Better tech needed for rapid response to reef nutrients

03 February 2022

Early intervention strategies to reduce nutrient damage to the Great Barrier Reef will require new' rapid diagnostic technologies to provide field assessments of water quality flowing into the Great Barrier Reef.

That's one of the key findings of a new article by CQUniversity PhD researcher Fiona Tan' published recently in Current Opinion in Electrochemistry.

The review article outlines the deficiencies in currently available tools for assessing dissolved inorganic nitrogen (DIN - nitrate' nitrite and ammonium) levels in waterways and that often require samples to be taken back to the laboratory for analysis.

However' she said if more efficient in-field diagnostic tools were developed they could dramatically reduce the time and cost of identifying a problem and the subsequent remediation of nutrient loads in the Reef.

'The release of nitrogen into our oceans via rivers and creeks is a major problem for the environment' leading to eutrophication' the proliferation of algae and plants in the water'' Ms Tan said.

'Currently DIN measurements' and gathering data for nitrates' nitrites and ammonium is conventionally done either through flow injection analysis or classical wet-chemistry experiments' both of which are time consuming' chemical reagent heavy' and can suffer from optical interferences.

'And although automated real-time spectrophotometric systems remain the more popular detection technique' they are expensive' require skilled personnel and routinely involve replacement of probes every few months.'

Ms Tan's PhD scholarship is sponsored by the Mackay Whitsunday Regional Council' which is supporting the project as part of its efforts to minimise nutrient run-off from local farms reaching the nearby Reef.

The work is also supported by the Queensland Government through the Queensland Water Regional Alliances Program.

In her work Ms Tan has pursued the development of an automatic in-field DIN detection tool through electrochemical and nano-technology approaches that show promise for their efficiency' cost and functionality.

'The main factors that need to be addressed in applying these technologies for real-time measurement of DIN are improving their sensitivity' robustness' and stability. We also need the technology to be able to ignore every other chemical found in the water and focus only on DIN'' she said.

'The technology needs to be accurate' easy-to-use' functional in the field and affordable – the laboratory equipment currently used costs upwards of $400'000 and that's a huge limitation for environmental monitoring organisations and government agencies.'

Ms Tan and her supervisors Dr Shaneel Chandra and Dr Amie Anastasi are now investigating the use of disposable strips that can be read by a portable instrument which uses electrochemistry as the detection method – much like a blood glucose meter that operates on a similar principle.

'This style of tool could be practical for in-field real-time monitoring and capable of transmitting wireless data to a remote laboratory' providing rapid responses for early intervention'' Ms Tan said.

Their work forms part of the activities of CQUniversity's Coastal Marine Ecosystems Research Centre (CMERC)' that works with industries and communities to develop practical and sustainable solutions to the challenges facing their environments.

From its laboratories in Central Queensland' the chemistry team within CMERC has been focused on developing better nutrient and contaminant detection methods in order to shift remediation strategies from post-event response to preventative monitoring and intervention.

Ms Tan was also recently selected as CQUniversity's ambassador to the Royal Australian Chemical Institute (RACI)' a role in which she will connect undergraduate and postgraduate students interested in chemistry with potential career opportunities.