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전구물질의 소수성 및 친수성 특성에 따른 트리할로메탄의 생성과 제거에 관한 연구
전희경 ( Hee Kyung Jeon ),김준성 ( Jun Sung Kim ),최윤찬 ( Yoon Chan Choi ),최해연 ( Hae Yeon Choi ),정용 ( Yong Chung ) 한국물환경학회 2008 한국물환경학회지 Vol.24 No.1
The Dissolved Organic Carbon (DOC) existing in a water includes both hydrophobic and hydrophilic substances however, most of the discussion focuses on hydrophobic substances. The hydrophobic fraction was easily removed by absorption or coagulation more than hydrophilic fraction. Therefore, control of the hydrophilic fraction is very important in water treatment process. This study is to determine the variation of DOC, the removal efficiency of DOC, and Trihalomethane formation potential (THMFP) after each stage of water treatment process by fractionating Natural Organic Matters (NOM) into hydrophobic and hydrophilic substance. DOC from raw water was fractionated at acidic pH (pH<2) using XAD 8 resin column, into two fraction : hydrophobic substance (i.e. humic substance) adsorbed on XAD 8 and hydrophilic substance which represent the organics contained in the final effluent. THMFP was carried out according to the following set condition: Cl2/DOC=4 mg/mg, incubation at 25°C in darkness, pH 7 adjust with HCl or NaOH as necessary, and 72hour-contact time. THMs analyzed in this study were chloroform, bromodichloromethane, dibromochloromethan, and bromoform. Sewage was almost evenly split between the hydrophobic (56%) and hydrophilic fraction (44%). But, Aldrich humic substance (AHS) was found to contain less hydrophilics (14%) than hydrophobics (86%). The formation of THMs may depend on the source which is characterized by the composition of organic matters such as AHS and sewage. The THMFP yield of sewage and AHS were assessed as follows. The value of the THMFP reaction yield, AHS 172.65 μg/mg, is much higher than that of sewage 41.68 μ g/mg. This illustrates possible significant difference in THMFP according to the component type and the proportion of organic matter existing in water source. Apparently AHS react with chlorine to produce more THMFP than do the smaller molecules found in sewage. Water treatment process may reduce THMFP, nevertheless residual DOC (the more hydrophilic substance) has significant THMFP. Further reduction in organic halide precursors requires application of alternative treatment techniques.
역 유동층 생물막 반응기를 이용한 유분함유폐수 처리에 관한 연구
최윤찬,나영수,추석열,김규식,송승구 한국환경과학회 1996 한국환경과학회지 Vol.5 No.3
An inverse fluidized-bed biofilm reactor (IFBBR) was used for the treatment of highly-emulsified oily wastewater. When the concentration of biomass which was cultivated in the synthetic wastewater reached to 6000㎎/L, the oily wastewater was employed to the reactor with a input COD concentration range of 50㎎/L to 1900㎎/L. Virtually the IFBBR showed a high stability during the long operation period although some fluctuation was observed. The COD removal efficiency was maintained over 90% under the condition that organic loading rate should be controlled under the value of 1.5 ㎏COD/㎥/day, and F/M ratio is 1.0㎏COD/㎏VSS/day at 22℃ and HRT of 12 hrs. As increasing organic loading rates, the biomass concentration was decreased steadily with decreasing of biofilm dry density rather than biofilm thickness. Based on the experimental results, It was suggested that the decrease in biofilm dry density was caused by a loss of biomass inside the biofilm.
담체의 표면거칠기와 전단응력이 미생물 부착에 미치는 영향
박영식,송승구,이채남,최윤찬 부산대학교 환경문제연구소 1995 環境硏究報 Vol.13 No.-
The propose of this paper was to examine the effect of surface roughness and shear stress of support medium on the development of biofilm in a rotating biological contactor. The surface roughness of PMMA as a support media was adjusted to 0.4, 0.8, 1.2, and 3㎛, respectively. Shear stress was varied with speed of rotating biological contactor. At low shear stress, bacterial attachment was not varied greatly with surface roughness. But at increased shear stress, bacterial attachment was changed sharply with surface roughness.
내부순환반응기의 scale-up에 따른 동력학적 특성의 변화
최윤찬,박영식,서정호,김동석,송승구 한국환경과학회 1997 한국환경과학회지 Vol.6 No.1
The variations of gas hold-up, overall volumetric oxygen mass transfer coefficients and liquid circulation velocity in an internal loop reactor were investigated to manifest scale-up effect. The relationship between superficial gas velocity and gas hold-up were found as Ugr = 0.045 εr in the pilot-scale and Ugr = 0.056 εr in the bench-scale reactor. The overall volumetric oxygen mass transfer coefficient, K_La was slightly increased in the pilotscale than in the bench-scale reactor. Flow regime was changed from the bubble flow to the churn-turbulent flow when the superficial gas velocity reached to 3.5 - 4 ㎝/sec in the pilot-scale.
안대명,이창한,최윤찬,조석호,안갑환,김성수 대한상하수도학회 2002 상하수도학회지 Vol.16 No.4
The paper introduces a domestic pump designed for dissolved air flotation (DAF). In the paper, the difference in performance between the domestic DAF pump and conventional pressure saturator is explained using the characteristics of air bubble released. The size distribution of air bubbles released from DAF pump is measured by image analyzer and particle size analyzer. And the mean diameter of bubbles is 43μm. The results are similar to that of pressure saturator. The air volume concentration in the water of domestic DAF pump and pressure saturator are 40 and 70% of theoretical amounts. In DAF system used domestic DAF pump, the removal efficiency of turbidity is 70%.
역 유동층 생물막에서의 기질제거 속도상수와 유효확산계수
추석렬,송승구,박문기,최윤찬,김동석 부산대학교 환경문제연구소 1994 環境硏究報 Vol.12 No.-
The substrate removal rate in a biofilm was investigated by the measurement of substrate concentration in an inverse fluidized bed operated batchwisely. When the biofilm thickness was below 60㎛, the overall reaction rate was found as first order but it turned out to zero order at the thickness of above 60㎛. The reaction rate constant and the effective diffusivity could be calculated by using a mass balance and a diffusion model in the biofilm and a typical effective diffusivity of zero and first order reaction were calculated as 5.49×??㎠/s and 2.3×??㎠/s, respectively. In the region of zero order reaction, the effect of diffusion on the effectiveness factor increased with increasing biofilm thickness. Therefore in the zero order region, the diffusion step controlled the system while the reaction step controlled in the first order region.
최윤찬,송승구,김동석,박영식,안갑환 부산대학교 환경문제연구소 1993 環境硏究報 Vol.11 No.-
A number of experimental runs were conducted to investigate the dependence of sand particles in sizes and volumes on a minimum fluidization velocity. The smaller sand particles was easily fluidized at a lower minimum fluidization velocity than the larger sand particles. The proposed model shown below was good enough to predict the minimum fludidzation velocity without the knowledge of bed voidage and shape factor within 98 % confidence. (N????)?? = [(29.99)² + 0.038095 N????]² - 29.99