Persulfate Persistence under Thermal Activation Conditions

Abstract

Contaminant destruction with in situ chemical oxidation (ISCO) using persulfate (peroxydisulfate, S2O8(2-)) can be enhanced by activation, which increases the rate of persulfate decomposition to sulfate radicals (SO4*-). This step initiates a chain of radical reactions involving species (including SO4*- and OH*) that oxidize contaminants more rapidly than persulfate does directly. Among current activation methods, thermal activation is the least well studied. Combining new data for environmentally relevant conditions with previously published data, we have computed three sets of Arrhenius parameters (In A and Eact) that describe the rate of persulfate decomposition in homogeneous solutions over a wide range of temperature and pH. The addition of soil increases the decomposition rate of persulfate due to reactions with organic matter and possibly mineral surfaces, but the kinetics are still pseudo-first-order in persulfate and conform to the Arrhenius model. A series of respike experiments with soil at 70 degrees C demonstrate that once the oxidant demand is met, reaction rates return to values near those observed in the homogeneous solution case. However, even after the oxidant demand is met, the relatively short lifetime of the persulfate at elevated temperatures (e.g., >50 degrees C) will limit the delivery time over which persulfate can be effective.

Heterogeneous degradation of refractory pollutants by peroxymonosulfate activated by CoOx-doped ordered mesoporous carbon

“…Therefore, it has the potential of becoming an alternative to the Å OH in wastewater treatment. Generally, peroxymonosulfate (PMS) and persulfate (PS) could be activated by alkaline [3,4], UV [5], heat [6,7] and transition metals [8] , Ce 3+ [8] and Cu + [9], among which Co 2+ has the highest reactivity for PMS. However, the possibly toxic and carcinogenic of Co 2+ limits its practical application in wastewater treatment.…”

Zero-valent iron/persulfate(Fe0/PS) oxidation acetaminophen in water

“…SO 4 Á-can be produced from activation of persulfate (PS) salts by different methods, such as heat (Eq. 1) (Johnson et al 2008;Mora et al 2009), transition metals (Eq. 2) (Anipsitakis and Dionysiou 2004;Tan et al 2012a, b), ultraviolet light (Eq.…”

Response surface methodological approach for optimizing removal of ciprofloxacin from aqueous solution using thermally activated persulfate/aeration systems

“…The pH of the activated Persulfate reaction has a significant effect on the efficiency of CIP removal, although degradation reactions at acidic pH most of the time improve the degradation of the contaminants by forming hydroxyl radicals (Matzek and Carter, 2016). In acidic conditions, auto-catalysis is more likely to happen along with the production of sulfate radicals resulting in higher CIP degradation (Johnson et al, 2008;. A similar finding was also reported by Liang et al (2007), who found out that phosphate and sulfate ions did not inhibit the degradation of aromatic compounds at acidic pH values (Liang et al, 2007).…”