Heated Water Recirculation for Biodegradation Enhancement

This technical report presents the theoretical basis and practical implementation of heated water recirculation to enhance both abiotic and biotic degradation of environmental contaminants, specifically at a Formerly Used Defense Site (FUDS) in Nebraska. The document outlines the methodology employed to increase subsurface temperatures, thereby accelerating biodegradation rates of trichloroethene (TCE) in groundwater. It details the design and optimization of the groundwater recirculation system, including the use of USGS and USEPA models to evaluate the effectiveness of heated water injection and extraction strategies. The report also discusses the monitoring processes, which included groundwater sampling and temperature measurements, to assess the impact of the treatment. Results indicate that the recirculation of heated groundwater significantly increased subsurface temperatures and reduced TCE concentrations by over 90%. Additionally, the report highlights the observed increase in bacterial populations in treated areas, suggesting the involvement of both abiotic and biotic degradation processes.