• Title/Summary/Keyword: 용존공기부상공정

Search Result 6, Processing Time 0.051 seconds

A study on dissolved air flotation (DAF) process control using decision algorithm (의사결정 알고리즘을 이용한 DAF 공정 제어에 관한 연구)

  • Jung, Woosik;An, Ju-Suk;Park, Ji-Young;Oh, Hyun-Je
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.31 no.5
    • /
    • pp.409-414
    • /
    • 2017
  • In this study, we divided the process operation scenarios into three categories based on raw water temperature and turbidity. We will select and operate the process operation scenario according to the characteristics of the raw water. The number of algae in the DAF treated water has been analyzed to be less than 100 cells/mL. These results indicated that the DAF process is effective in removing the algae. In addition, the scenario of the integrated management decision algorithm of the DAF process was developed. DAF pilot plants ($500m^3/day$) process has shown a constantly sound performance for the treatment of raw water, yielding a significantly low level of turbidity (DAF treated water, 0.21~1.56 NTU).

Simulation study of DAF flotation basin using CFD (전산유체해석기법을 이용한 용존공기부상공정의 유동해석)

  • Park, Byungsung;Woo, Sungwoo;Park, Sungwon;Min, Jinhee;Lee, Woonyoung;You, Sunam;Jun, Gabjin
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.27 no.2
    • /
    • pp.261-272
    • /
    • 2013
  • Algae boom (Red tide) in south coastal area of Korea has been appeared several times during a decade. If algae boom appears in the desalination plant, media filter and UF filter are clogged quickly, and the plant should be shutdown. In general, Algae can be removed from water by flotation better than by sedimentation, because of the low density of algal cell. The purpose of this study conducts the CFD simulation of DAF flotation basin to apply the design of the dissolved air flotation with ball filter in the Test Bed for SWRO desalination plant. In this study, Eulerian-Eulerian multiphase model was applied to simulate the behavior of air bubbles and seawater. Density difference model and gravity were used. But de-sludge process and mass transfer between air bubbles and seawater were ignored. Main parameter is hydraulic loading rate which is varied from 20 m/hr to 27.5 m/hr. Geometry of flotation basin were changed to improve the DAF performance. According to the result of this study, the increase of hydraulic loading rate causes that the flow in the separation basin is widely affected and the concentration of air is increased. The flow pattern in the contact zone of flotation basin is greatly affected by the location of nozzle header. When the nozzle header was installed not the bottom of the contact zone but the above, the opportunity of contact between influent and recycle flow was increased.

High Rate Dissolved Air Flotation (DAF) for the Removal of Algae Species (유입원수 조류제거를 위한 high rate DAF 최적화 연구)

  • Jung, Woosik;An, Ju-Suk;Song, Keun-Won;Oh, Hyun-Je
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.31 no.5
    • /
    • pp.415-419
    • /
    • 2017
  • In recent years there have been large increases in the hydraulic loading rates used to design dissolved air flotation (DAF) facilities for drinking water applications. High rate DAF processes are now available at loading rates of 20 to $40m^3/m^2{\cdot}h$. This research evaluated dissolved air flotation as a separation method for algae and organic compounds from water treatment plants. During the service period of 2016. 5. to 2017. 6., DAF pilot plants ($500m^3/day$) process has shown a constantly sound performance for the treatment of raw water, yielding a significantly low level of turbidity (DAF treated water, 0.21~1.56 NTU). As a result of analyzing the algae cell counts in the influent source, it was expressed at 100-120 cells/mL. In DAF treated water, the removal efficient of alge cell counts was found to be upto 90%. The stable turbidity and algae removal were confirmed by operating the high rate DAF process under the condition of the surface loading rate of $30m^3/m^2{\cdot}hr$.

Development of Dissolved Air Flotation Technology from 1st Generation to the Newest or 3rd One (Very Thick Microbubble Bed) with High Flowrates DAF in Turbulent Flow Conditions (차세대 고효율 용존공기 부상공정(High Rate DAF)의 개발)

  • Kiuru, H.J.
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.18 no.2
    • /
    • pp.228-234
    • /
    • 2004
  • Dissolved air flotation (DAF), in which suspended solids are removed from water by means of micro-size air bubbles raising slowly up in water and lifting solids from water (smaller than those) attached onto the micro-bubbles as well as those (larger than solids) being attached on these, have been used in water and wastewater since 1920s. The dissolved air flotation technology was originally based on the laminar flow conditions prevailing in water to be treated, but the latest development in that technology has led now to a situation, in which the flow conditions may also be turbulent ones in the modem dissolved air flotation units. Despite of that, the flotation phenomenon used in this unit operation for removal suspended solids from water or wastewater is still the same.

Remediation of Sediments using Micro-bubble (미세기포를 이용한 퇴적물 정화)

  • Kang, Sang Yul;Kim, Hyoung Jun;Kim, Tschung Il;Park, Hyun Ju;Na, Choon Ki;Han, Moo Young
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.38 no.8
    • /
    • pp.420-427
    • /
    • 2016
  • This study was conducted on the sediment remediation using micro-bubble to remove fine particles. For this study, characteristics of contamination and release in sediment were analyzed. And then, the characteristics of bubbles on removal efficiency was investigated at various operation conditions. In particle size distribution of the sediment used for the study, the proportion of clay and silt (<0.075 mm) was about 7.7%, sand (0.075~4.75 mm) was about 67.8%, and gravel (${\geq}4.75$) was 24.5%. Total nitrogen (TN) and total phosphorus (TP) of the sediment were 2,790~3,260, 261~311 mg/kg respectively. Ignition loss and water content were 4.1~9.6, 32.9~53.2% respectively. In analysis of removal efficiency according to operation conditions of micro-bubble, it was the highest when operation condition is pressure 6 atm, pressurized water ratio 30%, and coagulant dosage 15 ppm. At the time, the sediment's removal efficiency was 19.9%. Accordingly removal efficiency of TN and TP were 21.4, 22.6% respectively. Finally a research was found that fine particles in sediment were almost removed by micro-bubble, which led to decrease nutrients' release at about 20.1~64.3% in comparison to sediment including lots of fine particles.

Pretreatment Condition in the Full Scale Dissolved Air Flotation Process Using a DAF Pump (DAF 펌프를 이용한 실규모 용존공기부상 공정의 전처리 조건)

  • Lee, Chang-Han;An, Dae-Myung;Kim, Seong-Soo;Cho, Seok-Ho;Ahn, Kab-Hwan
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.31 no.1
    • /
    • pp.58-63
    • /
    • 2009
  • Dissolved air flotation (DAF) process is generally considered more effective than sedimentation process in raw water containing algae, humus materials, and low density particles. This study presents the treatment efficiencies by the coagulation and flocculation conditions at a drinking water treatment plant using a laboratory tester and the full scale DAF pump system. The full scale DAF pump system (F-DAF) in this study had a capacity of 5,000 $m^3$/d and a hydraulic surface loading of 10 m/hr. F-DAF in D drinking water treatment plant was continuously operated to determine the operational performance and pretreatment (mixing and coagulation) conditions. Results in the laboratory experiment showed that the optimum coagulant (PSO-M) doses required to 2.7~4.5 mL/$m^3$/NTU with raw water turbidity from 13.8 NTU to 56.3 NTU. F-DAF in the optimum coagulant dosage could be operated in effluent turbidity of 1 NTU or below for a month.