My research interests fall into three seemingly disparate but ultimately inter-related areas:
- Anaerobic Wastewater Treatment : Treatment of dilute (500 mg/l COD) and heavy metal/dye containing wastes using a "Baffled Reactor" (ABR). Production, characterisation and removal of Soluble Microbial Products (SMPs) from anaerobic digester effluents. Sulphate reduction to disinfect and remove metals from sludges. Use of solid-phase gas membrane separation in anaerobic digestion to control shock loads. The use of 16S rRNA molecular probes to understand the microbial ecology of anaerobic reactors. In addition, I am looking at immobilised (in PVA) nitrification/denitrification for high ammonia (1000 mg/l) wastewaters in gas-lift reactors.
- Downstream Separations in Biotechnology : Selectivity, activity recovery, kinetics and contactor design (Graesser) using reverse micelles (5 nanometer w/o microemulsions) to extract proteins from fermentation broths. Colloidal liquid aphrons (CLAs-5 micron o/w emulsions) to extract non-polar (erythromycin) and polar (phenylalanine) solutes from broths. Interfacial mass transfer in solvent extraction in the presence of proteins/surfactants and cell debris looking at Marangoni instabilities. Extraction of eicosapentanoic acid (EPA) from marine algae using solvent extraction, silver ion chromatography, and solid phase membrane/silver ion extraction.(3) Biotransformations : Production of chiral epoxides in solid-phase membrane bioreactors. Biphasic enzymatic reactions on colloidal liquid aphrons, as well as the development of crossflow membrane reactors with CLAs.
Selected Research Projects
- "Protein Extraction from Fermentation Broths using Reverse Micelles: Selectivity, Activity Recovery and Contactor Design" in collaboration with Dr. L. Poppenborg, S. Jarudilokkul and E. Paulsen. download PDF
- "The Treatment of Industrial Wastewaters in an Anaerobic Baffled Reactor (ABR): Acclimation and Microbial Ecology using 16s rRNA Molecular Probes" in collaboration with Dr. J. Plumb and L. Freese download PDF
- "The Immobilisation of Enzymes on Colloidal Liquid Aphrons (CLAs) for Bi-phasic Reactions: Stability, Protein Structure and Use in Crossflow Membrane Bioreactors" in collaboration with S. Lamb and F. Oloo download PDF