Method for the biological treatment of wastewater using an aerobic granular biomass

A method for the biological treatment of wastewater containing pollutants, using an aerobic biomass, comprising a plurality of successive cycles of a predefined duration in order to achieve pollutants removal efficiency of 90% or higher, each of said cycles comprising the following steps:

• introducing a wastewater effluent containing phosphorus and calcium in determined respective concentrations, into a reactor containing biomass;
• applying an aerobic phase by introducing into said reactor a gas flow containing oxygen for a predefined length of time, sufficient to form aerobic biomass granules in the reactor;
• decanting the aerobic biomass granules thus formed;
• and removing at least part of the treated effluent,
• characterized in that, after each step of introducing effluent into the reactor, the aerobic phase is preceded by a phase in anoxic conditions and the pH in said reactor is maintained at a value above 8 for a length of time at least equal to 10% of the cycle duration.