抄録
For applying the optimum backwash method to activated carbon absorption process, this study had performed an efficiency test of backwash method and a test for determination of backwash period at the M water purification plant in Daegu metropolitan city.
The minimum fluidization velocity was different according to kinds of carbon like spent carbon and reactivated carbon. Changing water position before backwashing was more efficient in backwashing than controlling backwash time. In the case of water position LL(a height of 60cm over the outer layer of activated carbon) before backwashing, the most efficient backwash method has turned out to be 10 min. of air wash and 18 min. of water wash.
The turbidity of activated carbon filter outflow water and organic matter change have no big difference according to the days of seasonal operation after backwashing. As backwash period is very related to microbiological growth and is influenced by outflow water change, the study has found that it's desirable to operate in consideration of HPC(Heterotrophic plate counter) distribution of filtered outflow water, water quality, the condition of a filter basin and the years of activated carbon use.
