Researcher finds way to reduce cost of phosphorus removal from wastewater

Posted 18 September 2017

Flavia Steinauer
Nominees for the 2017 WA Student Water Awards are having a direct impact on industry practice, with one candidate’s research aiming to help a major utility manage phosphorus removal from wastewater stabilisation ponds. 

GHD Graduate Chemical Engineer Flavia Steinauer has been nominated for her honours project, entitled Technical Assessment of Phosphorous Removal with Alum from Wastewater Stabilisation Ponds

With the help of GHD, Steinauer set out to find a way to help Water Corporation reduce the amount of alum used to remove phosphorous from wastewater stabilisation ponds. 

“In order to remove the phosphorus in the wastewater, which can cause eutrophication in downstream water bodies, destroy aquatic life and diminish the areas recreational and conservational value, utilities add the coagulant, aluminium sulfate [alum],” Steinauer said. 

“The issue with alum is that there is a lot of cost involved. Water Corporation are having to dose more alum than they would like, and they wanted to know if there was a reason for that and if I could come up with some recommendations for process optimisation.”

Steinauer’s research found that phosphate ions compete with other chemical compounds in reaction to alum, which is why more alum is needed to manage phosphate concentrations. 

“When alum is added to wastewater there’s a formation of highly charged complex polyaluminium hydroxide ions. Their high charge is necessary for effective charge stabilisation in the coagulation process, so that they can coagulate with the orthophosphates in the wastewater,” she said. 

“What’s happening is not only are phosphate ions reacting with the alum, but also other competitors. If you have competitors, you have to add more than you’d expect.”

Steinauer has made recommendations to the utility on how to be more efficient in their use of alum through dosing control, among other solutions.

“A lot of their ponds don’t have dosing control, so the amount of alum would get added, and they sometimes increase the dose two or four-fold but with no evidence that there was more phosphorous coming into the inflow,” Steinauer said. 

Steinauer said nominating for the award has been a great experience and she looks forward to seeing if Water Corporation can create more efficiency in their phosphorous removal processes as a result of her work. 

“Being part of the Student Water Awards has made me think about my research a lot more, and made me reflect on how my project has impacted my desire to pursue a career in the water industry,” Steinauer said.  

“At the moment I am very happy working for GHD in their Water Technology Service Group. But I’d be very happy to see the results of my research used by Water Corporation to help them optimise their wastewater treatment processes and save them some costs.”

The winner of the 2017 Student Water Awards will be announced at the Australian Water Association WA Awards Dinner on 20 October.

Are you a student in NSW, SA or VIC with a completed project that you would like to nominate for the Student Water Prize in your state? Click here for more information.
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