抄録
Contamination of bays and lakes is one of serious problems in many countries. Many kinds of heavy metals and organic materials are usually contained in the sediments on the bottoms of the bays and lakes. In this research we mention about the treatment of contaminated sediment using a swirl motion of a bubbling jet and ozone. As a first step, we investigate the condition under which the swirl motion preferably occurs in a bottomless cylindrical vessel. Secondly, the period, amplitude, starting time, and damping time of the swirl motion are measured. Theoretical and empirical equations proposed previously are compared with the measured values of these quantities.
