Waterless Toilet: A Sanitation Phenomenon

A quarter of all the water used in the bathrooms is flushed down the toilet.  It is totally irrational to use high quality, treated drinking water to flush toilets. A continuously running toilet can waste up to 60,000 litres of water per year

Waterless toilets help circumvent the use of sewers and central treatment plants.  Waterless toilets also avoid invasive on-site treatment systems such as septic systems.  These toilets are designed with the focus to minimize the adverse impacts on the environment as well as on human health, changing people’s lives for the better.

THE ENVIRONMENT:

It’s no secret that oceans and rivers are being used as scrapheaps for centuries to dump unwanted materials and waste products mainly via sewage that is totally contaminated with feces and urine. When this is done sewage refers to wastewater from sources including domestic, municipal, or industrial liquid waste products disposed of, usually via a pipe or sewer system.  At the same time millions of people around the world take cruise vacations every year. Cruise ships are not the most environmentally friendly vacation destinations on the planet. In fact, according to the latest Cruise Ship Report Card by Friends of the Earth, they might be about the worst. These floating resorts dump over a billion gallons of sewage into the open ocean every year.

Source: Global News

Sewage tends to be the main source of nutrients near cities, while agriculture predominates in rural areas. Increased nutrients may lead to eutrophication which is an excessive growth of marine plant life and decay.  Plants such as algae often experience a population increase (called an algal bloom) which limit the sunlight available and cause lack of oxygen in water. When oxygen levels decline, marine animals, coral reefs, seagrass beds and other vital habitats in the Wider Caribbean Region suffer and may die. Some algal blooms are toxic and may harm or even kill whales, dolphins and other marine mammals – and cause hundreds of millions of dollars’ worth of damage to commercial fisheries.

HUMAN HEALTH:

Andrea Bruce in her article, published in the New York Times, on September 4, 2018, stated that toilets that safely dispose of waste save lives because human feces spread diseases like cholera, diarrhea, typhoid and hepatitis. She discovered in her research that:

  • 950 million people around the world — with more than half of those in India alone — routinely relieve themselves outside. Around 60 percent of the global population either has no toilet at home or one that doesn’t safely dispose of human waste, according to the United Nations, while 1.8 billion people drink water from contaminated sources.

She also stated that in India, diarrhea kills more than 100,000 children a year.  India’s Prime Minister Narendra Modi campaigned on ending the unsanitary practice and set a deadline for Gandhi’s 150th birthday in October of next year. He has set aside more than $40 billion to build latrines and toilets and change public behavior.

Source: thebetterindia.com

There is a general appreciation for sanitation that it is the hygienic means of preventing human contact from the hazards of wastes to promote health. Examples of waste that can cause health problems are feces, solid wastes, domestic wastewater and industrial wastes. Hygienic means of prevention can be by using septic tanks sewage systems

Toilets in India
Source: globalcitizen.com

The Joint Monitoring Program for water and sanitation of World Health Organization (WHO) and United Nations International children’s Emergency Fund (UNICEF) defines improved sanitation as:

  • Connection to a public sewer;
  • Connection to a septic system;
  • Pour-flush latrine;
  • Simple pit latrine; and
  • Ventilated improved pit latrine.

BACKGROUND:

When toilets are flushed, feces and urine become a part of sewage, resulting in contaminating oceans and rivers. The focus of this article is to demonstrate how waterless toilets can improve hygiene by not connecting to sewage systems at all and can break down human waste into fertilizer.   

Conventional toilets in Europe. Source: homelivingstyle.com

About 4.5 billion people — more than half the world’s population – live without access to safe sanitation and unsafe sanitation which costs an estimated $223 billion a year in the form of higher health costs and lost productivity and wages.   Mr. Bill Gates told to attendees at the Reinvented Toilet Expo (Beijing), a chance for companies to showcase their takes on the simple bathroom fixture.

The reinvented toilets on display were a culmination of seven years of research and $200 million given by the Bill and Melinda Gates Foundation, which the former software tycoon runs with his wife, since 2011. Mr. Gates pledged to give $200 million more in an effort to get companies to see human waste as a big business.  However, he also said in an interview that:

  • It will be at least a decade” before the reinvented toilets reach tens of millions of people in the poorest areas, and they will have to prove both practical and economical. “Nobody wants overnight solutions” in sanitation.

More than a quarter of Chinese families still lack a sanitary toilet in their homes, according to official figures, and only about 60 percent of Chinese rural households have toilets that treat human waste.

Chinese Sanitation
Source: medicaldaily.com

Xi Jinping, the country’s top leader, has called for a “Toilet Revolution.” (Incidentally, the Reinvented Toilet Expo is called “Toilets in the New Era” in Chinese.) Having clean toilets, Mr. Xi said in 2015, is an important goal in “advancing the revitalization of the countryside.”

The Gates Foundation said the World Bank, the Asian Development Bank and the African Development Bank would commit $2.5 billion in financing for sanitation projects that provide people in all parts of a city — including the poorest neighborhoods — with safely managed sanitation services. 

The foundation issued a challenge to universities to design toilets that can capture and process human waste without piped water, sewer or electrical connections, and transform human waste into useful resources, such as energy and water, at an affordable price.  Here is a list of institutions which received financial incentives:

  • California Institute of Technology in the United States received the $100,000 first prize for designing a solar-powered toilet that generates hydrogen and electricity;
  • Loughborough University in the United Kingdom won the $60,000 second place prize for a toilet that produces biological charcoal, minerals, and clean water;
  • University of Toronto in Canada won the third place prize of $40,000 for a toilet that sanitizes feces and urine and recovers resources and clean water; and
  • Special recognition and $40,000 went to Eawag (Swiss Federal Institute of Aquatic Science and Technology) and EOOS for their outstanding design of a toilet user interface.

NANO MEMBRANE TOILETS:

The Water, Sanitation & Hygiene (WSH) initiative is part of the foundation’s Global Development Program, which addresses issues such as agricultural development and financial services—problems that affect the world’s poorest people but do not receive adequate attention. WSH has committed more than $370 million to this area, with a focus on developing sustainable sanitation services that work for everyone, including the poor.

Four years after the Bill and Melinda Gates Foundation awarded $710,000 for the development of a revolutionary waterless toilet; the technology has received a second financial boost. The Nano Membrane Toilet, as developers at Cranfield University call it, now has an additional grant that is “substantially more” than all prior funding, according to a Cranfield spokesperson, who declined to provide the exact amount. Researchers will use the money to continue developing the lab prototype and begin field trials in Africa.

The focus of the Nano Membrane Toilet is to make a new kind of toilet that can provide safe sanitation to the 2.5 billion people around the world who do not currently have it.

Alison Parker, a lecturer in International Water and Sanitation at Cranfield Water Science Institute, says her team’s new design is meant to serve poor urban areas, as those will be easiest to accommodate.  Since the toilet requires maintenance every six months, Parker says her team won’t move into remote areas until the technology proves itself in cities.

According to Parker, one toilet can accommodate up to 10 people for no more than $0.05 per day, per user — in line with the Bill and Melinda Gates Foundation’s original criteria for the prize. Field testing will begin later this year, Parker said.

TOILET CONFIGURATIONT:

Here is a graphic representation of waterless toilet (Nano Membrane Tolilet):


HOW THE TOILET WORKS:

TThe Nano Membrane Toilet will be able to treat human waste on-site without external energy or water. It is designed for single-household use (equivalent to 10 people) and will accept urine and feces as a mixture. The flush uses a unique rotating mechanism without using any water whilst simultaneously blocking odor and the user’s view of the waste.

Solids separation (feces) is principally accomplished through sedimentation. Loosely bound water (mostly from urine) is separated using low glass transition temperature hollow-fiber membranes. The unique nanostructured membrane wall facilitates water transport in the vapor state rather than as a liquid state which yields high rejection of pathogens and some odorous volatile compounds. The water will be collected for reuse at the household level in washing or irrigation applications.

Following release of unbound water, the residual solids are transported by mechanical screw into a combustor which will convert them into ash and energy. The energy will power the membrane processes, and there may be extra energy for charging mobile phones or other low voltage items.

Here how it works:

  1. After a person has done their business and closed the lid, the rotating toilet bowl turns 270 degrees to deposit the waste in a vat underneath. A scraper tool then wipes off any residual waste from the bowl;
  2. Extremely thin fibers, known as nanofibers, are arranged in bundles inside the chamber. They help move the water vapor that exists as part of the liquid waste into a vertical tube in the rear of the toilet; and
  3. Water passes through specially designed bundles that help condense the vapor into actual water, which flows down through the tube and settles in a tank at the front of the toilet.

As for the solid waste that’s left behind:

  1. A battery-powered mechanism lifts the remaining matter out of the toilet and into a separate holding chamber. There it’s coated in a scent-suppressing wax and left to dry out.

According to Parker, every week, a local technician visits the community to remove the solid waste and water, and replace the toilet’s batteries if needed. Residents can then use the water for tending to their plants, cleaning their homes, cooking, and bathing. The solid waste ends up at a thermo-processing plant to be turned into energy for the community.

PILOT:

Nano Membrane toilets are currently being trialed in Ghana. In addition to the environmental advantages from its self-sustaining treatment system, the toilet promises to provide people with a clean and safe household alternative to the public lavatories that many currently use. This is of particular value to women and girls, who are often vulnerable when going to the toilet outside the house.

In 2012, Jeffrey Sachs said a lack of funding was a key obstacle to progress. “If a country is in need of scaling up sanitation, there is no place to turn,” he said. “You do not go to the bank for your toilet and this is why after 12 years (since the MDGs were announced) we don’t have toilets.” It was around this time that championship of the cause from Bill Gates helped galvanise funding by the private sector for sanitation.

Combining strengths with a national government or the branding of a UN agency and the grassroots knowledge of an NGO mean that corporations can implement solutions that have lasting value. A forerunner in improving sanitation access, Unilever partnered with Ideo.org and Water and Sanitation for the Urban Poor (WSUP) in 2012 to tackle the problem of open defecation in Ghana. A popular delivery method there has been through toilet rentals, where families lease toilets on a monthly basis and have the waste cartridges picked up and replaced twice a week. Along with information campaigns, these rentals have helped cut the rate of open defecation in Ghana by 5 percent in two years, which in turn will help reduce water-borne diseases.

Another champion of the toilet is Nestlé. The company recently reinforced its commitment with the Red Cross Society and the International Federation of the Red Cross to improve access to water and sanitation in Cote d’Ivoire’s cocoa-growing communities. The initiative has helped fund the construction of toilets for 3,088 families and 68 schools, reaching almost 100,000 people by 2013. Not only is the community healthier, women are safer and girls stay in school longer.

Henderson, Nevada, USA 31 January 2019