In search of a more efficient toilet
World Toilet Day, which is observed by the UN today, serves as a reminder to the global community to prioritise sanitation and to break the stigma associated with using the toilet.
Nearly half of the global population lacks access to hygienic sanitation facilities and about 700 children under the age of five die daily from diarrhoea linked to unsafe water, sanitation and poor hygiene
The world uses two types of toilets: a flush toilet, which uses water, and a dry toilet, which uses no water.
The flush toilet tends to be the “gold standard” most users aspire to.
In urban city centres, these flush toilets need to be connected to sewers.
This type of system cannot be provided throughout SA.
Laying sewers is a lengthy and expensive task and challenging in unplanned housing settlements.
Crucially, water availability and energy supply are key requirements for the functionality of the system.
While recognising that most people aspire to have flushing toilets, do we really need to use nine to 12 litres of clean, drinkable water to flush?
SA is generally a waterstressed country, with our demand expected to exceed supply in about 10 years.
Periodic droughts throughout the country have shown us the importance of water availability and limiting our water usage to prevent day zero scenarios.
This is why innovation is important. It brings about efficiencies.
The basic design of flush toilet has not changed significantly over 200 years and is in desperate need of innovation to match today’s realities.
The modern-day flush toilet evolved from experiences in the UK and Europe, with engineering principles spreading to other continents.
Cholera outbreaks and river pollution in the UK and Europe in the 1800s catalysed governments to install sewer systems in their cities and remove human faecal waste from highly urbanised areas for subsequent treatment.
Developing countries have followed these engineering principles, but have not had the same success due to differences in population size, rates of urbanisation, differing climatic conditions and economic profiles.
This is where innovation is key. Can we not use one to two litres to flush? Do we have to use sewers to move human waste? Are we not able to treat waste on site?
The Water Research Commission and various international and national partners have been catalysing research into toilets for the future.
Smarter toilets have been designed and tested to treat all faecal waste without needing to tap into a piped line and water can be recycled for flushing.
There are few examples from SA.
The Arumloo uses one to two litres per flush. Indiscernible from a modern flush toilet, its inner vortex toilet bowl provides a more efficient flush.
It does not need any special fittings, is available in ceramic or plastic, and can be fitted by any qualified plumber.
The Eaziflush was another product that was commercialised through initial research and development studies from the Water Research Commission.
It also uses about two litres per flush. The toilet can be installed in sewered and nonsewered areas.
A newer technology is a flushing urine diversion toilet that separates urine from faeces.
Separation of urine from faeces allows phosphorus compounds to be extracted from urine.
Dysfunctional wastewater treatment plants have ineffective nutrient-removal processes which result in urine nutrients ending up in rivers, triggering eutrophication processes in that source.
Removing these nutrients and extracting value as fertilisers could go a long way in reducing downstream pollution events.
The University of Cape Town has done extensive research into this recycling paradigm and a local toilet manufacturer has secured the licensing rights to manufacture the urinediverting toilet in SA.
Recognising the need to stimulate market development for the next generation of sanitation technologies, the SA Sanitation Technology Enterprise Programme has successfully demonstrated recycling toilets at schools.
With water security becoming an increasing challenge, we wish to plan for the future by having a range of sanitation solutions available to meet our changing circumstances.