Technology used by breweries to check for diluted beer in kegs could soon be used to monitor water quality in treatment plants.
A new technique developed by an Irish firm determines how polluted water is by analyzing the colors in the light reflected from it.
The AquaPod could save money by cutting the chemicals needed to clean up water.
A similar device is used in breweries to check if tap water has been added to kegs. Before the device was invented, examining if the beer inside was diluted or not would have required a painstaking chemical analysis of each sample.
But the Spectral Signatures instrument provided a quicker alternative that simply involved shining light on the dregs and measuring its spectral profile to decipher the contents.
Recently, the firm applied for a patent for a device it calls AquaPod, which is designed specifically to monitor water quality.
Its uses range from checking the incoming water quality at drinking water plants to examining the content of sewerage inflows or outflows.
The main advantage of having a remote instrument is that, regardless of how dirty the water is, the instrument will not get fouled – a problem for many analytical instruments that need to be immersed in fluids.
The AquaPod is mounted above the water and without touching it determines how much absorbing material it contains.
Typical absorbing material is made up of two things: dissolved material and suspended matter. Dissolved material includes organic molecules, such as phosphates, nitrates and proteins.
They all produce the same color, which is why many liquids look brown. It is these dissolved materials that give, for example, beer and urine their brownish color.
Suspended matter in the water can be anything from sand and dirt to feces. This material scatters the light and makes the water appear cloudy.
Measuring just how much dissolved and suspended material there is determines how dirty the water is.
In water treatment plants, dirty water clogs up filters if there is too much suspended matter. Excess dissolved matter means the color of the water will be brown and this color needs to be removed to make it palatable.
This is done by adding chemicals such as aluminum or iron salts. Minimizing the use of chemicals is better for the water drinkers and also for company costs. And knowing the color of the incoming water and therefore the amount of dissolved material should cut these costs.
"AquaPod is essentially a laboratory spectrometer brought out into the open and made robust enough to keep working in all weathers," said Spectral Signatures director Dr Eon O'Mongáin.
"It is put in a box, acts like a web server and can be controlled from an operator's desk."
The company previously developed and patented a product called ChlorFlow which is used by the UK's Environment Agency for monitoring chlorophyll levels in English coastal waters.
A build-up of chlorophyll in the water, which is caused by too much nitrogen coming off the land, can kill off fish by depleting the oxygen in the water they need to breathe. It can also lead to large, smelly algae blooms being deposited on beaches.
The accuracy of the AquaPod is now being tested against traditional sampling methods at a water treatment plant in Dublin.
Source: BBC News
