3. Reactive barriers

This technique involves installing a permeable barrier from the ground surface to the base of the aquifer to intercept a plume of pollution. The barrier is filled with a reagent enabling the degradation of pollutants dissolved in water. Two types of barrier exist (figure 3 ): conventional permeable barriers and "gate system" barriers.

• Principle

  A reactive barrier is a trench created between the ground surface and the bedrock, oriented perpendicular to the direction of groundwater flow. This trench is completely filled with an active treatment principle, adapted to the type of pollution being treated.

  The pollution plume passing through the active treatment principle is depolluted.

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