• 한국물환경학회지
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• 제37권6호
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• pp.433-441
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• 2021

The aim of this study was to optimize the ozonation and ceramic membrane integrated process for greywater reclamation. The integrated process is a repeated sequential process of filtration and backwash with the same ceramic membrane. Also, this study used ozone and oxygen gas for the backwashing process to compare backwashing efficiency. The study results revealed that the optimum filtration and backwash time for the process was 10 minutes each when comparing the filtrate flow and membrane recovery rate. The integrated process was operated at three different operating conditions with i) 10 minutes for filtration and 10 minutes for ozonation, ii) 10 minutes for filtration and 10 minute for oxygen aeration, and iii) continuous filtration without any aeration for synthetic greywater. The integrated process with ozone backwashing could produce 0.55 L/min of filtrate with an average of 18.42% permeability recovery, while the oxygen backwashing produced 0.47 L/min and 6.26%, respectively. And without any backwashing, the integrated process could produce 0.29 L/min. This shows that the ozone backwash process is capable of periodically recovering from membrane fouling. The resistance of the fouled membrane was approximately 34.4% for the process with ozone backwashing, whereas the resistance was restored by 10.8% for the process with oxygen backwashing. Despite the periodical ozone backwashing and chemical cleaning, irreversible fouling gradually increased approximately 3 to 4%. Approximately 97.6% and 15% turbidity and TOC were removed by ceramic membrane filtration, respectively. Therefore, the integrated process with ozonation and ceramic membrane filtration is a potential greywater treatment process.

• Membrane and Water Treatment
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• 제10권2호
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• pp.113-120
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• 2019

To investigate surface properties and interception performances of the new modified PVDF membrane coated with Graphene Oxide (GO) and nano-$TiO_2$ (for short the modified membrane) via the interface polymerization method combined with the pumping suction filtration way, filtration experiments of the modified membrane on Humic Acid (HA) were conducted. Results showed that the contact angle (characterizing the hydrophilicity) of the modified membrane decreased from $80.6{\pm}1.8^{\circ}$ to $38.6{\pm}1.2^{\circ}$. The F element of PVDF membrane surface decreased from 60.91% to 17.79% after covered with GO and $TiO_2$. O/C element mass ratio has a fivefold increase, the percentage of O element on the modified membrane surface increased from 3.83 wt% to 20.87%. The modified membrane surface was packed with hydrophilic polar groups (like -COOH, -OH, C-O, C=O, N-H) and a functional hydrophilic GO-polyamide-$TiO_2$ composite configuration. This configuration provided a rigid network structure for the firm attachment of GO and $TiO_2$ on the surface of the membrane and for a higher flux as well. The total flux attenuation rate of the modified membrane decreased to 35.6% while 51.2% for the original one. The irreversible attenuation rate has dropped 71%. The static interception amount of HA on the modified membrane was $158.6mg/m^2$, a half of that of the original one ($295.0mg/m^2$). The flux recovery rate was increased by 50%. The interception rate of the modified membrane on HA increased by 12% approximately and its filtration cycle was 2-3 times of that of the original membrane.

• 대한환경공학회지
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• 제35권7호
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• pp.518-524
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• 2013

다목적 여과저류지에서 모래여재의 여과수 여과능, 적정한 표층폐색 제거주기 그리고 오염제거효율 등 설계와 운영요소를 파악하기 위하여 서로 다른 3가지 입경의 낙동강 준설토를 채운 파일럿 규모의 테스트베드를 운영하였으며, 여과저류지에서의 다양한 인공하천의 유속을 모사하기 위하여 표류수 유속을 0~40 cm/sec로 단계적으로 변화시켰다. 운영결과 여재표층의 슬러지를 7~13일의 주기로 제거함으로써 여과수량을 5~3 $m^3/m^2-day$로 유지할 수 있었고, 여과수량과 여재입경 그리고 표류수 유속 등의 차이에 의한 여과수의 수질차이가 없음을 알 수 있었다. 대부분의 오염제거는 표층 50 cm 부근에서 발생함을 알 수 있었고, 여과거리 2.4 m에서의 오염제거율은 탁도 80~95%, COD 20~30%, BOD 75~90%, T-N 5~20% 그리고 T-P 20~60%로, 주로 입자성 오염물의 제거율이 높은 것으로 나타났다.

• 한국환경과학회지
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• 제27권10호
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• pp.831-844
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• 2018

Riverbank Filtration (RBF) is a kind of indirect artificial recharge method and is useful in obtaining higher-quality source water than surface water when procuring municipal water. This study evaluated optimal riverbank filtered water and the productivity of the radial collector wells on Ttansum Island in the area downstream of the Nakdong River, where Gimhae City is constructing a municipal water plant for the purpose of acquiring high-quality water. The RBF wells are planned to provide water to the citizens of Gimhae City through municipal water works. Groundwater flow modeling was performed with the following four scenarios: (a) 9 radial collector wells, (b) 10 radial collector wells, (c) 10 radial collector wells and two additional vertical wells, and (d) 12 radial collector wells. This study can be useful in determineing the optimum production rate of bank filtrated water not only in this study area but also in other places in Korea.

• 한국어병학회지
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• 제28권3호
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• pp.125-131
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• 2015

본 연구는 기계적 여과 후 자외선 살균처리한 양식장 유입수의 살균효율과 넙치 치어의 질병저감 효과를 평가하였다. 유입해수의 살균효율은 99.27%로 조사되었고, 기계적 여과 및 UV 살균처리 해수로 4개월 동안 사육한 넙치 치어는 대조구에 비하여 20~30%의 폐사율 저감효과가 관찰되었다.

• Membrane and Water Treatment
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• 제5권2호
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• pp.73-86
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• 2014

Membrane fouling is a major challenge limiting the use of membrane applications. In this study high induced shear rates were utilized at the membrane surface in order to reduce the organic and inorganic scaling by using the torsional vibration of flat sheet membranes. The performances of a vibratory shear-enhanced processing (VSEP) system for the ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membrane filtration of industrial dairy wastewater were investigated. The vibration and non-vibration methods were compared with the same membrane and operational parameters during the purification of real dairy industrial process wastewater. In the initial experiments, short-term tests were carried out in which the effects of vibration amplitude, recirculation flow rate and transmembrane pressure were measured and compared. The permeate flux, turbidity, conductivity and chemical oxygen demand (COD) reduction of dairy wastewater were investigated by using UF, NF and RO membranes with vibration and non-vibration methods. In the subsequent experiments, concentration tests were also carried out. Finally, scanning electron microscopy (SEM) revealed that the vibration method gave a better performance, which can be attributed to the higher membrane shear rate, which reduces the concentration of solids at the membrane, and the transmission.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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• pp.94-97
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• 2003

This study performed the research about the recycling basin supernatant by pre-coat filtration in the D water treatment plant at Gwangju. Choice the prompt conditions with diatomaceous earth filtration which makes contaminant reduced in the basin supernatant. Element disk of candle used in this experiment are pore size 10$\mu\textrm{m}$(R), 20$\mu\textrm{m}$(B) and 40$\mu\textrm{m}$(Y). Diatomaceous earth are cake pore size 3.5$\mu\textrm{m}$(A), 7$\mu\textrm{m}$(B) and 17$\mu\textrm{m}$(C). The filtrate concentrations were from 0.18 to 0.92$\mu\textrm{g}$/1 of Chlorophyll-a. And then, removal rate percentage were from 78.30 to 95.57(R-A). In addition SS 80%, CODMn32% COD 61%, T-N 10% and T-P 39% on the D water treatment plant. The R(40$\mu\textrm{m}$) C(17$\mu\textrm{m}$) process can be substituted of reusing the recycled water of recycling basin supernatant view of capacity and removal rate of filtrate.

• Biomolecules & Therapeutics
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• 제8권2호
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• pp.132-139
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• 2000

This study was performed far investigation of influence on renal function of idazoxan, $\alpha_{2}$-adrenergic antagonist, using the dog. Idazoxan, when giver. into vein, produced the decrease of urine volume(vol) accompanied with the reduction of free water clearance($C_{H2O}$), amounts of sodium excreted in urine($E_{Na}$), with the increase of potassium excreted in urine($E_{K}$), and so ratios of potassium against sodium($K^{+}/Na^{+}$) were elevated, at this time, greatened reabsorption rate of sodium and diministered that of potassium in renal tubules were appeared. Idazoxan administered into a renal artery elicited the augmentation of vol, glomerular filtration rate(GFR), renal plasma flow(RPF) and no change of filtration fraction(FF) in only ipsilateral kidney, whereas $E_{Na},\;E_{K}\;and\;K^{+}/Na^{+}$ were increased and $C_{H2O}$ was decreased in both control and experimental kidney. Idazoxan given into carotid artery showed partial increased vol, remarkable expanded RPF and unchanged GFR, and so filtration fraction(FF) was markedly reduced. Above results suggest that anti- diuretic action of idazoxan given into vein is mediated by reduction of $C_{H2O}\;and\;E_{Na}$, diuretic action only in the ipsilateral kidney by idazoxan given into a renal artery is caused by hemodynamic improvement through expansion of vas afferens in glomeruli.

• 상하수도학회지
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• 제13권3호
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• pp.61-72
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• 1999

To obtain the experimental data for design and operation of actual filtration processes, a sand filter and three kinds of dual media filters in pilot-plant scale were operated in this study. We analyzed the effect of filter medium composition on the filter performance and the effects of backwash water flow rates, length of stream line and air flow rate on the filter backwash efficiency. We also compared the efficiencies of the combined air-water backwashing and the water backwashing in dual media filters. As the backwash water flow rates or the length of stream line increased, the final turbidity of backwash water was decreased and the filtration duration time after backwash was increased. In the case of the combined air-water backwashing, the backwash water quantity needed for backwashing the dual media filters could be decreased. The total volume of filtered water for the dual media filters during filter run was over three times larger than that for the sand filter. The dual media filters could be operated at a high filtration rate of 360 m/day.

• Membrane and Water Treatment
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• 제9권5호
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• pp.343-351
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• 2018

As membrane fouling is based on various factors, it is a complex phenomenon that is hard to estimate. This study investigated membrane fouling in a thermophilic jet loop membrane bioreactor (JLMBR). With this purpose, four different empirical membrane fouling models with different sludge retention times were applied on the flow data obtained in the system. As a result of the model implementation, it was found for all sludge retention times that, standard blocking is effective in the first 1.5 hours of filtration, while cake filtration was dominant in the remaining duration. Additionally, it was observed that as the sludge retention time increases, membrane fouling rate decreases.