Monopersulfate in water treatment: Kinetics

• Published in: Journal of hazardous materials 2022-05, Vol.430, p.128383-128383, Article 128383
• Main Author: Rivas, F. Javier
• Format: Article
• Language: English
• Subjects: Hydroxyl Radical; Kinetics; Kinetics modelling; organic matter; Oxidation-Reduction; Peroxides; Peroxymonosulfate; Radical mechanism; reaction mechanisms; Sulfates; ultraviolet radiation; Variables influence; Water; Water Pollutants, Chemical - analysis; Water Purification - methods; water treatment
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2022.128383

The kinetics of monopersulfate based systems in the elimination of potential harmful contaminants has been assessed from a theoretical point of view. A detailed reaction mechanism sustained in the generation of radicals (mainly hydroxyl and sulfate), propagation and termination stages has been proposed. The system of first order differential equations derived has numerically been solved. The effect of main influencing parameters such as contaminant and peroxymonosulfate initial concentrations, intermediate generation, presence of organic matter, role played by anions, has been theoretically obtained. Discussion of simulated results has been accomplished by comparison with experimental data found in the literature. At the sight of the theoretical and empirical data, use of simplistic pseudo first order kinetics is discouraged. Despite considering a significant number of elemental reactions, modelling of the system reveals that a high fraction of them can be neglected due to their insignificant role played in the mechanism. The entire mechanism has been tested when peroxymonosulfate has been activated by UV radiation, although results can be fairly extrapolated to other activation strategies. Finally, a generic model capable of accounting for the effect of a diversity of parameters is proposed. No theoretical background is behind the model, however the generic model clearly improves the results obtained by simple first order kinetics. [Display omitted] •A detailed radical mechanism of peroxymonosulfate decomposition is applied.•Some of the elemental reactions used can be neglected due to low/null influence.•Use of pseudofirst order kinetics is an oversimplified strategy in most cases.•Influence of main operating variables can be theoretically modelled.•A generic model is proposed to simulate peroxymonosulfate based systems.