extensive solutionsReading time:
Extensive solutions are purification processes that have a low concentration of purifying organisms. As a rule, they do not recycle any bacterial liquor except in certain cases where an algae-bacteria product recirculation system is applied. We can distinguish between suspended growth (lagooning) and attached growth (purification through the soil) techniques.
These techniques apply complex natural auto-purification phenomena that are dependant on climatic conditions and whose balance is not always easily controlled.
These extensive solutions require a large site footprint and site properties that combine a certain number of feasibility criteria. Implementation is of the essence and purification performances will partly depend on the quality of this implementation.
These systems do not usually require much in the way of electro-mechanical equipment and are known for their sturdiness and for their ability to adapt to fluctuating organic and hydraulic loadings. However, means for intervening on the process remain limited except in the case of aerated lagooning.