Acesulfame is a sugar-free sweetener, and because it cannot be metabolized in the human body, the sweetener ends up in wastewater after consumption and remains largely intact even in sewage treatment plants.
According to a new study, the persistence of the sweetener varies with temperature, just as the concentration of the sweetener in wastewater varies with the seasons.
The environmental geosciences team investigated how seasonal fluctuations in groundwater flows can be used to trace groundwater flows.
Because sweetener residues end up in drinking water, acesulfame serves as an indicator of the origin and composition of our drinking water.
An indicator for the flow paths of wastewater treated in sewage treatment plants
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Acesulfame, a sugar substitute, is one of the most widely used sweeteners in Europe, as per ScienceDaily.
It is nearly 200 times sweeter than sugar and temperature stable, making it suitable for sugar-free baking and sweetening the majority of diet lemonades.
According to a new study from the University of Vienna, the substance is broken down to varying degrees throughout the year depending on the temperature.
"It was long assumed that the potassium salt of acesulfame was not degraded at all in wastewater treatment plants. This is still true, but only in the cold season," explained Thilo Hofmann, deputy head of the Centre for Microbiology and Environmental Systems Science at the University of Vienna.
There were already initial indications that at least partial biodegradation takes place in summer.
Hofmann can demonstrate the study by systematically demonstrating how the concentration of the sweetener in the water changes with the seasons over a longer period of time.
Because this sweetener is not completely degraded both in wastewater treatment plants and in the environment - after it has been discharged into water bodies with the treated wastewater - detection of the substance in water indicates how much-treated wastewater has entered groundwater, rivers, or lakes.
"You can eventually trace flow paths of the wastewater and its mixing with groundwater if you follow the traces of the substance," Hofmann explained via ScienceDaily.
With the understanding of seasonal variations in the degradation of the substance, acesulfame becomes an even more useful tracer.
Other substances, primarily caffeine, and certain pharmaceuticals-all of which are used in such large quantities that experts say they are ubiquitous in domestic wastewater-have been used to identify water that has made its way down the drain, as per Scientific American.
Sucralose, the main ingredient in Splenda and found in a variety of other products such as protein bars and sugar-free candy, outperforms those because it is more stable.
It is popular among researchers because it does not degrade easily in the environment or in a water treatment plant.
When water quality managers detect sucralose in a river, for example, it can be interpreted as a red flag that some wastewater is present.
Sucralose enters a wastewater treatment plant along with raw sewage and exits with treated water that is discharged into the environment.
It's nearly impossible to test for every possible contaminant in wastewater, but if water quality managers detect sucralose in a river, for example, they can use it as a warning sign that some wastewater is present.
They can then investigate further to determine what other contaminants may be present and endangering the river's health.
According to Stuart Krasner, the district's principal environmental specialist, the Metropolitan Water District of Southern California, which serves the Los Angeles area, monitors its water for sucralose-to reveal the presence of treated wastewater-once a year.
Sucralose has been used for similar purposes in the United States and throughout Europe, and Henry Briceo, a professor at Florida International University, says he is collaborating with the U.S.
It will be used by the National Oceanic and Atmospheric Administration to assess the effects of Hurricane Irma.
Sweetener Traces End Up In Drinking Water
As a result, the sweetener acesulfame leaves a tracer trail from wastewater to river and groundwater, and then to our drinking water.
"The fact that acesulfame is not degraded is essentially a good thing for us hydrogeologists because it allows us to draw valuable information from it," Hofmann said.
This fact, however, makes us aware of how our lifestyle is reflected in wastewater and thus in drinking water: the sugar substitute we consume ends up in our drinking water - albeit heavily diluted.
