Change Coagulant To Save Sewers

An extensive survey and sampling campaign pinpoints aluminium sulfate coagulants as the cause of sewage corrosion.

AsianScientist (Aug. 21, 2014) – A team of researchers has found a way to save water providers hundreds of millions of dollars a year by reducing sewer corrosion. Their research has been published in the journal Science.

Team leader and Deputy Director of the University of Queensland (UQ)’s Advanced Water Management Center (AWMC) Professor Yuan Zhiguo said sewer systems were recognized as one of the most critical infrastructure assets for urban societies.

“Maintenance costs for these concrete sewers run into the billions of dollars a year across the world,” Prof. Yuan said.

The research team shows that a common coagulant added in the drinking water treatment, aluminium sulfate, can be a key contributor to the sulfate levels in sewage.

“This, in turn, is the primary source of hydrogen sulfide, which creates rapid concrete degradation and is the main cause of global sewer corrosion,” he said. “This could be avoided by switching to sulfate-free coagulants at little or no extra cost compared with the large potential savings in sewer maintenance and corrosion costs.”

“To get to this point, we performed a two-year sampling campaign in South East Queensland, an extensive industry survey across Australia, a global literature review, and a comprehensive model-based scenario analysis of the various sources of sulfate.”

Established ten years ago, Prof. Yuan said the AWMC’s sewer research team had received more than A$10 million (~US$9.3 million) in funding from industry and research grants.

“A decade ago we established the ‘Putting Science into Sewers’ research program and, since then, we have delivered more than A$400 million (~US$370 million) in documented savings to the Australian water industry, with much more to come,” he said.

“We are particularly pleased that we were able to simultaneously achieve both academic and industry impact in the same research program—something that we have always strived to achieve.”

The article can be found at: Pikaar et al. (2014) Reducing Sewer Corrosion Through Integrated Urban Water Management.

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Source: University of Queensland; Photo: runran/Flickr/CC.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

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