The presence of low-molecular-weight organic acids increased desorption of adsorbed F and their effects on F desorption were in a decreasing order of oxalic acid > malonic acid > citric acid > malic acid. The desorption of F increased with the concentration of organic acids and pH. Organic acids enhanced F desorption through two mechanisms; (1) competition for F adsorption sites and (2) dissolution of aluminum oxides. Based on short-term reactions, the former is the main one.