MSE Research Project Database

Rheology and Dewaterability of Anaerobic Lagoon Sludges

Project Leader: Anthony Stickland
Staff: Peter Scales
Collaborators: Nicky Eshtiaghi (RMIT University) Daniel Lester (RMIT University) Damien Batstone (University of Queensland) Paul Jensen (University of Queensland) Catherine Rees (Melbourne Water)
Sponsors: Melbourne Water, Barwon Water
Primary Contact: Anthony Stickland (
Disciplines: Chemical & Biomolecular Engineering
Research Centre: Particulate Fluids Processing Centre (PFPC)

Anaerobic lagoons and ponds are used in many industries to biologically digest large volumes of municipal, agricultural and industrial waste, with biogas a useful by-product. However, lagoon design is inadequate due to limited capacity to model the multi-phase hydrodynamic and biological behaviour.  Sedimented sludge and floated scum layers form within lagoons, and their properties change with location, temperature, composition and digestion.  A part of improving our understanding lies with how the material flow and deformation properties change throughout the lagoon. 

The PhD student will subject selected sludge and scum samples from laboratory, pilot and full-scale testing of anaerobic lagoons to a series of physicochemical characterisation experiments to measure permeability, compressibility and shear rheology. Other properties include particle size, solid and fluid density, and settling rate. The outcome of this work will be the rheological and dewatering behaviour of sludges and scum as functions of sludge type, extent of biological degradation, solids concentration, gas fraction and temperature. More broadly, this work will develop an understanding of the role of different extracellular polymeric substances in wastewater sludges and is applicable beyond anaerobic lagoons, helping to flesh out the broader relationship between treatment process and physical behaviour.

The project requires a Chemical Engineering graduate or similar with strong experimental skills. Some rheology and/or wastewater treatment experience is good but not necessary.  The student needs to well-organised and hard-working to undertake the experimental material characterisation, and have good analytical skills to interpret and collate the experimental results.