Reinvented Toilet Technology in Development
Foss Toilet
Water-Recycling Reinvented Toilet
The Foss Toilet is a flushing toilet that recycles the flushwater and doesn’t require any connection to water or sewer and is completely off-pipe. With a normal flush toilet user experience, it’s designed to be easily installed and require only connection to household electricity and a bathroom air vent. The innovation of the Foss Toilet combines biological processing with a distillation process, so that the treated and recycled flushwater is always clean and clear.
- Normal flushing toilet experience
- Zero-liquid discharge, with no connection to water or sewer required, flush and fill the system on installation only
- Removal of completely sanitary solids once or twice per year
- Installs with only connection to household electricity and a bathroom air vent
Status of Development
- TRL 6 – early commercial prototype
Use Cases
- Household: Designed as a bathroom unit for 2 person all-day usage
Product is Appropriate For:
| 2-4 | $0.50 | 10 |
|---|---|---|
| Capacity (users/day) | Est. Cost ($/user/day) | Life Expectancy (Years) |
How Does it Work?
Frontend
A low-flush macerating toilet
Processing
Solids and liquids are processed together in a single flow. A heated and aerated tank is used to biologically digest organic material while a humidification-dehumidification process produces a clear effluent for flushwater reuse.
Remaining undigested solids are dried for removal by the user once or twice a year. This solid is totally sanitary and has a light, inoffensive smell.
Inputs
Does the system require an external source of electricity?
Yes
Does the system require the use of water?
No. only during the installation
Does the system require any other "consumable" inputs?
No
Outputs
How much energy will be recovered?
The heat of the degraded organic material is utilized internally to maintain the temperature of the bioprocess.
How much water will be recovered?
The system is designed to provide 100% of the flushwater required to continually use the system.
How much fertilizer or other byproducts will be produced?
None
Treatment
Solids treatment
Drying
Liquids treatment
Aerobic, thermophilic digestion
Are chemical processes used?
No
Are mechanical processes being used?
No
Are biological processes being used?
Yes
Does the system require any off-site or additional processing?
No
Business Considerations
Estimated daily operating cost:
$30 per month for 2 people
Estimated capex:
$10,000
Size:
Designed to fit within the typical space of the tank behind a flush pedestal toilet, about 36” wide x 60” tall x 14” deep.
Maintenance Requirements:
Dry solids need to be removed once or twice a year, about 10 pounds. This sanitary solid can be safely disposed in the garbage or compost.
Life expectancy:
10 years
