The Toronto Toilet


  • Descriptive Overview
    A household-scale system with solid and liquid disinfection in the backend. In the frontend, feces and urine/wash water are mechanically separated by a specially designed mechanism that can be attached to standard squat plates. Attachment to pedestals is also possible. Dewatered fecal material is then mixed with granular particles and smoldered. Catalytic conversion of the generated pyrolysis gases supplies additional heat and mitigates emission. Heat generated is used to dry incoming fecal material in situ, and thermally disinfect liquid waste.
  • Key Features
    • Self-sustaining smoldering technology, under development since 2011, with TRL 4 results published in the journal Fuel in 2015
    • Continuous smoldering process for processing of fecal matter and consistent heat production
    • Catalytic conversion of the generated pyrolysis gases supplies additional heat, and mitigates emissions.
  • Use Case Details
    SURT – household and community 1. Designed as a self-contained, household unit, , ranging from 5 to 20 users, accommodates variable input rates. Suited for both "wash" and "wipe" scenarios. 2. Could be scaled-up for family application at 15-20 users per day, with potential for community(multi-stall) application with one system per stall.
  • Dimensions (meters)
    L 1.7 m X W 1.5 m X H 1.0 m
  • Use Cases
    • Single-stall Toilet
    • Multi-stall Toilet
  • Interface Type
  • Frontend Description
    Currently used with a standard squat plate. Can be adapted to a pedestal. Multiple gravity-based solid/liquid separation designs have been evaluated and field tested. Effective solid/liquid separation is achieved without modifying user behavior.
  • Flush Water Source
  • Users per Day (Expected)
    Currently designed for 5 to 20 users, accommodates variable input rates.
  • Users per Day (Maximum)
  • Type of Waste Treated
    Solids Processing
  • Core Processing Technology
  • Processing Overview
    Solid fecal material (fuel) is transferred via a pump to a column and mixed with granular beads which are still hot from the preceding smoldering cycle. Once the mixing/drying process concludes, air is introduced and smoldering beings.
  • Processing Capacity
    0.6 to 3 kg/day capacity
  • Processing Parameters
    Unique peristaltic pump is used to transfer solids through the system. Processing takes 6-8 hours at approximately 600oC and 1 bar.
  • Gas Processing
    Post smoldering gases undergo catalytic conversion for emissions reduction and additional heat generation.
  • Consumable Chemicals Needed
  • Type of Waste Treated
    Liquids Processing
  • Core Processing Technology
  • Processing Overview
    Liquid pasteurization is achieved by recovering the heat captured in steam during solid drying process. Further effluent treatment is intended to be adopted from other projects being conducted in the BMGF portfolio.
  • Processing Capacity
    35 L/day
  • Processing Parameters
    Pasteurization accomplished by holding liquid at 80oC for an extended period.
  • Power Systems Overview
    External power source is required.
  • Energy Balance
    Solar panels or other off-grid energy sources may be used to supply the <200 watts per day required. The aspirational goal that projections show is possible is to achieve a power requirement low enough to fit within the capacity of solar or other off-grid home systems that are common in many regions.
  • Operating Expense Estimate Notes
    Initial estimate is $0.07/ users/ day, based on electricity use and six users. Based on this estimate, annualized operating expense will be approximately $150 per year.
  • Current: Cost per user per day (USD)
  • Expected Design Lifetime (Years)
  • Currently in Active Development
  • Commercialization Status
    Seeking Licensees
  • Commercialization Activities
    System integration work has led to iterative development of functional prototypes for laboratory testing in Toronto, and multiple field tests in Coimbatore, India with local workers user group. Commercialization partners to license technology for further product development, manufacturing, and launch. Also seeking partners to integrate liquid treatment and develop products.
  • Intellectual Property Status
    Patent Pending
  • Intellectual Property Details
    1. PCT patent filed for solids processing.
  • Frequency of Emptying Outputs
    Solids (ash) to be emptied monthly by user
  • Solid Emission Characteristics
    Approximately 10g ash per person per day is produced.
  • Liquid Emission Characteristics
    10-15 L/day of non-potable water recovered. Total pathogen removal is confirmed.
  • Technology Development Milestones
  • Proof of Concept
    TRL: 3 (2015)
    A TRL 3 smoldering process was discussed by the team in the publication Fuel in 2015.
  • Laboratory Prototype
    TRL: 5 (2016)
    Functional lab prototype was reached in 2016
  • Field Tests
    TRL: 6 (2017)
    Field tests in Coimbatore, India with local workers user group began in 2017 and is on-going, with technology iterations underway.
Patent Number Description Link
WO2018010033 Treatment of fecal matter by smoldering and catalysis Link