Abstract
The purpose of our study is to evaluate the application of Biotope Sand (BTS) for controlling water bloom and water quality in a closed water area. BTS is a sand product recycled from waste casting. The field test utilizing BTS was demonstrated in a storage reservoir. BTS to be spread on floating water bloom and a filtering device with a BTS packed bed were introduced as two methods of BTS utilization. As a result, water bloom and water quality of the storage reservoir were improved within two years. The results suggested that the combination of BTS spreading and the filtering device caused the water bloom to settle, and the BTS filtering device contributed to water quality control. A laboratory-scale cultivation test using fish and aquatic plants was carried out to check the safety of BTS. As a result, it was confirmed that BTS has no negative effect on the growth of fish and aquatic plants. It was hypothesized that the existence of BTS promoted the growth of nitrite-oxidizing bacteria and inhibited the accumulation of nitrite.
