Mapping the National Phosphorus Recovery Potential from Centralized Wastewater and Corn Ethanol Infrastructure

Anthropogenic
discharge of excess phosphorus (P) to water bodies
and increasingly stringent discharge limits have fostered interest
in quantifying opportunities for P recovery and reuse. To date, geospatial
estimates of P recovery potential in the United States (US) have used
human and livestock population data, which do not capture the engineering
constraints of P removal from centralized water resource recovery
facilities (WRRFs) and corn ethanol biorefineries where P is concentrated
in coproduct animal feeds. Here, renewable P (rP) estimates from plant-wide
process models were used to create a geospatial inventory of recovery
potential for centralized WRRFs and biorefineries, revealing that
individual corn ethanol biorefineries can generate on average 3 orders
of magnitude more rP than WRRFs per site, and all corn ethanol biorefineries
can generate nearly double the total rP of WRRFs across the US. The
Midwestern states that make up the Corn Belt have the largest potential
for P recovery and reuse from both corn biorefineries and WRRFs with
a high degree of co-location with agricultural P consumption, indicating
the untapped potential for a circular P economy in this globally significant
grain-producing region.