| 摘要 |
<p>PURPOSE: To provide a method for circulating nitrified soln. and carrier by which a power for circulating the nitrified soln. is reduced, DO is not brought into a denitrification tank, and the carrier concn. in the denitrification tank and nitrification tank is maintained constant at all times. CONSTITUTION: Baffle walls 5 and 6 are formed respectively close to the outlet end of a nitrification tank 2 and close to the inlet end of a settling tank 3. A hopper 8 is furnished on the bottom of the nitrification tank 2 between the baffle wall 5 and a partition wall 7 to settle a polymer gel carrier therein. The carrier settled in the hopper 8 is sucked by an air-lift pipe 9 and returned to the inlet end of a denitrification tank 1. Meanwhile, a part of a nitrified soln. is sucked by a suction pipe 12 formed between the baffle wall 6 of the settling tank 3 and the partition wall 7 and returned to the inlet end of the denitrification tank 1.</p> |
