Activated Carbon Injection for In-Situ Remediation of Petroleum Hydrocarbons
In-situ remediation of petroleum hydrocarbons (PHCs) using activated carbon (AC) is an emerging technology intended to enhance sorption and biodegradation mechanisms in soil and groundwater systems. The combination of pore types, source material, activation process, and grind of a particular AC influences its efficacy in subsurface remediation. When high-energy injection techniques are employed, installation of carbon-based injectate (CBI) slurries can be conducted in practically any geological setting, from sandy aquifers to low-permeability zones and weathered or fractured rock. Following an adequate CBI installation throughout the target treatment zone or as a permeable reactive barrier, dissolved PHC concentrations are typically observed to rapidly decrease. After a new equilibrium is formed, PHC concentrations typically decrease over time due to the biodegradation. PHC biodegradation, in association with the CBIs, is indicated by the presence of appropriate microbial communities found to grow on AC and is supported by multiple lines of evidence. Further research is encouraged to optimize the biodegradation and regeneration processes of CBI products for in-situ remediation of PHCs.