Real-time water quality monitoring

Leader

Challenge

Surface plasmon resonance (SPR) optical sensors have been used in a wide range of applications for the detection of chemical and biological substances, including medical diagnostics, drug design, environmental monitoring, food safety and security. It might be possible to apply this technology in the desalination industry for the detection and monitoring of biofouling. This would require the SPR sensor to operate remotely and online. However currently available sensors are not able to do this due to their bulky size and presence of various optical and mechanical parts. A fibre-optic SPR sensor structure that overcomes these challenges and is capable of in situ measurement and remote sensing could be of benefit to the desalination industry.

Investigation

Develop a fibre-optic SPR sensor structure capable of remote real-time sensing of water quality.

Outcomes

The SPR sensor was designed and developed and includes an input fibre, a prism coated with a gold nano layer and a charged couple device camera. The sensor is capable of resolving salinity levels down to 5 ppm. The sensor was further miniaturised by integrating a gold-coated microprism into a fibre collimator.

Testing showed the sensor is capable of detecting salinity changes down to 5 ppm and as large as 30,000 ppm, making it attractive for sensing water quality with a high resolution.

To increase the lifetime of the sensor and increase its cost effectiveness, the 5mmx5mm “gold chip” in the prism is designed to be disposable and changed when performance drops, such as might occur due to corrosion from exposure to high salinity solutions.

The sensor was also able to detect polysaccharides in reverse osmosis membranes. This was achieved by employing a ligand-doped gold nano layer, which trapped specific polysaccharide compounds dissolved in water. Various experiments were performed demonstrating the ability of the sensor to detect Xanthan gum concentrations of up to 0.22 g/L. This will allow the sensor to be used for real-time biofouling monitoring in desalination plants.

Future Direction

Development of a much smaller prototype that features higher sensitivity, in-situ monitoring, lower production cost and ability to be integrated into a multi-functional sensor network. The addition of ligands into the gold nano layer of the SPR sensor should also enable high resolution detection of salinity, temperature, chemical and biological contents in water.

Technology Readiness

Version one prototypes have been developed and the Principal Investigator is interested in hearing from organisations that are willing to participate in a field trial or instrument manufacturers that are interested in the technology.

For further information please contact the Principal Investigator directly.


 

Total Value: $1,295,075 (cash and in-kind contributions)

Principal Investigator: Professor Kamal Alameh

Title: Fibre-optic sensor for water quality monitoring (Phase 1 and 2)

Length: 25 months (Phase 1) and 29 months (Phase 2)

Personnel: 3 collaborators contributing 1.6 FTE (Phase 1) and 4 collaborators contributing 2.1 FTE (Phase 2)

Related Projects: Modelling, monitoring and control of reverse osmosis biofoulingThe optimisation and improvement of direct filtration pre-treatment to reduce both organic and bio-fouling of reverse osmosis membranes

Further Information

ECU Alameh (Fibre-optic Phase 2) Milestone 6 summary poster 28042016

Project Summary Poster – fibre-optic sensor

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