London, April 14: A team of researchers has said the technology that
uses fluorescence sensors to pick up trace sewage contamination may
help increase public confidence in recycled water.

"A rapid,
highly sensitive and selective detector is urgently required to detect
contamination events in recycled water systems," Dr Rita Henderson of
the University of New South Wales Water Research Centre told ABC News.

Henderson said that fluorescence spectroscopy may provide the solution because of its high sensitivity.

Fluorescence
monitoring is also an attractive approach because it is a rapid
technique that requires no sample preparation before analysis, she
added.

Fluorescence spectroscopy is now used to monitor the quality of marine water and river ecosystems.

Plant decay products and protein material produced by microbes are known to fluouresce in water.

The fluorescence sensors are able to detect the presence of this organic material, as an indicator of microbial contamination.

According
to Henderson, current methods of online water monitoring generally rely
on chemical analysis, including assessment of conductivity (salt
content), total organic carbon and, in membrane processes,
trans-membrane pressure.

However, Henderson says fluorescence can detect changes in water quality that these techniques miss.

She
says there is a need for a sensitive technology that provides 24-hour,
real-time monitoring of water quality to increase public safety and
confidence.

Henderson and colleagues have been looking at the
ability of portable fluorescence sensors to detect microbial
contamination in dual reticulation systems.

In such systems,
both recycled and drinking-quality water are delivered to homes with
the recycled water used for flushing toilets and irrigation.

But, evidence shows that recycled water can sometimes be accidentally mixed with drinking water in dual reticulation systems.

Henderson
and team are developing a fluorescence sensor that can be held under
running water to detect whether drinking water in a dual reticulation
system has been compromised.

She says they have been able to detect recycled water at levels as low as 5 percent of the mix.

In
the future, fluorescence sensors could be installed in home pipes to
monitor the purity of water piped from a recycling plant to dual
reticulation systems in homes, according to Henderson.

Sensors could feed back information to the water treatment plant and set off an alarm should any contamination be detected.

Henderson
says further research is required to improve the stability of the
fluorescent light source used to detect contaminants. (ANI)