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Food waste recycling through collection with the Green Bag
Published on 31 August 2021
Sweden
Östra Mellansverige
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About this good practice
The Swedish government has previously decided on national targets that by 2018 at least 50 percent of food waste from households, commercial kitchens, shops and restaurants will be sorted out and treated biologically so that plant nutrients are utilized. This goal was also included in the national waste plan. Each municipality was then responsible for implementing appropriate measures based on its collection system.
In response to the national goal, the "green bag" collection was introduced in Linköping in 2012. The idea with the green bag is that it lets the municipal residents sort their food waste themselves a green bag which is then thrown in the same container as the other household waste. The bags are distributed free of charge to the residents. The bag is made of plastic and are smaller than ordinary plastic bags, this in order that the food waste does not remain all for long in the bags to avoid bad odor. When the waste has been collected and transported to the waste treatment plant, green bags is separates from the rest of the waste via an optical sorting machine. The automatic sorting takes place with the help of a camera in the facility who feel the green color of the bags. The food waste from the green bags is then digested together with other substrates and becomes biogas and biofertilizer. Bioogas that can be a substitute for fossil fuel in industry, public transportation and cars. At the same time, nutrient-rich biofertizer is formed and spread on arable land.
In response to the national goal, the "green bag" collection was introduced in Linköping in 2012. The idea with the green bag is that it lets the municipal residents sort their food waste themselves a green bag which is then thrown in the same container as the other household waste. The bags are distributed free of charge to the residents. The bag is made of plastic and are smaller than ordinary plastic bags, this in order that the food waste does not remain all for long in the bags to avoid bad odor. When the waste has been collected and transported to the waste treatment plant, green bags is separates from the rest of the waste via an optical sorting machine. The automatic sorting takes place with the help of a camera in the facility who feel the green color of the bags. The food waste from the green bags is then digested together with other substrates and becomes biogas and biofertilizer. Bioogas that can be a substitute for fossil fuel in industry, public transportation and cars. At the same time, nutrient-rich biofertizer is formed and spread on arable land.
Resources needed
Investments in an optical garbage sorting machine: SEK 45 million. 6 employees for monitoring and maintenance of sorting. Free bags: SEK 31.2/year/household. Initial marketing: SEK 1.65 million. The collection cost can be estimated to be the same as no measures are taken in the collection system.
Evidence of success
In Linköping, 80 % of all households used the green bag and ca 55 % of all food waste was collected separately in 2019, thus achieving the national target for separate collection. In addition to the investment cost for the sorting plant, this could be done without any major changes to the collection system. In addition, the marketing campaign for the green bag has also won Swedish Marketing Association award “this year's Marketer” to the municipalities behind the campaign.
Potential for learning or transfer
The concept with green bag collection is now widespread in Sweden, advantages of the system are i.a. that it can be done without any major changes to the collection system. Therefore the solution is mainly interesting in an existing functioning collection system where for various reasons it is not possible or appropriate to introduce sorting in separate containers. That it is implemented in so many Swedish municipalities indicates its transferability. Given the green bag design and that it can be thrown in existing waste bins, allows peoples daily waste management not to be complicated despite additional source sorting. In addition to the technical aspect, “green bag” have also succeeded as a brand. The strong brand of the green bag can contribute to an increased awareness of resource recycling and so on way reduced food waste, which gives rise to a socio-economic benefit.
Good practice owner
You can contact the good practice owner below for more detailed information.
Organisation
Tekniska Verken i Linköping AB
Sweden
Östra Mellansverige
Contact