Multicriteria Analysis of Glass Waste Application

Increasing amounts of glass waste present serious challenges in waste management to avoid environmental problems that might be created if it was to be deposited in landfills. Theoretically, glass waste is fully recyclable, but, if contaminated, containing impurities, broken or mixed colour, it makes the re-melting process impractical. A great practice of using secondary recycling material was reached by the construction industry involving glass waste in concrete mixtures as fine aggregates – reuse of waste glass in concrete production not only preserves natural resources, reduces greenhouse gas emissions, saves energy, furthermore, it may improve concrete sustainability and enhance the properties of concrete when used at the optimum quantity. In this study the container glass waste evaluation was performed, as well as experimental research of mechanical properties of four types of concrete mixtures containing glass waste as fine aggregate. The best alternative of replacement of sand by glass waste scenario in concrete production was determined, employing the multicriteria decision-making method TOPSIS

Ranking of Bioresources for Biogas Production

Production of biogas using bioresources of agricultural origin plays an important role in Europe’s energy transition to sustainability and to a climate-neutral economy. The usage of some substrates like maize has been increasingly denounced in the last years and there is currently an active discussion about future subsidies to biogas producers depending on the substrate used. The aim of this study is to compare and rank different substrates for biogas production considering their economic feasibility, substrate efficiency and environmental aspects. During the research, eight substrates were evaluated: cattle manure, pig manure, poultry manure, straw, wood, maize silage, waste, and sewage sludge. In order to reach the research goal, multi-criteria analysis using TOPSIS methodology was applied to objectively determine which of the substrates considered would be the most suitable for biogas production in Latvia. The results obtained showed that pig manure is the most suitable raw material for biogas production in Latvia, while poultry manure was ranked second, with little difference in value from pig manure