- Hafidz Alif Felyansyah
Can We Trace Wastewater to Indicate The Origin and Composition of Our Drinking Water?
Acesulfame is a non-sugar sweetener used in foods and beverages. The sweetener ends up in wastewater after use and is mostly unaltered even in sewage treatment facilities because it cannot be digested by humans. According to a recent study from the University of Vienna, the sweetener's persistence fluctuates with temperature just as its concentration in wastewater changes with the seasons.
Acesulfame Sweetener as Indicator for The Flow Paths of Wastewater Treated in Sewage Treatment Plants
Since acesulfame (ACE) does not completely degrade in wastewater treatment facilities or the environment after being discharged into water bodies with the treated wastewater, it is widely used as an indicator of wastewater discharges into surface waters and groundwater. The presence of the substance in water tells us how much treated wastewater has been discharged into groundwater, rivers, or lakes. However, the use of ACE as a transient wastewater tracer allows for the calibration of transient groundwater flow and mass transport models as well as the determination of mixing ratios and travel times through the aquifer. "If you follow the traces of the substance, you can ultimately trace flow paths of the wastewater and its mixing with groundwater," Hofmann, Researcher at University of Vienna, explains. ACE becomes an even more useful tracer when seasonal variations in the substance's degradation are considered.
ACE sweetener cycle as wastewater tracer (PhysOrg, 2023)
Computer models of groundwater flows enable risk prevention
Based on Hofmann, "Our study shows that the seasonally fluctuating concentration of ACE can be used to better visualize and understand the processes in the subsurface, i.e. groundwater flows." The amount of wastewater in drinking water, the speed at which groundwater is moving, and the proportions at which groundwater and river water mix can all be measured.
Simulated ACE concentrations for a complete seasonal oscillation cycle triggered by biodegradation (Marazuela et al, 2023)
The pre-alpine catchments routine groundwater and river sampling over a period of eight years was examined by environmental geoscientists. "Such computer models are the key to risk prevention, because they can be used to understand how much river water and how much groundwater end up in the population's drinking water and how to optimize the operation of waterworks," adds the head of the research group.
Based on simulation, it has given result that in the river water, data showed that ACE loads decreased from 1.5–4 mg/s in the cold season (December to June; T<10 ◦C) to 0–0.5 mg/s in the warm season (July to November; T>10 ◦C). This seasonal variability of >600% was detectable in the aquifer and preserved >3 km. Its employment as a transitory tracer of wastewater inflows and riverbank filtration is made possible by the substantial seasonal variation in ACE concentrations during wastewater treatment, in comparison to the other sweeteners (sucralose, cyclamate, and saccharin), and chloride.
As a result, the sweetener ACE leaves a tracer path from wastewater to rivers and groundwater, and then to our drinking water. According to Hoffman, "However, this fact also makes us aware of our lifestyle being reflected in the wastewater and thus also in the drinking water: The sugar substitute we consume ends up back in our drinking water—albeit heavily diluted, of course."
Another Perspective on the Use of Acesulfame Sweetener in the Indonesian Food and Beverage Industry
Use of Acesulfame Sweetener (Freepik, 2022)
ACE sugar substitute is one of the most commonly used sweeteners and is 200 times sweeter than sugar. Since the human body does not metabolize the substance, it ends up in wastewater when consumed in large quantities and remains there even after treatment, but in fluctuating concentrations. The use of ACE sweeteners in the food and beverage industry in Indonesia, especially in the syrup industry, is permitted under certain regulations. Based on research on the Determination of ACE-K Levels in Syrup by High Performance Liquid Chromatography (Fikriyyah, 2021), the results of the analysis showed that the average ACE-K level was 66.88 mg/kg. Based on the Regulation of the Food and Drug Supervisory Agency of the Republic of Indonesia No. 11 of 2019 concerning Food Additives, artificial sweeteners in ready-to-consume drinks may not exceed 600 mg/kg, so ACE-K in syrup meets the requirements. Even so, the use of ACE is not recommended to be done every day because it is indicated to have a health impact.
References
Fikriyyah, A. 2021. Penetapan Kadar Asesulfam-K dalam Sirup Secara Kromatografi Cair Kinerja Tinggi. Jakarta : Jurusan Analisa Farmasi dan Makanan Kemenkes Jakarta II.
Marazuela, M.; Formentin, G.; Erlmeier, K.; and Hofmann, T. 2023. Seasonal biodegradation of the artificial sweetener acesulfame enhances its use as a transient wastewater tracer. Water Research, 232.
University of Vienna. (2023). “Artificial sweetener as wastewater tracer: New study shows what the sweetener acesulfame reveals about groundwater flows”. PhysOrg. [Available at: https://phys.org/news/2023-02-artificial-sweetener-wastewater-tracer.html.]] Accessed on March 6, 2023.
University of Vienna. (2023). “Artificial sweetener as wastewater tracer: New study shows what the sweetener acesulfame reveals about groundwater flows”. ScienceDaily. [Available at: www.sciencedaily.com/releases/2023/02/230208125144.htm.] Accessed on March 6, 2023.
Glossary
Aquifer : Any geological formation containing or conducting groundwater, especially one that supplies the water for wells, springs, etc.
Artificial sweetener : Substances that are used as substitutes for natural sugar (sucrose) contain low calories.
Riverbank : The slopes bordering a river.
Tracer : Substances with atomic or nuclear, physical, chemical or biological properties that can help identify, observe or follow the behaviour of various physical, chemical or biological processes.