6. Biostimulation

Biostimulation involves using chemical or biochemical additives to stimulate the degradation of pollutants by indigenous micro-organisms (figure 6 ). Biostimulation is the basis of any biological technique that does not require the addition of specific, selected micro-organisms. It is one of the most widely used techniques, due to the very low cost of implementation.

• Metabolism and co-metabolism

  Biological treatment, whether of excavated soil or of soil still in place, involves using micro-organisms to transform toxic chemical substances into non-toxic ones. The micro-organisms used are often bacteria, although fungi play a role in some ex situ treatments.

  • Metabolism of pollutants...