A heating process for coating crystalline iron oxide on the sand surface was employed to synthesize the iron-coated medium. Iron-coated medium was then utilized to investigate the removal efficiency and mechanisms for lead ions in the presence of humic acid in batch and continuous column tests under various solution pHs. The results indicated iron-coated medium was effective for removing lead solution containing humic acid. The solution pH was found to have a noticeable effect on lead removal. Lead and humic acid would form the insoluble compounds at pH 5.5 to 6.5. Control of solution pH was important, and the following two removal mechanisms of lead were proposed: (1) adsorption of soluble humic acid/lead by surface sites of iron-coated medium, and (2) formation of insoluble lead and humic acid compound.