Performance of artificial sweetener sucralose mineralization via UV/O3 process: Kinetics, toxicity and intermediates

Abstract

Sucralose (SUC) is ubiquitously present in aquatic ecosystems in many parts of the world, owing to its widespread usage and ineffective elimination in wastewater treatment plants. This study investigated the mineralization of SUC in aqueous solution via UV/O3 process and found that SUC can be mineralized efficiently. Effect of several operating parameters like solution pH, O3 concentration, gas flow rate and initial SUC concentration, on TOC removal were explored. Results indicated that the mineralization efficiency of SUC reached almost 90% in 120 min after UV/O3 treatment at neutral pH. The intensity of hydroxyl radicals generated in sole O3 and UV/O3 processes were compared using the fluorescence spectra analysis. Toxicity tests carried out using Daphnia Magna indicated that the UV/O3 process under the used experimental conditions was much more effective in the detoxification of the SUC solution than sole O3 process. The presence of inorganic anion like NO3− exhibited an enhancement on the mineralization rate, while Cl− showed some positive effect at low concentration (1 mM) but inhibited SUC mineralization at higher concentrations (10–200 mM). Finally, the intermediates produced in UV/O3 process were identified by LC-MS analysis and a possible transformation pathway was briefly discussed.