Trond Mæhlum
Research Scientist
Biography
Education
PhD from NMBU (1998) in use of constructed wetlands for water pollution control in cold climates. Cand.agric. in mangagement of water resources fram NMBU (1991)
Key qualifications
Environmental engineering, specialising in water protection management hydrogeology and aquatic chemistry. Experience in planning, design and monitoring of nature based systems for treatment of point sources and diffuse pollution. Landfill leachates, domestic wastewater, urban runoff, agricultural wastewaters and runoff. Particular interest in treatment wetlands, ponds, soil infiltration and biological filters. Investigation of filter media and treatment processes - in laboratory, mesocosm and full-scale systems. University lecturer and examiner in environmental engineering and water resource management.
Authors
Petter D. Jenssen Trond Mæhlum Melesse Eshetu_Moges Bente Føreid Trine Hvoslef-Eide Jihong Liu Clarke Arve Heistad Manoj Kumar PandeyAbstract
Urban agriculture requires resources such as growth media, nutrients, and water. This report demonstrates how these resources can be locally sourced through a circular economy approach, in which waste materials are recovered and reused. Recycling helps reduce or eliminate the discharge of pollutants into water and air. Examples presented show how to convert waste from households—such as human excreta, wastewater, and organic household waste—into biogas, compost/growth media, biochar, and solid and liquid fertilizer for urban agriculture and urban greening. The solutions presented have been explored through desktop evaluations, practical trials, or full-scale demonstrations to see how the technologies can be improved or adapted for urban use. Products like liquid and solid fertilizers, compost, aquaponic fish feed, irrigation water, and energy (methane) can be used in urban food production or recreational areas. Regulations for the use of waste resources in the production of growth media, fertilizers, irrigation water, fodder, and energy vary between countries but are generally restrictive due to the risk of disease transmission and pollutant build-up. For urban agriculture to become more circular, there is a need for documentation of good waste treatment routines, changes in legislation, and changes in attitudes towards the use of local waste resources.
Authors
Trond Mæhlum Bente Føreid Maria Dietrich Melesse Eshetu_Moges Trine Hvoslef-Eide Ola Lødøen Vethe Petter D. JenssenAbstract
This report (D2.5) presents a qualitative and quantitative assessment for nutrients and energy regarding circular fertilizers and biogas production from waste resources. A transformation towards sustainable food production for the growing urban population requires improved circular urban nutrient management. Urban agriculture (UA), like any agricultural system, needs input of resources in terms of growth media, nutrients, and water. Resources that are often imported into cities, especially in the form of food, generate urban waste. Current environmental, social, and economic challenges of cities are seen as opportunities that can be derived locally, as this project demonstrates. The domestic organic waste and wastewater contains energy (thermal and chemical) and nutrients that could play a role in the urban circular economy if proper technology and management are applied. Urban organic waste contains relevant nutrients including nitrogen (N) and phosphorus (P), as well as organic matter, yet less than 5% of the global urban resources are presently recycled. One recycling approach is the composting of urban organic wastes, recovery of nutrients from source-separated urine and anaerobic digestate of blackwater, and biogas and biochar produced as sources of energy. At the NMBU showcase different technologies were assessed to demonstrate how to achieve sustainable and circular urban farming systems. Qualitative and quantitative information about organic fertilizers, making budgets for the nutrient contents of waste resources and organic fertilizer and comparing this with the nutrient needs of the plants in the relevant cultivation area, as shown in this report, can provide better fertilization and less loss to the environment. We need more information on the fertilizer value of waste resources and how these nutrients can be best utilised. Due to the increased interest, more information about health and environmental challenges by implementing circular UA should be obtained
Authors
Trond MæhlumAbstract
No abstract has been registered