Mineralogical Characteristics of a Durable Manganese Oxide Coating for Environmental Assessment.

Iron oxide minerals have been used in IRIS (Indicator of Reduction In Soils) technology for the last decade to conduct environmental assessment  in wetlands.  This was made possible through a formulation of ferrihydrite and goethite in suspension (ranging between 40% and 60% of each) that could be easily applied to PVC devices and which produced a durable oxide coating.  Wetland and other environmental researchers have been seeking a similar approach using devices coated with manganese oxides, but the search for a durable manganese oxide coating has been elusive. Some researchers have reported using a poorly crystalline birnessite to create such devices, but extraordinary application techniques are required to obtain a durable coating. Recently, a formulation has been developed for an easily applied manganese oxide coating that is also durable. Efforts to document the mineralogical composition and to distinguish changes occurring during synthesis have been both enlightening and perplexing. This paper will report on the mineralogical assessment of these synthetic manganese oxides by XRD and FTIR.