Evaluating the environmental impact of artificial sweeteners: A study of their distributions, photodegradation and toxicities

Ziye Sang, Yanan Jiang, Yeuk Ki Tsoi, Kelvin S Y LEUNG*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

92 Citations (Scopus)

Abstract

While having a long tradition as safe food additives, artificial sweeteners are a newly recognized class of environmental contaminants due to their extreme persistence and ubiquitous occurrence in various aquatic ecosystems. Resistant to wastewater treatment processes, they are continuously introduced into the water environments. To date however, their environmental behavior, fate as well as long term ecotoxicological contributions in our water resources still remain largely unknown. As a first step in the comprehensive study of artificial sweeteners, this work elucidates the geographical/seasonal/hydrological interactions of acesulfame, cyclamate, saccharin and sucralose in an open coast system at an estuarine/marine junction. Higher occurrence of acesulfame (seasonal average: 0.22μgL-1) and sucralose (0.05μgL-1) was found in summer while saccharin (0.11μgL-1) and cyclamate (0.10μgL-1) were predominantly detected in winter. Seasonal observations of the four sweeteners suggest strong connections with the variable chemical resistance among different sweeteners. Our photodegradation investigation further projected the potential impact of persistent acesulfame and sucralose compounds under prolonged exposure to intensive solar irradiation. Real-time observation by UPLC-ESI/MS of the degradation profile in both sweeteners illustrated that formation of new photo by-products under prolonged UV irradiation is highly viable. Interestingly, two groups of kinetically behaved photodegradates were identified for acesulfame, one of which was at least six times more persistent than the parent compound. For the first time, acute toxicity for the degradates of both sweeteners were arbitrarily measured, revealing photo-enhancement factors of 575 and 17.1 for acesulfame and sucralose, respectively. Direct comparison of photodegradation results suggests that the phototoxicity of acesulfame degradation products may impact aquatic ecosystems. In an attempt to neutralize this prolonged environmental threat, the feasibility of UV/TiO2 as an effective mineralization process in wastewater treatment was evaluated for both sweeteners. Under an environmental and technical relevant condition, a >84% removal rate recorded within 30min and complete photomineralization was achieved within 2h and delivering the best cost efficiency comparing to existing removal methods. A compilation of distribution, degradation, toxicity and attenuation results presented in this paper will go through critical discussions to explore some current issues and to pinpoint solutions for a better control in the emergent contamination of artificial sweeteners.

Original languageEnglish
Pages (from-to)260-274
Number of pages15
JournalWater Research
Volume52
DOIs
Publication statusPublished - 1 Apr 2014

Scopus Subject Areas

  • Ecological Modelling
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution

User-Defined Keywords

  • Artificial sweetener
  • Emerging environmental contaminant
  • Photodegradation
  • Phototoxicity
  • Wastewater treatment

Fingerprint

Dive into the research topics of 'Evaluating the environmental impact of artificial sweeteners: A study of their distributions, photodegradation and toxicities'. Together they form a unique fingerprint.

Cite this