From Waste to Plate: Examining the Role of Urban Biosolids in Recycling Phosphorus

Phosphorus, a nutrient found in soil, is vital to plant life and therefore essential to our global food supply. Naturally recycled by ecosystem services, human cities have interrupted this cycle as phosphorus now accumulates in urban areas rather than returning to the land. In turn, we have turned to mined phosphates to supplement fertilizers and ensure our global food supply. As phosphorus deposits are a limited resource, however, we face future phosphorus shortages and threats to the security of our food supply. Biosolids, or treated waste, is a byproduct of our sewage treatment system and represent an opportunity for phosphorus recovery and recycling. This research (1) examines the role of biosolids in replenishing the natural phosphorus cycle and reducing our dependence on mined-phosphates by (2) examining the case study of NYC biosolid management in order to gain insight that can be extracted and applied to other global cities. Ultimately findings suggest biosolids can relink the natural cycle, framing biosolids as a resource, rather than a waste, for urban areas and recommend cities promote biosolid demand through contracting, land application siting, and investments in nutrient recovery technologies