Abstract
As a method for collecting suspended substances and polluted sediment particles in sea water, the effectiveness of dredging a concave on the sea floor has been investigated by researchers. In this study, particulate materials were collected by using a polyvinylchloride cylindrical vessel (50cm in diameter, 70cm in depth) which was set on the sea floor of Osaka Bay area as the mouth of the vessel level out the sea floor and the collection effectiveness of this method was also inventigated.
The PVC vessel collected nine times as much particulate material as those under a natural condition and 5% of the horizontal flux of suspended substances in the bottom layer water. The collected particles consisted of 30% suspended substances and 70% surface sediment particles. If this particle collection system of dredging a concave on the sea floor is used jointly with a system of recovering the collected particles, it can be an effective method of purifying polluted sediment in the sea.
