Application of Processed Organic Municipal Solid Waste on Agricultural Land – A Scenario Analysis

Kurzfassung

Source-separation, composting and anaerobic digestion with associated land application is increasingly being considered as alternative waste management strategies to landfilling and incineration of municipal solid waste (MSW). To assist political decisions about waste management strategies, environmental life cycle assessments may be a useful tool.
However, due to the diversity of the processed organic MSW and the situations under which it can be applied, the environmental impacts of the land applications are very hard to determine by experimental means. In the current study, we use the agroecosystem model Daisy to simulate a range of different scenarios representing different geographical areas, farm and soil types under Danish conditions and legislation. Generally, the application of organic MSW resulted in increased emissions compared with the corresponding standard scenarios, but with large differences between scenarios. The emission coefficients of nitrogen leaching to the groundwater ranged from 3 to 87%, and for nitrogen lost to surface waters through tile drains ranged from 0 to 30%. Emission coefficients of N2O formation ranged from 1.3 to 2.2% and from 1.6 to 11% of ammonia volatilization. These estimates are within reasonable range of observed values under similar conditions. Furthermore, a sensitivity analysis showed that the estimates are not very sensitive to the mineralization dynamics of the processed organic MSW. The results are very useful for lifecycle assessments of different waste management options and shows that agroecosystem models can be powerful tools to estimate the environmental impacts of land application of processed MSW under different conditions. Despite this, agroecosystem models have only been used to a very limited degree for this purpose.