Processes I.W.W.

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INDUSTRIAL WASTE WATER (I.W.W.)

Tertiary Treatments - Elimination of nitrogen and phosphorus pollution load

Removal by biological process

In a biological treatment process nitrogen and phosphorus are assimilated in the bacteria-cell and eliminated simultaneously with the excess sludge.

If the nitrogen-load exceeds the assimilation capacities of the excess sludge, supplementary nitrogen removal needs a special nitrification / denitrification process. This needs complementary tanks and / or modification of the periods of aeration and non-aeration (anoxic conditions).

  • Anoxic tank upflow the aeration tank (recirculation of the nitrates)

    BACT - A/N

  • Two stages anoxic / aeration

    BIBACT - A/N

  • Two tanks, each with alternated periods of anoxic and aerobic conditions

    BIO2ALTERCYCL - N/DN

  • One tank with alternated periods of anoxic and aerobic conditions

    ALTERCYCL - N/DN

  • ...

If the phosphorus-load exceeds the assimilation capacities of the excess sludge, supplementary phosphorus removal needs a special dephosphatation process. This needs complementary tanks with anaerobic conditions. It is installed as a complement to the nitrification / denitrification process.

  • Anaerobic tank upflow the aeration tank with simple recirculation

    BACT - DP/A/N

  • Anaerobic tank upflow the aeration tank with multiple recirculation

    MULTIBACT - DP/A/N

  • Anaerobic tank upflow the aeration tank with multiple recirculation and intermediary anaerobic tank.

    MULTIBACT - DP/A/N/DP

  • ...

Removal by chemical process

 

  • Stripping of nitrogen as ammoniac

    HYDROGAZ

  • Chemical precipitation of phosphorus (ferric chloride, aluminium salts, ...)

    R.A.P.T. ("Réacteur d'Agrégation de Particules par Transport") connected with a settling or flotation unit.

  • Settling with plates (with or without sludge recirculation)

    Solid – liquid separation is improved by forcing the flow between plates mounted at an angle in the clarification zone

    HYDROPAC CL

    HYDROPAC - R CL

     

For some examples, click here.