Untangling the biophysical interactions governing biofilm hydraulic resistance using cyrogel membrane microfluidics

Membrane biofouling is an inevitable factor severely effecting the permeate flux of ultrafiltration systems.

This impacts the scalability of cheap, decentralised, low hydrostatic pressure methods such as Gravity driven membrane filtration (GDM).

The hydraulic resistance of the biofouling layer is primarily controlled by biofilm, microbial communities embedded within a self-secreted extracellular polymeric matrix (EPS), a structure akin to a colloidal gel.

Mesoscale experiments have shown biofilm hydraulic resistance to vary with hydrostatic pressure, however the microscale biophysical interactions inducing this behaviour are unclear.

Understanding how hydrostatic pressure shapes EPS composition, spatial distribution and physical development of biofilm structures is crucial to establishing hydrodynamic strategies to reduce biofilm hydraulic resistance.

With this proposal I will evaluate how EPS spatiotemporal distribution and local mechanical properties influence microscale fluid transport and the emergence of internal biofilm structures, to impact bulk biofilm hydraulic resistance, under a range of GDM hydrostatic pressures.

To achieve this, I will develop a microfluidic platform embedded with a cryogel membrane barrier, enabling detailed monitoring of membrane bound biofilm development and hydraulic resistance under different hydrostatic pressures.

Deploying a correlative imaging approach, I will quantify EPS regulation, composition and local mechanics using state of the art optical visualisation techniques paired with microrheological methods from soft matter physics. Evolution of fluid transport will be mapped using particle imaging velocimetry.

Relationships between composition and hydraulic resistance established on the microscale will then be tested for scalability on the mesoscale.

By directly quantifying biofilm biophysical evolution, this project will offer invaluable insights untangling the microscale interactions governing biofilm hydraulic resistance.