Corrosion of sewage pipes inevitably means unwanted aromas and costs the Australian water industry around $100 million a year. A new chemical to be applied to pipes once a week, will kill off the organisms that result in corrosion and smell, before being killed off itself by the microbial community that lives within the sewage systems.
Scientists from University of Queensland Advanced Water Management Centre have found a way to curb the cost – and smell – of sewage transportation. Professor Zhiguo Yuan said bad smells were only one cost of transporting sewage.
“Bad pipes caused by hydrogen sulfide corrosion are another more noxious side-effect that costs the Australian water industry around $100 million a year,” Professor Yuan said.
“Our plan is to change all that by applying to the pipes a once-a-week dose of environmentally friendly free nitrous acid (FNA). “This will be good for both the environment and our senses.”
Currently, expensive chemicals are used to deal with the inevitable smells and corrosion caused by unwanted biofilms that grow on the surfaces of wastewater infrastructure.
Apart from the cost of the chemicals, the existing “solutions” create further problems in the sewage treatment and reclaiming process, as it becomes yet another chemical to be neutralised.
“Our challenge was to find an affordable chemical that didn’t harm the environment,” Professor Yuan said.
The FNA kills the organisms that create the smells and corrosion, and is then removed itself by the microbial community living within the sewage pipes.
“The pipes won’t rot, nor will they smell, and should actually last the 100 years they were designed for, instead of the sometimes only 10 years they currently do,” Professor Yuan said.
Building on work conducted over the past decade, Professor Yuan and his team of engineers and microbiologists recently made the ground-breaking discovery that, at parts per million level, FNA is a strong biocidal agent, causing cell-death and biofilm disintegration.
“This was a very exciting breakthrough and allows us to turn our technology into a valuable business,” he said.
UniQuest is managing the commercialisation of the FNA technology under the start-up company, Cloevis Pty Ltd.
Cloevis and the research team have recently demonstrated the technology in a real sewer line in southern Queensland and are now looking towards further commercial trials of the technology in both Australia and the US.
The research team is also looking at how FNA can be adapted for the control of other types of biofilms.