Organic waste management studies : inventory in Juva

Two different organic waste management systems have been studied in the BERAS project. The most extensive study was of biowaste and nutrient flows in the community of Juva, Finland. The research methods used were waste flow and substance flow studies

Towards a breakthrough in nutrient recycling : State-of-the-art and recommendations for developing policy instruments in Finland

The report has been complemented on 11.9.2018This report describes the state-of-the-art in phosphorus and nitrogen recycling in Finland and looks at basic data on the volumes and geographical distribution of biomasses and their nutrients. Based on this data, the report makes proposals for measures aiming to promote nutrient recycling. This report was prepared collaboratively by experts at the institutions making up the Finnish Partnership for Research on Natural Resources and the Environment (LYNET) to underpin a national action plan on nutrient recycling. Of all sectors in Finland, agriculture is the largest user and recycler of phosphorus and nitrogen. Different biomasses contain an annual total of approximately 26,000 t of recyclable phosphorus, which exceeds the fertilisation needs of grasslands and cereal crops in the entire area of Finland. The volume of nitrogen contained in biomasses is approximately 95,000 t. Still, approx. 11,000 t of phosphorus and 152,000 t of nitrogen are annually used in Finland as conventional inorganic fertilisers. There is a regional imbalance between manure production and crop nutrient requirements. The breakthrough in nutrient recycling means increased implementation of manure processing, thus making manure nutrients easier to transport and reducing the use of conventional inorganic fertilisers. At minimum 20% of the entire volume of manure generated in Finland will require advanced processing to enable long-distance transport of the manure phosphorus to areas in need of it. This requires separation of water. The highest demand for advanced processing is experienced in the regions of Ostrobothnia (approx. 60% at minimum), South Ostrobothnia and Satakunta (approx. 30 %) and Southwest Finland (13%). In the agricultural sector, fertilisation is currently guided by a wide array of different policy instruments, which make up an incoherent and unstructured whole. The instruments cause considerable amounts of regulatory burden, but appear to do little to promote sustainable nutrient recycling. This report proposes a total reform of the policy instruments to boost the recycling of nutrients. All legal standards related to fertilisation should be merged into a single statute, for example by developing the Nitrate Decree. At the same time, the current policy that controls nutrient use via the EU agri-environmental scheme should be abandoned, and the role of the environmental permit for livestock installations and its relationship with general regulatory instruments be clarified. A field plot specific nutrient database should be created to support guidance. The knowledge base of nutrient recycling should be developed by creating and maintaining a comprehensive data system on the quantities, properties and locations of nutrient-rich biomasses and ashes and their current processing methods. The report also proposes setting regional processing targets for livestock manure. Key objectives should include reducing excessive fertilisation in crop production. The goal of normative guidance should be nutrient use according to the crop needs.201

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

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

Sustainable recycling of compost products in plant production

In the research project "Sustainable recycling of compost products in plant production" we study and verify the effects of the use of biowaste and sewage sludge composts in plant production

Disease suppression of potting mixes amended with composted biowaste

Peat mining destroys valuable nature areas and contributes to the greenhouse effect. This warrants the search for alternatives for peat in potting mixes. Composted biowaste could provide such an alternative. An additional advantage of (partially) replacing peat by compost is the increased disease suppressiveness. In this study, nine commercial composted biowastes were tested for disease suppressiveness using the pathosystems Pythium ultimum-cucumber, Phytophthora cinnamomi-lupin and Rhizoctonia solani-carrot. Increased disease suppression was found in compost-amended potting mixes for all three pathosystems. The level of disease suppression ranged from slight stimulation of disease to strong suppression. Suppressiveness against one disease was not well correlated with that against the other diseases. The CO2 production, a measure of general microbial activity, was the parameter most strongly correlated with the level of disease suppression. Wetsieving the biowaste with tap water over a 4-mm sieve prior to composting yielded a compost with an 2.4-fold increase in organic matter and a twofold decrease in EC and Cl--concentration of the compost. The latter reductions allow for an increase of the amount of peat that can be replaced by compost. A linear relation was found between the amount of compost added to the potting mix and the level of disease suppression indicating the potential for increasing disease suppressiveness of potting mixes by replacing peat by high-quality composted biowastes

Biogas plant in Järna

The Biodynamic Research Institute in Järna developed an on-farm biogas plant integrated within the highly self-supporting farm organism, Skilleby-Yttereneby, one of the farms studied in the BERAS project. The biogas plant digests dairy cattle manure and organic residues originating from the farm and the surrounding food processing units

Ammonia based sanitation technology

Water-borne sanitation of toilet waste is not a viable option for the estimated 2.6 billion people that lack improved sanitation throughout the world. In Environmental Systems Analysis, source separating sewage systems have proven to be of interest, since both energy and nutrients are saved compared with conventional systems. As the urine and faecal matter contribute with the majority of nutrients to wastewater but constitute a small part of the volume, these fractions are suitable for nutrient recycling to agriculture. The potential content of pathogenic (disease causing) microorganisms makes it a necessity to sanitise the material before use as a fertiliser, especially as many pathogens are zoonotic, infecting both man and animal. The main objective of this study was to evaluate ammonia based sanitation technology for source separated urine and faeces aiming for production of safe fertilisers. To achieve this objective, the inactivation kinetics of several groups of organisms was investigated in relation to concentration of free ammonia, NH3, temperature and dry matter content. Inactivation of Ascaris suum eggs, Salmonella spp. Enterococcus spp., S. Typhimurium phage 28B, an f-specific RNA phage MS2 and a coliphage ΦX 174 was monitored in spiked human urine and faeces. Storage of urine diluted 1:0, 1:1 and 1:3 with water was studied at 4, 14, 24, and 34°C. Faecal material, source separated dry, was treated with urea at concentrations ranging from 0.5% to 2% at 14, 24, and 34°C. Faecal material with ash amendments was studied at 24 and 34°C, separately and with supplementary addition of 1% urea. Temperature was found to be a key factor for the efficiency of the ammonia based sanitation, both through synergy and by affecting transformation of ammonia into NH3. At 34°C the NH3 concentrations in urine and faecal material resulted in short decimal reduction (D) values for microorganism concentrations, except for the bacteriophage 28B, which showed little inactivation in stored faecal material. At 24°C, treatments of both urine and faeces with NH3 concentrations of 50 mM and above gave significant reductions whereas at lower concentrations (urine 1:3 and storage of faecal matter) little inactivation of bacteriophage 28B and ascaris eggs was observed. This means that urine must be collected as concentrated as possible in order to contain sufficient ammonia to reduce pathogens by storage. Treatment with urea, a 2% addition resulted in stable pH and NH3 concentrations that resulted in fast Salmonella spp. inactivation even at 4°C and 14°C, and inactivation of ascaris and the bacteriophage at temperature 24°C and above. Coverage with ash and lime during collection can give an enhanced pathogen inactivation when later treated in closed containers. Accompanying urea treatment of faeces collected with ash is possible but with a high pH (>10) in the material urea will not be degraded and thus not contribute to inactivation

Organic Soil Management: Impacts on Yields, Soil Quality and Economics

Understanding organic management practices is a key in developing sustainable organic farming systems. We report the results of four different organic fertilization strategies in a field trial on yields, soil quality and economic performance. We found highest yields and economic performance in two direct plant feeding strategies. One of these strategies, a newly developed strategy based on biowaste compost (GFT) and an additional fertilizer performed well in terms of yields but looks also very promising in terms of soil quality and biodiversity. The economic perspective of this strategy renders it promising in regions with little animal manures

Energetic and environmental benefits of co-digestion of food waste and cattle slurry: a preliminary assessment

The research evaluated the feasibility of centralised pre-processing and pasteurisation of source-separated domestic food waste followed by transport to farms for anaerobic co-digestion with dairy cattle slurry. Data from long-term experiments on the co-digestion of these two substrates was used to predict gross energy yields; net yields were then derived from full system analysis using an energy modelling tool. The ratio of cattle slurry to food waste in the co-digestion was based on the nutrient requirements of the dairy farm and was modelled using both nitrogen and phosphorous as the limiting factor. The model was run for both medium-size and large farms in which the cattle were housed either all year round or for only 50% of the year. The results showed that the addition of food waste improved energy yields per digester unit volume, with a corresponding increased potential for improving farm income by as much as 50%. Data for dairy farms in the county of Hampshire UK, which has a low density of dairy cattle and a large population, was used as a stringent test case to verify the applicability of the concept. In this particular case the nutrient requirements of the larger farms could be satisfied, and further benefits were gained from the reduction in greenhouse gas emissions avoided through improved manure management and fertiliser imports. The results indicated that this approach offered major advantages in terms of resource conservation and pollution abatement when compared to either centralised anaerobic digestion of food waste or energy recovery from thermal treatmen

Municipal waste composts in organic agriculture, aiming to the future

The Finnish study shows possibilities for using high quality municipal waste composts as fertilizers without any negative effects on soil heavy metals, hygienic quality or microbiological functions