Patent ID: 7060185

Claim:
An apparatus for treating sewage by using granulated activated sludge, comprising: an anaerobic granulation tank having an agitator for granulating suspended microorganisms with irrigation force of influent sewage or returned water and agitation power by a first agitator to thereby generate sludge; a first transport pipe for transporting supernatant of the anaerobic granulation tank except the sludge granulated in the anaerobic granulation tank; an indirect aeration tank for supplying oxygen to the supernatant transported through the first transport pipe; a second transport pipe for transporting aqueous solution saturated with dissolved oxygen by receiving oxygen in the indirect aeration tank; an aerobic granulation tank for granulating suspended microorganisms with irrigation force of the aqueous solution transported through the second transport pipe and agitation power by a second agitator, the aerobic granulation tank including the second agitator; a third transport pipe for transporting supernatant of the aerobic granulation tank to the anaerobic granulation tank except the sludge granulated in the aerobic granulation tank; and a discharge pipe for discharging supernatant of finished water which is obtained after circulating a series of the anaerobic granulation tank, the first transport pipe, the indirect aeration tank, the second transport pipe, the aerobic granulation tank, and the third transport pipe repeatedly.