Two ways of local recycling of te solid fraction of biowaste, one of which is combined with the production of biogas, have been studied within the BERAS-project. On-farm biogas plant treatment in Juva could also support agriculture

Granstedt, Artur

Lehto, Tiina

English

Organic Eprints

E K O L O G I S K T   L A N T B R U K   N R   4 6   •  D E C E M B E R   2 0 0 5ENVIRONMENTALIMPACTS OF ECO-LOCAL FOOD SYSTEMS– final report fromBERAS Work Package 2Artur Granstedt, Olof Thomssonand Thomas Schneider (eds.)Centrum för uthålligt lantbrukBaltic Ecological Recycling Agriculture and Society (BERAS) Nr. 5107C H A P T E R   VIIevident if the nutrient balance evaluation considers not only the biogasplant but also the nutrient cycle of the farm organism over a wholecrop rotation period. Not only the quantity but also the quality of thenutrients affects soil fertility, fodder quality and animal health and bothneed to be taken into considerationTiina Lehto, South Savo RegionalEnvironment Centre, Finland, andArtur Granstedt, SwedishBiodynamic Research Institute,Järna, SwedenPossibilities for developing combined recycling andrenewable energy production in Juva and JärnaThe plant nutrients in food stuffs from agriculture end up in slaughter-house wastes, domestic wastes (wastes from household and foodindustry) and sewage wastes. These three fractions contain 4, 3 and 2kg N per capita and year and 2, 0.5 and 1 kg P per capita and year(Calculated from Magid et al. 2002). About 60 % of the nitrogen and45% of the phosphorus are in the liquid wastes residues mainly in thehuman urine fraction. Of the total phosphorus taken up by plants (20kg P per ha) about 75 % can be recycled within the farming system onecological recycling agriculture (ERA) farms if nutrients in manure areoptimally utilized. However, 15 % of the P is found in the sewage fractionfrom human consumption. This could be re-circulated for use in agri-culture through urine separation if the hygienic aspects can be takencare of in a secure way. Another 10 % of the P is found in slaughterwastes which could also be an important resource for the sustainableagriculture.Two ways of local recycling of the solid fraction of biowaste, oneof which is combined with the production of biogas, have been studiedwithin the BERAS-project. Their goal is the safe recycling of nutrients,reduced emissions of greenhouse gases and reduced emissions ofreactive nitrogen. One way is the central recycling at community leveldescribed above for Juva that often is combined with production ofbiogas and other energy recovering systems. However, centralisedbiowaste treatment raises problems with quality control and with thehigh risk of contamination from heavy metals, medicaments, and ani-mal (including human) pathogens. For these reasons these nutrientsare not allowed to be used on soil for food production.The second option is to have a smaller-scale system with betteropportunities to choose and control the material treated. An exampleof this is the recycling of food residues introduced in the small-scalebiogas plant on Yttereneby farm in Järna described above. This small-scale biogas plant for use at farm level may be a better solution forrecycling of nutrients from human food (local processors, ecologicalpublic kitchens and consumers) as it provides opportunities for effectivecontrol against contamination from pathogens and harmful substances.This technology was established as an essential link in the local ecologicalrecycling system that at the same time reduces emissions of greenhouse108     E K O L O G I S K T   L A N T B R U K   N R   4 6   •   D E C E M B E R   2 0 0 5C H A P T E R   VIIgases. Only organic residues from ecological farms, ecological smallscale food processors and ecological consumers are used. Permissionfor this local recycling was obtained from the local government. Patho-gens in the biowaste are destroyed by heating for one hour at 70 0Cwith the help of the energy from the biogas plant. For the farmer, therecycled nutrients from the food chain combined with the treatedmanure from the farm become a trustworthy and valuable resource. Afurther step would be to also use slaughter wastes from a local slaughter-house. Receiving selected biowastes (as slaughter offals) from outsidethe farm also seems to improve the input material, increasing the bio-gas production. Gate fees could bring incomes to farmers.On-farm biogas plant treatment in Juva could also supportagriculture. A preliminary design for a biogas plant in Juva wasdeveloped in 1997 (Citec Environmental Technology, 1997). Nine foodactors, waste producers and users of hydrolysis residuals were includedin that design but of different reason it has not been built.ReferencesAgronet. 2005. Feed tables and recommendations. Agrifood Research Fin-land. Available at: http://www.agronet.fi/rehutaulukotAngervuori.  2002.  Etelä-Savon  ympäristökeskuksen  alueellinenjätesuunnitelma. Seuranta ja tarkastaminen 2001. Etelä-Savonympäristökeskuksen moniste 40. Mikkeli.Citec Environmental Technology. 1997. Biokaasulaitoksen esisuunnitteluJuvalle 1997. Juvan kunta, ECOTECH. Vaasa.Jyväskylän yliopisto. 2005. Ympäristötutkimuskeskus. Tutkimustodistus2005-1648. 07.06.2005.Magid, J., Granstedt, A., Dyrmundsson Ó., Kahiluoto H. & Ruissen T.(eds.) 2002. Urban Areas - Rural Areas and Recycling - The organicway forward? Proceedings from NJF-seminar No. 327. Copenhagen,Denmark 20-21 August 2001. Danish Research Centre for OrganicFarming.Möller, K. 2003. Systemwirkungen einer “Biogaswirtschaft” im ökologischenLandbau: Pflanzenbauliche Aspekte, Auswirkungen auf den N-Haushaltund auf die Spurengasemissionen. Biogas Journal 1, 20-29.National Public Health Institute. 2005. Fineli -Finnish Food ConsumptionDatabase. Available: http://www.fineli.fi/Pelkonen, Rauta, Tanskanen.  Yhdyskuntajätehuollon päästöjenjärjestelmätarkastelu. Teknillinen korkeakoulu.Savolab Oy. 2003. Juvan kunta. Juvan kunnan jätevedenpuhdistamo.Vuosiyhteenveto 2002. 22.9.2003.Schäfer W. 2003. Biogas on-farm: energy and material flow. Paper presentedat Nordic Association of Agricultural Scientists 22nd Congress,“Nordic Agriculture in Global Perspective”, Turku, Finland, July1-4 2003.Schäfer W., Evers L., Lehto M., Sorvala S., Teye F. & Granstedt, A. 2005.Nutrient balance of a two-phase solid manure biogas plant. In:109C H A P T E R   VIIProceedings of NJF seminar 372 “Manure - an agronomic andenvironmental challenge”, 5-6 September 2005, Nils Holgersson-gymnasiet, Skurup, Sweden. NJF Report Vol. 1. No. 2. 2005.Available at: www.njf.nu (Proceedings).Sokka, Antikainen, Kauppi. 2004. Flows of nitrogen and phosphorus inmunicipal waste: a substance flow analysis in Finland. Progress inIndustrial Ecology. Vol. 1 No. 1/2/3 2004.Statistics Finland. 2004. Waste management in households in 1994. Availableat: http//:www.tilastokeskus.fi/tk/yr/ye16.html Referred2.8.2004Tuhkanen, H-R. Personal communication 30.5.2005. Information ofnutrient  content.  Agrifood  Research  Finland.  hanna-riikka.tuhkanen@mtt.fiYTI-tutkimuskeskus. 2004. Biojätteiden ja jätevesilietteiden nykytila jatavoitteet. Biojätteen ja jätevesilietteen käsittelymenetelmät ja niidensoveltuvuus Etelä-Savossa –hanke. Raportti 20.9.2004.

Possibilities for developing combined recycling and renewable energy production in Juva and Järna

Abstract

Similar works

Full text

Available Versions

Organic Eprints