Operators of reverse osmosis plants diagnose system performance by monitoring and normalising changes in permeate flow, net driving pressure and permeate conductivity. Unfortunately, simple monitoring of flow and pressure is not sufficiently sensitive to detect the critical interactions occurring at the molecular level which initiate the attachment and growth of microorganisms that cause fouling. Identifying the early onset of fouling would necessitate monitoring of the conditions on the membrane.
Modify the surfaces of a suite of high rejection commercially available seawater reverse osmosis membranes using plasma polymerisation and determine the rate of organic deposition using electrical impedance spectroscopy.
Membranes with zwitterionic surfaces were generated and demonstrated improved hydrophobicity and reduced fouling potential.
The impedance and capacitance of the original membranes both increased as a result of compaction. In contrast, the impedance of the modified membrane after compaction increased more significantly compared with the original membrane, while the capacitance was found to be reduced. These observations suggested that the microstructure of the modified membrane was denser than that of the unmodified membrane.
Fouling studies indicated that the modified membrane could prevent the absorption of alginate.
Conduct a field trial and thorough assessment of the biological characterisation techniques.
Total Value: $148,338 (cash and in-kind contributions)
Principal Investigator: Professor Greg Leslie
Title: Real time detection and management of biofouling conditioning films in seawater reverse osmosis
Length: 6 months
Personnel: 7 collaborators contributing 1.0 FTE