Regulating aeration in biological wastewater treatment tank to treat carbon and nitrogen pollution, by measuring concentration of ammonium and oxygen dissolved in tank and adjusting aeration output having nitrogen pollution present in tank

摘要

The method comprises continuously measuring a concentration of ammonium and oxygen dissolved in biological wastewater treatment tank, and adjusting an aeration output having nitrogen pollution present in the tank while maintaining the concentration of oxygen necessary for degradation of the pollution to be treated. The nitrogen pollution present in the tank is controlled by measuring the concentration of ammonium using an in situ ammonium probe. An aerobic and/or anoxic state of the tank is controlled by measuring concentration of dissolved oxygen using an in situ oxygen probe. The method comprises continuously measuring a concentration of ammonium and oxygen dissolved in biological wastewater treatment tank, and adjusting an aeration output having nitrogen pollution present in the tank while maintaining the concentration of oxygen necessary for degradation of the pollution to be treated. The nitrogen pollution present in the tank is controlled by measuring the concentration of ammonium using an in situ ammonium probe. An aerobic and/or anoxic state of the tank is controlled by measuring concentration of dissolved oxygen using an in situ oxygen probe. The aeration output is adjusted: to maintain the concentration of ammonium in the tank between two threshold values such as lower ammonium threshold value (0.8-1 mg/l) and higher ammonium threshold value (2-5 mg/l); and to maintain the concentration of oxygen dissolved in the tank at a level below a threshold value such as an excess oxygen threshold value (0.1-0.5 mg/l). If the concentration of ammonium is higher than the lower threshold and lesser than the higher threshold and if the ammonium concentration decreases, the dissolved oxygen concentration is controlled to verify that there is no excessive aeration. If the dissolved oxygen concentration is higher than the excess oxygen threshold, the aeration output decreases by decrementation, and if the dissolved oxygen concentration is less than or equal to the excess oxygen threshold, the aeration output remains unchanged. If the concentration of ammonium is greater than the lower ammonium threshold and lesser than the higher ammonium threshold, the aeration output remains unchanged, and if the concentration of ammonium increases, the aeration output increases by incrementation. If the concentration of ammonium decreases, when the entry of pollutions in the tank in night, the aeration output progressively decreases by successive decrementation until reaching a minimum aeration output. The aeration is carried out in the tank through diffuser membranes.