More‘ gold’
With up to 13 litres of water— or as much as 25 – 35 % of all domestic use— being used for flushing toilets, it is time for cities to move on to non-water toilet systems, says Jayant Bhagwan of South Africa’ s Water Research Commission( WRC).
Municipalities and entrepreneurs must start to view human faeces and urine as“ brown gold”, rather than seeing its disposal as a problem, he adds.
The percentages of water cited, he says, is to“ move around 150g to 200g of human waste … and then we use another 150 to 200l to convey it down the system”, he adds. However, by turning human waste into products, thousands of jobs could be created, Bhagwan points out.
He was one of the speakers during a session at the biennial conference of the Water Institute of Southern Africa, in Cape Town.
Bhagwan’ s message is simple: human waste is a valuable commodity that can be monetised for profit, rather than soaking up valuable water resources.
Many of the sewers in use in cities around the word pre-date“ bathrooms as we know them” and water sanitation accounts for 60 % of the cost of disposing of human waste.“ Yet people are conditioned into viewing flush toilets and centralised sewage treatment works as the preferred options … the‘ gold standard’ … while the poor are excluded.”
And as the world runs out of its traditional sources of energy, potable water, and plant nutrients, water resources are declining, energy costs are rising, and climate change is an issue.
Despite this, the basic design of toilets has barely changed over the past 200 years, he says, adding that current types of toilets, including flush arumloo
The Arumloo, which uses just two litres for a full flush.
and chemical toilets, pit latrines and septic tanks, were“ full of problems”.
An example of an innovative solution and design is the Arumloo, which has the same lines as an arum lily. It uses just two litres for a full flush and the designer is trying to reduce this to just half a litre a flush. Other innovative systems that are showing promise include experimenting with drying, dehydrating, biological, carbonisation, combustion, solar, and thermal treatment for the disposal and repurposing of human waste, says Bhagwan. Some prototypes of different new-age toilets are already being tested in South Africa.
Jayant Bhagwan speaking at the WISA 2018 conference.
WISA innovations industry debate environment infrastructure municipalities