Fate of sucralose during wastewater treatment

Sucralose, a chlorinated carbohydrate, is used as an artificial sweetener in more than 80 countries and in excess of 4,000 products. Thus far, minimal research has been done on the degradation and fate of sucralose in municipal wastewater treatment plants (WWTPs). We collected samples from WWTPs and surface waters in Arizona, United States. The average sucralose concentration of seven WWTP effluents was 2,800 ± 1,000 ng/L. Similarly, surface waters in Arizona contained sucralose at concentrations up to 300 ± 30 ng/L, which corroborates sucralose discharge from WWTPs into the environment. Biological degradation and chemical oxidation processes were evaluated to remove or transform sucralose under potential WWTP operation scenarios. Sucralose did not degrade in aerobic or anaerobic biological reactors, either metabolically or co-metabolically (in the presence of sucrose), after 42-62 days of experiments. Prolonged exposure to ultraviolet radiation did not oxidize sucralose significantly, and chlorine and ozone addition led only to slow sucralose oxidation. Sucralose is not expected to degrade by free chlorine or ozone under typical WWTP operational conditions. Our results suggest that no significant sucralose degradation occurs in WWTPs, that it is present in their effluent waters, and that it reaches environmental water sources. We report for the first time the presence of sucralose in U.S. inland surface waters. Our measurements of sucralose concentrations in WWTP effluents and surface waters also confirm the low degradability of sucralose.