METHOD FOR CLEANING SOIL AND/OR GROUND WATER

PROBLEM TO BE SOLVED: To decompose pollutants efficiently without blocking an injection well and a ground-water channel by adding a chelating agent and an oxidizing agent into soil and/or ground water polluted with oxidation-reactive organic compounds. SOLUTION: When soil and ground water polluted with oxidizable organic compounds are purified by being added with an oxidizing agent, a chelating agent is added. As a method for adding the chelating agent and the oxidizing agent, a well is formed to reach the depth where the pollutants exist, and the aqueous solutions of the agents are injected with the use of the well. The chelating agent and the oxidizing are injected simultaneously, or when they are injected separately, the chelating agent is injected first. Citric acid, gluconic acid, and others are preferable as the chelating agent. As the oxidizing agent, hydrogen peroxide and a permanganate are preferable. In this way, the generation of water-insoluble substances such as iron oxyhydroxide generated by the oxidation of a divalent iron ion is controlled. troubles such as blocking are prevented, and the treatment can be carried out stably and efficiently.