Method for treating used electroplating solution

A method for treating a used electroplating solution is disclosed. By using an ozone/ultraviolet (UV)/additive system to treat the organic substances in the used electroplating solution, the organic substances can be decomposed and thus removed by the oxidation of ozone, which is a strong oxidant. The ozone may be combined with UV and additive so as to catalytically oxidize the organic substances. The additive may also absorb the residual organic substances. The used additive, which absorbs the residual organic substances, may be further removed by filtration. The removal efficiency of organic substances by the combined ozone, UV and additive can exceed 90%. The used electroplating solution, after being treated by this method and adjusted by the addition of some fresh organic substances to fit the recipe, can then be reutilized again. By doing this, one can achieve the goal for the removal of the organic wastes as well as the recovery and reutilization of the resources.