METHOD FOR ELIMINATING NITROGEN AND PHOSPHATE FROM WASTEWATER

摘要

PURPOSE: By installing anoxic buffer tank in front of a denitrification RBC (rotating biological contactor), dissolved oxygen contained in wastewater is exhausted before inflow in a denitrification RBC. Therefore, hydraulic retention time is short, and maintenance cost is low. CONSTITUTION: The method for eliminating nitrogen and phosphate from wastewater comprises the steps of (i) settling solids in a grit chamber and a primary settling tank; (ii) dissolved oxygen stripping step where a portion of wastewater pretreated through the grit chamber and the primary settling tank (2), mixed liquor recycled from a nitrification RBC reactor, and return sludge from secondary settling tank are transferred into a buffer tank; (iii) denitrification step where the rest of wastewater pretreated through the grit chamber and the primary settling tank, dissolved oxygen-free wastewater from the buffer tank are transferred to an anoxic RBC reactor (6); (iv) nitrifying denitrified wastewater in a nitrification tank (8); (v) a final step where a portion of nitrified wastewater (12) is returned to the buffer tank (4) and the rest of wastewater is transferred to a secondary settling tank (10) for liquid/solid separation.