Oxidation. Oxidation, in waste remediation, refers to the movement of a contaminant to a more oxidized or more environmentally benign state. Oxidation technologies form part of the many treatment alternatives that have the capability to reduce or eliminate both the volume and toxicity of contaminants. Three technologies are summarized that utilize oxidation as a treatment method: 1) chlorine dioxide and hydrogen peroxide additives, 2) photolysis, and 3) reductive dechlorination.