Subtleties of Iron and Manganese Removal From Groundwater

Abstract

This month's question concerns the treatment of iron and manganese. In general, it involves high dosages of chlorine and a reactive filter medium. Various treatment schemes are discussed and include: permanganate with greensand or other oxide‐coated filter media; iron with free chlorine in an oxidation scheme; alum coagulant; using more than one oxidant requires careful sequencing of chemicals; special consideration is required for the concentration and type of dissolved organic carbon (DOC) present, oxidant demand of the water, and the removal of colloidal solids through coagulation. The article urges the use of pilot or full‐scale testing to determine the appropriate treatment strategy. AWWA resources are listed for further information.