Biofilm Barrier for In Situ Groundwater Denitrification

Biofilm barriers are a promising new technology for the containment and remediation of groundwater contaminated with nitrate and other pollutants. These barriers are formed by subsurface injection of bacteria and/or nutrient solutions to stimulate the growth of bacteria that produce extracellular polymeric substances (EPS) and also may degrade contaminants. The engineered accumulation of biomass and EPS in the subsurface is used to control groundwater flow and enhance treatment strategies. For example, a biofilm barrier can be used as a "funnel" to channel contaminated groundwater to a treatment zone. Unlike many other barrier technologies, biofilm barriers cause minimal surface disturbance and have no obvious depth limitation. MSE Technology Applications, Inc., along with collaborators at the Center for Biofilm Engineering, Montana State University, has successfully demonstrated the effectiveness of biofilm barriers in systems ranging from small laboratory models to a large-scale test cell. This test cell contained a 180-foot long by 20-foot deep biofilm barrier that was used as part of Phase I SBIR research to show complete denitrification of a nitrate plume. The next logical step in the development of this technology is field-scale research. The primary objectives of this research are to evaluate, under actual field conditions, the ability to control groundwater flow using a biofilm barrier system and to determine the effectiveness of the biofilm barrier to remove nitrate from groundwater. Following successful completion of this field demonstration, MSE will market the technology for the cleanup of nitrate-contaminated groundwater.