Remediation

Business Lines:

Antea Group and its subsidiary HMVT (www.hmvt.nl) have a broad experience, professional knowledge, a pragmatic attitude and the combination of advice and execution to come to a cost-effective solution.

Since 1990 new methods and innovative techniques were tested and introduced for the remediation of polluted soil (in situ techniques such as the use of bacteria so nature can do the work, two phase extraction, iSOC, Ozone and Fenton's Reagent).

Anteagroup/HMVT is an all-round in-situ remediator and utilizes the following treatment principles:

  • Removal of pollutants via the groundwater;
  • Removal of pollutants via the soil vapor;
  • Biological - aimed at biological degradation of pollutants in the soil;
  • Chemical - aimed at chemical degradation of pollutants in the soil;

If necessary we are able to apply conventional techniques. Certainly on the surface and in core areas it can sometimes be more efficient to excavate contaminated soil and take it away. Frequently this is done in combination with an additional in-situ technique for the subsoil and the plume area.

For extractive, biological as well as chemical orientated sanitations we often uses the same basic in-situ soil sanitation techniques:

Soil vapor extraction
Soil vapor extraction is used to evaporate volatile pollutants out of the soil, another method is to inject oxygen into the soil.

The oxygen accelerates the degradation of pollution in the zone above the groundwater table. This method is called bio venting: aerobic biodegradation in the unsaturated zone. Frequently, nutrients are also injected to give biology a helping hand. 

Air sparging 
As with soil vapor extraction air sparging is used to evaporate volatile pollutants out of the soil - but from the saturated zone. In addition, air sparging is also used to inject oxygen into the saturated zone to enhance the natural degradation process. Air sparging is also used in chemical oxidation projects to distribute the oxidants through the soil.

Ground water  extraction
Ground water extraction is used to extract polluted ground water, this technique is also an aid to distribute injected nutrients or oxidants. We use different types of ground water extraction techniques, varying from deep wells, vacuum extraction or multi phase extraction.

Multi phase extraction is specially aimed on the interface of water table and soil vapor. Multi phase extraction is a proven technology to remove free floating products.

Infiltration
Techniques in which nutrients, carbon sources or chemical additions are injected have been particularly increasing during recent years.

To stimulate the natural biodegradation of pollutants, we often infiltrate dissolved nutrients or carbon sources. If possible, we use extracted and purified groundwater for this. The additions are harmless for the environment and give the biology a helping hand in the soil.
These remediation techniques offer an affordable alternative, especially in plume areas.
Information about a specific infiltration technique, the ENNA concept, can be found at www.ennasanering.nl.

Chemical oxidation
A technique that has proven itself during recent years is chemical oxidation. This involves infiltrating oxidants into the polluted parcel of soil. This technique is especially useful in core areas with high concentrations of pollutants.

List of techniques
Using our basics methods, we can carry out a range of in-situ techniques. These techniques have proved themselves in practice and are accepted and recommended by authorities and soil agencies.

Purification plants are often an essential component of the soil remediation. For this reason, our purification units are closely interwoven with the soil remediation techniques that we apply.

We design and construct our cleansing and purification plants ourselves. In doing so, we use existing components and items of equipment. In this way, each soil remediation has its own tailor-made plant and equipment. The following purification units are part of our standard range.
Water purification units:

  • oil/water separator 
  • plate aerators and stripping towers 
  • waterside active carbon filters 
  • bio-rotors and bio-reactors 
  • sand active carbon filtration 
  • iron removal plants 
  • ion exchange units 
  • physical-chemical units 
  • air purification units 
  • bio-filtration 
  • (regenerative) active carbon filtration 
  • catalytic oxidation

 

We are not only an all round in-situ soil remediation company, but we are also specialized in Management & Aftercare
Since the 1990s, we have gained extensive experience in relieving its customers’ concerns and implementing turnkey or performance contracts. Assessing the remediation risks correctly is extremely important. To anticipate customer needs even better, we have developed this product. 
 
Complex and extensive in-situ soil remediation
We have extensive experience with complex remediation, remediation where, for example, there is a great deal of pollution or where there is actually exotic pollution. This also applies to remediation in which several techniques must be combined, or where there is social complexity, for example with people living in the neighbourhood in inner-city areas.

Smart (on-line) remediation
In-situ remediation is becoming increasingly 'smarter'. Simply extracting large flows has never seemed very efficient. Precisely by cleansing small flows in turn through filters, frequently provides a better result.

Catalytic & Thermal Oxidation of Soil Vapor
In projects with a high intensity of pollution, the treatment of fumes being released is frequently a very expensive problem. Use of a biological filter is unsuitable in such cases; because the fumes are simply too toxic for the microorganisms.

Soil Vapor Survey
Since our establishment, we have advised consulting firms about the possibilities of in-situ remediation. We frequently become involved with the soil survey for conducting a soil vapor investigation, or the implementation of a pilot test to check the feasibility of a specific remediation technique.

We want to carry out our remediation as inventively and efficiently as possible. We also believe that the social and other costs of a soil remediation must not be too high. For this reason we strive for practically attainable cleansing goals, and we try to perform our remediation with the minimum possible resources and energy consumption.

Innovation & Product Development
Innovation is extremely important to us. In the technical area, we continually try to improve our existing cleansing and purification processes. In addition, we are always searching for new, suitable techniques to take on our remediation even more efficiently. We also develop new techniques ourselves. We do this together with students, other consulting firms or research institutes.

We have done remediation projects in industrial areas / brown fields, harbours, refineries, gas stations, fuel storage areas, railways, pipelines, oil & gas production and treatment facilities, former gasworks sites, laundries, landfill sites, water sediments with all kind of pollutants, such as:

  • Mineral Oil
  • Aromatic Hydrocarbons (Benzene, Toluene, Ethylbenzene, Xylenes)
  • Gas Condensates
  • Naphta
  • Styrene
  • Chlorinated Hydrocarbons
  • PAH
  • Toluene sufonamide
  • Heavy Metals
  • PCB/OCB
  • Asbestos