This research evaluates the potential environmental impacts of implementing a circular economy for phosphorus (P) based on using urine-derived P fertilizers in food systems. Anticipatory life cycle assessment was used to quantify the environmental impacts of replacing conventionally mined P fertilizer with urine-derived P fertilizer when producing beef and plant-based burger patties. Urine-derived P fertilizer replacing conventional P fertilizer generates benefits across all environmental impact categories, with global warming, eutrophication, and water consumption being the focus of this study. Urine-derived P fertilizer in beef burger patty production decreased water consumption by 42% (45% for plant-based), global warming by 4% (2% for plant-based), and eutrophication by 15% (1% for plant-based). Despite uncertainty in the inventory data, urine-derived P fertilizer outperforms conventional P fertilizers for beef burger patty production in 76, 100, and 97% of the Monte Carlo runs for global warming, eutrophication, and water consumption, respectively. To extend the contributions of this research, total nutrient recovery from urine should be coupled with different food systems to quantify the environmental impacts, and P recovery from other waste streams should focus on creating P fertilizers that are useful in agriculture to expand a circular economy for P.
Evans et al. (Fri,) studied this question.