Abstract: In accordance with the principles of the present invention, fluid is treated with MCM-41 amended with a metallic reducing agent. The iron undergoes anaerobic corrosion and produces hydrogen gas. The hydrogen gas is used at the MCM-41 to carry out dehalogenation reactions. The body of metal containing MCM-41 amended with a metallic reducing agent can be much thinner than conventional bodies of metal and therefore easier to install. In one embodiment the treated fluid can be water while in another embodiment the treated fluid can be a gas. A body of metal containing MCM-41 amended with a metallic reducing agent can be placed below the ground surface to treat contaminated groundwater in-situ. For pumped fluid, in one embodiment treatment units as small in size as a water softener can allow for treatment of relatively high flow rates of pumped contaminated fluid.