| 摘要 |
<p>In closed circuit aeration liquid sewage treatment systems, a need exists for a device and method for preventing back-mixing of aerated liquid into the intake of the aerator, and for aerating the sewage efficiently at least once per circuit-flow cycle by bringing the air and all of the liquid into singly occurring contact. The invention comprises a barrier (22), which divides an aeration ditch (10) into an intake channel (75) and a discharge channel (77), and at least one submerged aerating pump (28) which pumps sewage in circuit from the intake channel to the discharge while it is being aerated by a supply of compressed air. Back-mixing of aerated liquid to the intake channel is thereby completely prevented, and the oxygen transfer efficiency to the liquid is thereby increased. By independently controlling the submerged pump speed and the amount of compressed air, the aerobic/ anaerobic ratio can be varied through seasonal temperature changes.</p> |
