Secondary raw materials (SRMs) tend to be a valuable replacement for finite virgin materials especially since construction works (i.e., building and civil engineering work such as road construction) ...require vast quantities of raw materials. Using SRM originating from recycling a broad range of inorganic waste materials (e.g., mining waste, different industrial wastes, construction, and demolition waste) has been recognized as a promising, generally more cost-efficient, and environmentally friendly alternative to the exploitation of natural resources. Despite the benefits of using SRM, several challenges need to be addressed before using SRM even more. One of them is the long-term durability and little-known response of construction works built using such alternative materials. In this paper, we present the activities to establish a fully functioning digital twin (DT) of a road constructed using SRM. The first part of the paper is devoted to the theoretical justification of efforts and ways of establishing the monitoring systems, followed by a DT case study where an integrated data environment synthesizing a Building Information Model and monitored data is presented. Although the paper builds upon a small scale, the case study is methodologically designed to allow parallels to be drawn with much larger construction projects.
Temperature control is the primary concern during the design and construction process of mass concrete structures. As the concrete production has an enormous negative environmental impact, the ...development of green mass concretes will eventually become as important as the thermal characteristics. Therefore, this paper investigates the use of Electric Arc Furnace (EAF) steel slag aggregate for the partial replacement of the natural aggregate in the production of mass concrete. The impact of EAF steel aggregate on mass concrete workability, strength, and thermal behaviour was analysed. In addition, a cradle-to-gate LCA study was conducted to evaluate the environmental footprint and sustainability potential of the tested mass concrete mixtures. The study results suggest that the use of EAF steel slag aggregate in combination with a low-heat cement with a high content of blast furnace slag can significantly lower the temperature, reduce the environmental impact, and increase the sustainability potential of mass concrete, while at the same time providing sufficient workability and compressive strength. The study results indicate that EAF steel slag can be upcycled into an aggregate for the production of green mass concrete mixtures.
Fine particulate matter (PM2.5), a detrimental urban air pollutant primarily emitted by traffic and biomass burning, poses disproportionately significant health risks at relatively limited exposure ...during commuting. Previous studies have mainly focused on fixed locations when assessing PM2.5 exposure, while neglecting pedestrians and cyclists, who often experience higher pollution levels. In response, this research aimed to independently validate the effectiveness of bicycle-mounted low-cost sensors (LCS) adopted by citizens, evaluate temporal and spatial PM2.5 exposure, and assess associated health risks in Ljubljana, Slovenia. The LCS quality assurance results, verified by co-location field tests by air quality monitoring stations (AQMS), showed comparable outcomes with an average percentage difference of 21.29 %, attributed to humidity-induced nucleation effects. The colder months exhibited the highest air pollution levels (μ = 32.31 μg/m3) due to frequent thermal inversions and weak wind circulation, hindering vertical air mixing and the adequate dispersion of pollutants. Additionally, PM2.5 levels in all sampling periods were lowest in the afternoon (μ = 12.09 μg/m3) and highest during the night (μ = 61.00 μg/m3) when the planetary boundary layer thins, leading to the trapping of pollutants near the surface, thus significantly affecting diurnal and seasonal patterns. Analysis of exposure factors revealed that cyclists were approximately three times more exposed than pedestrians. However, the toxicological risk assessment indicated a minimal potential risk of PM2.5 exposure. The collaborative integration of data from official AQMS and LCS can enhance evidence-based policy-making processes and facilitates the realignment of effective regulatory frameworks to reduce urban air pollution.
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•PM2.5 poses significant health risks at limited exposure during commuting.•Air quality monitoring stations and citizens' initiatives data integration enhances air pollution assessment.•Air quality monitoring stations co-location validation of low-cost sensors results yielded comparable outcomes.•PM2.5 increased in cold months due to thermal inversions hindering pollutant dispersion.•Cyclist had three times higher PM2.5 exposure than pedestrians.
Anion-exchange high performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was used for simultaneous speciation of chromate, molybdate and arsenate. The ...repeatability of measurement tested for multielemental standard solution of chromate, molybdate and arsenate (50 ng mL
of Cr, Mo and As, pH 12) was ± 0.9%, ± 4.9% and ± 4.1%, respectively. Limits of quantification (LOQs) were low (0.53 ng mL
for chromate and arsenate and 1.03 ng mL
for molybdate, expressed as elemental concentrations). A wide linear concentration range (from LOQs to 500 ng mL
) was obtained. The performances of this method enabled simultaneous speciation analysis in samples of water from lysimeters, in which three geotechnical composites, made of recycled waste, were installed in parallel in compacted and uncompacted, 20 times less dense form. The release of toxic chemical species of elements into lysimetric waters from each composite was studied. The results revealed that the degree of compaction and the composition of composites both have a significant influence on leaching of chromate, molybdate and arsenate. The study proved that multielemental speciation analysis is fast and cost-effective method for investigations of environmental impacts of materials, made from recycled waste, and can be used in other similar applications.
Significant criteria for choosing materials (consolidants and protective coatings) for the conservation of the built cultural heritage were gathered from the literature and by consultation with ...experts working on the preservation of cultural heritage. Ten criteria were chosen from these, and a questionnaire was prepared and sent to stakeholders in the cultural heritage conservation domain in order to evaluate, score and rank the importance of the proposed criteria. Based on the results obtained a decision support tool was developed, aimed at conservators and other stakeholders, to help them to make sustainable decisions with regard to the selection of conservation materials for treatment of the built cultural heritage. Performance characteristics and health and safety were identified to be the most important criteria. A preliminary decision can be made based on these two criteria, however, reversibility, minimum intervention and re-treatability are also of very high importance and additional information about these characteristics of the material are required to support decisions. Information about environmental performance, peer recommendation, the application techniques, the price and availability of the materials, which are also integrated in decision support tools, can help conservators and stakeholders to reach a final decision on interventions. The study also provides feedback for the manufacturers of conservation materials. For the users of material, it is very important that the manufacturers clearly identify key characteristics (i.e. criteria) on the product, including those related with environmental performance of the materials.
The environmental properties of three geotechnical composites made by recycling wastes were investigated on a laboratory scale and in the field with the use of lysimeters designated for the ...revitalization of degraded mining sites. Composites were prepared by combining the mine waste with paper-mill sludge and foundry sand (Composite 1), with digestate from municipal waste and paper ash (Composite 2), and with coal ash, foundry slag and waste incineration bottom ash (Composite 3). The results of laboratory leaching tests proved that Composites 1 and 3 are environmentally acceptable, according to the legislative limits, as the potentially hazardous substances were immobilized, while in Composite 2, the legislative limits were exceeded. In the field lysimeters, the lowest rate of leaching was determined for optimally compacted Composites 1 and 3, while for Composite 2 the leaching of Cu was high. This study proved that optimally installed Composites 1 and 3 are environmentally acceptable for use in construction as an alternative to virgin materials, for the revitalization of degraded mining sites or, along with Composite 2, for closure operations with landfills. In this way, locally available waste streams are valorised and channelized into a beneficial and sustainable recycling practice.
This study reports on the assessment of the environmental sustainability of different management practices for an environmentally degraded site in Slovenia: the Old Zinc-Works in the town of Celje. ...Life Cycle Assessments (LCAs) were applied in order to evaluate possible trade-offs by comparing a proposed in situ remediation scenario with two other reclamation scenarios (scenario 2: incineration, metal extraction, underground disposal and reclamation of the site by refilling it with replacement material, and scenario 3: underground disposal and reclamation of the site by refilling it with replacement material) and with a no-action scenario. The results of the comparisons performed show that in the case of the in situ remediation scenario, the consumption of resources is smaller by a factor of 51 compared to that in the second scenario and by a factor of 7 compared to that in the third scenario. The impacts on human health and ecosystem quality are approximately 30 and 3.5 times less in the first scenario than in the second and third scenarios, respectively. Compared to the impact of the no-action scenario, the impact on human health of the in situ soil remediation scenario is approximately 6 times less, whereas its impact on the ecosystem is approximately 4 times less. The results confirmed that the in situ soil remediation scenario is the most sustainable practice from an environmental point of view. Its main advantage lies in the achieved conservation of natural resources. Despite the recovery of valuable metals (Zn, Pb, Cu, and Ni) from the bottom ash, the second scenario is significantly more environmentally burdensome compared to both the first and third scenarios. This outcome is due to the significantly high impacts related to the consumption of fuels needed to support the incineration of low-calorific contaminated soil and to electricity consumption. The present study demonstrates that the results of LCA studies, in addition to technological, economic and social indicators, yield important information about the sustainability of different management practices and therefore should be an important part of decision-making when approaching the reclamation of environmentally degraded sites.
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•In situ remediation of contaminated soil yields relatively low impacts.•Disposal of contaminated soil causes more resource consumption than its remediation.•Benefits of metal recovery from ash do not balance the burdens of soil incineration.
Review of: Skupnost znanja in inovacij EIT Urbana mobilnost –prijetnejše in bolj trajnostno bivanje v evropskih mestih z uporabo inovativnih rešitev. EIT Urban Mobility (2021) EIT urban mobility ...strategic agenda 2021–2027. Barcelona. Reviewed by: Anja Ilenič, Alenka Mauko Pranjić, Darko Kokot, Ana Mladenovič, Mateja Košir.
Light eutrophication in show caves and other light-deprived humid environments can support visible growth of microbial mats, with photoautotrophs as the dominant group of organisms. Photosynthetic ...pigments of aerophytic cyanobacteria and eukaroytic algae impose a greenish patina upon surfaces to which -- with other community members -- they adhere strongly. Diverse eukaryotic algae, fungi, flagellates and amoebozoans were also identified within the community. These "human induced diversity hotspots" in caves are responsible for the biodeterioration of colonized surfaces that is a common result of the synergistic effects of phototrophs and heterotrophs. When sites become colonized by higher plants, such as mosses, liverworts and ferns in species succession, irreversible biodeterioration impact on rocks and speleothems becomes an even more urgent issue. Historical inscriptions and rock-art paintings are particularly sensitive to biodeterioration. Lampenflora also affects components of the cave fauna, which not only graze upon it, but also facilitate its dispersal to other parts of the caves. It can be considered a direct indicator for light eutrophication and of the available energy within the cave ecosystem.
Based on a road reconstruction case study, the advantages and disadvantages of two alternative road pavement rehabilitation techniques, a hypothetically defined comparable traditional approach and an ...actually used cold-in-place-recycling approach, both of which enable a comparable extension of road service life of about 20 years, were investigated by means of Life Cycle Assessment. The results showed that the considered environmental impacts of the traditional approach exceeded those of the cold-in-place-recycling approach: by only 1% with regard to Global Warming, by 18% with regard to Acidification, by 15% with regard to the Abiotic Depletion of Fossil Fuels, and by 16% with regard to primary energy consumption. In the case of the traditional approach, the use of larger amounts of natural aggregate and the transportation of materials significantly contributed to emissions and the consumption of fossil fuels and energy, whereas the cold-in-place-recycling approach was sensitive to the use of cement, whose production results in relatively high emissions, especially of greenhouse gasses. In the case of the traditional approach, sensitivity analyses were carried out with regard to the use of aggregate from a quarry instead of a gravel pit, and to the delivery distance of material hauled away from the distressed road during rehabilitation works (extending the one-way delivery distances from 20 to 100 km). It was found that, if aggregate from a quarry is used instead of from a gravel pit, then the various environmental impacts of the traditional approach would exceed those of the cold-in-place-recycling approach by factors which range between 1.3 and 1.7. Increasing the transportation distance of hauled-away materials from 20 km to 100 km, the impacts of the traditional approach would exceed the impacts of the cold-in-place-recycling approach by a factor of 1.4 (Global Warming) and 1.6 (Acidification and Abiotic Depletion of Fossil Fuels). A further sensitivity analysis was carried out in the case of the cold-in-place-recycling approach, with regard to the use of Portland cements containing different amounts of clinker. It was found that the use of cements with a higher clinker content results in an increase in the Global Warming impact to a level significantly higher than that of the traditional approach.
•Environmental benefit of recycling versus conventional scenario was confirmed.•However, carbon footprints of two compared scenarios are similar.•Recycling scenario is very sensitive to the type of Portland cement.
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