Dr Kristen Bremmell, chemical engineer

Chemical engineer

Dr Kristen Bremmell received a PhD from the University of Newcastle in chemical engineering. Her doctoral studies investigated the fundamental nature of chemicals used in treating industrial wastewater.

After finishing her PhD, she was a research fellow at the University of Melbourne in the Particulate Fluid Processing Centre, where she worked on a project involving alumina industry tailings.

As a research fellow at the Ian Wark Research Institute at the University of South Australia, her research area is in colloid and interface science. She investigates particle interactions and the effect of different molecules in suspensions of particles. This work is important to the minerals industry in the processing of ores and tailings treatment. A second area of application of her research is the biological and pharmaceutical area where she is working to measure the deformability of red blood cells and looking at titanium bone implants.

Teachers' notes to accompany this transcript.
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Interviewed by Ms Marian Heard in 2001.

Contents


Early experiences in practical science

Kristen, would you tell us about your early life and how your interest in science began?

I was born in Newcastle, in New South Wales, in 1970. I had one brother, and we shared a lot of time playing in the garden and around the house, and going on holidays together.

As I was growing up I was always interested in looking at nature – at bugs and plants and how they lived and were made up – and at how things around me worked. My grandfather bought me a chemistry set and was very interested in teaching me things, helping me learn about life and where things came from.

You were good at science at high school, weren’t you?

Yes, I enjoyed science, particularly the practical aspects of it. My physics teacher, Mr Donald, inspired us a lot and we used to enjoy doing the experiments, going outside to look at light refracting, and making little solar instruments that would work in the sun. It was a lot of fun.

While I was at school, thinking I might like to be a vet, I did some work experience at an animal house at the University of Newcastle. That involved me doing all the menial tasks, though – every day, for example, I had to clean out the messy cages for the rats and the three dogs, and feed the sheep. But I had an interesting experience when a kookaburra came in with a broken wing and the vet decided to operate to fix it. I was helping out, but because kookaburras have hollow bones, the gas that was used to anaesthetise the bird came out of its wing and I couldn’t stop yawning!

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Excitement and independence in hands‑on chemistry

What subjects did you study for your science degree at the University of Newcastle?

I started out in first year studying chemistry, psychology, computer science and maths. Later on I did a little bit of geology, and majored in chemistry. I ended up doing all the chemistry subjects that I could do.

Did you, like most students, have a part-time job during that time?

Yes, I did – actually, two part-time jobs. I worked in a shoe shop and also in a coal lab, Carbon Consulting, where we analysed coal for moisture and for ash content. We did a lot of ultimate analysis as well, like fluorine and carbon dioxide.

That led to another interesting experience, when one day I was pressuring a vessel with carbon dioxide. Suddenly, as I was filling this vessel, I felt the floor rumble underneath me and there was a big bang – ‘Oh, what have I done?’ I thought. But it turned out to be an earthquake, and we all went outside and watched BHP burning. It was an exciting time.

Did BHP’s large presence in Newcastle influence your decision to go into chemistry?

It had a big influence, I think. I’d grown up with BHP always around, and it was always talked about in school. Many people were encouraged to do science, and engineering in particular, because of BHP. The company provided a lot of scholarships and part-time jobs.

In fact, at the end of third year I was lucky enough to get a job at BHP Research. They gave me the independence to take on projects myself, even as an undergraduate student, and investigate a variety of different things. I looked at the copper sediments from Ok Tedi mines, and at gold leaching; I looked at water treatment and we also did a bit of work on site remediation.

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Honours projects in waste treatment

After that you obtained a BHP scholarship to do your Honours in chemistry at Sydney University. What work did you do for that?

I did a waste water treatment project that BHP were interested in. In their rolling mills, in particular, they use an emulsion – a fine dispersion of oil in water – to lubricate the steel as it is rolled. But the emulsion gets quite dirty after a while, so we were trying to break the emulsion, separating the oil from the water, for the water to be reused and the oil disposed of.

Also I did a lot of flotation experiments, supplying air bubbles through a solution. The waste products stick to the air bubbles because they are hydrophobic, and they rise to the surface. You can then remove them and concentrate them up.

PhD work: the chemical treatment of waste water

To do your PhD you returned to the University of Newcastle. What did that involve?

I’d never planned to keep going and do a PhD; I always thought that I would get out and get a job. But I really enjoyed the independence of staying at uni. I think doing a PhD is very independent work.

I was working with a waste-water treatment business, treating industrial waste. There are two different chemicals that they use: a polymer, or a flocculant, and a surfactant, which is a detergent, something that you might use to wash up your dishes. I was looking at the interaction between these two molecules and also how they interact on the surface of a particle. It is important to know how this works so that you can best utilise the chemicals that you are adding to separate the solid waste product from the water. (You don’t want to add too many chemicals, both from an economical perspective and also with respect to the environment.)

We were hoping to understand something about how these chemicals work and how to select the correct chemicals, and then the correct amounts and order of addition, to get the most efficient separation of the waste from the water.

Your PhD graduation was unusual in one respect, wasn’t it?

Yes. It was in the middle of the year, when there is a smaller graduation. Only four chemical engineers graduated, and they were all females, which was quite unusual.

Amazing experiences in a sugar refinery and beyond

For your PhD work you travelled across to Western Australia. Tell us about your experiences there.

I was working as a consultant. We used to do a lot of pilot plant trials, and this particular one was commissioning a plant in a sugar refinery at Kununurra – installing the plant and keeping it working for a little while.

It was a very exciting and interesting time. I worked in the sugar mill, which was an experimental-type mill. They were experimenting with a lot of different technologies, and one reason we were there was to look at inserting some new technology to separate the sugar liquor from the crushed sugarcane.

While I was there I not only got to work on my little bit of the plant, but also found out a lot about how the plant worked and the different processes happening in the plant, right from the crushing through the separation of the sugar juice from the cane, the crystallisation and the drying process, to using the gas to generate electricity for the plant and for the town as well. And I had the incredible experience of going into the control room, where the computer controlled the plant. They actually taught us how to control the whole plant from this room, even changing the chemicals and changing the speed and things that happened. It was a continuous plant, and if you had problems with the sugarcane and you weren’t getting enough feed, you had to slow down the rest of the process so that you didn’t actually ever have to stop.

The town and surrounding area is an amazing place as well, and I went on a few day trips. We went to the Ord River, which was dammed to provide water for agriculture and so on. They grow a lot of different produce around there and also have lots of wonderful fishing. It’s a popular place to go. And during a flight over the beautiful Bungle Bungles we went over the Kimberley diamond mine, another very interesting thing to see. On one trip we went in our four‑wheel drive to El Questro station, where we had a swim in the swimming-hole. The station is a tourist-type place but again is very beautiful, as were the Aboriginal rock paintings that we saw, to our great surprise, on our way to it. So going there was a fabulous experience.

Projects in mineral processing

What did you do after your PhD?

I got a research position at the University of Melbourne, working on an industrial project in the alumina industry. Like a lot of other mineral processing-type industries, they put their waste products into a tailings dam – eventually the water will evaporate off and they can reclaim the land. We were looking at how you could better separate the solids from the liquids, using various mechanical techniques, and also at the various chemicals that are added to do this. If we could end up with a drier product, the land could be reclaimed a lot faster.

And in your current work, at the Ian Wark Research Institute, in Adelaide, two of your projects relate to mineral processing, don’t they?

Yes. One project is on optimising dewatering in mineral processing. That is a little bit similar to the work I did at Melbourne Uni but it involves looking at the whole process, right from the ore extraction through to the tailings dams, and again the different chemicals and mechanical techniques that you can add to optimise the mineral processing.

Another project is looking at polymers in mineral processing. A polymer has a long-chain carbon backbone. We are studying how these molecules adsorb onto particles and flocculate them, or how they might form a steric barrier to allow the particles to slide over each other in a more efficient way for pumping. We do a lot of fundamental work, from looking on a small scale at how the chemicals interact with a surface, right up to looking on a larger scale at the rheology, or flow, of these systems with chemicals present. So we go from the nanometer scale right up to the plant scale, where we do a lot of plant visits and testing of the actual product.

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Biological applications

Isn’t there also an interesting biological aspect of your work?

There is. Since I started at the Ian Wark Institute I have been interested in coming into the biological area, and one of the projects I’m involved in is looking at how red blood cells deform to fit through your small capillaries. We plan to use an atomic force microscope, which comes into contact with the red blood cells and measures the force as a sphere approaches a red blood cell, to measure how that red blood cell deforms and also its elasticity. We hope to then be able to apply that to red blood cells from people with different diseases – to look at how these diseases (and different pharmaceuticals) might affect the red blood cells. Then we can apply this to other types of cells as well.

The other project I’m involved in, with a PhD student, is looking at titanium bone implants. When you implant something into your body, you want it to be accepted by your body and then you also want it to adhere quite quickly and become part of your bone structure. We’re looking at the different proteins, which are what adsorbs first onto your bones: how they adsorb, and how quickly and how strongly they adsorb. Once the proteins have adsorbed, then the bone cells are able to come and grow on your implants.

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Fundamental science, funding and commercialisation

How is the research at the Ian Wark Institute funded?

The director began the institute on industry money and I’m currently funded that way as well, from the different industry projects that I’m involved with. Other people within the institute are actually funded as part of a Special Research Centre for which the Australian Research Council gives money each year.

Having worked closely with commercial companies in your research, what do you think about the commercialisation of science?

I enjoy the practical, applied aspect of science, so I’m very happy that science is becoming more commercial. Also, the industry provides quite a lot of funding for science which would otherwise be quite difficult to come by. I can see a possible conflict of interest, in that you might be forced to do certain work that a company requires, and in that respect it is important to have very fundamental science as well – which I guess comes from government funding. But I’ve been very happy to work with companies. As long as you supply them with the answers that they want, you can also manage to study fundamental things along the way.

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Wide-spread interests and opportunities

Kristen, as well as your research you have a range of other interests, some of which I think began during your school years.

Yes. I like to keep fit. I go to the gym, I do a lot of walking and riding my bike, and I enjoy hiking. When I was young I started dancing in what was called Physical Culture, and I did that until I was in my teens; now I enjoy Latin dancing. I also learnt the piano and I still like to play (but occasionally, when I find a piano). And travel is a big passion of mine. I used to travel a lot with my family around Australia. We had a caravan and we used to go to different places and look around, going caving and walking in the bush, going to zoos and swimming a lot.

Being in science, I’ve been lucky enough to travel overseas quite a few times, sometimes to quite exotic places. On one special occasion I went to a Colloid and Interface Science Conference in Sophia, Bulgaria. A few Australians that I knew were there and also I met a lot of international people, from Europe, the UK and the US. And before coming home I went for a holiday through Croatia and Boznia-Herzegovina, spending a few days in Sarajevo to visit my friend who works for the United Nations. The war there had just finished, and I had the opportunity to experience an amazing combination of different cultures, plus a lot of peacekeepers and UN workers, all in one city. It was like a big party – although it was very sad to see so much destruction. The people have an incredible ability to laugh and enjoy life, simply to get on with life even amidst such destruction and sorrow. It made me feel very lucky.

Three years later I went to a similar conference in Bristol and visited my French friend Sophie, who had gone back to live in France after we did our PhDs together. She was now working with Exxon. We travelled around France, around Normandy, we went to Monet’s garden in springtime. And after the conference, I travelled around Ireland for about 10 days. So that was another amazing trip.

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Getting the message out that science is an exciting place to be

What would you tell a young person were the most rewarding or exciting aspects of a career in science?

There are a lot more opportunities available for someone in science than I realised when I started. One, of course, is travel: you can travel overseas with your job (going to a lot of overseas conferences, as I do, gives you the chance to see a wide variety of life and to travel a little bit while you’re there) and also you can get work overseas quite easily, either as a postdoc or in a longer-term job. It’s very much up to you.

I enjoy the wide variety of work you can do, wherever your job may be. You can work in the lab, work with students, work with companies, go on site visits, prepare reports and grant proposals. It’s just an exciting place to be.

What skills do you think are important in science today?

You need a wide variety of skills, not just in your particular area of science or technology. Good communication skills are very important to attract funding and also to talk about your results and excite people about them. You need very good people skills, to interact with a wide variety of people – international people, government people, funding people, students, business people. Yes, you need very good communication skills.

Where do you see yourself in 10 years’ time?

Actually, I’m interested in a variety of things, including science management and policy development, and the communication of science, promoting science awareness. I hope to work on the skills that those things involve, and to just look for opportunities and take them as they come up.

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© 2017 Australian Academy of Science

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