Decomposition of hydrogen peroxide in the presence of activated carbons with different characteristics

Abstract

BACKGROUND: Catalytic ozonation promoted by activated carbon is a promising advanced oxidation process used in water treatment. Hydrogen peroxide generated as a by-product from the reaction of ozone with some surface groups on the activated carbon or from the oxidation of some organic compounds present in the water being treated seems to play a key role in the catalytic ozonation process. Hydrogen peroxide decomposition promoted by two granular activated carbons (GAC) of different characteristics (Hydraffin P110 and Chemviron SSP-4) has been studied in a batch reactor. The operating variables investigated were the stirring speed, temperature, pH and particle size. Also, the influence of metals on the GAC surface, that can catalyze hydrogen peroxide decomposition, was observed.

The role of activated carbons functionalized with thiol and sulfonic acid groups in catalytic wet peroxide oxidation

“…It is observed that the best results are obtained under acidic pH, the pollutant removal decreasing with the increase of the reaction pH. This behavior is explained by the reduced adsorption of C2R when pH increases (adsorption is favoured when pH < PZC, as explained previously) and by the increased decomposition of hydrogen peroxide to non-reactive oxygen molecules, due to lower stability of hydrogen peroxide in alkaline media [33]. As evidenced from the results obtained in this work and from the proposed mechanism, the degradation of organic pollutants by CWPO over activated carbons is a complex issue, since it involves competitive adsorption of pollutants and hydrogen peroxide on the catalyst surface, decomposition of hydrogen peroxide molecules on the catalyst surface to yield reactive hydroxyl radicals, reaction of the hydroxyl radicals with either the pollutant molecules or other hydrogen peroxide molecules, among other processes.…”

Hybrid magnetic graphitic nanocomposites towards catalytic wet peroxide oxidation of the liquid effluent from a mechanical biological treatment plant for municipal solid waste

“…4a The participation of HO • radicals in the process was indirectly evaluated. For that purpose, tert-butanol (tBuOH) − a strong HO • scavenger [25], was added before a CWPO experiment performed in the presence of CoFe 2 O 4 /MGNC. When the CWPO runs performed in the presence and absence of tBuOH are compared (cf.…”

“…For that purpose, the CoFe 2 O 4 /MGNC catalyst was removed after 30 min of reaction at the reaction temperature (80 • C), and the reaction solution was allowed to progress further. The participation of the HO • radicals in the CWPO process was indirectly shown by adding tert-butanol (tBuOH) -a strong HO • scavenger [25].…”

Fe/Nanoporous Carbon Catalysts Obtained from Molasses for the Limonene Oxidation Process

“…Taking into account the literature data [37][38][39][40], the mechanism of the ·OH and ·OOH radicals formation over the NPC material obtained from molasses for the active carbon (AC) can be proposed.…”