Tuesday, June 26, 2012

Reinvention of the Toilet by the Missile Technologists

Reinvent The Toilet Challenge

There is a need for developing cost-effective ways of neutralizing human waste - the Bill & Melinda Gates Foundation has announced  ~ $42 million program to promote safe, affordable sanitation in developing countries (2011). The effort will include research and tech development funding "to spur innovations in the capture and storage of waste, as well as its processing into reusable energy, fertilizer, and fresh water," according the group's press release.

The centerpiece of the project, under the umbrella of sanitation science and technology, is what's succinctly called the "Reinvent the Toilet Challenge." The foundation has awarded eight grants, totaling $3 million, to universities, to spur the "concept development, design, and prototyping of a waterless, hygienic toilet that costs less than $0.05 per user per day," according to the program's documentation.

Such stringent cost constraints are directly connected with the goal of making the designs affordable and thus deployable among the 2.6 billion people worldwide, who, the foundation says, don't have access to conventional flush toilets. The announcement cites 1.5 million annual child deaths from diarrheal disease as part of the devastation caused by lack of access to safe sanitation.

The technical component of the round of grants also includes at least $2.6 million in funding for what are called "Grand Challenge Explorations" of the next generation of sanitation technologies. In addition, the London School of Hygiene and Tropical Medicine is getting $4.8 million to develop better ways to break down human waste biochemically.

Design challenges
For the design engineering community, the product-focused work is occurring at the eight universities funded under the "Reinvent the Toilet Challenge." The eight projects variously attempt to neutralize the waste or to process it to extract energy:

  • Loughborough University. The toilet transforms solid waste into charcoal, with water and salt as byproducts.
  • Delft University. Microwaves are used to convert waste into a gas, which is then fed into a solid oxide fuel cell to generate electricity.
  • Swiss Federal Institute of Electric Science. The toilet diverts urine and recovers water.
  • University of KwaZulu-Natal. A community toilet system that can safely dispose of pollutants and recover water and carbon dioxide.
  • Climate Foundation and Stanford University. A self-contained system that converts waste into charcoal.
  • University of Toronto. Mechanical dehydration and smoldering are used to sanitize feces.
  • CalTech. A solar-powered toilet.
  • National University of Singapore. A pneumatic-flushing community toilet that separates urine and feces

Biotoilets technology from Indian DRDO (the same folks who develop the Missile technologies)

Union Rural Development Minister Jairam Ramesh on Sunday announced that his Ministry would soon sign a Memorandum of Understanding (MoU) with the Ministry of Defence for installation of bio-toilets in 1000 gram panchayats across the country. It would go a long way in improving sanitation in rural India, Mr. Ramesh said.
The project will be implemented in coordination with the Defence Research and Development Organisation (DRDO) at a cost of Rs. 400 crore, which will be provided by the Union Rural Development Ministry, he said.

Go Green Solutions with support of technology developed and approved by DRDO – Ministry of Defence offers an innovative technology for disposal of human waste in eco friendly manner. These Bio toilets can function at any atmospheric temp between -55 to 60 degree C. The bacterial consortium degrades night soil at temp as low as -55 degree C and produces colourless, odourless and inflammable bio gas containing 50 – 70% methane.

The main constituents of Bio -Toilet are Pre fabricated above the ground shelter and Bio Digester tank. Bio digester tank is a cylindrical structure with the provision of inlet for human waste and out let for Bio gas. Temp in the bio – digester is maintained between 5-30 degree C. A person can use the toilet which is connected to the bio-digester. Night soil degradation occurs through microbial reaction which converts it into bio gas. The smell of night soil, the disease causing organisms in the night soil and the solid matter are eliminated totally. On dry weight basis 90% of the solid waste is reduced. The gaseous effluent (bio-gas) is continuously let off to the atmosphere. Bio Gas can be used for various energy incentive activities like cooking water and room heating. Liquid effluent can be drained to any surface or soak pit with out any environmental hazards.

Human waste disposal in high altitude and low temp areas, Moving Railway coaches, Buses, Big Cities, Mines, remote areas, Beaches, Rural areas, long distance buses is a burning problem. 
The problem has further aggravated in glaciers where ambient temperature drops to -40 degree C and lower. The low temp stops/ delays the natural bio-degradation of the waste leading to its preservation (accumulation) for long time resulting in environmental hazard. Local heating by direct sunlight exposes the waste buried in the ice causing nuisance and foul smell. The melting ice takes the waste to rivers disturbing the aquatic eco system. More over human waste is also responsible for spreading of water born diseases like typhoid, cholera, Shigellosis, Amebic Dysenteries, Diarrhea etc. 

This technology is suitable for any area/ application in India. The process under this technology culminates in to treated effluent which is free from Pathogens and is also environmentally acceptable. The technology has major two components:
  • a- Low temp active inoculums
  • b- Temp controlled Bio digester
A consortium of anaerobic bacteria has been formulated and adopted to work at temp as low as 5 degree C. This is the component which acts as inoculums (seed material) to the bio digester and converts the organic waste into methane and carbon-dioxide. The anaerobic process in- activates the pathogens responsible for water born diseases. Bio digester serves as reaction vessel for bio methanation and provides the anaerobic conditions and required temp for the bacteria. The optimum temp is maintained by microbial heat, insulation of the reactor and solar heating.

1 comment:

  1. hi..Im college student, this article is very informative, thanks for sharing :)