| Title |
Performance Evaluation of Ball Media Filter in DABF applied to SWRO pretreatment process |
| Authors |
최석호 ( Seokho Choi ) ; 이정현 ( Junghyun Lee ) ; 박성주 ( Sungju Park ) ; 이영근 ( Younggeun Lee ) ; 노형근 ( Hyungkeun Roh ) ; 김용범 ( Yongbeom Kim ) |
| DOI |
https://doi.org/10.15681/KSWE.2019.35.6.567 |
| Keywords |
Ball filter; Dissolved air flotation; Hydraulic loading rates; Pretreatment; Turbidity |
| Abstract |
DABF(Dissolve Air Flotation with Ball Filter) is developed as the DAF with the addition of a fiber ball at the lower part of the DAF. The DABF with a capacity of 4,500 m3/h was constructed at Gijang SWRO plant in Busan. Since the ball filter has high filtration rate, the loading rate of DABF was designed from 20 to 42 m3/h/m2. When one DABF basin is in the back washing mode, the loading rate of other two DABF basins is increased to 42 m3/h/m2. Turbidity at the BF outlet in DABF is <2 NTU at turbidity of 5-10 NTU at the BF inlet. If there is no algae bloom and turbidity is low in raw seawater, only BF in DABF is operated and meets <2 NTU at the BF outlet. Even if BF is operated at high hydraulic loading rates, no significant differential pressure increases and reduction in the turbidity removal rate is minimal in a day. Thus, DABF is the pre-treatment technology that provides stable water quality even with BF onlyoperation without DAF operation. Compared with the DAF, DABF requires additional facilities such as valves, piping, and drainage systems for backwashing the BF. But in terms of footprint and operating costs, DABF has more advantages than DAF. With DABF application, the load of the downstream filtration equipment is decreased so that the capacity of the filtration equipment can be reduced. Also, if the downstream filtration equipment is to be maintained the same regardless of DABF, the operating cost of DABF is less than DAF. |