Tap water can sometimes taste or smell funny. This is due to tiny amounts of odorous compounds that are in fact harmless to health.
Due to their volatility however, they can be quite difficult to trace, which impedes effective water treatment. Over a period of a couple of years, ARISTOT was developed by Veolia R&D in order to detect such compounds and analyze more positively the drinking water that fills consumers' glasses.
A particular taste in water may stem from where the water originates, its treatment to make it drinkable, the supply network, etc. or even from - and although quite frequent this is more difficult to identify - the domestic system itself including pipework, fittings and seals.
Faced with existing time-consuming techniques that couldn't cope with more than around 3% of samples submitted, Veolia R&D decided to investigate faster alternatives that could give a clearer picture of water composition.
For two years, R&D pursued a two-pronged research effort. While the team designed a prototype domestic water system to get a good grasp of what happens with still/moving water, a consumer survey was conducted to ensure the investigations reflected real-life conditions.
The final step was actually to identify any odorous compounds. The work of Veolia R&D was backed by the expertise of the Research Institute for Chromatography, the organization behind the Twister™ concept. This is essentially a magnetic stirring rod incorporated in a silicone-coated glass jacket. ARISTOT combines 7 of these devices in a barrel that, when fitted to a tap outlet, provides a highly sensitive sampler.
ARISTOT is a clever bag of tricks, halfway between a plumber's kit and a mini laboratory. It comes with a complete set of fittings for most tap types, and is installed at the consumer's point of use for a period of 1 to 4 days, after which the barrel is sent to the Water Research Centre laboratory for analysis. This enhanced capability allows Veolia to address effectively any issues with water taste or odour.
And indeed, ARISTOT has lead to the discovery of further odorous compounds and provided the means to carry out statistical sampling.
Two local councils in the Tarn region of France (Saïx and Navès) experienced at first hand in 2007 the benefits of the Twister™ system on which ARISTOT is based.
The Water Research Centre traced the cause of a complaint with the water supply, which could be then appropriately treated, mainly by active-carbon filtering.
As a result, 89% of customers rated the water quality as above average while 35% were of the opinion that it tasted better.
David Benanou, ARISTOT Program Manager at the Water Research Centre
"Our customer satisfaction investigations highlighted a preoccupation with water taste, before health considerations even." (...) ARISTOT "allows a close view of what happens at the consumer end". (...) "And should an odour or taste problem arise, we can address the issue with appropriate advice, monitoring or treatment based on data collected."
Taste and odour trap
Water can be savored like wine, as the opening of water bars shows. Yet saying that tap water has a taste or smell means that it tastes or smells bad: no one wants to drink it and people even fear for their health. Why?
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