Our methods
The following are some of the methods we use. As contamination is complex, we usually apply various methods in series or sequence to obtain the optimum outcome. Techniques are in alphabetical order.
Air Sparging
Removal of dissolved gas from extracted groundwater by sparging it with air or oxygen-enriched air. This has the added benefit of encouraging biodegradation of the contaminant through naturally-occurring micro-organisms.
Air Stripping
Removal of dissolved volatile organic compounds (VOC) from groundwater, by sheering the liquid across a predetermined counter current air flow with a precise flow rate. Air stripping can utilize packed tower strippers or a simpler system of a tower filled with high surface area packing.
Bio Filtration
Extraction of contaminants from vapour or liquid by passing them through a membrane impregnated with micro-organisms, which extracts and breaks down specific compounds.
Bio-remediation Infrastructure
Use of naturally-occurring bacteria to consume contaminants in groundwater, often in conjunction with a pump-and-treat system. The groundwater is recycled many times to encourage oxygenation and bacteria growth, with care taken to avoid excess bacterial build-up or colony crashes.
Bio-Piles
Reduction of contamination in soil by extracting adsorbed Volatile Organic Compounds (VOCs), to enable natural or seeded biological degradation. Bio-piles are active soil plots, with constantly controlled air flow rates, water and exposure to the elements, enabling significantly shorter treatment times than soil farming (below).
Catalytic and Thermal Oxidation
Removal of contaminants from groundwater by catalyzing conversion into relatively harmless components like carbon dioxide, water vapour and salt water. Using precious metal catalysts, 95-99% of these particles can be removed.
In situ oxidation
Removal of soil and groundwater contaminants through injection of strong oxidants such as hydrogen peroxide, ozone gas, potassium permanganate or persulfates. Oxygen-enriched air or ambient gas ambient air injection are economical alternatives.
Multiphase Vacuum Extraction (MPVE)
Also known as Multi Phase Extraction (MPE), removal of water, phase separate hydrocarbons (PSH) and soil vapour from soil and groundwater. Usually combined with Soil Vapour Extraction (SVE) and Pump & Treat Systems.
Pump and Treat
Extraction of groundwater from a formation and removal of contamination by physo-chemical means. The process can include a series of vessels containing and adsorbent material like activated carbon and zeolite. Flocculants, dissolved air floatation (DAF) chambers, sand filters and other strategies may also be used to remove the target chemicals.
Soil Farming
Reduction of VOC contamination, by increasing contact time with air to accelerate and enhance natural biological degradation in soil. Soil is laid in wind rows and regularly turned for up to several weeks. These are passive soil plots, with air flow, water and exposure to the elements, weather and other factors not easily controlled. Treatment time is therefore longer than for bio-piles where these factors are tightly controlled.
Soil Vapour Extraction (SVE)
Removal of vapour from soil by inducing a flow of air within a geological formation with an above-ground blower or pump/ blower combination. The induced airflow provides a carrier that enhances the removal of Non Aqueous Phase Liquids (NAPL) and provides oxygen to enhance natural aerobic biodegradation.
