Enhanced Materials for Reactive Barriers

72412S03-I For permeable reactive barriers used to treat contaminated groundwater plumes, most installations use zero-valent iron to reduce halogenated hydrocarbons and oxyanions, such as chromate. In highly oxygenated, carbonate-rich groundwater, the corrosion rate of the iron is accelerated, impacting the longevity of the barrier, and biofilms of autotrophic bacteria may clog the porosity, diverting unremediated water around the barrier. This project will use low cost, granular, chemically amended silicates to create reactive materials that will combine optimal hydrologic characteristics with fine-grained, highly reactive reductants. This family of materials can be engineered to meet a variety of hydrological, groundwater chemistry, and contaminant challenges. Phase I will evaluate the amended silicates with a number of chlorinated hydrocarbons and metals. The testing will include both batch and column tests. The column tests also will provide a simplified evaluation of the changes in hydrological performance over time. Commercial Applications and Other Benefits as described by awardee: The amended silicates should lead to a new family of reactive barrier materials that can be engineered to meet applications that are not addressed by current technologies. This should lead to a wider implementation of the Permeable Reactive Barrier approach to groundwater contamination.