Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.cej.2023.147170
Licence creative commons licence
Title (Primary) Oxidation of organic pollutants over MnO2 in cold water assisted by peroxydisulfate
Author Salvestrini, S.; Fenti, A.; Qian, L.; Kopinke, F.-D.
Source Titel Chemical Engineering Journal
Year 2024
Department TECH
Volume 479
Page From art. 147170
Language englisch
Topic T7 Bioeconomy
Keywords MnO2; Peroxydisulfate; Heterogeneous catalysis; 4-Hydroxybenzoic acid; Perfluorooctanoic acid; In situ groundwater treatment
Abstract MnO2 can be used in advanced oxidation processes to activate peroxydisulfate (PS) and generate reactive species such as sulfate radicals (SO4•-), hydroxyl radicals (OH) and singlet oxygen (1O2) for the abatement of organic water contaminants. Alternatively, one can use MnO2 as particulate oxidant which, in contrast to PS, is active already at low temperatures. This low-temperature activity is particularly attractive for in situ groundwater treatment. The roles of PS and MnO2 as oxidant and catalyst, respectively, may invert: MnO2 functions as primary oxidant and PS works as re-oxidant of reduced Mn-oxides. In this way, the limited oxidation capacity of particulate MnO2 can be overcome. So far, such reaction systems have not been extensively explored.
In the present study, the degradation of 4-hydroxybenzoic acid (HBA) by PS + MnO2 was studied under various experimental conditions, by varying reaction temperature (15–45 °C), reagent concentrations, and water matrix. Both PS and MnO2 alone have the ability to effect the oxidation of HBA. In the co-presence of PS and MnO2, a fast removal of HBA from water was achieved even at low temperatures (half-life of HBA about 0.5 h with 2.4 g/L MnO2 at 25 °C), owing to a synergic effect between the two components.Quenching experiments indicate that the primary HBA oxidation step is a heterogeneous reaction on the MnO2 surface rather than a homogeneous reaction driven by SO4•- or 1O2, as frequently reported in literature. This is in line with results from the PS driven oxidation of perfluorooctanoic acid which is not significantly enhanced in the presence of MnO2.
Persistent UFZ Identifier
Salvestrini, S., Fenti, A., Qian, L., Kopinke, F.-D. (2024):
Oxidation of organic pollutants over MnO2 in cold water assisted by peroxydisulfate
Chem. Eng. J. 479 , art. 147170 10.1016/j.cej.2023.147170