From Blackwater and organic waste to fertilizer

Transcription

1 From and organic waste to fertilizer John Morken Using organic waste as fertilizer Hygienic aspects treatment and application Available nutrients treatment, reduce losses of ammonia The value of increased content of organic matter in the soil Input The path from producing nutrients to using them Animal waste Heating Treatment Biogasreactor Biogas Output District heating Electricity Treated waste Sewage sludge Separator 3 4 Liquid (N,P,K) Dry Fertilizer Soil improvement Amount NUTRIENTS IN BLACKWATER AND ORGANIC WASTE Dry matter content (%) Volatile solids (% of DM) Total nitrogen (g/kg) Ammonia nitrogen (g/kg) ~500 kg/person and year < (8) ~100 kg/person and year Wheat NUTRIENT REQUIREMENTS Ley (grass) Potato Yield (Norway) Nitrogen Phosphorus Potassium Nitrate (% of DM) Phosphorus (g/kg) 1,1 1.4 Potassium (g/kg)

2 Nutrients and sustainability Nitrogen: use of energy when produced Phosphorus: rock, non-renewable resource that will last for years Recycling will lead to reduced energy consumption of production of nitrogen, and reduced extraction of phosphorus Nitrogen biochemical processes and definition 7 8 N-flux Treatment Storage (NH 3) NH 3, (N 2 O) Nitrogen decomposition Organic matter -Urine -Protein -Amino acid Possible loss Ammonia + CO2 + water Nutrient Nitrification Air Nitrate 9 Application NO 3-10 Nutrient Crop utilization Water Farm 11 Ammonia volatilization NH 3 + H 2 O NH 4+ + OH - Colloids Reducing the loss: A. Weather Rain B. Waste ph Dry matter Injection Incorporation C. Soil 1. ph 2. CEC 3. Clay content Waste Soil K + 2:1 minerals Tetrahedron Octahedron 12 Ammonia loss [% of applied Rainfall vs. time of day Time of spreading [houres]

3 13 Ammoniakktap, % Ammonia loss, % of applied Ammonia loss v.s. dry matter content Dry Tørrstoffinnhold, matter content, % 14 Why we want to incorporate or inject waste? Reduce emission of ammonia, and use the nitrogen as fertilizer Reduce hygienic risk (run off, aerosols, flies and birds) Locally recirculation of nutrients Injection principles A schematic diagram of one ski Slurry from the pump Driving chain Ski Travelling direction Nozzle (hole in the ski) Rotating knife

4 Principle of DGI 6m Pockets

5 Ammonia loss, % of applied Ammonia volatilization Yield response, ley Covariance analysis: DGI gave significant higher yields than did broadcast spreading Water dilution gave significant higher yields YIELD Broad spread Bandspread Open slot Closed slot Pressurised Deep , 2, 3, 5, 6, 7, 8, TECHNOLOGY 1=Control, 2= Broadcast, 3 =Broadcast, water, 5=Band spread, water, 6=DGI, 7=DGI, water, 8=fertilizer A hilly terrain technique Other advanatges Could be used as a direct driller => agroforsetry possible (no tillage or disturbance of soil layer) lead to reduced evaporation of water No increased decomposition of organic matter from soil tillage, which could lead to desertification Conclussions and food waste is a potential fertilizer if treated before application Hygienic Decomposition of N Reduce resource usage (energy for N, P sources) Nitrogen can be lost as ammonia and therefore Measures must be taken to avoid the loss Dilution Injection (direct ground ) Yield response is better when dilution and/or is used 29 5