Environment

Soil Decontamination

DISC Environmental possesses knowledge covering several soil decontamination techniques.

This is elaborated below.

Biotechnological Soil Decontamination

This method is faster, more economical and usable in many instances. Bio remediation has proven to be fast and effective in clay ground.
A decontamination plan is necessary depending on the situation. A number of techniques have been developed to decontaminate organic pollutions biologically. In nearly all cases this method is equally fast as soil decontamination that uses excavation, but is more cost effective and has a high environmental efficiency.

Natural Attenuation

Organic pollutions are decomposed even under anaerobic conditions in many cases. The risk of spreading appears to be low in most occasions after monitoring and that there does not appear to be a pressing case of soil decontamination. Soil pollution on industrial estates often does not present direct risks for mankind and the environment. In these cases one can opt to monitor the biological decomposition and the dispersal only. Natural attenuation limits the biological decomposition to monitoring only. The decontamination will be decomposed over a period of 5 to 30 years, depending on the concentration and the situation.

Biological restoration using mini-purification

In the event of a large pollution with high concentrations than can this situation be considered as an urgent case of soil pollution after measuring or in certain instances. A biological mini-purification can offer a solution in many instances. The mini-purification unit can be installed for a relatively low investment. The biologically active effluent can be injected into the ground to assist there the biological decomposition of the pollution. Depending on the local legislation, this process does not even need a permission to discharge into the drains. The pollution is decomposed within a period of 3 to 10 years.

Bio-injection

Bio-injection is a newly developed technique to very effectively biological treatment of soil that is polluted with organic compounds like mineral oils and aromatics. The in-situ method is very cost effective, has a short project period of a few months and a very high environmental efficiency. This technique has been especially developed for homogeneous, well drainable sandy soil. Under certain conditions this technique can also be applied to less well drainable and non-homogeneous types of soil. This technique cannot be applied to homogeneous clay soil.  

Principle

The principle of bio-injection is very simple. Depending on the extent of pollution and the structure of the soil, firstly filters are positioned at various depths. Nutrients and a mass of bacteria are injected with filter tubes in the top layer and in the zone below the groundwater level. The mass of bacteria comes from a local waste water treatment plant. This is followed by the introduction of oxygen into the filter tubes. The biological decomposition process will proceed very quickly as the soil is saturated with mass of bacteria. The oxygen will be injected into the ground over a period of several months until the decontamination process has been completed.

Advantages

• Rapid reduction of the pollution
• Simple and low cost technique
• Reliable
• Poor filterable soil can also be treated
• Installations and buildings above ground do not need to be (temporarily) dismantled

Extensive and Intensive land farming

It has been demonstrated recently that even clay soil contaminated with organic pollution, can be decontaminated very effectively with biological techniques. This can be achieved with extensive as well as intensive land farming.

Extensive land farming

Pollution is removed by excavation and ground water decontamination. The soil is hauled away and cleansed against reasonable cost. The soil is mixed with compost and mass of bacteria, and deposited on a layer of compost as a top layer. Grass is sown and after ½ - 2 years the contamination of the soil is reduced to an acceptable level. The soil has been made suitable for every use. Continued decontamination will only further improve the quality of the soil.

Intensive land farming

Pollution is removed by excavation and ground water decontamination. Also in this process, the soil is hauled away and cleansed against reasonable cost. The soil is mixed with compost and mass of bacteria, and deposited on a layer of compost as a top layer. This is followed by intensively aerating the soil using flexible hoses and a compressor. The soil has been decontaminated to an acceptable level in 1 to 4 months. The soil has been made suitable for every use. Continued decontamination will only further improve the quality of the soil.

We request you to contact us for specific information concerning our services in this field.