# Nutrient Separation Systems: Current Progress and Future Opportunities

## TL;DR

This paper reviews current and future technologies for recovering nutrients from wastewater to create sustainable fertilizers.

## Contribution

The paper provides a comprehensive analysis of nutrient recovery systems and identifies opportunities for future development.

## Key findings

- Millions of tons of nitrogen and phosphorus remain untapped in global wastewater.
- Current nutrient management processes have performance limitations that need improvement.
- Emerging electrified technologies show promise for scalable nutrient recovery.

## Abstract

As energy, environmental, supply chain, and economic
risks escalate
in today’s linear fertilizer manufacturing processes, there
has been growing interest in developing technologies that enable a
circular nitrogen-based fertilizer economy. Achieving this goal requires
significant advancements in wastewater treatment, with a specific
focus on the design of technologies and complete systems that can
capture and recycle waste nutrients into usable fertilizers. Every
year, millions of tons of nitrogen and phosphorus remain untapped
in global municipal and industrial wastewater, presenting a significant
opportunity for fertilizer utilization. Herein, we explore current
and future opportunities for nutrient recovery systems to provide
recycled fertilizers for agricultural use. We first quantify recoverable
nutrient wastewater sources, examine current nutrient management processes
(e.g., nitrification–denitrification, EBPR), and highlight
the performance and limitations of current nutrient management processes.
We also review the current commercialization landscape for nutrient
recovery systems and detail efforts made in advancing full-scale deployments.
Finally, we review emerging electrified technologies and compare nutrient
recovery technologies in terms of technology readiness, scalability,
optimal feedstock, and environmental trade-offs, pairing them with
optimal wastewater feed streams. A gap analysis is also conducted
to guide future research and development efforts in nutrient recovery.