Date of Award

2022

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Natural Resources

First Advisor

Christopher Koliba

Abstract

Identifying and implementing strategies for recovering resources from waste streams for reuse helps to minimize natural resource extraction and reduces waste generation. Spatial modeling can guide resource cycling by optimizing co-location of recovery and reuse. These models can help assess feasibility and effectiveness (e.g., meeting crop nutrient needs) of circular economy practices at a landscape scale. Though many useful models exist, there is a need for an adaptable grid-based tool to address reuse on a per area basis (e.g., kg nitrogen per hectare of cropland). A model like this could be applied to any landscape and would utilize input data that are available for most locations. Sri Lanka’s recent government policy to eliminate the use of synthetic fertilizers and shift to green agriculture positions it as a timely case study for testing such a model. A network of organic waste management facilities created under a nationwide composting initiative presents an opportunity for large scale production and use of municipal solid waste (MSW) compost. Opportunities also exist to recover nutrients in human fecal sludge. In this study, a grid-based resource recovery and distribution model was used to assess the potential for MSW compost to serve as an organic nutrient source and soil amendment. Scenarios tested also included recovery of fecal sludge nutrients. Results highlight that the available alternative nutrient sources considered cannot fully replace synthetic fertilizer for existing production systems in Sri Lanka, with reuse of recovered nutrients largely proximal to high population areas distant from much of the nation’s agriculture. Beyond the Sri Lanka context, the model could be applied to other case studies to facilitate the planning and development of efficient and sustainable closed loop material management systems.

Language

en

Number of Pages

91 p.

Available for download on Saturday, April 29, 2023

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