抄録
This paper deals with an improvement of settling tank performance. The new equipment is proposed and the usefulness of this method is confirmed. In combined sewerage systems, storm waters often exceed the capacity of the treatment plant, which may cause environmental problems. To meet this problem, the enhancement of the settling tank capacity is an important and urgent issue to the sewage treatment plant in the city. Although the lamella settler is widely used to improve the settling performance of the space limited settling tank, the capacity of this method is limited by the surface area of the tank, since the parallel plates are arranged horizontally. The newly developed settler is an improvement of the lamella settler, which arranges the inclined parallel plates in the vertical direction. In this method, the separated clear water is removed directly by suction from the top end of the parallel plates. For the removal of clear water, the right and left edges of the plates are closed, to make a tube with rectangular cross section. These are the unique and original points of our equipment. Since each settling tube acts as a small settling tank, the treatment power is proportional to the number of the settling tube. Furthermore, this system is less restricted by the surface area of the tank, since the tubes are arranged vertically. It was shown from our laboratory and onsite experiments, that the new system can enhance the capacity of the settling tank more than 5 times grater than the conventional one.
