The UV/peroxymonosulfate process for the mineralization of artificial sweetener sucralose

As one of non-nutritive and commonly used artificial sweeteners, sucralose (SUC) is now ubiquitous and detected in aquatic environments, which has already been recognized as an emerging contaminant. The mineralization of SUC in aqueous media by UV/peroxymonosulfate (PMS) process is investigated herein. Influences of several operating parameters, including pH, oxidant concentration and initial SUC concentration, on SUC mineralization were evaluated. Changing the pH from 3 to 9 had a weak effect on the mineralization of SUC, but the mineralization efficiency dropped sharply at pH 11. Nearly complete mineralization (> 95%) of SUC was achieved after 60 min treatment with 3.780 mM oxidant at neutral pH. Both hydroxyl and sulfate radicals were demonstrated to participate in the oxidation of SUC according to EPR analysis. Under neutral pH condition, the presence of inorganic anion such as Cl-, NO3- or NO2- exhibited a varied inhibition effect on the mineralization efficiency with the order being NO2- > NOT > Cl-. Activated sludge inhibition tests and Daphnia magna acute immobilization tests were performed to evaluate the detoxification efficiency of the UV/PMS process. The by-products formed were identified using LC-MS technique and a possible pathway of SUC degradation was proposed. In summary, the obtained result provides meaningful information on the application of UV/PMS process for the mineralization of SUC or other artificial sweeteners. (C) 2017 Elsevier B.V. All rights reserved.