As applied to organic compounds, such as the substances classiﬁed as hazardous wastes or organic sludges, the goal is, in general, to ‘‘mineralize’’ the compound, that is, with carbon dioxide, water, and ions (e.g., Cl), as products. More often, however, the products are compounds that are of lesser molecular weight and possibly more biologically reactive. As an example, ozone is used sometimes as pretreatment for activated sludge treatment. Also, ozone may be used as pretreatment for granular activated carbon (GAC) adsorption, since the resulting lower molecular weight organic molecules may adsorb better. Inorganics, for example, Mn2þ, may be oxidized for removal as oxide particles, for example, MnO2; the intent is to cause the reaction to occur within the treatment plant so that removal takes place, as opposed to within the distribution system.