Urine is one of the most overlooked fertilizer streams on earth.

Urine is not waste. In conventional plumbing, it becomes waste.

Human urine accounts for less than 1% of total domestic wastewater volume, yet contributes approximately 80% of nitrogen, 55% of phosphorus, and 60% of potassium entering the wastewater stream. (Thela et al., 2026)

Source separation keeps the nutrient-rich liquid from being diluted, allowing treatment to be designed around the chemistry of urine rather than the complexity of mixed sewage.

The Rich Earth Institute has conducted field trials since 2011 and reports that hay fertilized with sanitized urine produced yields comparable to synthetic fertilizer.

The challenge is not whether urine contains nutrients. The challenge is water.

Urine is approximately 95% water, which makes raw collection, storage, hauling, and field application difficult at scale. Moving raw urine means moving mostly water. That is why concentration technology matters.

The U.S. EPA describes reverse osmosis as a membrane separation process in which pressure forces water through a semi-permeable membrane, creating a treated-water stream and a concentrate stream. The U.S. DOE describes RO as the most common membrane technology in desalination.

In desalination, the clean water is the desired product. In urine recovery, the nutrient-rich concentrate is the product. Instead of boiling off water through thermal evaporation, RO uses pressure to remove water and leave behind a more concentrated fertilizer stream.

RO avoids the phase-change energy penalty of evaporation or freezing.

The 2026 UCT pilot study cites much lower estimated energy demand for RO than alternatives.

Source: Thela, Tofie, Courtney & Randall (2026), Frontiers in Environmental Science.

UCT pilot-scale RO system: 67–69% water removal, 11.5 g-N/L urea in concentrate.

The April 2026 Frontiers in Environmental Science paper — Thela, Tofie, Courtney & Randall — evaluated a 300 L/h pilot-scale RO system for source-separated urine.

The study identified calcium carbonate scaling as a key technical risk and found CO₂ sparging as an effective pretreatment. RO performance after pretreatment was governed primarily by osmotic pressure rather than fouling or scaling.

PeeCycling and the UCT Future Water Institute.

PeeCycling is a University of Cape Town spin-out company that turns human urine into high-quality sustainable fertilizer. It was shortlisted for the 2026 Africa Prize for Engineering Innovation. UCT News reported the shortlist on March 27, 2026.

PeeCycling uses reverse osmosis — a globally established technology with mature parts and membranes available worldwide. Prof. Randall describes the approach as scalable because the team is not building bespoke machines; it is using a proven industrial platform.

For Virro, this creates a clear pathway: commercial sanitation sites can become decentralized nutrient-recovery sites. Solids move toward compost. Urine moves toward membrane concentration and fertilizer.