Osaka City is first in Japan to employ plate settler by means of coping with CSO. Construction of the settler at Ebie Sewage Treatment Plant was commenced in 1991, and will be completed in a few years. Prior to the construction was conducted an experiment of settling treatment using sloping-plate with an existing pre-aeration tank. The detention time in the experiment device was about 10 minutes to attain an average removal rate of 70% for influent SS.
This report describes the experiment of the settling treatment using sloping-plates, and outlines the design of plate settler that are currently under construction.