Results document the biodegradation of contaminants from colloidal activated carbon
The following white paper provides an abbreviated overview of two laboratory experiments and a fieldwork demonstration that showed evidence for the biodegradation of contaminants from CAC.
The colloidal activated carbon (CAC) technologies developed by REGENESIS, PetroFix® and PlumeStop®, are often paired with biostimulating electron acceptors or donors to destroy adsorbed contaminants. Early laboratory and field research with our CAC-based technologies has shown the ability of bacteria to fully mineralize adsorbed contaminants and increase in population in the presence of CAC and electron acceptors or donors added to the system even though the CAC has a tiny diameter (1–2 micrometers in diameter). In the case of PetroFix, soluble electron acceptor salts are included to provide nitrate and sulfate, favorable electron acceptors used for biostimulation of hydrocarbon biodegradation.
We hypothesize that biostimulated bacteria form biofilmson the PetroFix or PlumeStop surfaces coating the soil grains, and this close contact allows for contaminant destruction. Concentrated contaminants make for a ready food source for bacteria to grow. Recent work by the University of Waterloo’s Bill McLaren, as presented in a poster at Battelle in 2022, showed that the presence of activated carbon, even small carbon particles, appeared to enhance the rate of anaerobic biodegradation of petroleum hydrocarbons 1.