Optimising drinking water treatment
by Rodney Magazinovic
With
the recent drought highlighting just how precious every drop of water
is, two masters students have developed a water quality monitoring
system to optimise disinfection that will ultimately save on water
wastage during the disinfection process.
French students, Lise Cruveiller and Greg Gnos, developed a low-cost online monitoring system for the drinking water treatment process, chloramination, as part of their Masters of Science studies.
While chlorination is the most commonly used drinking water disinfection process in Australia, chloramination (a combination of chlorine and ammonia) is often used when water needs to distributed over large distances. As the combined disinfection residual of this process is more persistent than chlorine alone, it allows the water to be distributed further without any compromises in quality.
In South Australia the process is used at the Morgan Water Treatment Plant with treated water then making a two-week journey through the pipeline to Whyalla.
Presently the management of a chloramination process suffers from high capital and maintenance costs as the ratio of ammonia and chlorine needs to be carefully controlled and requires continual monitoring – which is traditionally done by manual sampling and analysis in a laboratory, as existing ammonia analysers are too expensive to be used.
Cruveiller and Gnos developed an online system with a highly sensitive sensor that can be slotted into the existing treatment infrastructure and constantly monitors ammonia levels. Furthermore this allows the automation of ammonia dosage as it then becomes dependent on the levels measured by the sensor. Such a low-cost technology will allow the water industry to rethink their control strategy to optimise chloramination usage.
The project is expected to have significant commercialisation value due to potential applications, which range from the management of water treatment facilities through to the aquaculture industry.
The project, a joint research initiative between the Cooperative Research Centre for Water Quality and Treatment, and the Australian Water Quality Centre was supervised by Dr Chris Chow, UniSA Adjunct Senior Research Fellow.
While each student developed a separate part of the system, they both agreed that the success of the project as a whole was due to a combination of teamwork and world-class research supervision and experimental facilities.
"While we each did our own part of the project, it was great to be able to work with Greg to achieve the overall goal," Cruveiller said.
"The research facilities and technical expertise we had access to during the project was excellent and helped us succeed in developing this unique application," Gnos said.
Both students have returned to France to work as engineers in the water industry.