Water treating method and arrangement integrating a fixed-bacteria biological treatment and flocculation-decantation

摘要

The biological and flocculation-decantation treatment of water comprises transferring biologically treated flow to a mixing area (2) and a decantation area, extracting granulated material from decantation sludges, recycling entities in the mixing area, and removing the decantation sludges separated from the granulated material. The water treatment is carried out by flocculation-decantation using ballasted flocs. A bio-cleaned flow is obtained at the end of the treatment, contains less than 2 mg/l of suspended matters. The biological and flocculation-decantation treatment of water comprises transferring biologically treated flow to a mixing area (2) and a decantation area, extracting granulated material from decantation sludges, recycling entities in the mixing area, and removing the decantation sludges separated from the granulated material. The water treatment is carried out by flocculation-decantation using ballasted flocs. A bio-cleaned flow is obtained at the end of the treatment, contains less than 2 mg/l of suspended matters. Velocity gradient of the transformation of biologically treated flow is 10-1000 s -1. An insoluble granulated material is injected into the mixing area in which the material is denser than water. The suspended matters are aggregated around the granulated material particles. The separated decantation muds of granulated material are recycled towards the mixing area. The biological treatment of water is carried out by fixed biomass comprises bacterial bed, mobile bed bio reactor, biofilters and biological discs. The biomass is fixed on a fixed support of marbles, pebbles, plates, tapes, pall ring, raschig ring, disc/drums, or in a suspension of the water treatment. The concentration of the biologically treated flow in the suspended matter (less than 3 minutes) is obtained with an exit of the biological treatment, which is lower than 1 g/l. A flocculating reactant is injected into the mixing area. Coagulant reactant is injected in an upstream of the flocculating reactant. An independent claim is included for a water treatment device.