We developed a dry source-separating toilet with on-site ultrafiltration water recovery for wash and “flush” water increasing user comfort and cleanliness of the toilet. The toilet features an innovated dry source separating squatting pan which can be cleaned with water from the on-site water recovery. By foot activation, the squatting pan transforms by rotation of 90 degrees into a washing pan.

In the back wall of the toilet the compact water recovery technology is contained. While feces and urine are collected under the separation pan, the soiled water from hand-washing, pan flushing, anal cleansing and menstrual hygiene is fully recycled on-site.

The toilet is designed for the set up in informal settlements, each toilet shared by two families. As a (re)movable piece of furniture it can be retrofitted into existing toilet superstructures, or in any other bathroom and allows for setting up a “Rent a Toilet” system. Treatment of the separated feces and urine does not take place on-site, but in a semi-decentralized Resource Recovery Plant (RRP), recovering the waste of 800 -900 toilet users. Source-separation and the economy of scales in the RRP are main reasons that we are able to meet the RTTC goal of $0.05 per person and day. The toilets are connected to an RRP via a logistic concept, which is part of a sanitation business, which also runs the RRPs and rents out the toilets.

So far, we focused on the toilet design and the technology development of the on-site water recovery. Moreover we delivered a proof of concept for transport logistics and developed a viable sanitation business model. We worked only conceptually on the treatment technology of the RRP. There are various numbers of recovering technologies for separated urine and feces. For urine treatment, we suggest nitrification followed by distillation, because this process is available at RRP scale on a TRL of 5 (developed within the BMGF-financed project Vuna). For feces, the best technology still needs to be chosen. Since many of you have been developing innovative feces treatment technologies, we are confident that one or more of those are suitable at RRP scale.

We look very much forward to an inspiring meeting in Seattle. See you!