Waste disposers deal with food waste in Malmö

Under InFOrMATIOn FACTS The SwedISh ePA PreSenTS FACTS AbOUT dIFFerenT IS-SUeS

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wASTe LIP – LOCAL InVeSTMenT PrOGrAMMeS SePTeMber 2008

waste disposers deal with food

waste in Malmö

The City of Malmö has run a pilot project in which kitchen waste disposers have been installed as an easy-to-manage method of dealing with food waste. The waste disposers have proved to be an effective way of dealing with organic household waste in order to produce biogas.

Before demonstrating sustainability solutions at the housing fair Bo01, the City of Malmö wanted to also try out new solutions for the separation of domestic refuse. The City applied for and received grants from the Local Investment Programme (LIP) in 2000 for a trial with sink waste disposers.

PositiVE EnVironmEntaL anD Economic imPacts

The project was primarily a pilot project intended to try out a new solution. It is there­ fore difficult to put the environmental and financial benefit into figures. But it is evident that waste disposers offer environmental and financial gains.

• The system produces 0.9–4.9 m3 _{biogas per apartment and year, compared with}

0.6–1.8 m3 _{per apartment and year for ordinary refuse separation.}

• The biogas is used to produce electricity and heating, which lowers CO ₂ emissions. • The food waste disposer has acted as a catalyst for personal environmental thinking

for many residents.

• The quality of the organic matter has been high. No post-processing or processing is needed for it to be possible for the waste to be used for biogas production, which saves costs.

swedish EPa Se-106 48 Stockholm. Visiting address: Stockholm - Valhallavägen 195, Östersund - Forskarens väg 5 hus Ub, Kiruna - Kaserngatan 14.

Tel: +46 8-698 10 00, fax: +46 8-20 29 25, e-mail: registrator@naturvardsverket.se Internet: www.swedishepa.se orders Ordertel: +46 8-505 933 40,

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information facts beST PrACTICe eXAMPLeS

wASTe LIP – LOCAL InVeSTMenT PrOGrAMMeS SePTeMber 2008 ISbn: 978-91-620-8595-7

imPLEmEntation

In cooperation with the developers, the municipality installed waste disposers in the kitchens of 200 of the homes within the Bo01 area.

The waste disposers are the size of a large thermos and were installed beneath the sink. Owing to the risk of leakage to already polluted watercourses, the municipality did not want there to be more organic particles in the sewage system. Separate pipes were therefore routed from the waste disposer. The pipes run to a collecting tank below the ground outside the building.

The ground food waste falls to the bottom of the tank, while the water runs onward to the wastewater pipes. A sludge suction truck sucks up the collected waste and transports it to the local wastewater treatment plan, where it is digested and produces biogas.

The developers themselves had to install and maintain the waste disposers and the pipes that were needed in their buildings. The municipally owned water company VA Syd installed and maintains tanks and emptying, and deals with the waste slurry. VA Syd has started offering waste disposers as an alternative to the separation of food waste in the development areas in Malmö.

It was originally intended that the nutrients in the digestion residues would be extracted and used, but this project has not been implemented.

PotEntiaL anD fUtUrE BEnEfit

There are environmental objectives to increase the biological treatment of food waste. Waste disposers can provide efficient management of organic waste, replacing the need for waste transport. Food waste becomes biogas, which is an important aspect of the switch of society from fossil to renewable fuels.

Biogas produced from waste and residues offers several advantages, It eliminates a waste management problem with possible adverse impacts on the environment, and production does not create any conflicts on land use for example to produce food.

whY beST PrACTICe

The project has provided knowledge on how it is appropriate to design future systems for the separation of organic waste. The technique of using a collection tank for the ground waste is innovative.

The project has shown that cooperation across traditional organisational boundaries makes it easier to start and run projects of this type. Other municipalities have shown interest in the system. FOr FUrTher InFOrMATIOn

Contact

henrik Aspegren, VA Syd,

+46 (0)40-635 01 78, henrik.aspegren@vasyd.se Contractors/providers

The waste disposers were installed by Uson Marine Ab.

The participating developers were MKb, JM bygg and hSb.

Much of the work is relatively routine heating and plumbing work.

The project on the Internet: www.malmo.se

www.ekostaden.se

Further information on best Practice www.swedishepa.se/bestpractice www.naturvardsverket.se/mir FACTS

LIP Malmö, bo 01 2000 Action 6

environmental investment: SeK 2m Grant: SeK 1m