1,721,193 research outputs found
LCA of Single Use Plastic Products in Denmark
No full textThis study provides an environmental Life Cycle Assessment (LCA) of the production of Single Use Plastic Products (SUP) and the production of alternative Single Use Non Plastic Products (SUNP) and their waste management in Denmark, in 2018.The commissioner of this study is the Danish Environmental Protection Agency (Miljøstyrelsen) and the study was conducted by DTU (Danmarks Tekniske Universitet) Environment in the period August to October 2018.The LCA was modelled using EASETECH, a software developed at DTU Environment for the environmental assessment of waste management systems. The LCA has been conducted according to the requirements outlined in DS/EN ISO International Standards 14040 and 14044; however, the report is not intended to strictly comply with the standard. <br/
Life Cycle Assessment of grocery carrier bags
Full text linkThe report provides a lifecycle assessment (LCA) of production, use and disposal of shopping bags available in Danish supermarkets in autumn 2017.16 different environmental parameters have been compared, and the results are shown by how many times a given type of carrier bag should be used to be as environmentally good as a regular plastic carrier bag
Integrated Resource Management and Recovery
No full textA significant part of the environmental consequences related to activities in society is associated with our consumption of resources. Modern products become more and more complex and rely on more complex sets of resources than before. This emphasizes the need for continuous access to high quality resources, i.e. security of supply, but also the need for efficient recovery of the same resources after the use-phase of the products. While this recovery may appear simple, considerable challenges exist. Management and recovery of resources in waste materials, or in general residual streams in society, depends on the quality of these resources and technological abilities to extract resources from mixed materials, e.g. mobile phones, solar cells, or mixed domestic waste. The "effort" invested in recovery of secondary resources should not be more than the "benefit" associated with the secondary resources. Over the recent decades, DTU Environment has worked extensively both with resource recovery technologies and life cycle assessment (LCA) models (www.EASETECH.dk) dedicated to evaluating resource management and recovery systems. Advanced sustainability assessments of resource recovery and utilization have been carried out e.g. in relation to household and industrial waste systems, biomass residues from agriculture and forestry, energy producing technologies as well as entire energy systems. The presentation provides an introduction to key challenges in relation to sustainability assessment of resource recovery as well as examples of recent research
Characterization of leaching from waste incineration air-pollution-control residues
Full text linkWaste incineration generates solid residues with high contents of salts and heavy metals that may leach to the surrounding environment upon disposal. Residues from flue gas cleaning, i.e. air-pollution-control (APC) residues, are highly alkaline and have potentials for leaching in very long periods of time. This leaching needs to be quantified and evaluated in a long-term perspective in order to manage the residues in a sustainable manner, however the time frames involved render this unfeasible using traditional leaching tests. This thesis provides a methodology for estimating long-term leaching from APC residues. A relation between pH of a residue leaching system and the liquid-to-solid (L/S) ratio can be produced based on data for leaching of alkalinity as a function of pH. By relating alkalinity leaching at specified pH-values to losses in residue alkalinity, it is possible by a simple mass balance approach to associate pH of a leaching system with the L/S ratio. This may further be combined with relationships between metal leaching and pH to provide estimated leaching as a function of L/S until depletion from the solid phase. Typically, APC residues have natural pH-values of 11-12.5 and may maintain alkaline pH-levels for L/S ratios above 2000 l/kg. For a typical landfill, this corresponds to about 100,000 years. This means that metal leaching is most important with respect to high pH. Elements like Ca, Cl, K, Na, Pb and S typically leach in very high concentrations at low L/S, i.e. in mg/l and g/l. Although leaching may continue for very long time, concentrations generally decrease significantly compared to the initial level. Within L/S 5000 l/kg, only Al, Mg and Zn are predicted to have higher leachate concentrations than what can be observed at L/S 2-10 l/kg. Uptake of atmospheric CO2 may somewhat increase the leaching of Ca and S. These two elements can be completely removed from the solid phase within L/S 300-800 l/kg, whereas other elements generally require leaching for more than L/S 2000 l/kg to remove about 20-30 % of the solid content. In a long-term perspective, leaching of most elements can be considered controlled by mineral solubility, however, specific elements such as Cr may possibly be affected by other mechanisms. In batch leaching experiments, Cr is highly affected by the redox conditions of the test and reaction kinetics. Cr(VI) reduction capacity provided by Al(0) in the residues may significantly lower Cr concentrations within a few hours of experiment, whereas Cr(VI) dissolution may require a day to complete. Al-O2-Cr interactions appear to control the release of Cr in batch experiments
Process-oriented life cycle assessment modeling of waste biorefinery technologies: an outlook
No full textTraditionally life cycle assessment (LCA) of waste management technologies have been based on so-called “black-box” inventory datasets representing the inputs and outputs from a technology (and thereby the emissions and subsequent environmental impacts). This approach limits the applicability of these datasets in other studies and reduces the transparency of LCA modeling results. The dedicated waste LCA model EASETECH is now taking a different approach by implementing more flexible modeling of individual unit processes within integrated and muliti-output waste solutions such as biorefineries. As these technologies represent combinations of a variety of bioconversion processes, evaluating the importance and configuration of individual unit processes offers significantly more insight than traditional “black-box” LCA modeling can provide. The next generation of EASETECH offers a consistent and flexible way to provide this new insight
Waste containing asbestos and other environmentally problematic substances:Characterization, risks and management
No full textIn Denmark, waste containing asbestos (WCA) is separately collected, handled, and landfilled. Waste contaminated with environmentally problematic substances such as PCBs, PAHs, and heavy metals is also separately collected; incineration is the adopted disposal method for some waste fractions and substances, with landfilling and recycling used only in specific situations. In some cases, besides asbestos, the waste also contains other environmentally problematic substances (e.g., PCBs, PAH, heavy metals) in concentrations exceeding the limit values for hazardous waste. When a combination of waste and other environmentally problematic substances occurs, the waste is likely to be classified as hazardous for multiple reasons. The combined presence of asbestos and other environmentally problematic substances makes managing this type of waste is challenging. While incineration of waste containing asbestos is currently not done in Denmark, the presence of organic substances and heavy metals may limit the possibilities for landfilling. Given the variety of situations (and combination of sub-stances) no general guidelines exist, and Danish municipalities have to make specific decisions on a case-by-case basis.The objective of this project was to identify and evaluate possibilities for handling waste containing both asbestos and other environmentally problematic substances (WCAPS) in Denmark. The focus was in particular on two potential solutions: i) Landfilling of waste containing asbestos and heavy metals; ii) Thermal treatment of waste containing asbestos and PCB/PAH.The main objective of the project was achieved through the following specific activities:•Review of existing literature concerning relevant information and previous assessments of suitable treatment options for asbestos-containing waste.•Map relevant waste fractions containing asbestos in combination with either i) heavy metals or ii) organic compounds such as PCBs and PAHs, and identify the most important (i.e., largest or more frequently present) at the national level.•Assess the potential for compliance of the above waste fractions with acceptance criteria for disposal of hazardous waste in accordance with the Landfill regulation, based on laboratory leaching experiments on waste samples containing both asbestos and heavy metals.•Based on laboratory-scale thermal tests, assess the possible transformation of asbestos fibers and related potential emissions induced by high-temperature conditions.•Screen the risk of asbestos leaching from landfills to the aquatic environment towards humans (via drinking water) and organisms in the receiving surface waters in Denmark.About 200 Mton of asbestos have been produced since 1920 up to nowadays. Because of its carcinogenicity, the marketing and use of asbestos-containing products have been banned in the EU since 2006; however, about 2 Mton of asbestos are still produced globally every year. The use of asbestos is linked to a variety of products and applications, most of them related to the construction sector. It is, for example, estimated that, in the 80s, about 70% of asbestos was used in cement products and 10% in vinyl/linoleum flooring.The generation of waste containing asbestos, originating from products used in the past, is currently in the order of 90,000 ton per year in Denmark. Precise data on the amount of asbestos contained in the waste are not available, but an overall estimate is around 10,000-30,000 ton of asbestos fibers per year. The main treatments for asbestos-containing waste in Denmark are landfilling or exporting for special treatment.Statistical data about WCAPS are not readily available. Hence Danish municipalities and companies dealing with this type of waste – either demolition or waste handling companies - were contacted to collect information via a questionnaire; 46 municipalities and 8 companies provided a response. While confirming that information is lacking, it was estimated that few hundred ton WCAPS may be generated yearly in Denmark. The most relevant material fractions, either because of frequency or amounts, are:•Vinyl/linoleum flooring + asbestos + heavy metals;•Tiles + asbestos + heavy metals;•Roofing felt + asbestos + organic pollutants.Experimental activities were carried out to evaluate two potential scenarios for the management of waste containing both asbestos and other environmentally problematic substances:•“Landfill scenario” focusing on waste samples containing asbestos and relatively high con-tents of heavy metals, to investigate the potential for compliance with the leaching criteria defined for landfilling of hazardous waste;•“Thermal treatment scenario” focusing on waste samples containing both asbestos and relatively high contents of organic pollutants, to investigate the pontial for destruction of asbestos fibers and organic pollutants at high temperatures.Four samples of WCAPS - as classified in the respective Environmental Mapping Report (i.e. Miljøkortlægningsrapport) - were obtained from waste management companies and analyzed for their content of asbestos, PCB, PAHs, heavy metals and hydrocarbons. Procedures for screening, mapping and classifying WCAPS were discussed; options for improving the procedures were identified. This included for example:•the establishment of a coordinated system for recording the occurrence of waste containing both asbestos and other environmentally problematic substances;•preparation of an official guideline describing how sampling should be done, to ensure objectivity and consistency across municipalities in screening/mapping and the subsequent hazardousness classification;•implementation of routines so that, for materials known to be potentially inhomogeneous, additional samples are taken and analyzed for the presence of asbestos;•improvement of material classification strategies by encouraging more sampling of waste materials also during the demolition phase, to cross-check and confirm the results of the mapping phase, and eventually re-classify the waste accordingly.Samples of tiles and linoleum were tested for compliance with acceptance criteria at hazardous waste landfills. The release tests showed that both materials would comply with the acceptance criteria for all classes of landfills approved for hazardous waste disposal.Samples of linoleum and roofing felt were treated at 1100 °C, to assess the efficacy of thermal treatment in destroying asbestos and organic pollutants. The results indicated that high temperatures are effective in significantly reducing or eventually almost completely destroying the organic pollutants contained in the waste. With regards to asbestos, results were only available for linoleum flooring (because of the lack of asbestos in the roofing felt samples, despite the fact that their documentation indicated presence). While conclusions beyond the specific samples cannot be made, the experiments indicated that heating of waste to 1100 °C can be effective in destroying the asbestos fibers, in agreement with existing literature on the topic.The risk screening evaluated leaching of asbestos from landfills to the aquatic environment. The screening indicated that there is low risk towards humans (via drinking water) and organisms in the receiving surface waters. The project further identified that there is no scientific evidence regarding toxicity effects or risks from the combination of asbestos and other contaminants. These finding further support the results obtained via the compliance tests.Based on the results, potential options for management of the waste evaluated in this project containing both asbestos and other environmentally problematic substances were identified (TABLE 1), together with key parameters to be checked during the decision-process. Regarding the risk screening more knowledge and data on source characteristics, asbestos leaching from waste, exposure and toxicity towards sensitive sub-populations (e.g. children) are required to improve the results. It should be noted that the risk screening is based solely on available data and general assumptions, and specific data collection and stakeholder involvement e.g. for site descriptions was beyond the scope of the project
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