• 한국습지학회지
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• 제13권2호
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• pp.161-169
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• 2011

본 연구는 여과와 침투기작을 이용한 개선된 여과형 시설의 비점오염물질 처리효율을 평가하고자 수행되었다. 저감시설은 지리학적 기후학적인 인자를 고려하여 기존의 저감시설의 단점을 보완하여 설계되었다. 저감시설의 처리효율 평가는 실험실 규모로 수행되었으며, 3가지 유형의 유속[초기강우(120 mL/min), 일반적인 강우(242 mL/min), 집중호우(500 mL/min)]을 적용하여 실험을 진행하였고, 이를 통하여 수질 분석 및 물수지를 산정하였다. 실험결과, 저감시설의 입자상 물질 제거 효율은 90%이상으로 높게 분석되었다. 3가지의 유속변화 실험 중, 집중호우의 경우에서 11~91% 범위로 낮은 제거효율을 보였는데, 이는 다른 유속에 비해 짧은 체류시간을 갖기 때문으로 판단된다. 또한 저감시설의 물수지 산정결과 침투량은 유출량의 약 1%에 불과하여 향후 저감시설 설계 시, 침투를 증가시키기 위해서 시설하부의 토양치환 등을 통한 침투량 및 저류량을 증가시킬 수 있는 기술적 접근이 필요하며, 이는 오염물질의 저감에 크게 기여할 것으로 판단된다.

• 멤브레인
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• 제13권3호
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• pp.174-181
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• 2003

본 실험에서는 십자형 흐름 정밀여과 모듈에서 분리막 투과시 막표면에 일어나는 입자층의 형성을 고속비디오 시스템으로 관찰하였다. 공칭세공이 0.2 {\mu}m$ 정밀여과막과 기공크기보다 휠씬 큰 100 내지 180{\mu}m$ 크기의 polyacryl-copolymer 0.05 wt%의 농도 용액을 제조하여 투과실험에서는 공급유속을 0.5, 0.75, 1.0, 1.25 그리고 1.5 cm/sec으로 변화시키면서 공급유속의 $20{\pm}3%$로 투과유량을 유지하였다. 공급유량이 증가할수록 입자가 보다 신속히 분리막 표면에 축적되는 것을 관찰할 수 있었고 공급유량이 낮은 0.5 cm/sec 에서는 입자층이 형성되지 않았다. 또한 입자층 형성 후 공급 유속을 1.88 cm/sec로 증가시키면 30초이내에 분리막 표면에 입자들이 대부분 제거됨을 확인하였다.

• 한국물환경학회지
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• 제35권6호
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• pp.567-573
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• 2019

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 ㎥/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 ㎥/h/㎡. When one DABF basin is in the back washing mode, the loading rate of other two DABF basins is increased to 42 ㎥/h/㎡. 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.

• 대한환경공학회지
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• 제39권4호
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• pp.214-219
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• 2017

건물의 우수관에 연결하여 초기빗물의 부유물질을 처리할 수 있는 장치를 개발하기 위하여 건물옥상 유출 빗물의 수질특성 변화를 파악하고 다양한 여재를 활용해 초기빗물의 부유물질 제거를 연구하였다. 건물옥상 유출빗물의 입자성 물질은 대부분 $10{\sim}30{\mu}m$의 크기로, 부유물질 농도는 강우시 초기 10~20분까지 높았고 점진적으로 감소하였다. 옥상유출빗물의 용존성 유기물과 무기물의 농도도 유출 초기에 높게 나타났다. Anthracite (AC), Polyurethane (PU), Polypropylene (PP) 여재로 여과시 초기에 50%의 부유물질을 제거할 수 있었으나 20분 이상 여과시 제거율이 급격히 낮아졌다. 세척후 반복여과를 고려하면 AC 여재만 9회까지 재사용가능하였다. 여재층의 높이가 높을수록, 통과유량이 적을수록 시간에 따른 SS 제거율 감소폭은 적었고, 여재층 30 cm, 유량 12 L/min 이하로 운전할 경우 초기빗물(SS = 450 mg/L)의 SS 제거율 50%를 달성할 수 있었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.526-531
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• 2000

Application of electrodewatering (EDW) to mechanical dewatering system was studied to decrease water content in the sludge generated from waste water treatment process. Experiments realized the reduction of water content in the sewage sludge. EDW enhancing the conventional filtration by an electric field is an emerging technology with the potential to improve dewatering. In this study, a piston filter press was constructed, the digested sludges were dewatered by EDW under conditions of DC electric field and constant pressure in the piston filter press. Constant electric field from $0{\sim}120\;V/cm$ and constant pressure $98.1{\sim}392.4\;kPa$ were used. The results showed that as electric field was increased the dewatering rates increased and as pressure was increased the dewatering rates decreased. Also as polymer was added the dewatering rates increased. This experiments produced final sludge cake with water content of 60 wt% using EDW, compared with 80 wt% using pressure filtration alone.

• 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.

• ALGAE
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• 제39권1호
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• pp.51-56
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• 2024

The use of droplet digital polymerase chain reaction (ddPCR) has greatly improved the quantification of harmful protists, outperforming traditional methods like quantitative PCR. Notably, ddPCR provides enhanced consistency and reproducibility at it resists PCR inhibitors commonly found in environmental DNA samples. This study aimed to determine the most effective filter material for ddPCR protocols by assessing the reproducibility of species-specific gene copy numbers and filtration time across six filter types: cellulose acetate (CA), mixed cellulose ester (MCE), nylon (NY), polycarbonate (PC), polyethersulfone (PES), and polyvinylidene fluoride (PVDF). The study used two species of Chattonella marina complexes as a case study. Filtration rates were slower for NY, PC, and PVDF filters. Moreover, MCE, NY, PES, and PVDF yielded lower DNA amounts than other filters. Importantly, the CA filter exhibited the lowest variance (38-39%) and the highest determination coefficients (R² = 0.92-0.96), indicating superior performance. These findings suggest that the CA filter is the most suitable for ddPCR quantification of marine protists, offering quick filtration and reliable reproducibility.

• 한국해양바이오학회지
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• 제9권1호
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• pp.8-13
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• 2017

Cost-effective microalgae harvesting methods are necessary for economical production of algal biodiesel. In this study, membranes with various pore sizes and materials were examined for their potentials in application to gravity-filtration of Tetraselmis sp. KCTC12432BP. For this test, 10 L of Tetraselmis sp. culture (2 g/L) was loaded on each membrane and filtration rates were measured. Among the tested materials, a woven cotton fabric showed the fastest water drain rate (0.73 L/hr) without serious cell leakage. Cell density of the concentrates after filtration was 6.8 g/L, indicating 3.4-fold concentration compared with the initial algal culture. The result suggests that the woven cotton fabric could serve as filtration membrane for harvesting Tetraselmis sp. among the tested ones.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권4호
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• pp.1-12
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• 2010

Well production by a riverbank filtration facility with multi-radial collector well systems in Jeungsan-ri, Changnyeong gun, Korea was evaluated. In this study, the drawdown at collector wells due to pumping and groundwater inflow rates along the horizontal arms of the collector wells were computed through numerical simulations. Sensitivities of the well production to hydraulic conductivity and well flow coefficient, which represents the resistance to the flow from the aquifer to the horizontal arms, were analyzed. Simulation results showed that, with given proposed pumping rate conditions, the drawdown in the caisson exceeded maximum drawdown constraints in the study site and the adjustment of the pumping rate at each well is needed. The drawdown is affected by the hydraulic conductivity of the main aquifer and the well flow coefficient, which means the profound field investigation of the study site is needed to accurately estimate the efficiency of riverbank filtration through radial collector wells.

• 한국환경보건학회지
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• 제23권4호
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• pp.57-66
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• 1997

Successful energy conservation and good indcfor air quality (IAQ) are highly dependent on ventilation system. Air filtration is a primary solution of indoor air control strategies in terms of reducing energy consumption and improving ihdoor air quality. A conventional system with bypass filter, as it is called variable-air-volume/bypass filtration system (VAV/BPFS), is a variation of the conventional variable air volume (VAV) systems, which is designed to eliminate indoor air pollutant and to save energy. Bypass filtration system equipped with a high-efficiency particulate filter and carbon absorbent provides additional cleaned air into indoor environments and maintain good IAQ for human health. The objectives of this research were to compare the relative total decay rate of indoor air pollutant concentrations, and to develop a mathematical model simulating the performance of VAV/BPFS. All experiments were performed in chamber under the controlled conditions. The specific conclusions of this research are: 1. The VAV/BPFS system is more efficient than the VAV system in removing indoor air pollutant concentration. The total decay rates of aerosol, and total volatile organic compound (TVOC) for the VAV/BPFS system were higher than those of the conventional VAV system. 2. IAQ model predictions of each pollutant agree closely with the measured values. 3. According to IAQ model evaluation, reduction of outdoor supply air results in decreased dilution removal rate and on increased bypass filtration removal rate with the VAV/BPFS. As a results, we recommends the VAV/BPFS as an alternative to conventional VAV systems.