포말부상법과 가압부상법의 고액분리 효율 비교 (I) - 표면활성물질의 영향 -

김익열 ( Ig-yeol Kim ),이경동 ( Gyeong-dong Lee ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2012 한국환경기술학회지 Vol.13 No.4

표면활성물질을 첨가한 포말부상법과 가압부상법을 이용하여 현탁액의 고액분리 실험을 수행한 결과 다음과 같은 결론을 얻었다. 포말부상과 가압부상 실험에서 적합한 pH는 Casein 4, Gelatin 5이었다. 이때 고액분리 효율은 포말부상에서 Casein을 첨가했을 때 60.5%, Gelatin 37.4%, 가압부상에서 Casein을 첨가 했을때 74.1%, Gelatin 48.9%의 고액분리 효율을 나타내었다. 표면활성물질 첨가량이 증가할수록 고액분리 효율은 증가하였으나, 적합한 첨가량은 두 방법 모두 40mg/L정도로 나타났다. 표면활성물질을 첨가한 현탁액의 고액분리 효율은 가압부상이 포말부상에 비하여 우수하였다. 가압부상이 포말부상에 비하여 Casein을 첨가하면 13.6%, Gelatin을 첨가하면 11.5%의 고액분리효율이 증가되었고, 표면활성물질은 Casein이 Gelatin보다 우수하였다. This study was conducted to test the removal efficiency of suspended solid by dissolved air flotation adding surface active materials. Accomplished result is same as following. The optimum conditions to solid-liquid separate on each method, form flotation and dissolved air flotation, were shown pH 4 on case of casein and pH 5 on gelatin, respectively. Additionally, the efficiency of solid-liquid separation by casein and gelatin were accomplished to 60.5%, 37.4% on form flotation and 74.1%, 48.9% on dissolved air flotation. Even though the separation efficiency was increased with surface active material dosage, the optimum dosage rate was determined to 40mg/L on each method. On comparing the solid-liquid separation efficiency for surface active material added into suspension, the case of dissolved air flotation was superior to form flotation. Additionally, when the surface active materials, casein, gelatin, were added to each method, the efficiency for dissolved air flotation were increased to 13.6%, 11.5% comparing to foam flotation result. And casein was more effective in accomplishing the above result than gelatin as a surface active material.

표면활성물질을 첨가한 현탁액의 가압부상 분리

김익열 ( Ig-yeol Kim ),김상호 ( Sang-hoo Kim ),유찬서 ( Chan-seo You ),이경동 ( Gyeong-dong Lee ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2013 한국환경기술학회지 Vol.14 No.1

표면활성물질을 첨가한 가압부상법을 이용하여 현탁액의 제거실험을 수행하였다. 표면활성물질을 첨가한 가압부상법에서 현탁액의 제거를 위한 최적조건은 Casein을 사용한 경우pH 4, 압력 3kgf/㎠, Casein의 농도 40mg/L, 가압수량비는 0.5이었고, Gelatin을 사용한 경우 pH 5, 압력 3kgf/㎠, Gelatin의 농도 40mg/L, 가압수량비는 0.5 이었다. 이 최적조건에서 현탁액의 제거효율은 Casein이 74.1%, Gelatin은 48.9%를 나타내었다. This study was conducted to test the removal of suspended solid by dissolved air flotation. Accomplished result is same as following. The optimum removal efficiency for dissolved air flotation that was adding the surface active material was determined; pH 4, 3kgf/㎠ of pressure, 40mg/L of casein, 0.5 of pressured water flow ratio on case of casein and pH 5, 3kgf/㎠ of pressure, 40mg/L of gelatin, 0.5 for pressured water flow ratio on case of gelatin. From the optimal condition, removal efficiencies of suspended solid for case of casein and gelatin were recorded 74.17%, 48.92%, respectively.

가압펌프와 공기포화탱크를 연계한 하이브리드형 미세기포 발생장치의 운전특성

김원재 ( Weon-jae Kim ) 한국수처리학회(구 한국수처리기술연구회) 2021 한국수처리학회지 Vol.29 No.3

Dissolved air flotation (DAF) process has been applied to the entire environmental fields. The micro-bubble generator, which is a key facility in DAF process, can be classified according to its generation methodology. In Korea, saturator and DAF-pump types are widely utilized. The feature of saturator type is the application of an air saturation tank (AST), and it has a disadvantage in that operation and maintenance are not easy due to relatively complicated facilities. On the other hand, DAF-pump type uses a micro-bubble generating pump (MGP) alone, so the device configuration is very simple, but the ranges of optimal operating conditions are narrow. In this study, a new hybrid-type microbubble generator has been developed by linking a pressure pump and an AST by converging the advantages of the existing saturator and DAF-pump types. As a result of examining the operation characteristics of this microbubble generator including operating pressure, air flow rate, water flow rate, power consumption, A/W ratio (air/water ratio), DO, and particle size distribution, the appropriate operating conditions could be determined as operating pressure of 4.0 - 6.0 kgf/㎠, air flow rate of 4.0 - 5.0 L/min, water flow rate of 57 - 68 L/min, and A/W ratio of 5.9 - 8.7%. The average diameter of the generated microbubbles showed a stable distribution in the range of 25.0 - 26.7 μm. Based on the above results, it could be verified that the novel hybrid-type microbubble generator had excellent performance at a level that can be applied to the field.

용존공기부상법 유동해석을 위한 난류모델 비교연구

박민아(Min A Park),이균호(Kyun Ho Lee),정재동(Jae Dong Chung),서승호(Seung Ho Seo) 대한기계학회 2015 大韓機械學會論文集B Vol.39 No.7

용존공기부상법이란 오염물에 미세기포를 부착하여 수표면으로 부상시킴으로써 이를 제거하는 수처리 방법이다. 본 연구에서는 난류모델에 따른 용존공기부상조 내부 유동해석의 변화를 고찰하기 위해 물과 기포의 혼합물에 대한 2상 유동을 모사하였다. 이때, 주어진 용존공기부상조 형상 및 조건에 대하여 다양한 난류모델에 따른 용존공기부상법 내부의 미세기포 분포량, 계산시간 및 수렴성 등을 비교하였으며, 그 결과 기존에 주로 사용되었던 표준 k-? 모델이 타 난류모델과는 다른 거동을 예측하는 것으로 확인되었다. The dissolved air flotation (DAF) system is a water treatment process that removes contaminants by attaching micro bubbles to them, causing them to float to the water surface. In the present study, two-phase flow of air-water mixture is simulated to investigate changes in the internal flow analysis of DAF systems caused by using different turbulence models. Internal micro bubble distribution, velocity, and computation time are compared between several turbulence models for a given DAF geometry and condition. As a result, it is observed that the standard k-ε model, which has been frequently used in previous research, predicts somewhat different behavior than other turbulence models.

DAF공정에서 기포층의 분포측정

한무영 ( Moo Young Han ),김충일 ( Tschung Il Kim ),김용하 ( Yong Ha Kim ) 한국수처리학회 2009 한국수처리학회지 Vol.17 No.1

인 고도처리를 위한 일체형 침전부상공정(SeDAF)의 슬러지 발생특성

장여주(Yeoju Jang),정진홍(Jinhong Jung),장향연(Hyangyoun Chang),박나리(Nari Park),미라툴 매크피로(Miratul Maghfiroh),김원재(Weonjae Kim) 대한환경공학회 2020 대한환경공학회지 Vol.42 No.11

목적: 공공수역의 부영양화를 방지하기 위하여 환경부에서는 공공하수처리시설의 방류수 수질기준을 강화한 결과, 국내 하수처리시설에는 다양한 인 고도처리공정이 도입되었다. 기존의 인 고도처리시스템은 일반적으로 과도한 약품비 및 슬러지 발생 등의 문제를 안고 있기 때문에 새로운 공정의 개발이 필수적이다. 방법: 본 연구에서는 침전과 부상분리를 통합한 일체형 침전부상공정(SeDAF)을 개발하고, 해당 공정의 운전조건을 최적화하기 위하여 여러 모의실험을 수행하였다. 수정된 Jar-test 기법을 사용하여 SeDAF 공정에서의 수질 변화 및 슬러지 발생특성을 집중적으로 분석하였다. 결과 및 토의 : 전 수질항목에서 침전공정 대비 침전부상공정의 제거효율이 우수하고 안정적인 것으로 나타났다. SeDAF 공정에서는 응집제 주입농도의 증가에 따라 슬러지 발생량이 4 ㎎・L<SUP>-1</SUP> as SS / ㎎・L<SUP>-1</SUP> as Al₂O₃씩 비례하여 증가하는 것으로 나타났다. 최적처리조건(최적 응집제 주입조건)에서 부상슬러지 및 침전슬러지 내 고형물질(suspended solids, SS) 및 총인(total phosphorus, T-P)의 부하비율(ratio)과 총 슬러지 대비 부상슬러지 내 SS 및 T-P의 부하분율(fraction)은 일정한 범위로 수렴하는 것으로 나타났다. 결론: 슬러지 내 부하비율(ratio) 및 부하분율(fraction) 인자를 모니터링함으로써 일체형 침전부상공정(SeDAF) 운전조건의 적정성을 판단할 수 있는 것으로 나타났으며, 응집제 주입농도의 저감이 슬러지 발생량의 감소로 직결됨을 확인하였다. Objectives : In order to prevent eutrophication and algal blooms, Ministry of Environment in Korea reinforced the effluent standards of wastewater treatment facilities. As a result, many advanced wastewater treatment processes have been implemented nationwide. Current conventional treatment systems have usually been facing high operational costs and large sludge production problems. Therefore, it is essential to develop more economic and efficient process to cope with these issues. Methods : The sedimentation and dissolved air flotation (SeDAF) process has been developed, that integrates sedimentation and dissolved air flotation. Several simulation experiments were carried out to verify and optimize the operation conditions of the SeDAF process. Removal efficiencies of each water quality item and sludge mass balance were analyzed intensively in the SeDAF process using the modified jar-test. Results and Discussion : Removal efficiencies of the SeDAF process were higher and more stable than those of sedimentation process. Several ‘sludge production / coagulant dosage’ ratios were analyzed and the representative value of 4 ㎎・L<SUP>-1</SUP> as SS / ㎎・L<SUP>-1</SUP> as Al₂O₃ was obtained in the SeDAF process. Fractions of suspended solids (SS) and total phosphorus (T-P) in sludge were measured; the ratios of flotation sludge to sedimentation sludge and fractions of flotation sludge in total sludge had their typical convergence ranges for the conditions of optimal coagulant dosage. Conclusions : The ratios or fractions of SS and T-P in sludge could be applied as the evaluation indicators of the SeDAF process. The reduction of coagulant dosage could be corresponded directly to the reduction of sludge production.

고탁도시 DAF 정수장의 운영 및 진단

권순범,안효원,강준구,손병용 대한상하수도학회 2004 상하수도학회지 Vol.18 No.2

DAF process has been designed considering raw water quality characteristics in Korea. Although direct filtration is usually operated, DAF is operated when the freshwater blooms occur or raw water turbidity become high. Pre-sedimentation is prepared in case when raw water turbidity is very high by rainstorms. A main feature of this plant is that the operation mode can be changed (controlled) based on the characteristics of raw water to optimize the effluent quality and the operation costs. Treatment capacity (surface loading rate) and efficiency of DAF was found to be better than conventional sedimentation process. Moreover, lowdensity particles (algae and alum flocs) are easily separated while it is difficult to remove in sedimentation. One of the main concerns in adoption of DAF (Dissolved-Air-Rotation) process is a high raw water turbidity problem. That is, DAF is not adequate for raw water, which is more turbid than 100MU. In order to avoid this problem, pre-sedimentation basins are prepared in OAF plant to decrease the turbidity of DAF influent. For simulation of the actual operation, bench and full-scale tests were performed for highly turbid water conditions. Consequently, DAF process coupled with sedimentation is suggested that pre-sedimentation with optimum coagulation prior to DAF would be appropriate.

Flotation Efficiency of Powdered Activated Carbon in Dissolved Air Flotation Process

( Do Young Choi ) 조선대학교 공학기술연구원 2011 공학기술논문지 Vol.4 No.2

Dissolved air flotation (DAF) system is an effective solid/liquid separation process for low density particle such as algae and color particles, yet it is limited in removing of organics compound which are dissolved in water. In the meantime, powdered activated carbon (PAC) has been successfully applied for the removal of organic compound. Combining two processes of DAF and activated carbon adsorption seems to be and be excellent process for simultaneous removal of both suspended solids and PAC adsorbing dissolved organic compounds. Before studying the PAC-DAF hybrid process, this study focused on a fundamental investigation of the flotation efficiency of PAC with the measurement of zeta potential and particle size distribution. The flotation efficiency of PAC was compared in the presence of low (3 NTU), medium (10 NTU) and high (100 NTU) turbidity. It was found that the removal efficiency of PAC-bubble agglomerates by DAF was over 90% within 10 mini regardless of PAC dose and turbidity. However, the smaller PAC flocs of less than 20 μm are hardly removed. Therefore, we are very careful in selecting the particle size of PAC for the combination of PAC-­DAF hybrid process. The rise velocity and removal efficiency of PAC-bubble agglomerates by DAF was evaluated using the population balance model.

포말부상법과 가압부상법의 고액분리 효율 비교 (II) - 표면활성물질과 응집제의 영향 -

김익열 ( Ig-yeol Kim ),김성진 ( Sung-jin Kim ),정정조 ( Cheong-jo Cheong ),이경동 ( Gyeong-dong Lee ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2013 한국환경기술학회지 Vol.14 No.4

표면활성물질과 응집제를 첨가한 포말부상법과 가압부상법을 이용하여 현탁액의 고액분리 실험을 수행한 결과는 다음과 같다. 포말부상 실험에서 Al(OH)₃ 흡착콜로이드에 Casein을 첨가한 경우 pH 9에서 90.0%, Gelatin을 첨가한 경우 pH 6에서 67.2%, Fe(OH)₃ 흡착콜로이드에 Casein을 첨가한 경우 pH 9에서 98.5%, Gelatin은 pH 7에서 95.9%의 고액분리 효율을 나타내었다. 가압부상 실험에서 Al(OH)₃ 흡착콜로이드에 Casein을 첨가한 경우 pH 9에서 82.0%, Gelatin을 첨가한 경우 pH 7에서 73.6%, Fe(OH)₃ 흡착콜로이드에 Casein을 첨가한 경우 pH 9에서 80.7%, Gelatin은 pH 7에서 80.7%의 고액분리 효율을 나타내었다. 표면활성물질 첨가량은 Casein 40 mg/L, Gelatin 60 mg/L, 응집제 첨가량은 Casein과 Gelatin의 경우 모두 Alum은 10 mg/L, FeCl₃는 5 mg/L에서 가장 높은 고액분리 효율을 나타내었다. 현탁액의 고액분리 효율은 포말부상법이 우수하였고, 표면활성물질은 Casein, 응집제는 FeCl₃을 사용하는 것이 효율적이었다. This study was conducted to test the solid-liquid separation of suspended solid by foam flotation and dissolved air flotation adding the surface active materials and the coagulants. Accomplished result is same as following. On the foam flotation, when the casein and gelatin were added to adsorption colloid such as Al(OH)₃, the optimum pH and the maximum solid-liquid separation efficiency were shown to pH 9, 90.0% and pH 6, 67.2% on each surface active material. On the other hand, the case of adsorption colloid like to Fe(OH)₃, each results was recorded as pH 9, 98.5% on casein and pH 7, 95.9% on gelatin. On the dissolved air flotation, when the casein and gelatin were added to adsorption colloid solution such as Al(OH)3, the optimum pH and the maximum solid-liquid separation efficiency were shown to pH 9, 82.0% and pH 7, 73.6% on each surface active material. The case of adsorption colloid like to Fe(OH)₃, each results was recorded as pH 9, 80.7% on casein and pH 7, 80.7% on gelatin. The maximum solid-liquid separation could be accomplished by adding casein 40 mg/L, gelatin 60 mg/L on each surface active material dosing condition and alum 10 mg/L, ferric chloride 5 mg/L on coagulant and its concentration. After all, foam flotation was superior to dissolved air flotation in solid-liquid separation. And casein and ferric chloride was more effective to increase the separate efficiency comparing to gelatin, alum.

가압부상 분리공정에서 표면활성물질과 응집제의 첨가가 현탁액의 제거효율에 미치는 영향

김익열 ( Ig-yeol Kim ),유찬서 ( Chan-seo You ),정정조 ( Cheong-jo Cheong ),이경동 ( Gyeong-dong Lee ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2013 한국환경기술학회지 Vol.14 No.2

가압부상법에 표면활성물질과 응집제를 첨가하여 현탁액의 제거 실험을 수행한 결과 다음과 같은 결론을 얻었다. 현탁액의 제거를 위한 최적조건은 Alum-Casein을 첨가한 경우, pH 9, 압력 3 kgf/㎠, Alum의 첨가량 10 mg/L, Casein의 첨가량 40 mg/L, 가압수량비 0.5, Alum-Gelatin의 경우 최적조건은 pH 7, 압력 3 kgf/㎠, Alum의 첨가량 10 mg/L, Gelatin의 첨가량 60 mg/L, 가압수량비 0.5로 나타났다. FeCl3-Casein의 경우 pH 9, 압력 3 kgf/㎠, FeCl₃의 첨가량 5 mg/L, Casein의 첨가량40 mg/L, 가압수량비 0.5, FeCl₃-Gelatin의 경우 pH 7, 압력 3 kgf/㎠, FeCl₃의 첨가량 5 mg/L, Gelatin의 첨가량 60 mg/L, 가압수량비는 0.5로 나타났다. 이와 같은 최적조건에서 현탁액의 제거효율은 각각 82.0%, 73.6%, 80.7%, 80.7%를 나타내었다. This study was conducted to test the removal of suspended solid by dissolved air flotation which was using the surface active material and the coagulant. The each optimum condition for four cases of alum-casein, alum-gelatin, ferric chloride-casein and ferric chloride-gelatin were same as following; pH 9, 3 kgf/㎠ for pressure, 10 mg/L for alum, 40 mg/L for casein, 0.5 for pressured water flow ratio(R) on case of alum-casein, pH 7, 3 kgf/㎠ for pressure, 10 mg/L for alum, 60 mg/L for gelatin, 0.5 of R on case of alum-gelatin, pH 9, 3 kgf/㎠ for pressure, 5.0 mg/L for ferric chloride, 40 mg/L for casein, 0.5 for R on case of ferric chloride-casein, pH 7, 3 kgf/㎠ for pressure, 5.0 mg/L for ferric chloride, 60 mg/L for gelatin, 0.5 for R on case of ferric chloride-gelatin. The removal efficiencies of suspended solid for four conditions, alum-casein, alum-gelatin, ferric chloride-casein, and ferric chloride-gelatin on dissolved air flotation were shown as 82.0%, 73.6%, 80.7% and 80.7%.