Institute for Residential Innovation Inc.


SOSWEC-based Sanitation:
The Sewage Containment and Mineralization system (SeCoM)

I have finally come to the conclusion that a good reliable set
of bowels is worth more to a man than any quantity of brains.

Josh Billings

Features of the SeCoM

No char or toxic liquid residues are generated
No contaminated water is discharged or reused.
No harmful amounts of gas are discharged.
No supporting infrastructure is needed.

Sanitation animation   World Toilet Day   Jack Sim at TEDx Taipei 2012    Water for life and peace  

» design criteria
» schematic
» benefits
» climate
toilet SciFi





SeCoM design criteria

A micro-sanitation appliance:
• more reliable than any other on-site system or sewer-connected service
• fully automated
• autonomous
• high throughput (>6L/min)
• discharges only greenhouse-neutral amounts of CO2
• uses exclusively non-microbial processing technologies
• silent
• odor-free
• fail-safe
• low cost
• low maintenance
• generates thermal and electrical energy
• delivers a secure supply of continuously repurified potable water
• has a near-zero environmental footprint
• can be configured as a micro-channel chemical reactor
• suitable for high-volume automated mass-manufacture
• small enough to create a fully autonomous toilet
• includes a mechanical back-up power source (not further discussed)
• incorporates a passive, hi-flow, nanomesh sterilization filter for emergency treatment of feces-free water

The Future:
• capture CO2 for synthesis of additional fuel, or other materials
• recover minerals from sewage
• redesign the form and function of the toilet (see ' Toilet Sci-Fi')

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SCHEMATIC: SeCoM* operation

Biomass Processing Modules:      

Slurry accelerated through a serial sequence of constrictions in a branching conduit by injection of high pressure steam from the SOSWEC. Explosive decompression pulverizes and sterilizes the slurry. Slurry is further micronized by ultrasonic irradiation.

Proprietary broad-specturm deionization

Measure slurry COD1, then pressurize and inject into the SOSWEC at rate determined by the COD.

The SOSWEC*:  

Slurry mineralized by electrochemical oxidation in SCW. Electrical power and heat are generated, and pot
able water is produced.

Chemical 'fingerprint' of purified water is continuously assessed by Dielectric Spectroscopy (Electrochemical Impedance Spectroscopy). System shuts down if contaminants detected.

Alternative 'fingerprinting' devices:
Schottky junction2
field effect transistor3


1. Electrochem. Comm. (2012);,
Ultrasound electrochemical determination of chemical oxygen demand (COD) using boron-doped diamond electrode.

2. Adv. Mater. (2012); Polar Liquid Molecule Induced Transport Property Modulation at LaAlO3/SrTiO3 Heterointerface.

3. Biosens. Bioelectron. 2012;
Boron -doped (1 1 1) diamond solution gate field effect transistors.

* Patents Pending

© Institute for Residential Innovation inc.

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The SeCoM: benefits and applications

The SeCoM is an autonomous micro-sanitation device suitable for all residences, terrestrial or aquatic; permanent, temporary, and
emergency, built on-site or factory manufactured.

Terrestrial B&As.

A. Residential

1. Provides:
• reliable sanitation and a secure, unlimited supply of fresh water regardless of the condition of regional infrastructure.

2. Mitigates:
• stress imposed on existing infrastructure by new residential development.
• multibillion dollar cost of renovating WatSan infrastructure by enabling homes to disconnect from deteriorating waterpipes and sewers.

3. Enables:
• development of the autonomous1 toilet.
• residential development on land currently considered unsuitable or uneconomic for either sewer hook-up or septic -- more than 1 Billion acres in the USA alone, about three times as much as is currently available. Since approximately 40% of new build in the US, even in the suburbs is now on septic, the SeCoM could greatly reduce the amount of land required for a single family residence thus reducing urban sprawl.
• ‘Rescue’ of older homes with substandard on-site sanitation systems that can’t be upgraded.

4. Eliminates:
• competition between property developers and farmers for the soil type that is both optimal for septic leach fields, and a distinguishing characteristic of prime farmland. Eliminating competition for this scarce acreage (~18% of USA) would enhance global food security by stemming the loss of small suburban farms, and facilitating preservation of prime farmland world-wide.
• increased frequency of gastrointestinal infections that typically occur when residential developments rely on single-family septic sanitation.
• inactivation of micro-organism dependent sanitation systems by biological poisons or mutagens.
• environmental contamination from discharge of synthetic or genetically modified microorganisms following containment failure of microbial sanitation systems. If such systems gain wide acceptance then the number of containment failures will increase; ignorance of the microbial ecosphere however precludes meaningful assessment of the consequences -- the risks are unknown. Rapid transfer of genetic material into the indigenous microbia is virtually certain and its incorporation into the microbiomes of more evolved organisms, including humans, is highly likely. Such changes would be irreversible, with the latter leading to unknown but potentially catastrophic disruption of normal physiology and psychology 2,3,4,5,6,7,8.

B. Autonomous, Portable, Improved Public Facilities.

Widespread deployment of prefabricated, SeCoM- equipped, IPFs would allow communities that have no sanitation or reliable source of potable water to set up ‘instant’ service networks, configured according to their own priorities, and easy to reconfigure as needed -- faster to install than conventional fixed infrastructure, more resilient, more flexible, and less expensive.

Aquatic B&As.

Provides continuous re-supply of potable water and discharge-free mineralization of sewage, thus obviating the need for large volume holding tanks and related through-hull fittings.

1. ~2.4 MJ/person/day (UK): Environ. Sci. Technol., 2011; doi: 10.1021/es103058w ‘Determination of the Internal
Chemical Energy of Wastewater’.
2. PLoScollections, 2012; doi/10.1371/issue.pcol.v01.i13 ‘The Human Microbiome Project Collection’
3. Nature, 2012; doi:10.1038/nature11234 ‘Structure, function and diversity of the healthy human microbiome’
4. Nature, 2012; doi:10.1038/nature11234 'Structure, function and diversity of the healthy human microbiome'
5. Nature Rev. Microbiol. 2013; doi:10.1038/nrmicro2973 'The microbiome explored: recent insights and future challenges'
6. Nature Rev. Microbiol. 2013; doi:10.1038/nrmicro2974 'The gut microbiota - masters of host development and physiology'
7. Nature Rev. Microbiol. 2013; doi:10.1038/nrmicro2989 'Blooming' in the gut: how dysbiosis might contribute to pathogen evolution'
8. Science 2013; doi: 10.1126/science.1226850 'Dilute Concentrations of a Psychiatric Drug Alter Behavior of Fish from Natural Populations'


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The SeCoM: adaptation to climate change

A 2°C (minimum) rise in global temperature now seems unavoidable. Policy decisions must be made1,2,3, and novel technologies4,5 developed as soon as possible if we hope to mitigate the severity of the societal dislocations6 and conflicts that a warming planet is expected to engender 7,8,9,10,11.

In 1990, the Intergovernmental Panel on Climate Change (IPCC) noted12 that “...the greatest single impact of climate change could be on human migration...”.And in 2005 Myers predicted13 that “the issue of environmental refugees promises to rank as one of the foremost human crises of our times..[that]..could readily become a cause of turmoil and confrontation, leading to conflict and violence. Yet... environmental refugees have still to be officially recognized as a problem at all”.

Novel technologies for (re)generation of potable water, and reliable methods of sanitation, that are suitable for high density populations will be of paramount importance. Providing drinking water and sanitation is already a major problem for refugee and emergency camps and for many developing nations. Extending such services to the unprecedented numbers of mobile14, semi-nomadic ‘climate refugees’ of uncertain legal status expected to be moving within and across national borders, migrating away from continuously evolving “..climate change scenarios that, directly or indirectly, cause human displacement”15,16, presents a challenge that will likely be impossible to overcome with current technologies.

The “central plant - fixed infrastructure” (CPFI) model provides a reliable means of delivering sanitation and drinking water to stable communities that live on stable land, and that have populations that change slowly over time. It Is neither resilient enough, cheap enough, nor flexible enough however to respond to sudden, large changes in regional population density either in established communities or in previously unoccupied areas some of which may also be difficult to access.

The CPFI is a labor intensive, expensive, system that consumes large amounts of energy for its maintenance and operation (in the USA pumping aqueous fluids through the watsan networks currently accounts for ~3% of the total power generated). The CPFI is also slow to construct, especially over difficult terrain, difficult to reconfigure, and cannot be extended across national borders without approval of the destination governments -- unpredictable during times of mass migration, especially if denial of essential services is used as way to discourage stabilization, or accomplish mass evictions from impromptu settlements.

In 2012 the IPCC ‘SREX’17 re-emphasized the vulnerability of existing infrastructure and how this lack of resillience virtually ensures catastrophic collapse of function in the face of even current extremes of weather.

The continuous physical networks of the CPFI are vulnerable to disruption by earthquakes, floods, extremes of weather, and physical or cyber-sabotage. Underground piping is also chronically leaky; fresh water pipes waste water, and sewers are a source of chronic microbial and chemical contamination.

One effective remedy would be to eliminate the infrastructure -- replace the CPFI with intra-residential repurification and recycling of used water and mineralization of sewage at its point of production.

1. Nature; doi:10.1038/445597a 'Climate change 2007: Lifting the taboo on adaptation'
2. Proc. Natl. Acad. Sci.; doi:10.1073/pnas.1007887107 'A framework to diagnose barriers to climate change adaptation'
3. EIA: Environmental Impact Assessment Review, 2012, 33(1):32-40; doi:10.1016/j.eiar.2011.09.003,
'Mind the gap in SEA: An institutional perspective on why assessment of synergies amongst climate change mitigation, adaptation and other policy areas are missing'
5. Nature 463, 2010, doi:10.1038/nature08823 'The next generation of scenarios for climate change research and assessment'
6. Engineering the Future 'Infrastructure, Engineering and Climate Change Adaptation - ensuring services in an uncertain future' Feb. 2011. Available online at:
7. IASC Highlights the Humanitarian Impacts of Climate Change
8. UNHCR 'The Storm Ahead'
9. Environment and Urbanization; doi:10.1177/0956247807076960 'The rising tide: assessing the risks of climate change and human settlements in low elevation coastal zones'
10. Proc. Natl. Acad. Sci.; doi/10.1073/pnas.1104268108 'The causality analysis of climate change and large-scale human crisis'
11.,; hosted by UN International Strategy for Disaster Reduction.
12. Brown, O. 2007. 'Climate change and forced migration: Observations, projections and implications,' a background paper for Human Development Report 2007/2008. Geneva: United Nations Development Program )
13. Myers, N. 2005. 'Environmental Refugees: An Emergent Security Issue.' Presented at the 13th Economic Forum, Prague, 23-27 May)
14. 'Crisis or adaptation? Migration and climate change in a context of high mobility'
15.'The Climate Change - Displacement Nexus'
16. 'Population and Environment'; doi: 10.1007/s11111-011-0136-2 'Understanding the demographic implications of climate change: estimates of localized population predictions under future scenarios of sea-level rise'
17. "Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX)"


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Toilet SciFi

The first generation autonomous toilet will be a SeCoM partnered with a conventional vacuum flush system. Future versions however will be considerably different.

The toilet as Prosthetic.

The future toilet is a detachable prosthetic; a zero-discharge device that collects and contains urine and feces, accelerates decomposition of the carbonaceous content, captures the energy released, reconstructs de novo its own fuel, or other useful material, and regenerates pure water.

The seat or squat platform remains. The toilet bowl itself however is replaced by flexible self-sterilizing tubes with malleable, conformable terminations that auto-locate* in apposition to the anus and the urethral orifice.

Docking gently under slight negative pressure, they capture the urine and feces, eliminating the spray of atmospheric aerosols that typically accompany the use of open-bowl toilets, then cleanse and dry the orifices before disengaging and retreating for self-sterlization

The tubes themselves may be impermanent; made of carbonaceous material and synthesized within the SeCoM, they will be processed along with their contents, then recreated on demand.

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