WASTEWATER TREATMENT APPARATUS

摘要

PROBLEM TO BE SOLVED: To enhance reaction efficiency and a reaction speed by adding a magnesium compd. and a pH control agent to wastewater containing ammonium ions and phosphate ions so stirr the wastewater by a screw type stirring blade and separating and recovering a formed magnesium ammonium phosphate hexahydrate. SOLUTION: Wastewater containing ammonium ions and phosphate ions flowing in from a wastewater inflow part 4 is charged in a large diameter cylindrical body 2 along with magnesium ion-containing water supplied from a magnesium compd. supply part 5 and the pH of water in a reaction tank 1 is adjusted by a pH control agent supplied from a pH control agent supply part 6. Wastewater and magnesium ion-containing water fall along the inner peripheral side of a small diameter cylindrical body 3 by the stirring action and falling flow forming action of a screw type stirring blade 71 to rise through the gap between the outer peripheral surface of the small diameter cylindrical body 3 and the inner peripheral surface of the large diameter cylindrical body 2 to form a circulating flow. Crystal of a formed magnesium ammonium phosphate hexahydrate(MAP) sediment on the bottom portion of the reaction tank 1.