Kylie Close

Postdoctoral Research Fellow (The School of Chemical Engineering UQ)
Creating a phosphorus circular economy through removal and recovery of phosphorus from wastewater.

Kylie Close


Phosphorus is a key nutrient that must be removed from wastewater to avoid unwanted algal blooms (eutrophication). While phosphorus removal is a step towards eliminating its accumulation in the environment, phosphorus recovery is crucial to enabling a successful circular economy. My research focuses on using special bacteria that can accumulate phosphorus in excess as an inorganic polymer to both remove and recover phosphorus from wastewater. 
In addition to my technical research, I see my personal role as an advocate to increase the numbers of the next generation of First Nations in STEM. 


The bulk supply of phosphorus comes from finite sources of mined phosphate rock and is predominantly utilised in the manufacture of fertiliser to support global food supplies. As Australia is a net importer of phosphorus, its stakeholders like the agricultural industry are vulnerable to international market volatilities, as recently seen during the Covid-19 pandemic. Phosphorus is also a base component in the surging lithium iron phosphate battery market. With an international shift to renewable energy and vehicle electrification, phosphorus demand is expected to cause constraints in supply. To reduce Queensland’s reliance on importing phosphate rock, renewable phosphorus supply chains need to be developed. Phosphorus recovered from wastewater is a promising alternative to phosphate rock and could be a key to creating a renewable supply line for Australia.
Phosphorus recovery at wastewater treatment plants (WWTPs) can be achieved through thermal treatment technologies such as incineration of waste sludge or crystallisation from digester liquid as struvite or brushite. While these methods provide an avenue for phosphorus recovery, these methods can be energy intensive, and have limited application, thus and are not widely implemented in Australia. Phosphorus recovery from enhanced biological phosphorus removal (EBPR) processes is however recognised as an emerging area with increased potential for phosphorus recovery.  
In EBPR processes, special microorganisms take up phosphorus and store it in polymer form, known as polyphosphate. These organisms are referred to as polyphosphate accumulating organisms (PAOs). Leveraging the unique ability of these microorganisms to sequester phosphorus, my work aims to investigate a range of recovery pathways and compounds to generate a renewable phosphorus pipeline for Queensland.  
While that broadly defines the technical aspects of my research, as a First Nations person with bloodlines to Quandamooka and Minjungbal on the Tweed, the non-tangential aspects of my work have equal, if not more benefit. There is a saying “If you can’t see it, you can’t be it” and as a First Nations person I have an immense responsibility to stand up, be counted and demonstrate to the world what we are capable of. Notwithstanding the opportunities and mentorship that have been provided on my journey have been paramount to getting me to where I am today. In my culture, giving back and reciprocity is fundamental to who we are. 
Hopefully through my continued work in the STEM field I can come full circle and have the opportunity to be a mentor, role model and act as a support mechanism for the next generation of female and First Nations chemical or bioprocess engineers. 

Role Model

I am a role model every day for my 11-year-old daughter Emily. I am fortunate, as this provides me with perspective on what drives girls in the later years of primary school and early high school. Particularly when they start thinking about what they are going to do when they finish high school. I would love for her to succeed and work in a STEM related field, however what I have found over the last four years since re-engaging in the STEM field is that visibility is paramount. As I mentioned before, if you can’t see it, you can’t be it and being aware of the various career pathways that are available is crucial to increasing the pipeline of females in STEM. This is of particular importance with respect my peoples as a First Nation Australian. Reflecting on my own family’s history, education is key in helping lift the next generations to a more prosperous position. Having completed my PhD and now being in a position to give back, I see my existential role to engage in outreach programs with our young females and First Nations people to promote careers and pathways in STEM. 
Additionally, what makes me a good role model for women and young girls is my career has not been in a straight-line. My pathway has had a number of deviations based on things that were going on in my personal life. This is why I am a huge advocator for emphasising failures and setbacks are ok in both our personal and working lives. It provides us with an opportunity to learn and grow. We’re all on our own individual journeys and need to be reminded to afford ourselves compassion. 


I have been fortunate to engage with the CSIRO Young Indigenous Women's STEM Academy and be provided the opportunity to speak at two of their events. I was able to share my experiences with our young people on progressing through high school, course selection, getting into university, navigating the transition from high school into university. Aspects of transitioning from university to industry. I also spoke about having a career break and the decision to get back into STEM by pursuing my PhD. 
In addition to the CSIRO talks, as part of my new postdoctoral research fellowship I have volunteered to be a part of the school of chemical engineering’s high school outreach team. I have had the opportunity to present at two local high schools. The first engaged with the school’s year 7 students and focused on the novel ‘A long walk to water’ by Linda Sue Park they were reading. We discussed a range of simple techniques to create safe drinking water if we didn’t have access to electricity. 
The second high school visit coincided with the universities experience day. The goal of this visit was to engage with year 10 students at the all-girls school on opportunities/pathways in chemical engineering. 
I have been actively involved in the School of Chemical Engineering’s experience days and industry nights by setting up bioreactors and projection of these microbes onto a large television screen. This provides but the diversity of organisms at the microscopic level we have in the laboratory. 
Over the course of my postdoctoral fellowship, I am aspiring to expand our work with outreach and engage with regional schools on career opportunities in chemical engineering. 

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