• Environmental Engineering Research
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• 제10권4호
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• pp.199-204
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• 2005

Experiments were performed to estimate the organic release from the aquifer soil in riverbank and/or riverbed filtration via a kinetic approach. Organic release was assumed as a reaction of first order regarding concentrations in both soil and water phases. The reaction rate constants were obtained by comparing the model predictions with the experimental data of organic release reaction and the equilibrium distribution of organic matter between water and soil phases. Results show that the organic release from the aquifer soil was not negligible under normal conditions in Korea reaching 4.7mg-COD/L-day. This indicates that manganese and iron start to be released from aquifer soil in the riverbank filtration in the middle reach of the Nakdong river if the travel time of the filtrate exceeds about 5 days. It was also seen that the COD of the soil organic matter was 0.89mg-COD/mg-OM and that 65% of the COD was BOD5.

• Environmental Engineering Research
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• 제16권4호
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• pp.237-242
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• 2011

In this study, three pilot-scale plants with the capacity 30 $m^3$/day were designed and set up to treat reservoir water for the production of drinking water. Three treatment processes were compared in the pilot testing: process 1 (coagulation- flocculation- sedimentationsand filtration- ozone- BAC); process 2 (coagulation- flocculation- sedimentation- microfiltration-ozone- BAC); and process 3 (coagulation- flocculation- sedimentation- sand filtration- GAC). The quality of water has been evaluated on the basis of selected parameters such as turbidity, color, consumption of $KMnO_4$, dissolved organic carbon (DOC), trihalomethane formation potential (THMFP), geosmin and 2-MIB. A detailed assessment of performance was carried out during a five months operation. Process 2 was found to have better removal efficiency of DOC, THMFP, geosmin and 2-MIB than process 1 and process 3 under identical conditions, although the removal rate of color was found to be the same in the three cases.

• 한국환경과학회지
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• 제4권5호
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• pp.481-488
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• 1995

This study was carried out to evaluate the variations of headloss rate and of specific deposit to depths with effective size of media and configuration of filter layer during algae blooming period. 0.51mm size media was disqualified because most of headloss occurred rapidly below 5cm from surface layer however 0.91mm size media acted deep filtration more than 20cm from top, as result 0.91mm sixte media filter had 2~3 times longer filtration time than 0.51mm sixte media filter, but 0.91mm size media have break-through potentiality. multi-layer filter with 1.02mm anthracite and 0.51mm sand had large deposit volume in upper layer that could longer filtration time, moreover smaller media in lower layer that could protect break-through.

• 한국막학회:학술대회논문집
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• 한국막학회 2008년도 춘계 총회 및 학술발표회
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• pp.33-47
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• 2008

Non-equilibrium (irreversible) themodynamics is used to investigate colloidal back-diffusion during crossflow membrane filtration. The chemical potential is generalized as a superposition of equilibrium and irreversible contributions, originating from Brownian and shear-induced diffusion, respectively. As a result, an effective drag force is derived using the irreversible thermodynamics for a particle undergoing both Brownian and shear-induced diffusion in a sheared concentrated suspension. Using the drag force, a hydrodynamic force bias Monte Carlo method is developed for crossflow membrane filtration to determine the critical flux of hard sphere suspensions. Effects of shear rate and particle size on the critical flux are studied, and results show a good agreement with experimental observations reported in the literature.

• 약학회지
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• 제25권1호
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• pp.15-25
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• 1981

This study was attempted to investigate the action of debrisoquine, a sympathetic blocking agent presently employed in treating hypertension, on renal function and to elucidate the mechanism of its action. Debrisoquine, given intravenously, elicited increased urine flow, osmolar and free water clearances, along with marked increases in excretion of both sodium and potassium. Glomerular filtration rate also increased, but renal plasma flow tended to decrease, so that the filtration fraction tended to increase. Rates of reabsorption of sodium and potassium in renal tubules were also significantly diminished. The diuresis induced by debrisoquine was completely blocked by treatment with phentolamine and reserpine, and also markedly inhibited by acute renal denervation. Debrisoquine, when injected directly into a renal artery, produced antidiuretic effect and a reduction in urinary excretion of sodium and potassium, along with diminished renal plasma flow and increased filtration fraction. The above observations indicate that debrisoquine, when given intravenously, induces diuresis in the dog as a result of both diminished tubular reabsorption of electrolytes and of renal hemodynamic changes, which seem to be related to its inhibitory action of catecholamine-release from the sympathetic nerve endings.

• 한국유체기계학회 논문집
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• 제15권2호
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• pp.20-29
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• 2012

The green house on the waterfront is air-conditioned by a water-source heat pump system with riverbank filtration water. In order to supply riverbank filtration water in alluvium aquifer, the riverbank filtration facility for water intake and recharge, two pumping wells and one recharge well, has been constructed. The research site in Jinju, Korea was chosen as a good site for riverbank filtration water supply by the surface geological survey, electrical resistivity soundings, and borehole surveys. In the results of two boreholes drilling at the site, it was revealed that the groundwater table is about 3 m under the ground, and that the sandy gravel aquifer layer in the thickness of 6.5 m and 3.5 m occurs at 5 m and 7 m in depth below the ground level respectively. To prevent the recharge water from affecting the pumped water which might be used as heat source or sink, the distance between pumping and recharge wells is designed at least 70 m with a quarter of recharged flow rate. It is predicted that the transfer term, the recharge water affects the pumping well, is over 6 months of heating season. Hydrogeological simulation and underground water temperature measurement have been carried out for the pumping and recharge well positions in order to confirm the capability of sustainable green house heating and cooling.

• 한국대기환경학회지
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• 제24권4호
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• pp.483-491
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• 2008

The filtration characteristics of $CYBAGFILTER^{(R)}$ unit with pleated filter bags were evaluated by comparing the performance of the unit with the lower part of cyclone shape with that of the unit with conventional lower part. Results from the test were also compared with those from the previous research with the $CYBAGFILTER^{(R)}$ in which round filter bags were installed. $CYBAGFILTER^{(R)}$ is the unit which combines the centrifugal separation mechanism and the fabric filtration mechanism in a single unit for efficient removal of particulate matters. The pleated filter bags are made of pleated fabric with an extension of the filtration area about 3 times compared with the conventional round filter bags. The results from the test using pleated filter bags showed an overall collection efficiency of over 99.9% regardless of the shape of lower part installed. When the lower part of cyclone shape was installed, the filter cleaning interval was over 2 times longer compared with that when the conventional lower part was installed. At the same conditions of filtration velocity and filter pressure drop, the $CYBAGFILTER^{(R)}$ with the lower part of cyclone shape, in which the pleated filter bags are installed, can be operated with a flow rate of round 3 times higher than that with conventional round filter bags.

• 대한환경공학회지
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• 제31권1호
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• pp.70-78
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• 2009

지형도를 이용하여 전국 주요하천의 홍수터 면적을 조사하였고, 원판형 부압침투계를 이용하여 홍수터 토양의 투수특성을 조사하였다. 문헌조사와 불포화 흐름해석용 코드를 이용하여 홍수터에서 도시하수의 2차 처리수에 대한 토양처리의 가능성도 평가하였다. 이들 자료를 바탕으로 우리나라의 홍수터여과 용량을 산정하였다. 연구결과 우리나라의 홍수터는 토양여과에 적합한 표층토를 가지며, 하천연장 전체에 걸쳐 홍수터가 골고루 분포되어 있어서 홍수터여과가 하수의 추가처리로 활용되기에 유리한 여건임을 알 수 있었다. 우리나라 전체의 홍수터여과 용량은 약 182,000,000 $m^3$/day이고, 대부분의 하천들은 2차 처리수를 모두 홍수터여과를 통해 추가적으로 처리할 수 있을 것으로 계산되어 이 공법을 적용할 경우 하천수질이 개선 될 것이라고 기대한다. 또한, 본 공법은 상수원수의 수질개선에도 활용될 수 있을 것으로 기대되었다.

• 멤브레인
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• 제30권2호
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• pp.131-137
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• 2020

본 연구에서는 가압식 분리막 여과에서 무기입자의 존재가 유기파울링에 미치는 영향을 관찰하였다. 유기파울링의 유발을 위해 알긴산나트륨(sodium alginate, SA)를 이용한 정밀여과 실험에서 무기 실리카(SiO₂) 입자의 존재 유무와 상관없이 분리막 파울링은 여과초기 완전공극막힘에서 여과시간이 경과할수록 케이크 형성에 의해 주로 지배되었다. 그러나 무기입자의 존재 시 정압여과에서 알긴산나트륨 파울링 케이크 비저항값과 압축성은 상대적으로 낮게 관찰되었고 이로 인해 낮은 파울링 속도가 관찰되었다. 동일한 시료를 이용한 정량여과 실험을 수행한 결과 정압여과에 비해 정량여과에서 여과초기 공극막힘현상 및 파울링 속도는 더욱 증가하였다. 이와 같은 현상은 파울링층이 지닌 압축성으로 막간차압의 증가 시 케이크 비저항값이 함께 증가하였기 때문인 것으로 판단된다. 알긴산나트륨과 실리카 입자가 함께 존재 시 알긴산나트륨이 단독으로 존재하는 것보다 수리학적 세정을 통한 파울링 제거효과는 더욱 좋은 것으로 관찰되었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제4권1호
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• pp.46-50
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• 1999

The application of pulsed electric field was investigated in the crossflow ultrafiltration of BSA (bovine serum albumn) to economize the application time of electric current as well as to avoid inherent problems of long-term application of electric field. During the application of various cyclic patterns of pulsed electric current, the averaged filtration flowrate and the degree of concentration were maintained higher than those obtained in the absence of electric current application. The temperature increase, pH change, and BSA loss by electrodeposition were all negligible during the operation. The averaged filtration flowrate increased as the ON/OFF duration ratio of electric current was higher and as the period of ON/OFF cycle was shorter. The re-establishment of concentration polarization was dependent to the duration of current OFF state and, therefore, a longer duration of OFF state was not favorable in maintaining higher filtration flow rate. Although the averaged filtration flowrate was enhanced as the magnitude of electric current increased, the flowrate enhancement became smaller as the magnitude of current value above which the degree of electrokinetic depolarization is no further improved.