OXIDATION (OXIDIZING)

(1) A chemical reaction that involves combination with oxygen or the loss of electrons. (2) The process of increasing the positive valence or of decreasing the negative valence of an element or ion. (3) The process by which electrons are removed from atoms or ions, also, reduction. (4) (Water Quality) The addition of oxygen that breaks down organic waste or chemicals such as cyanides, phenols, and organic sulfur compounds in sewage by bacterial and chemical means.