Re-Engineering an Artificial Sweetener: Transforming Sucralose Residuals in Water via Advanced Oxidation

Abstract

Sucralose is an artificial sweetener persistently present in wastewater treatment plant effluents and aquatic environments impacted by human activity. It has a potential to accumulate in the water cycle due to its resistance to common water and wastewater treatment processes. This study examined UV/H2O2 advanced oxidation and found that hydroxyl substitution of the chlorine atoms on the sucralose molecule can form a carbohydrate consisting of fructose and sugar alcohol, very similar to environmentally benign sucrose. The second-order reaction rate constant for loss of parent molecule via reaction with hydroxyl radical was determined to be (1.56 ± 0.03)·10(9) M(-1)s(-1). The degradation pathway involves substitution of a single chlorine by a hydroxyl group, with cyclic moiety being a preferential site for initial dechlorination. Further reaction leads to full dechlorination of the molecule, presumably via hydroxyl group substitution as well. No direct photolysis by UV wavelengths above 200 nm was observed. Because of its photostability when exposed to UV wavelengths ≥200 nm, known stability with ozone, limits of quantification by mass spectrometry close to or below environmental concentrations (<5 μg/L) without preconcentration, and otherwise stable nature, sucralose can be used as an in situ hydroxyl radical probe for UV-based and ozone-based AOP processes. As a compound safe for human consumption, sucralose makes a suitable full scale hydroxyl radical probe fit even for drinking water treatment plant applications. Its main drawback as a probe is lack of UV detection and as a result a need for mass spectrometry analysis.

Artificial Sweeteners in Pig Feed: A Worldwide Survey and Case Study in Pig Farms in Tianjin, China

“…The half-life of SUC was up to 124 days in soil, 14 and its biodegradation potential in the aquatic environment was much lower. 7 Meanwhile, it has been reported that the transformation products of ACE can be more toxic than the parent compound. 15−17 to clarify the sources and mass loads of ASs to the environment in order to comprehensively evaluate their ecological risk.…”

An efficient strategy for full mineralization of an azo dye in wastewater: a synergistic combination of solar thermo- and electrochemistry plus photocatalysis

“…Advanced oxidation processes (AOPs) have been successfully applied for the treatment of wastewater [17][18][19][20][21][22] due to the fact that the hydroxyl radical (cOH) generated in AOPs can non-selectively oxidize most organic pollution. [23][24][25][26] However, the application of AOPs is currently not accepted because of expensive investment and operational problems. 3,4,12 Electrochemical technology has been widely investigated for the prevention and remediation of pollution because electrons are clean reagents.…”

Effect of operational and water quality parameters on conventional ozonation and the advanced oxidation process O3/H2O2: Kinetics of micropollutant abatement, transformation product and bromate formation in a surface water

“…where[SUC] 0 and[SUC] are the respective concentrations of sucralose at times and t, and k •OH,SUC is the second-order rate constant for the reaction of sucralose with •OH (k •OH,SUC =1.5-1.6•10 9 )(Keen and Linden 2013, Toth et al 2012).…”