Zero-valent iron for removal of inorganic contaminants from low pH water

The coal mine waste dumps located in the southern provinces of Poland pollute groundwater with metals. As a result of batch experiments presented in the paper, it can be said that it is possible to remove chromium and copper from the groundwater (which is affected by acid mine drainage, thus characterized by low pH) with the use of zero-valent iron in permeable reactive barrier technology. The contaminants are removed from the aquifer by the flow of groundwater through a reactive barrier filled with a special reactive material. Rapid metal removal likely occurred due to the reduction and the precipitation/co-precipitation and/or due to the adsorption onto the iron metal surface or/and onto the iron corrosion products. In accordance with the research it has also been found that in more alkaline environment, the oxidation of Fe(0) proceeds slower. A rapid decrease of the redox potential as well as the increases of pH have also been observed in the batch tests when the dose of Fe(0) in solutions increased.