfully detected and blown out as PLA for all the conducted trials. Additionally, it was also seen that an appropriate backlight setting is important to be able to correctly sort the transparent PLA products in the used chute-type sorter.","PeriodicalId":44191,"journal":{"name":"Detritus","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46758245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-14DOI: 10.31025/2611-4135/2022.15214
G. Guebitz, Felice Quartinello, D. Ribitsch
Novel strategies allowing environmentally friendly recycling of plastics are strongly needed. Enzymes have shown high potential, especially for the recovery of building blocks from multilayer materials which will be discussed in this paper. It has been shown that enzymes can specifically hydrolyze and solubilize certain components of blended packaging materials or mixed wastes. This allows a step—wise recovery of valuable building blocks which can be used for re-synthesis or for bioproduction (e.g. recovered glucose). However, despite the high potential of biocatalysts, even more efficient enzymes are required for economic industrial implementation. In this paper, which is based on a contribution to the SUM 2022 conference, we will consequently demonstrate how enzyme discovery can lead to more powerful tools for plastics recycling and provide some examples.
{"title":"ENZYME BASED RECYCLING PROCESSES","authors":"G. Guebitz, Felice Quartinello, D. Ribitsch","doi":"10.31025/2611-4135/2022.15214","DOIUrl":"https://doi.org/10.31025/2611-4135/2022.15214","url":null,"abstract":"Novel strategies allowing environmentally friendly recycling of plastics are strongly needed. Enzymes have shown high potential, especially for the recovery of building blocks from multilayer materials which will be discussed in this paper. It has been shown that enzymes can specifically hydrolyze and solubilize certain components of blended packaging materials or mixed wastes. This allows a step—wise recovery of valuable building blocks which can be used for re-synthesis or for bioproduction (e.g. recovered glucose). However, despite the high potential of biocatalysts, even more efficient enzymes are required for economic industrial implementation. In this paper, which is based on a contribution to the SUM 2022 conference, we will consequently demonstrate how enzyme discovery can lead to more powerful tools for plastics recycling and provide some examples.","PeriodicalId":44191,"journal":{"name":"Detritus","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43958422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-14DOI: 10.31025/2611-4135/2022.15215
A. Holzer, Mathias Baldauf, Lukas Wiszniewski, Stefan Windisch-Kern, H. Raupenstrauch
In terms of an efficient circular economy in the field of the steadily increasing use of lithium-ion batteries, sustainable recycling methods are of fundamental importance. Therefore, the Chair of Thermal Processing Technology at Montanuniversitaet Leoben has developed the so-called InduRed reactor, a carbo-thermal concept to recover valuable metals from this waste stream. For optimization and further development of this technology, it is essential to have a sound knowledge of the cathode materials' behavior in combination with various impurities in the high-temperature range under reducing conditions. Detailed experiments were carried out in a heating microscope at temperatures up to 1620°C and argon purge. Aluminum from the electrode conductor foils and an excessive proportion of graphite from the anode were identified as the impurities with the most significant negative influence on the process. An optimum melting behavior was found during the tests at an admixture of 10 wt. % C and 1.95 wt. % Al to the cathode material NMC622 (LiNi0.6Mn0.2Co0.2O2).
{"title":"Influence of Impurities on the High-Temperature Behavior of the Lithium-Ion Battery Cathode Material NMC under Reducing Conditions for Use in the InduRed Reactor Concept","authors":"A. Holzer, Mathias Baldauf, Lukas Wiszniewski, Stefan Windisch-Kern, H. Raupenstrauch","doi":"10.31025/2611-4135/2022.15215","DOIUrl":"https://doi.org/10.31025/2611-4135/2022.15215","url":null,"abstract":"In terms of an efficient circular economy in the field of the steadily increasing use of lithium-ion batteries, sustainable recycling methods are of fundamental importance. Therefore, the Chair of Thermal Processing Technology at Montanuniversitaet Leoben has developed the so-called InduRed reactor, a carbo-thermal concept to recover valuable metals from this waste stream. For optimization and further development of this technology, it is essential to have a sound knowledge of the cathode materials' behavior in combination with various impurities in the high-temperature range under reducing conditions. Detailed experiments were carried out in a heating microscope at temperatures up to 1620°C and argon purge. Aluminum from the electrode conductor foils and an excessive proportion of graphite from the anode were identified as the impurities with the most significant negative influence on the process. An optimum melting behavior was found during the tests at an admixture of 10 wt. % C and 1.95 wt. % Al to the cathode material NMC622 (LiNi0.6Mn0.2Co0.2O2).","PeriodicalId":44191,"journal":{"name":"Detritus","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42462689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-14DOI: 10.31025/2611-4135/2022.15213
Geo Jacob, Frank Dienorowitz, Nele Jaschke
Composting experiments with heat recovery reveal spatial non-uniformity in parameters such as temperature, oxygen concentration and substrate degradation. In order to recover heat from static compost piles via integrated heat exchanger there is the need to investigate the temperature distribution for placing the heat exchangers and the interaction between heat recovery, substrate degradation and oxygen concentration to ensure quality of composting process. This study introduces a spatial model to predict the variation in controlling parameters such as temperature, oxygen concentration, substrate degradation and airflow patterns in static compost piles with heat recovery using Finite element method (FEM) in COMSOL Multiphysics ® Version 5.3. The developed two-dimensional axisymmetric numerical model considers the compaction effects and is validated to real case pilot-scale compost pile experiments with passive aeration. Strong matching with the real case experiment was achieved. The spatial model demonstrated that the compaction effect is extremely important for realistic modeling because it affects airflow, temperature distribution, oxygen consumption and substrate degradation in a compost pile. Heat recovery did not disrupt the composting process. Case studies revealed strong influence of convective heat loss through the edges and a 10 % improvement of heat recovery rate with ground insulation. The simulation indicates that an optimized placing of heat recovery pipes could increase the average heat extraction by 10-40 %.
{"title":"SPATIAL MATHEMATICAL MODELING OF STATIC COMPOST PILES WITH HEAT RECOVERY","authors":"Geo Jacob, Frank Dienorowitz, Nele Jaschke","doi":"10.31025/2611-4135/2022.15213","DOIUrl":"https://doi.org/10.31025/2611-4135/2022.15213","url":null,"abstract":"Composting experiments with heat recovery reveal spatial non-uniformity in parameters such as temperature, oxygen concentration and substrate degradation. In order to recover heat from static compost piles via integrated heat exchanger there is the need to investigate the temperature distribution for placing the heat exchangers and the interaction between heat recovery, substrate degradation and oxygen concentration to ensure quality of composting process. This study introduces a spatial model to predict the variation in controlling parameters such as temperature, oxygen concentration, substrate degradation and airflow patterns in static compost piles with heat recovery using Finite element method (FEM) in COMSOL Multiphysics ® Version 5.3. The developed two-dimensional axisymmetric numerical model considers the compaction effects and is validated to real case pilot-scale compost pile experiments with passive aeration. Strong matching with the real case experiment was achieved. The spatial model demonstrated that the compaction effect is extremely important for realistic modeling because it affects airflow, temperature distribution, oxygen consumption and substrate degradation in a compost pile. Heat recovery did not disrupt the composting process. Case studies revealed strong influence of convective heat loss through the edges and a 10 % improvement of heat recovery rate with ground insulation. The simulation indicates that an optimized placing of heat recovery pipes could increase the average heat extraction by 10-40 %.","PeriodicalId":44191,"journal":{"name":"Detritus","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43419455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-25DOI: 10.31025/2611-4135/2022.15211
G. Bonifazi, G. Capobianco, S. Serranti, S. Malinconico, F. Paglietti
Asbestos has been widely used in many applications for its technical properties (i.e. resistance to abrasion, heat and chemicals). Despite its properties, asbestos is recognized as a hazardous material to human health. In this paper a study, based on multivariate analysis, was carried out to verify the possibilities to utilize the hyperspectral imaging (HSI), working in the short-wave infrared range (SWIR: 1000-2500 nm), to detect the presence of asbestos-containing materials (ACM) in construction and demolition waste (CDW). Multivariate classification methods including classification and regression tree (CART), partial least squares-discriminant analysis (PLS-DA) and correcting output coding with support vector machines (ECOC-SVM), were adopted to perform the recognition/classification of ACM in respect of the other fibrous panels not containing asbestos, in order to verify and compare Efficiency and robustness of the classifiers. The correctness of classification results was confirmed by micro-X-ray fluorescence maps. The results demonstrate as SWIR technology, coupled with multivariate analysis modeling, is a quite promising approach to develop both “off-line” and “on-line” fast reliable and robust quality control strategies, finalized to perform a first evaluation of the presence of ACM.
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