NITROGEN AND PHOSPHORUS REMOVAL METHOD AND NITROGEN AND PHOSPHORUS REMOVAL APPARATUS

摘要

- 36 - ABSTRACT (FIG. 1)"NITROGEN AND PHOSPHORUS REMOVAL METHOD AND NITROGEN AND PHOSPHORUS REMOVAL APPARATUS"5There is provided a nitrogen and phosphorus removal method including i) when NH4-NNlim and PO4-PPlim, driving a DTA in the high-speed mode to aerate and stir the anaerobically treated water in a10multiple-use tank, thereby increasing a ratio of a water volume in an aerobic condition to a water volume in an anaerobic condition, ii) when NH4-NNlim and PO4-PPlim, driving the DTA in the low-speed mode to stir the anaerobically treated water, thereby15increasing a ratio of a water volume in an anaerobic condition to a water volume in an aerobic condition, iii) when NH4-NNlim and PO4-PPlim, reducing a volume of the wastewater to be introduced, or switching the DTA from the high-speed mode to the low-speed mode or20stopping the driving a pump, thereby decreasing a ratio of a water volume in an anaerobic condition to a water volume in an aerobic condition, and iv) when NH4-NNlim and PO4-PPlim, driving the DTA in the low-speed modeuntil the concentration of the nitrogen compound25becomes NH4-N=Nlim or the concentration of the phosphorus compound becomes PO4-P-Plim, thereby increasing a ratio of a water volume in an anaerobic condition to a water volume in an aerobic condition.