Sorting of Food Waste in Households on Bornholm: An empirical case study combining LCA and practice theory
Translated title
Sortering af madaffald i husholdninger på Bornholm
Authors
Thulstrup, Nina Helle ; Hägerstrand, Lasse Langstrup ; Drejer, Yannick Kofoed
Term
4. Term
Education
Publication year
2022
Abstract
Specialet undersøger, hvordan beslutningstagere kan hjælpe husholdninger med at øge kildesorteringen af madaffald. Fokus er Bornholm, der arbejder mod en cirkulær økonomi og visionen om en ø uden affald. Inden udgangen af 2022 skal bornholmske husholdninger sortere 12 forskellige affaldsfraktioner. Madaffald udgør næsten halvdelen af vægten i restaffald og er derfor vigtigt at skille ud for at genvinde næringsstoffer og energi. Det kildesorterede madaffald behandles i et anaerobt biogasanlæg, hvor der produceres biogas og gødning. Studiet peger på, at husholdningernes rolle i systemet ofte er underbelyst, selv om deres daglige praksis er afgørende for, at ressourcerne kan udnyttes. Gennem en empirisk case kombinerer specialet praksisteori (hvordan vaner, materialer og rutiner formes), etnografiske metoder (observationer af hverdagsliv) og livscyklusvurdering (LCA) af miljøpåvirkninger. Det viser, hvordan praksissen at sortere madaffald kan etableres, hvilke barrierer der opstår, og hvilke miljøgevinster genanvendelsen giver. Resultaterne munder ud i anbefalinger til den lokale affaldsaktør om, hvordan husholdninger kan støttes. Fra et miljøperspektiv kan det betale sig at sortere madaffald og sende det til biologisk behandling, selv når det skal transporteres væk fra øen. For at nå en høj sorteringsgrad er især tre elementer vigtige: tydelig information om, hvad der tæller som madaffald, husholdningernes villighed til at sortere, og adgang til det rette udstyr (spand, poser og beholdere). Endelig peger studiet på, at kombinationen af praksisteori og LCA kan understøtte løsninger, der er både miljømæssigt og socialt bæredygtige.
This thesis examines how decision makers can help households increase source sorting of food waste. The case is Bornholm, which aims for a circular economy and a “Bornholm without waste.” By the end of 2022, households on the island are to sort 12 different waste fractions. Food waste makes up almost half of the weight of residual household waste, so separating it is key to recovering nutrients and energy. Source-sorted food waste from Bornholm is treated in an anaerobic digester, where biogas and fertilizer are produced. The study finds that the household’s role in the system is often overlooked, even though daily practices are crucial for recovery to happen. Using an empirical case, it combines practice theory (how routines, materials, and habits shape behavior), ethnographic methods (observations of everyday life), and life cycle assessment (LCA) of environmental impacts. It shows how the practice of sorting food waste can be established, what barriers may arise, and what environmental benefits recycling provides. The results lead to recommendations for local decision makers, particularly the waste management company, on how to support households. From an environmental perspective, it is worthwhile to sort food waste and send it to biological treatment, even if it must be transported off the island. Three elements are vital to achieving high sorting rates: clear information about what counts as food waste, households’ willingness to sort, and access to the right equipment (bins, bags, containers). The study also suggests that combining practice theory and LCA can help design solutions that are both environmentally and socially sustainable.
[This summary has been rewritten with the help of AI based on the project's original abstract]
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