Patent ID: 6808629
Filing Date: 2004-10-26
Classification: C02F,Y02W,Y10S

Abstract:
Process for purifying wastewater effluent in order to treat the nitrogen and phosphorus contained in this effluent, this process being performed in a plant comprising an anaerobic tank, a second tank equipped with aeration means selectively being brought into service to operate aerobically, or taken out of service for an anoxic operation, a clarifier and means for injecting metal salts into the second tank, this process comprising the following steps:a) rating the tanks and the aeration means on the basis of the lowest pollution load, referred to as the low load, which corresponds to the plant load during dry weather; b) running the plant during dry weather, or at low load, according to a nitrogen treatment in a tank with biological dephosphatation; c) running the plant during wet weather, or at high load, by performing the phosphorus treatment and the nitrogen treatment in two tanks, and d) controlling the plant by detecting whether the load is in high load or low load and to adapt the operating configuration of the tanks to the actual load.