2. Natural attenuation

Natural attenuation is often presented as the natural capacity of soil and groundwater to degrade pollutants (figure 2 ). Natural biodegradation plays a key role in natural attenuation. This technique is becoming increasingly sophisticated as modelling and investigation techniques evolve.

• Principle

  Sometimes, the total mass and/or concentration of contaminants in soil and groundwater decreases with time and distance from the "source" pollution, without human intervention. This phenomenon is known as natural attenuation.

  The mechanisms behind natural attenuation are numerous:

  • volatilization,

  • abiotic degradation in contact...