Webinar - Thu, Jun 18, 2015 2:00 PM - 3:00 PM EDT
Presented by Dr. Jeremy Birnstingl
Vice President of Environmental Technology
Enhanced biodegradation and monitored natural attenuation (MNA) are effective, widely-used tools for elimination of organic contaminants in groundwater. The timeframe for treatment by these methods is on the order of months to years, during which time the contaminants are biodegraded to non-toxic end products. To significantly improve remediation performance beyond that of traditional enhanced bioremediation, a new in situ technology has been developed that accelerates biodegradation and drastically shortens the timeframes for reaching groundwater treatment goals.
This presentation demonstrates the efficacy of a colloidal in situ remediation agent that consists of highly sorptive activated carbon particles (1-2 microns in size) stabilized to transport widely through an aquifer upon injection. The stabilized colloids deposit on soil surfaces, forming a biomatrix that traps contaminants and accelerates their degradation. Upon reagent injection, target contaminants partition out of the aqueous phase and into the reagent, thereby removing mobile contaminants from the immediate risk pathway. Concentration of the contaminants in this manner results in a direct increase in the overall instantaneous rate of contaminant destruction, given the quasi first-order biodegradation kinetics characteristic of environmental systems. This phenomenon can be doubly important at low contaminant concentrations, which may otherwise prove insufficient to support appreciable growth and activity of a degrading microflora.
Laboratory and field based performance data will be presented. Early field studies (at the time of abstract submission) confirm wide-area dispersion, with order of magnitude reductions (>90%) in dissolved-phase concentration at initial post-application sampling, increasing to two orders of magnitude (>99%) within two months for both chlorinated solvent and hydrocarbon species alike. Laboratory and field data providing confirmation of post-sorption biodegradation will also be presented.
It is anticipated this technology will be of interest to users, prescribers and regulators of bioremediation alike, who may be confronted by the concerns stated above. The technology may be particularly welcomed by those challenged by back-diffusion and performance-tailing issues in dual-porosity or mixed-permeability sites.