• 상하수도학회지
• /
• 제20권2호
• /
• pp.235-244
• /
• 2006

A PCF(Pore Controllable Fiber Filter) process was applied as a pretreatment of water treatment for reduction of turbidity. The experimental results obtained from the PCF showed that the removal efficiency of turbidity without coagulation was around over 70 percent. However, the removal efficiency of turbidity by the coagulation-PCF process was high as much as over 95%. Thus, the coagulation pretreatment was required for the better operation of the PCF. The SEM (Scanning Electron Microscope) images of fiber before and after filtration showed that the filtration mechanism of PCF filter is both controlling attachment mechanism and Sieving mechanism through fiber pore. For the coagulation-PCF process, optimum dosage of coagulant was needed for the economical operation, and for this, determining the optimum dosage by using a filter column test. Also only 16mg/L of alum was used to obtain high algae removal efficiency over 90%. Therefore, it can be concluded that coagulation-PCF process is very effective pretreatment process for algae removal.

• 상하수도학회지
• /
• 제19권2호
• /
• pp.135-143
• /
• 2005

It was evaluated that the effect of turbidity removal by Pore Controllable Fiber Filter(PCF) installed in NS(Naksang) small water treatmant plant(system) using under flow water as raw water in the study. The results of the study are as the followings. Firstly, the removal efficiency of turbidity by PCF without coagulation(in operation mode not using coagulants) was mostly below 20 percent. On the other hand, when operation using proper coagulants, that of turbidity was mostly over 80 percent. Secondly, slow sand filtration after PCF, total turbidity removal efficiency of final treated water was 84.3 percent, and the contribution by PCF was 57.1 percent and that of slow sand filtration was 27.7 percent. Therefore the introduction of PCF as pre-treatment process would be helpful to reduce the loading of high turbidity of slow sand filtration. Thirdly, the results of particle counter measurements showed that when operated PCF with coagulants, fine flocs captured or adsorbed at the pore of PCF were flow out into the effluents from 120 minutes after backwashing because of the increase of headloss of PCF. Therefore the decision of backwashing time should made consideration into the outflow of fine flocs from PCF. Fourth, coagulant dosages on PCF at the same turbidity was largely variable because of the effect of the raw water characteristics and the turbidity increase velocity at rainy days, therefore flexible coagulant dosages should be considered rather than fixed coagulant dosage by the influent jar-test result.

• 상하수도학회지
• /
• 제33권6호
• /
• pp.437-446
• /
• 2019

Reverse osmosis seawater desalination facilities can extend the cleaning cycle and replacement time of the reverse osmosis membrane by pretreatment process. Selection of pretreatment process depends on water quality. It was attempted in this study to select approriate pretreatment process for the Masan bay, which was high in particles and organic content. For this purpose, performances of pretreatment processes such as filter adsorber (FA), pore controllable fiber (PCF), and ultrafiltration (UF) were compared based on the silt density index (SDI). The SDI value of the filtrate should be less than 3. The study results showed that UF can produce the filtrate quality satisfying the requirement. However, the transmembrane pressure (TMP) of UF increased quickly, reaching 0.6 bar within 4 days. In order to secure stable operation, FA and PCF were combined with UF. The study results showed that combination of PCF and UF was able to extend the filtration duration (more than 2 months) until to reach TMP of 0.6 bar.

• 멤브레인
• /
• 제20권2호
• /
• pp.97-105
• /
• 2010

2009년 1월 3일부터 12월 1일까지 11개월간 공업용수를 주변지역에 공급하는 A정수장 응집침전조의 상등수를 대상으로 실험을 진행한 본 연구는 RO막 전처리 장치로서의 압력식 섬유여과기인 PCF 여과기 2대를 직렬연결한 공정의 적용 가능성을 평가한 것이다. 성능평가는 SDI (Silt Density Index)를 통해 간접적으로 RO막에 대한 전처리 성능을 평가하였다. 실험 기간 동안 PCF Filter로 유입된 원수의 탁도는 평균 0.79 (0.28~4.01) NTU이었으며, 처리수의 탁도는 평균 0.16(0.04~0.50) NTU로 탁도 제거효율은 평균 77%이었다. 일일 평균 처리유량은 약 230 $m^3$/day고 평균 역세유량은 8.7 $m^3$/day로 평균 역세수량은 3.8%로 나타났다. 여과수의 탁도 및 SDI 값은 측정 전 보관시간에 따라 증가하는데 이번 실험에서 몇몇 시료는 1~11일 동안 보관한 후 탁도 및 SDI가 측정되었으며, 이들 전체의 평균 SDI 값은 3.6 (2.26~5.00)으로 RO 제조업체에서 RO의 수명보증을 위해 통상 요구하는 SDI 값인 5.0 이하를 나타내었다. 따라서 RO 전처리공정의 SDI 측면에서 2단 섬유여과 공정이 적합함을 알 수 있었다.