Dr K R (Ken) Davey
Senior Lecturer
B.E. (Chem.) RMIT, M.Eng.Sc., (Melb.) Ph.D., (Melb).
FIChemE., FIEAust., FAIFST, MSAM(UK).
Location: Room 212b Engineering North
Email: kenneth.davey@adelaide.edu.au
Phone: + 61 8 8303 5457
FAX: + 61 8 8303 4373
Interests
Our research interests lie mainly in the area of biochemical engineering and presently cover five principal areas. These are outlined below.
Through our Food Safety Alliance we collaborate closely with government and industry.
Quantitative Risk Assessments:
We are particularly interested in researching the notion that no matter how good the design and operation of process plant there is an occasional, and usually catastrophic, failure - or Friday 13th event. In the food and pharmaceutical industries this is a serious risk to public health. Often there is too small a data set for detailed analyses, especially if failure is simply put down to human error. New approaches have emerged that offer insight to the (bio) chemical engineer into process failure. In contrast to traditional approaches, which we have titled Single Value Assessment (SVA), process simulation is based on a distribution of values or Monte Carlo Assessment (MCA). A Quantitative Risk Assessment (QRA) is a statement of the probability of plant failure. It is hoped this research will lead to a greater understanding of process failure - and to an increased confidence and reliability in the design and performance of unit operations.
Modelling of Chemical Residuals of Polychlorinated Dibenzo-p-dioxins, Polychlorinated Dibenzofurans (PCDD/Fs) and Polychlorinated Biphenyls (PCBs) in Tuna:
Because of high lipophilicity, PCDD/Fs (dioxins) and PCBs can bioaccumulate in the fatty tissue of fish. Feed baitfish is believed to be a major source of dioxins and PCBs. The aim of this research is to develop a quantitative through-chain predictive model for dioxins and PCBs in tuna. Southern Bluefin Tuna (SBT) is an economically important ranched marine finfish in South Australia. The framework for modelling dioxins and PCBs in ranched SBT is being developed from a Quantitative Risk Assessment (QRA). This is a first step to documenting residue traceability for ranched SBT. A validated model derived from this framework will provide increased confidence in international market acceptance
Biological Filtration of Algal Metabolites:
The aim of this research is to develop a biological filter for removal of cyanobacterial metabolites from drinking water. Focus is on 2-methylisoborneol (MIB) and hepatotoxin microcystin. These commonly occur in surface waters. Understanding the origin of the acclimatisation, or lag, period of the filter and ways to minimise it are important in a practical situation. We are looking at ways of seeding the filter with selected degrading bacteria and introducing compounds which are known to promote the degradation of the metabolites.
Filtration of Liquid Foods:
Diatomaceous earth is a form of volcanic clay that is widely used as a filter-medium for the polishing of wines and the clarification of beers. We are interested in the development of practical substitute filter media as possible replacements. Our work continues to involve extensive experimental investigations with both wine and beer. We are interested in the development of alternative media, protocols for media preparation and in the adequate simulation of process conditions and practices using pilot plant.
Modelling the Effect of Combined Process Parameters on the Growth and Death of Contaminating Bacteria:
An adequate mathematical model is an essential step to longer-term process control and optimisation. Mathematical models therefore have a central place in planning and design. We are interested in the synthesis and application of kinetic models that include the combined effect of a number of environmental factors in addition to time, principally, T, pH and aw, to describe the behaviour of contaminant micro-organisms. We are currently investigating the thermal processing of liquids and the optimisation of models for microorganism growth during packaging, storage and handling of foods.
Ultra High Pressure - Cold Pasteurisation:
Ultra High Pressure-Cold Pasteurisation (UHP-CP) (< 700 MPa, < 35 0C) of microbial contaminants in vacuum-packed foods is an emerging alternative to commercial thermal processing. Present operating conditions however have evolved empirically. An over-estimate of treatment will mean that there are actually more microbial survivors than expected. This is potentially a serious risk to public health. Our research focuses on the synthesis and validation of an adequate mathematical process model. The research can be justified by an increased reliability of operation and is a necessary first step in the optimisation of UHP-CP technology.
UV Disinfection of Water:
Irradiation with ultraviolet light is an effective means for disinfection of contaminating micro-organisms in potable water and wastewater. We are interested in the performance characteristics of existing equipment and in the geometry of reactor design for optimal processing. This type of research can involve extensive experimental investigations to help assess the value of key parameters characterising a particular flow system. We are interested in the synthesis of mathematical models which can describe the experimental results and which can be used in computer simulations for appraisal of design and optimisation.
Value-Adding to Food Industry Wastes:
We are interested in investigating possible options to value add to food-industry wastes, especially those derived from marine sources. Nutraceuticals derived from marine sources have a commercial premium, in contrast to synthesised alternatives. We are currently involved in optimising supercritical CO2 extractions of material and in the development of a process and economics model. This work is carried out as a commercial and in confidence study in co-operation with industry.
Previous Research Interests
Specialised instrument development
Textural and sensory measurement
Meat and related food chilling
Heavy metal contamination of water
Recent Publications
- Davey, K.R., Phua, S.T.G., "Letter to the Editor", Food Microbiology, 22 2005) 483-487.
- 17. Patil, R. A., Davey, K. R. and Daughtry, B. J., "A New Quantitative Risk Assessment Model of a Fermenter for Friday 13th Syndrome" Chemeca 2005, Smart Solutions - Doing More with Less" 25-28 September 2005, Brisbane Queensland.
- 18. Phua, S.T.G., Davey, K.R., D.J. Daughtry, "Application of a Modified Davey-Linear Arrhenius Model for high pressure (= 600 MPa) - Cold Pasteurisation of Vacuum Packed/Liquid Foods", Chemeca 2005, Smart Solutions - Doing More with Less 25-28 September 2005, Brisbane Queensland.
- 19. Phua, S.T.G., Davey, K.R., D.J. Daughtry, "Framework for modelling chemical residuals of Polychlorinated Dibenzo-p-dioxins, Polychlorinated Dibenzofurans (PCDD/Fs) and Polychlorinated Biphenyls (PCBs) in Australian Ranched Southern Bluefin Tuna (Thunnus maccoyii)", Chemeca 2005, Smart Solutions - Doing More with Less" 25-28 September 2005, Brisbane Queensland
- Davey K R & Phua S T G 2005 Kinetic analysis of Escherichia coli inactivation by high hydrostatic pressure in broth and foods. Food Microbiology 22, 483-7.
- Amos S A, Davey K R & Thomas C J 2004 A new Weibull model for prediction of tailing in UV disinfection survivor data. In: Proc. 32nd Australasian Chemical Engineering Conference (Sustainable Processes), CHEMECA 2004, Australian Technology Park, Sydney, NSW, Australia, September 26-29, paper 106 (ISBN 1 877040126).
Selected Book Reviews
Davey K R 2005 Food Microbiology 22, 489-90.
McKellar R C and Lu X (Eds) 2004
Modelling Microbial Responses in Food
CRC Series in Contemporary Food Science, CRC Press, 343 pages (ISBN 0 8493 1237 X)
Davey K R 2002 The Chemical Engineer October (2002), 57.
Venables J 2002
Communication Skills for Engineers and Scientists
3rd Edn, The Institution of Chemical Engineers, 99 pages (ISBN 0 85295 455 7)
Davey K R 2000 Transactions of the Institution of Chemical Engineers, Part C, Food and Bio products Processing 78, 105.
Sharma S K, Mulvaney S J and Rizvi S S H 2000
Food Process Engineering - Theory and Laboratory Experiments
John Wiley & Sons, 348 pages (ISBN 0 471 32241 5)
Davey K R 1998 Transactions of the Institution of Chemical Engineers, Part C, Food and Bio products Processing 76, 170.
Gardner J F and Peel M M (1988)
Sterilization, Disinfection and Infection Control
3rd Edn, Churchill Livingston, 267 pages (ISBN 0 443 05435 5)
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