Zero-valence iron activated persulfate sustained-release candle for in-situ oxidative remediation of underground water

The invention discloses a zero-valence iron activated persulfate sustained-release candle for in-situ oxidative remediation of underground water. The candle is cylindrical and comprises an oxidant, an activating agent, a dispersing agent and a coagulator and is formed by sequentially melting and connecting an oxidant sustained-release layer and an activating agent sustained-release layer, wherein the oxidant is persulfate, and the activating agent comprises zero-valence iron powder and high-iron fly ash and has a zero-valence iron and magnetic self-activating function. The zero-valence iron activated persulfate sustained-release candle has the advantages that the candle can be self-activated when making contact with water, has controllable sulfate radical sustained-release capability, and is applicable to the in-situ oxidative remediation of the underground water of different types of organic pollution sites.