Technology to improve water safety

Dr Erica Ji and Dr Zuliang Chen of CRC CARE and the University of South Australia have developed an ultra-sensitive technique for detecting the toxic metals lead and cadmium in water.

This technology, for which CRC CARE has filed a provisional patent application, equips a special electrode with a novel chemical film that selectively seeks out lead or/and cadmium ions.

"The electrode provides lower detection limits and higher selectivity for lead and cadmium ions," Chen said.

"It means that we now have a much more efficient way of detecting and tracking contamination."

According to co-researcher Dr Erica Ji, one of the advantages of a chemical-based system like this is that it is very quick.

"You get a result in a few minutes, whereas taking samples back to a lab for analysis can take days,"  Ji said.

"It offers the possibility of a real-time early warning system to report when toxins have entered the water supply."

Ji said that the new electrodes have so far been tested in the laboratory and shown to have a very high sensitivity of measurement. However, more research is needed to ensure the special coatings are robust enough for continuing use in the field.

CRC CARE managing director Professor Ravi Naidu said that as Australia's water supplies become increasingly stretched, the pressure to use all our resources, including groundwater and recycled water, will rise.

"As it does, water safety from chemical contamination, both natural and man-made, will become an even bigger issue than it is now. We know from the terrible example of arsenic poisoning in Bangladesh and India that a polluted water supply can potentially affect tens of millions of people — and we must use the best technologies to ensure such things never occur here," Naidu said.

"Many water resources are polluted by naturally occurring heavy metals or from mining, but our city effluent is also contaminated by discharge from factories and industrial activities which can make it unsuitable for recycling.

"This technology offers the water industry a very promising way to test for, and potentially exclude, certain natural and industrial pollutants from drinking water supplies."