Pump and Treat
Pump and treat solutions generally entail the installation of a network of pumps to recover free phase and/or dissolved phase contamination from groundwater. The recovered liquids are then separated and the extracted treated to appropriate standards for release or re-use. GeoRem makes use of a variety of pumps and treatment options. For hydrocarbon contaminants intrinsically safe piston or bladder pumps are used in a variety of configurations. For free phase recovery, self adjusting Specific Gravity intake skimmers are used in conjunction with either a piston or bladder pump depending on site geohydrology.
Organic light non aqueous products are separated using gravity separation or are separated in hydro cyclone systems for more efficient recovery. Remaining dissolved phase contaminants are treated through absorptive media, air stripping or biological reactors.
SVE and Sparging
Soil vapor extraction and sparging is generally used for volatile substances . “Sparging” entails the forced injection of air into the subsurface soil. Volatile contaminants coming into contact with this air evaporate into the air. The partitioned or stripped contaminants are then drawn upward through and collected at the soil vapor extraction (SVE) points. The air is then either released or piped to a SVE treatment system (depending on the level of contamination of the released air, local environmental sensitivity and legislation).
Vaccuum Enhanced Recovery (VER)
Vacuum Enhanced Recovery or Multiphase extraction is used to enhance the recovery of free or dissolved phase contamination and volatile organic compounds in soil gas. A variety of equipment is used to induce the vacuum and transport the liquid phase to the surface. For low vacuum – high volume applications, regenerative blowers are used. For higher vacuum applications liquid ring vacuum pumps are used. VER can be applied on a continuous basis at a site with a fixed or container based system, or event based using our mobile units.
Georem operates several fixed and mobile VER systems throughout Southern Africa. Our mobile trailer based systems can quickly be mobilized to sites for emergency recovery or event based remediation projects.
Naturally occurring organisms in soil and groundwater break down a large range of organic contaminants. Through enhanced bioremediation these organisms are provided with an environment where they can grow and break down contaminants at a higher rate. This is done by the addition of oxygen (either through sparging or oxygen releasing compounds) and nutrients. A variety of other environmental factors may be manipulated to enhance the natural processes breaking down pollutants.
GeoRem has undertaken several bioremediation projects, treating up to 1200 cubic meters of hydrocarbon contaminated soil at a time. Bioremediation can be undertaken in situ or ex situ depending on site conditions and client requirements. Our Microbiologists determine the required amendments and are able to monitor biological action throughout the project, providing feedback on any further amendments or treatment that will be required. Amendments used include microbial and enzyme additives, nutrients, stimulants and oxygen releasing compounds.
Chemical Remediation and ISCO
Chemical remediation involves the addition or injection of specific chemical compounds to break down or neutralize contaminants. A wide variety of processes and reactions are available, depending on contaminant chemistry and receiving environment. These may include: Oxidation / Reduction, Neutralization, Stabilization, Solidification or Mobilization.
GeoRem has undertaken several In Situ Chemical Oxidation (ISCO) projects for the treatment of lighter fraction hydrocarbon products including fuels and solvents.
Monitored Natural Attenuation
A risk based approach may determine that no specific action should be taken. This is often the case where the contaminants can be broken down through natural processes and no significant environmental or health risk exists. Contaminant concentrations are then simply monitored regularly to ensure that natural attenuation is taking place. This option is re-evaluated on a constant basis and further action is taken if the monitoring results are not satisfactory.