Wastewater purification apparatus and process for purifying wastewater

A wastewater purification apparatus for purifying wastewater, comprising:

• an undivided elongate tank, on a first narrow side, has an inflow for feeding wastewater,
• a first vertical agitator with a first hyperboloid agitator body mounted on a vertical first agitator shaft, wherein the first vertical agitator is configured to form a first treatment portion downstream of the inflow on the first narrow side in the undivided elongate tank,
• a second vertical agitator with a second hyperboloid agitator body mounted on a vertical second agitator shaft, wherein the second vertical agitator is configured to form a second treatment portion downstream of the first vertical agitator in the undivided elongate tank,
• an aeration device with a fan for aerating wastewater received in the tank,
• a first drive device for rotating the first hyperboloid agitator body in a first rotation direction,
• a second drive device for rotating the second hyperboloid agitator body in a second rotation direction, which is opposite the first rotation direction, and
• a decanter, which is provided for discharging purified wastewater in a third treatment portion on a second narrow side in the undivided elongate tank, which is opposite the first narrow side, wherein the first treatment portion is a zone where a first circulating flow of wastewater is formed by the rotation of the first hyperboloid agitator body of the first vertical agitator in the first rotation direction, wherein a flow circulates axially about the vertical first agitator shaft toward the first hyperboloid agitator body, and the second treatment portion is a zone where a second circulating flow of wastewater is formed by the rotation of the second hyperboloid agitator body of the second vertical agitator in the second rotation direction opposite the first rotation direction, wherein a flow circulates axially about the vertical second agitator shaft toward the second hyperboloid agitator body, wherein the first circulating flow and the second circulating flow circulate in opposite directions.