Water Recovery Technology

The core principle of the on-site water recovery technology is a gravity-driven ultrafiltration unit integrated in the back wall of the toilet.

With this approach an innovative drinking water technology (gravity-driven membrane filtration), developed by Eawag's scientists, is applied to the recovery of wash and flush water. The special feature of the gravity-driven ultrafiltration is its passive biological activity maintaining the membranes permeable, thus making chemical cleaning or maintenance unnecessary as long as moderate aeration is provided.

Wash water quality is guaranteed by a three-barrier approach including:

1. a gravity-driven ultrafiltration
2. polishing by electrolysis
3. protection against re-growth through chlorination.

Further information: Poster "Water Recycling" at the "Reinvent the Toilet Fair", Seattle, August  2012 [pdf]