Ozonation for the chemical modification of carbon surfaces in fly ash

Ozone as an oxidant is capable of attacking carbon surfaces in ash in the dry state and at ambient temperature. The effectiveness of ozone for reducing the surfactant adsorptivity of fly ash carbon was demonstrated. Sharp reductions in adsorptivity are observed between 0 and 3 gm-O3/kg-ash. The time-resolved measurements of ozone exit concentration yield traces which vary with conditions exhibiting an initial period of near zero concentration followed by a rapid rise. The mechanism of adsorptivity reduction is reactive modification of carbon surfaces leading to loss of accessible area and changes in surface chemistry.