Definition English:
|
|
It aims at removing settling suspended solids, including that heavy part of the organic matter in suspension, being predominant the physical mechanism of sedimentation and the phase of digestion and stabilization of organic matter settled by the anaerobic pathway. It has the purpose of allowing sewage to follow to the secondary treatment units, or eventually to be sent to the receiving bodies of water, although this is a very special condition, currently difficult to grant in environmental licenses, for failing to comply with the minimum standard legislation. Normally, the removal percentage are of 40 to 70 percent in suspended solids, 25 to 40 percent in BOD and in coliforms in this step. (Free translation from the original: Brasil. FUNASA, 2018) |