Calcium phosphate scale deposit formation is common in dairy processing, especially where elevated temperatures are involved. Mineral scaling in dairy processing equipment is undesirable because:
- Scale acts as a surface for bacterial growth, increasing the likelihood of contaminating the product; and
- Scale reduces the heat transfer efficiency of the surface upon which it forms, which increases energy use and reduces plant life.
Mineral scale is managed using an industry standard cleaning solution that contains sodium hydroxide, nitric acid, phosphoric acid and surfactants. The cost of managing mineral scaling is through the purchase of water softening & cleaning fluids, but importantly, also in the equipment downtime.
Research into cleaning efficiency has taken a process-scale approach – optimising both chemical and physical cleaning parameters (NaOH concentration, temperature of fluid, residence time, flow rate) based on the ability to return a ‘clean’ surface (as determined by macro-scale properties). A nano-scale assessment & understanding of the cleaning process will provide new insights into scale formation and dissolution processes, and will allow for the optimisation of cleaning processes to minimise equipment down time, resulting in more cost-effective cleaning processes.
- Liaise with our industry partners to understand and document:
- the key processes & equipment that experience mineral scaling in their operations
- the current cleaning processes that are employed
- Explore the current literature on mineral scaling in the dairy industry, with a focus on the molecular-scale mechanisms of nucleation & deposition and fragmentation & dissolution.
- Design & implement methodologies to:
- collect, sample and characterise mineral scale from dairy processing
- measure the efficacy of current cleaning processes
- identify any relationship between the amount of residual scaling post-clean and the rate at which new scale builds up
- determine, using industry-available technologies, when a surface is clean at the nano-scale
- test the efficacy of alternative cleaning processes
- (This includes making use of the advanced characterisation facilities available at Deakin University, the Australian Synchrotron & the Australian Centre for Neutron Scattering).
- Make recommendations for adaptation of cleaning processes to improve cost-effectiveness.
Applications will remain open until a candidate has been appointed.
This scholarship is available over 3 years.
- Stipend of $27,596 per annum tax exempt (2019 rate)
- Relocation allowance of $500-1500 (for single to family) for students moving from interstate or overseas
- International students only: Tuition fee and overseas health coverage for the duration of 4 years
To be eligible you must:
- be a domestic or international candidate
- meet Deakin's PhD entry requirements
- be enrolling full time and hold an honours degree (first class) or an equivalent standard master's degree with a substantial research component.
- have a degree in Civil Engineering, Environmental Engineering, Chemistry, Geochemistry or related disciplines
Please refer to the research degree entry pathways page for further information.
Additional desirable criteria include:
- practical laboratory experience
- reporting/publication track record or aptitude for written communication
How to apply
Interested applicants should email the expression of interest form and CV to Dr Ellen Moon
For more information about this scholarship, please contact Dr Ellen Moon
Dr Ellen Moon
Lecturer in Environmental Engineering
Email Ellen Moon
+61 3 522 78656