Kinetic modeling of powdered activated carbon ozonation of sulfamethoxazole in water

Ozonation of sulfamethoxazole promoted by a powder activated carbon (PAC) of neutral nature has been studied for mechanistic and kinetic purposes. The main advantage of using powder activated carbon was the removal of both liquid–solid and internal diffusion mass transfer resistances. In addition, at the operational conditions applied the influence of the gas–liquid mass transfer was eliminated. As a result, in the absence of any physical mass transfer resistances, a mechanism that involves both homogenous and heterogeneous reactions for the mineralization of the water matrix was proposed and a mathematical kinetic model was obtained from the corresponding mass balances of main species present. In order to properly solve the kinetic model a term indicative of the changing nature of the water matrix was introduced. In that way the promoting or non-promoting character of water constituents was considered in the mechanism.