The present invention provides an advanced oxidation system for the treatment of offensive odors and toxic substances of foundry waste, e.g., sand, and a treatment method using the same, which can effectively remove offensive odors and toxic substances produced during a sand reclamation process for reclamation of foundry waste. For this purpose, an advanced oxidation system for the treatment of offensive odors and toxic substances of foundry waste by implementing a spray device for spraying a diluted solution of hydrogen peroxide onto foundry waste a stirring device for mixing the foundry waste with the diluted solution of hydrogen peroxide sprayed thereto an ultraviolet irradiation device for activating the hydrogen peroxide mixed with the foundry waste to produce radicals and a local exhaust system for collecting dust generated when the foundry waste is mixed with the hydrogen peroxide by the stirring device.
