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Opis: The welfare of domestic animals, which is a core part of livestock farming today, depends strongly on the rearing system. While free-stall systems are encouraged, tied rearing systems are still the most widely used in cattle farming, although considered less suitable due to restricted freedom of movement. As an alternative to this system, free-stall rearing, which allows movement, is proposed as a minimum standard. Although it seems self-evident that free-stall rearing is better than tied rearing system, there is still a lack of research on whether this is true for all categories of cattle or whether it might be appropriate for some of them (e.g. depending on age). The aim of the present study was therefore to compare the welfare of heifers in tied and free-stall rearing during the fattening period (at different ages). In general, we have suggested higher welfare scores in free-stall system, with the tied stall being more problematic for younger animals. The study comprised five heifers in each system per repetition (20 animals in total). Data were collected using the Welfare Quality® protocol, which involves the assessment of four main principles: feeding, housing, health and behaviour. The assessments were carried out approximately every three months during the fattening period (from 6 to 27 months of age). The results showed significant differences in animal welfare scores between tied and free-stall systems only in terms of housing and the tendency of differences in behaviour. For both principles, the scores were relatively low compared to feeding and health, where no differences were found between the rearing systems. In terms of temporal dynamics, differences were only found for housing, with values decreasing with age in both rearing systems. In the free-stall system, the scores were almost optimal in young animals (>90), but decreased rapidly with increasing age, while in the tied housing system, a suboptimal welfare scores were already observed in young animals (≈40). This means that tied rearing system is a clear disadvantage for the welfare of younger animals, which are generally more exploratory and active. Our results confirmed tied stall as less suitable in terms of animal welfare, especially for young animals. It is therefore encouraged that young animals should primarily be housed in a freestall pens if both systems are available in the breeding facilities.
Ključne besede: animal wefare, cattle, heifer, rearing system, assessment protocol
Objavljeno v DKUM: 23.04.2025; Ogledov: 0; Prenosov: 0
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Opis: Microplastics (MPs) that are ubiquitous in aquatic environments and industrial wastewater streams have been identified as key hotspots of MP contamination. It is significantly more effective to remove MPs at these points before they enter municipal wastewater streams. This study is an environmental assessment of a novel pilot plant for the removal of MPs and the chemical oxygen demand (COD) from wastewater with a high MP contamination from a plastics manufacturer in Germany. MP removal is based on physical–chemical agglomeration–fixation by organosilanes. Formed agglomerates are separated using a belt filter. The COD is removed by an adsorption process. The resulting MP removal was 98.0 ± 1.1% by mass and 99.9987 ± 0.0007% by particle count, while the COD was reduced by 96 ± 2.7%. The system’s sustainability is evaluated using the Life Cycle Assessment methodology, evaluating system construction, operation, and end-of-life considerations. The current pilot plant is also compared to an optimized circular and sustainable upgrade, where drivers of environmental burdens are eliminated and collected MPs are reused. Significant reductions in environmental impact categories are achieved and the global warming potential is reduced by 96%. This study provides a sustainability assessment of a novel technology and circular solution to remove MPs from highly polluted industrial wastewater.
Ključne besede: microplastics, life cycle assessment, impact analysis, removal technology, sustainable process design, carbon footprint, water quality, circular economy
Objavljeno v DKUM: 14.03.2025; Ogledov: 0; Prenosov: 4
Celotno besedilo (1,70 MB)

Opis: An integrated top-down methodology for assessing and promoting progress towards a circular economy at macro (national) and micro (company) levels is presented. It is based on the MICRON (MIcroCirculaR ecOnomy iNdex) framework developed by Baratsas et al. (2022) for companies. In this paper, it has been extended to enable a consistent assessment for companies and countries. The methodology facilitates the analysis of key categories: energy, emissions, water, materials, and waste. A quantitative analysis of circularity, including a sensitivity analysis, is conducted at the macro level, identifying critical areas and the most influential factors for the circular economy. Based on this analysis, existing national strategies are evaluated, and implementation plans with specific measures are developed. This is followed by micro-level implementation, which involves techno-economic assessment of circular projects. Using this methodology, coordinated improvements in circularity are achieved at all levels. The methodology was tested in Slovenia, where the national circularity index revealed stable performance over five years, averaging slightly above 50 points out of 100. Analysis identified significant improvement potential in areas such as energy and emissions, aligning with the country's focus on decarbonization and energy efficiency in its climate strategies. At the company level, circularity assessments highlighted critical challenges in renewable energy use and overall energy efficiency. The proposed measures showed potential for significantly improving circularity and reducing emissions, while the results provided valuable insights into the economic feasibility of these transitions.
Ključne besede: circular economy, integrated assessment framework, micro level, energy transition, renewable energy
Objavljeno v DKUM: 10.02.2025; Ogledov: 0; Prenosov: 4
Celotno besedilo (9,03 MB)

Opis: Step towards resilience and sustainability through exploring renewable biomass and waste streams to produce higher-added value products and energy is among key aspects for closing the loops, saving resources, and reducing the resource and emission footprints. In that respective, crustacean shells waste can offer rich spectre of valuable compounds such as proteins, chitin, carotenoids. This waste is produced in large quantities worldwide, thus allowing for commercial valorisation. An overview of technologies is undertaken for more sustainable and environmentally friendly chitosan production via chitin isolation and conversion and compared to the conventional processes. Furthermore, an assessment of the environmental burden and energy demand distribution for conventional and more sustainable alternative processes was performed, based on lab-scale experimental data. Three different chitin extraction routes and three distinct chitosan conversion processes were considered and compared for their greenhouse gas footprint, abiotic depletion, acidification, eutrophication and other potentials. Finally, the energy demand distribution was analysed considering electricity production patterns from three European countries, Slovenia, Portugal and Norway. The results showed that alternatives 3-A and 3-B (conventional eco-solvents - conventional deacetylation with 40 % and 50 % NaOH) generate the lowest environmental burden (184 g CO2 eq./g chitosan). Electricity was the main hotspot of the processes, used either for extraction, plasma treatment or deacetylation. The sensitivity analysis proved that the Norwegian electricity mix has the lowest environmental impact (4.2 g CO2 eq./g chitosan). This study highlights the impact of blue biorefineries by transforming marine waste to valuable biopolymers such as chitin and chitosan.
Ključne besede: shrimp shells waste, blue biorefinery, value-added products, chitosan, sustainable production, comparative environmental assessment
Objavljeno v DKUM: 08.01.2025; Ogledov: 1; Prenosov: 5
Celotno besedilo (2,16 MB)

Opis: The salient scope of this paper is to enable the knowledge and understanding of urban freight transportation and provide guidance for implementing sustainable policies and measures in a city. To achieve this goal, an evaluation framework for city logistics policies and measures is developed, which demonstrates the complexity of urban freight transportation systems, through selected performance indicators, taking into account divergent stakeholders’ interests, conflicting business models and operations. Evaluation follows a hierarchical process; sustainability disciplines (economy and energy, environment, transportation and mobility, society), applicability enablers (policy and measure maturity, social acceptance and users’ uptake), multiple criteria and indicators, capturing the lifecycle impact of policies and measures and multiple stakeholders. Apart from the multicriteria context, the framework embeds methodologies, including, Impact Assessment, Social Cost Benefit Analysis, Transferability and Adaptability, and Risk Analysis. To demonstrate its applicability a case study is set for the City of Graz assessing the establishment of an Urban Consolidation Center. Results show that there is an overall improvement of 2.2% in the Logistics Sustainability Index when comparing before and after implementation cases of the Urban Consolidation Center.
Ključne besede: framework, logistics assessment, sustainability, urban logistics
Objavljeno v DKUM: 22.08.2024; Ogledov: 49; Prenosov: 9
Celotno besedilo (1,28 MB)
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