碩士 / 國立臺灣海洋大學 / 水產養殖學系 / 96 / The suspended solids (SS) presented in either flow-through or recirculating aquaculture systems are mostly from excretion of aquaculture organisms and residual feeds. These solids will clog and hurt the fish gills to cause a decreasing of fish immunity or even fish death. Thus the suspended solids in aquaculture system should be removed and treated as soon as possible, in order to prevent its hazards to fish and reduce its pollution to the environment after discharged.
In present study, the tangential flow bead filters were used to treat the artificial waste water with powder of feed and the water of an outdoor grouper culture pond. The performances of bead filters were measured for filters operated under various hydraulic retention times (HRT). The optimum value of HRT for bead filter was determined. In addition, the optimum backwash frequency for bead filter was determined via an experiment with bead filters treating waste water of an indoor recirculating system for abalone culture.
The results showed that the removal rates of SS were increased when the HRT value of bead filter was increased from 5 to 20 min, in the experiments of artificial wastewater and grouper pond water. The maximum removal rates of SS in various filters were 26 ~ 45 % during each filtration cycle. The effluent water of bead filters had increasing concentrations of ammonia, nitrite and biochemical oxygen demand (BOD) degraded from SS in filters, but were all under the tolerance level for culture organism. The results suggested that bead filters can be used in the grouper culture system and abalone culture system to control the suspended solids. And an HRT of 5 min was the best choice for bead filter design to treat a greater amount of water for each backwashing cycle. The maximum SS removal rate could reach 45 %, and filter could be run for 18 ~ 24 hrs continuously to be backwashed. The amount of backwash water was 10 % of the filtered water if the filter was backwashed each day.
| Identifer | oai:union.ndltd.org:TW/096NTOU5086001 |
| Date | January 2008 |
| Creators | Keng-Hung Liao, 廖耿宏 |
| Contributors | Kuo-Feng Tseng, Huei-Meei Su, 曾國鋒, 蘇惠美 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 86 |
Page generated in 0.0015 seconds