Creating cleaner-tasting desalinated water

One of the issues with desalinated water is that it can be expensive, both financially and with energy use. Elkia Szczecinski has studied modification of the target bromide concentration in desalinated seawater to find efficiencies and benefits.

One of the issues with desalinated water is that it can be expensive, both financially and with energy use. Elkia Szczecinski has studied modification of the target bromide concentration in desalinated seawater to find efficiencies and benefits.

People don’t often think about bromine. It’s a brownish-red liquid that dissolves in water. It’s a naturally occurring element, primarily found in the earth’s crust and seawater as bromide. So why should people care about bromine?

It’s the desalination segment of the water industry that cares about the bromide levels in their product water. This is because a range of bromophenols (an organic compound that contains bromine) can occur in water in a consumer’s household based on the bromide levels at the customer’s tap. The impact of these bromophenols is that some of them create an unusual taste in drinking water.

This is where Elkia Szczecinski comes in. She is a Water Safety Planning Technical Advisor at Water Corporation in Western Australia. When Inside Water spoke to her, she was a Research Assistant at Edith Cowan University in the Centre for Integrative Metabolomics and Computational Biology.

Szczecinski won the Student Water Prize at the Australian Water Association‘s Ozwater’22 for her Chemistry Honours project at Curtin University. She delivered an innovative method for analysing bromophenols, as well as studying bromophenol formation. Her goal was to improve the efficiency and cost-effectiveness of desalinated water production. By re-examining bromophenol formation conditions, Szczecinski hoped to create long-term sustainability benefits.

Why the focus on chemistry?

“I had an excellent Year 12 chemistry teacher,” said Szczecinski. “Up to that point, I was like many other high school students in that I didn’t know what I would do at university. That teacher helped me understand that there is more going on when it comes to chemistry and science in general.”

Her willingness to take a risk with chemistry led her to do well in her studies. The average person may not think about how chemistry interacts with the water industry, but they are heavily intertwined. When looking into drinking water for her Honours project, Szczecinski wanted to focus on things that made her mind tick over.

“I was looking for something that was definitely in my interests,” she said. “I’ve always been interested in climate change and how we will move forward with the world changing the way it is. The southwest of Western Australia will struggle with less rainfall refilling groundwater sources, so I wanted to investigate seawater desalination as a drinking water source. It was my supervisor who reminded me that everyone needs water.”

What was she studying?

Szczecinski was aiming to make desalination more sustainable. Desalination plants tend to use large amounts of energy to desalinate seawater, so any outcome that can reduce the amount of energy needed is a positive one.

This is where bromine comes into play. Szczecinski was studying how bromide and the creation of bromophenols are related to desalinated seawater.

“Bromophenols are compounds that create an unpleasant taste at certain levels in drinking water,” she said. “Their presence makes the water taste a little like plastic, which needs addressing.”

The existing approach was to limit the amount of bromide in desalinated seawater to a low level. Szczecinski was curious about going the other way – how much bromide can be in the water without impacting the water quality delivered to customers.”

The technique for analysing bromophenols is not dissimilar from the distillation used in making gin or vodka. A fibre layer is placed on top of the water sample. When Szczecinski heats the water sample and adds a reagent to modify the structure of the bromophenols, they exit the water sample and attach to the fibre.

“I would then take the fibre and put it in a gas chromatograph,” said Szczecinski. “I would then heat the fibre so the modified bromophenols enter the instrument. Essentially, I’m selectively extracting the bromophenols I want to examine.”

What did she find?

Bromophenols are problematic because as little as 0.5 nanograms of bromophenols per litre can be tasted by humans. This mass of bromophenols is incredibly small, given that it represents 0.0000000000005 kilograms of bromophenols per litre.

“The fact that people can taste this means that the Water Corporation is very interested in solving the problem,” she said.

Szczecinski’s project was looking at avoiding the formation of bromophenols from desalinated seawater. From earlier studies at Curtin, she knew that bromophenols are not found in distributed drinking water but sometimes form in people’s homes.

“The bromophenols tend to form when drinking water containing bromide comes into contact with particular plastic materials in the customer’s home or office,” Szczecinski said. “The phenol part of the bromophenols generally leaches out from plastic kettles, dishwasher tubing, containers, water bottles and other such items.”

Szczecinski acknowledged that she can’t get people to stop using plastic since it is everywhere. That’s why Water Corporation opted to limit the amount of bromide in the distribution systems by limiting the bromide in desalination product water. However, Szczecinski had a different approach.

“Seawater has about 65 milligrams of bromide per litre,” she said. “Once it’s gone through all the desalination processes, it’s down to 0.1 milligrams per litre. However, I found that increasing the amount of bromide does not significantly impact water quality, in terms of bromophenols.”

By increasing the concentration of bromide by as much as a factor of two in desalinated product water, Szczecinski found no significant change in the formation of bromophenols, and there was unlikely to be a difference in the taste of water. This is a big deal for water authorities and desalination plants.

“By allowing for a slight increase in bromide levels in desalinated water, they can save a huge amount of energy,” she said. “This comes from reducing the amount of reverse osmosis treatment required. That’s less energy used, which improves their sustainability outcomes.”

Winning Student Water Prize

While it’s been over a year since she won the Student Water Prize at Ozwater’22, the impact has not been lost on Szczecinski. One area that she did not expect was the number of presentations she was offered.

“I’ve done a couple of presentations at Water Corporation based on my research,” Szczecinski said. “I did a recap presentation at their offices, and since then, I’ve become a staff member. I also got to present at the University of Queensland after I won the prize, which was fantastic.”

Following her win, she was overwhelmed with job offers and interest in her research. She believes meeting people across the water industry was an excellent opportunity.

Working for Water Corporation

Szczecinski’s work is a shift from her analytical chemistry studies, but not that far. She runs risk assessments, utilising a comprehensive risk assessment approach for all drinking water quality processes and steps in a water supply system.

“I’m looking at all the known hazards to improve water quality within the existing frameworks,” she said. “I also need to promote drinking water quality management and provide advice on various issues.”

Looking back on her studies and win, Szczecinski can see her future involved in emerging contaminants such as microplastics and PFAS.

“A lot is going on in the emerging contaminants in water space,” she said. “I am particularly interested in developing strategies to identify and eliminate emerging contaminants from drinking water.”

In Szczecinski’s opinion, Water Corporation did a lot of groundwork in supporting her research.

“They would reach out to my supervisor, Professor Cynthia Joll, and me on a regular basis,” she said. “They’ve supported my research and had no issues giving me permission to conduct my research.”

Since joining Water Corporation, Szczecinski has been making waves in her research, and a future in the water industry beckons.

“My journey into the water industry has been fantastic. I’d recommend it to other young people still trying to decide what to do in their lives. It’s a fascinating industry full of collaborative people that want to make changes for the betterment of society.”

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