Artificial Sweeteners as emergent contaminants in the environment: can constructed wetlands remove these compounds from water? (16.01.2014)

Artificial sweeteners (AS), although having a long tradition as safe food additives, are a newly recognized class of environmental emergent contaminants due to their extreme persistence and ubiquitous occurrence in various aquatic ecosystems (1).

As a result of the widely use of AS, compounds like acesulfame, cyclamate, saccharin and sucralose are being detected in effluents, rivers, lakes and groundwater around the world (2). In fact, research on artificial sweeteners in water started about their use as indicators/markers for sources of anthropogenic contamination followed by usage as tracers to study traditional wastewater treatment plants (WWTPs) efficiency for emergent contaminants removal from wastewater's.

Presently, most WWTP considered a major source of several different emerging micropollutants, including pesticides, pharmaceuticals and personal care products (PPCPs) and flame retardants among other, also are proven to be inefficient to remove AS from their influents (3). Despite the low concentrations usually found (from ng/L to mg/L level), and being marketed as metabolically inert sugar substitutes, studies have revealed that they are not entirely inert in the environment. One study has found a potential xenobiotic interference in the normal biological functions in ecosystem (e.g. photosynthesis and feeding behaviours in zooplanktons) when and because these compounds invoke organisms' biological response to natural sugar (1). Although some studies of the effects of sucralose on aquatic biota have been done, the ecological effects of AS on aquatic organisms are largely unknown. Furthermore, even less is known about the chemical breakdown products of AS in the aquatic environment or their toxicity (2). Therefore, development of innovative approaches that ensure an efficient removal of these contaminants is important.

Constructed wetlands (CWs) have been researched in the last years has alternative and/or additional treatment systems for emergent pollutants removal from effluents, specially PPCPs with promising results (4). CWs have been gaining considerable attention as low cost and efficient means of cleaning up many different types of wastewaters at secondary and tertiary levels (5). This is an environmentally friendly method of wastewater treatment that does not use hazardous chemicals, and is based on the high productivity and nutrient removal capability of the wetland that relies on its complex ecosystem structure and function. However, CWs ability for AS removal is not yet known. Therefore, a new exploratory research project on this topic is launched for a MSc student.

 

 

References

1. Sang, Z., Jiang, Y., Tsoi, Y.-K.and Leung, K.S.-Y.; Evaluating the environmental impact of artificial sweeteners: A study of their distributions, photodegradation and toxicities; Water Research.

2. Spoelstra, J., Schiff, S.L.and Brown, S.J.; Artificial Sweeteners in a Large Canadian River Reflect Human Consumption in the Watershed; PLoS ONE, (2013); 8: e82706.

3. Loos, R., Carvalho, R., António, D.C., Comero, S., Locoro, G., Tavazzi, S., et al.; EU-wide monitoring survey on emerging polar organic contaminants in wastewater treatment plant effluents; Water Research, (2013); 47: 6475-6487.

4. Matamoros, V., Arias, C., Brix, H.and Bayona, J.M.; Preliminary screening of small-scale domestic wastewater treatment systems for removal of pharmaceutical and personal care products; Water Res., (2009); 43: 55-62.

5. Brix, H.; Use of constructed wetlands in water pollution control: Historical development, present status, and future perspectives; Water Science and Technology, (1994); 30: 209-223.

Kontakt: Pedro Carvalho (pedro.carvalho@bios.au.dk) og Hans Brix (hans.brix@bios.au.dk)