In Situ Sorption and Biodegradation

At a Glance


Contaminants are adsorbed onto activated carbon to halt migration and/or promote subsequent biodegradation


Rapid results (days)

Concentration Level

Addresses low to moderate. Also high concentrations when used with Source Treatment Service

Treatable Contaminants

Treats a wide range of contaminants,
including chlorinated solvents, petroleum, and PFAS


Works in saturated and unsaturated zones

Applications Frequency

Effective after a single application

In Situ Sorption and Biodegradation: An Overview

In situ sorption involves the injection or direct mixing of activated carbon into groundwater and soil for the primary purpose of rapid removal of contaminants from the mobile phase. Sorption via activated carbon is a powerful approach that is most often deployed to achieve complete remediation at sites characterized by low-level, lingering contamination; address back diffusion of contaminants emerging out of low permeability zones; or reach stringent cleanup targets quickly.

To achieve successful results using sorption, REGENESIS has developed technologies using colloidal activated carbon. This is activated carbon that is milled down to 1-2 microns (most granular activated carbon used for remediation is 1,000 microns in size). In the case of PlumeStop® Liquid Activated Carbon, it is suspended in water using advanced polymer chemistry. As a result of their colloidal properties, all REGENESIS activated carbon products, including SourceStop™, PlumeStop and PetroFix Remediation Fluid, distribute in situ under low pressure injection, and achieve very rapid sorption of contaminants.

Once the colloidal activated carbon has been applied in the subsurface, the sorbed contaminants are removed from the mobile phase and can then be treated to promote enhanced biodegradation. When using PlumeStop to treat chlorinated compounds, this strategy is often combined with other technologies such as 3-D Microemulsion® or S-MicroZVI® to promote enhanced biodegradation or chemical reduction of contaminants. When using PlumeStop to treat petroleum hydrocarbons, the activated carbon is often combined with ORC Advanced and/or our ISCO amendments to biodegrade or oxidize contaminants.

In Situ Sorption – A Powerful Standalone Solution for PFAS

In situ sorption can also be used as a stand-alone tactic without biodegrading contaminants. This remediation approach is often strategically selected when dealing with contaminants that do not readily degrade, such as PFAS compounds. Using this approach, PFAS plumes can be sequestered so that they do not impact sensitive receptors.

Because colloidal activated carbon injections represent a small fraction of the cost when compared to alternative carbon pump and treat methods, PlumeStop is often selected in plume areas of PFAS contaminated sites, to remove environmental and human health risk rapidly and cost-effectively.

SourceStop™ is used to target the vadose zone, capillary fringe and groundwater of PFAS source areas to rapidly sorb high levels of PFAS contamination. The sequestration of the PFAS source enhances the natural attenuation of the PFAS source-plume system and reduces the impact on downgradient receptors. More information: Why target PFAS Source Zones?

In Situ Sorption & Bio – Treatment of Petroleum Hydrocarbons

PetroFix Remediation Fluid offers an approach to treat petroleum contaminants quickly and effectively using in situ sorption and biodegradation. PetroFix removes hydrocarbons from the dissolved phase by adsorbing them on to the micron-scale activated carbon particles and then stimulates hydrocarbon biodegradation by adding electron acceptors.

Learn More

REGENESIS welcomes the opportunity to provide you and your team with the tools you need to successfully plan and execute your next sorption/ bioremediation project.

Have questions or want to explore some ideas? Contact Us to get in touch with a local representative.

Typical results using colloidal activated carbon:
Typical results using colloidal activated carbon
Typical results from a REGENESIS in situ sorption and biodegradation project. PFAS and PCE contaminants are reduced to non-detect within days. Dotted lines are upgradient (non-treated) monitoring wells.