Urban Utilities and Veolia Water Technologies have unveiled new treatment technology that harnesses the natural power of the anammox (anaerobic ammonium oxidation) bacteria to create a shortcut in the essential sewage treatment process.
The full-scale sidestream Anita Mox treatment is up and running at Queenland’s largest wastewater treatment plant – Urban Utilities’ Luggage Point Resource Recovery Centre.
Organic nutrients like ammonium and nitrogen must be removed from sewage to protect the environment. Traditional sewage treatment processes produce a by-product called centrate, which is rich in nitrogen and ammonium and needs to be returned to the head of the plant for further treatment.
Urban Utilities’ process engineer, Justin Todhunter, said anammox bugs not only made the treatment process cheaper and more environmentally friendly, but they are also more efficient that some traditional methods that are utilised.
“Using the side-stream plant, the anammox bugs naturally remove the ammonium and nitrogen, requiring less energy for aeration and eliminating the need to add carbon,” he said.
“By using less energy and chemicals, the anammox creates a more efficient treatment process. The process will save around $500,000 per year in operational costs and boost capacity at the Luggage Point Plant, which treats around 60 per cent of Brisbane’s sewage – the equivalent of around 50 Olympic swimming pools – every day.”
Urban Utilities has spent 10 years researching and farming the slow-growing anammox bugs at the Luggage Point Innovation Centre to have enough to use in the sidestream plant.
Todhunter said the most exciting part of the milestone was that the completion of the plant meant other wastewater utilities in Australia could have instant access to anammox bugs if they were looking to implement the same innovative technology.
“We’ve finally grown enough bugs to introduce them into the treatment process and start reaping the benefits, as they’re very efficient at removing ammonium and nitrogen from sewage,” he said. “The increased efficiency means Urban Utilities’ Luggage Point plant will have more capacity to cater for Queenland’s population growth.”
Veolia Water Technologies general manager for projects, Michelle Moroney, said farming the anammox was one of the most time-consuming parts of the process.
“Due to biosecurity laws, you can’t import anammox bugs into Australia so it’s taken a long time to grow them for this project,” she said. “The plant will operate as a biofarm, which means other wastewater utilities can have instant access to seeded carriers if they’re interested in using the technology.”
Moroney said the bugs grow on special disc-shaped carriers in the Anita Mox process, which was one of the other reasons the technology was unique.
“The carriers provide a home for the biofilm to grow on and they’re a critical part of the process,”she said. “Around 500 cubic metres of carriers were craned into the sidestream tanks at Luggage Point.”
Urban Utilities was able to retrofit existing unused aeration tanks at the Luggage Point Resource Recovery Centre for the sidestream plant, which helped them reduce the capital investment the needed to get the system up and running.