Online monitoring of biofouling potential



Membrane fouling is a major cost to the desalination industry typically alleviated by replacing the membrane. Biofouling is arguably the principal process, which involves the build-up of bacterial biofilms that feed on organic contaminants in the feedwater termed assimilable organic carbon (AOC). The level of AOC can be considered the initiator of biofouling but AOC levels in the feedwater of reverse osmosis (RO) plants are largely unknown and cannot currently be monitored or determined in real-time. An online sensor for AOC that can predict the biofouling potential of feedwaters would be of great benefit to the desalination industry.


Characterise AOC oxidisation by a biofilm sourced and grown in contaminated feedwater, which will provide the following advantages; 1) the biofilm should be similar to those found on RO membranes; 2) the availability of AOC can be evaluated directly; 3) rather than bacterial growth this test will more accurately measure the respiration of the biofilm; 4) enable real-time monitoring.


The successful adaptation of a freshwater microbial fuel cell (MFC) to operate in a marine environment enabling the bio-electrochemical oxidation of organic pollutants (such as AOC) in ocean water. The biosensor was miniaturised to the size of about 50mL, which was operated and monitored in real-time, making the technology suitable for low maintenance industrial operation.

The combination of an electrochemical cell for dissolved oxygen removal with a MFC-biosensor demonstrated successful AOC detection in oxygen saturated seawater. Seamless integration of electrochemical oxygen removal and bio-electrochemical AOC detection operating as a continuous online operating device was achieved. The two-stage device allows AOC monitoring under practical conditions for real-time monitoring.

Future Direction

On site installation and field evaluation.

Technology Readiness

The technology is ready for prototyping and contact from interested parties is encouraged.  Please contact the Principal Investigator directly.


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Total Value: $889,098 (cash and in-kind contributions)

Principal Investigator: Dr Ralf Cord-Ruwisch

Title: Modelling, monitoring and control of reverse osmosis biofouling

Length: 43 months

Personnel: 6 collaborators contributing 2.2 FTE

Related Projects: The optimisation and improvement of direct filtration pre-treatment to reduce both organic and bio-fouling of reverse osmosis membranesFibre-optic sensor for water quality monitoring (Phase 1 and 2)

Further Information

FR3 MURDOCH Cord-Ruwisch Summary Poster

Project Summary Poster – biofouling monitoring

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