• Journal of Environmental Science International
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• v.7 no.1
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• pp.74-80
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• 1998

Because permeate flux was very low as It has the suspension soled of higher concentration In the trafiltration membrane separation treatment of dyestuff wastewater, pre-treatment of Ponton reaction was carried out. In the case of pH 3, COD removal rate was the hi각erst of 58%. When PAC was added into the pre-treatment supernatant, the COD removal rate was found to be 53% , and when COD was 153mg/L, the removal rate was 92.3% in the trafiltration separation. In addition, the effect of the addition of PAC on the permeate flux was also investigated. The decrease of permeate flux In the presence of PAC was higher than In the abscence of PAC, but the recovery of permeability by cleaning was better In the case of PAC system.

• Journal of Environmental Science International
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• v.9 no.2
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• pp.173-176
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• 2000

This study was carried out to investigate the filtration characteristics of membrane modules according to hollow fiber dispersion for direct solid-liquid separation of activated sludge. 2 bundle, 4 bundle, and 10 bundle, and 10 bundle module used in this experiment according to hollow fiber dispersion was manufactured at laboratory and permeate flux and transmembrane pressure(TMP) of each module were observed under a suction pressure of 0.5kgf/c$m^2$. As the hollow fibers were dispersed, permeate flux was increased and TMP was decreased. Permeate flux and TMP of each module was 15.0 $\ell$/$m^2$.h and 31.8 cmHg for 2 bundle, 16.0 $\ell$/$m^2$ .h and 17.4 cmHg for 4 bundle, and 20.4 $\ell$/m2 .h and 31.8 cmHg for 10 bundle. In conclusion, the membrane fouling is expected to be decrease by maintaining lower TMP with hollow fiber dispersion.

• Korean Membrane Journal
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• v.11 no.1
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• pp.15-20
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• 2009

The periodic water-back-flushing using permeate water was performed to minimize membrane fouling and to enhance permeate flux in tubular ceramic ultrafiltration (UF) system for Gongji stream water treatment in Chuncheon city. The filtration time (FT), which was the water-back-flushing period, 2 min with periodic 15 sec water-back-flushing showed the highest value of dimensionless permeate flux ($J/J_o$), and the lowest value of resistance of membrane fouling ($R_f$), and we acquired the highest total permeate volume ($V_T$) of 6.35 L. Consequently FT 2 min at back-flushing time (BT) 15 sec could be the optimal condition in advanced UF water treatment of Gongji stream. Then the average rejection rates of pollutants by our tubular ceramic UF system were 99.4% for Turbidity, 31.8% for $COD_{Mn}$, 22.6% for $NH_3$-N and 65.9% for T-P.

• Membrane and Water Treatment
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• v.10 no.5
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• pp.321-330
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• 2019

The objective of this study was to examine the recovery of the power plant cooling tower blowdown water (CTBD) by membrane distillation. The experiments were carried out using a flat plate poly vinylidene fluoride (PVDF) membrane with a pore diameter of $0.22{\mu}m$ by a direct contact membrane distillation unit (DCMD). The effects of operating parameters such as transmembrane temperature difference (${\Delta}T$), circulation rate and operating time on permeate flux and membrane fouling have been investigated. The results indicated that permeate flux increased with increasing ${\Delta}T$ and circulation rate. Whereas maximum permeate flux was determined as $47.4L/m^2{\cdot}h$ at ${\Delta}T$ of $50^{\circ}C$ for all short term experiments, minimum permeate flux was determined as $7.7L/m^2{\cdot}h$ at ${\Delta}T$ of $20^{\circ}C$. While $40^{\circ}C$ was determined as the optimum ${\Delta}T$ in long term experiments. Inorganic and non-volatile substances caused fouling in the membranes.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.199-203
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• 1992

This study was aimed to optimize the required condition for recovering the low soluble taste component obtained from sea tangle extract using ultrafiltration, and to investigate effects of membrane type, temperature, transmembrane pressure and flow rate respectively. We also compared relationship between the profile of permeate flux and the recovery yield of taste component under the selected optimal condition using ultrafiltration and diafiltration. Hydrophobic GR 51 PP membrane kept higher average permeate flux than hydrophilic FS membrane, and average permeate flux also had increasing tendency in relation to rising flow rate but it showed limit value of 3.7 l/min. Average permeate flux decreased as transmembrane pressure increased but it showed little change with rising temperature. Investigation upon average permeate flux, total dissolved solid and recovery yield of taste components using ultrafiltration and diafiltration resulted in relatively higher recovery yield in ultrafiltration. Compared ultrafiltration and diafiltration, average permeate flux was lower in ultrafiltration.

• Membrane Journal
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• v.18 no.4
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• pp.354-361
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• 2008

Effects of operational conditions and solution chemistry on permeate flux in a hybrid ozone-ceramic ultra-filtration (UF) membrane system treating natural organic matter (NOM) were investigated. Results showed that the extent of permeate flux decline was higher at higher cross-flow velocity and ozone dosage, but it was higher at lower transmembrane pressure (TMP). The mechanism of fouling mitigation was found to be more dependent upon reaction between ozone and natural organic matter at/near catalytic membrane surface than scouring effect due to ozone gas bubbles. Addition of calcium into model NOM solution at high pH led to significant decline in permeate flux while the calcium effect on permeate flux decline was less pronounced at lower pH. After permeate flux decline during the early stage of filtration, the flux started recovering and approached fully to the initial value of it due to degradation of NOM by catalytic ozonation at ceramic membrane surface in the hybrid ozone-ceramic membrane system.

• Membrane Journal
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• v.21 no.3
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• pp.236-246
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• 2011

In this study, we used prepared a cylindrical module consisting 100 hollow fibers of commercialized (hydrophobic) polyethylene membrane of $0.4{\mu}m$ pore size and systematically studied performance of direct contact membrane distillation (DCMD) and sweep gas membrane distillation (SGMD) in terms of variation of permeate flux and salt rejection with respect to temperature drop across the membrane, salt concentrations in feed, and flow rates of cooling water and sweep gas. SGMD was regarded as DCMD with a sweep gas layer between permeate-side membrane surface and cooling water. Sweep gas flow decreases the permeate flux from that of DCMD by providing an additional gas-layer resistance. We compared DCMD and SGMD performance by using mass balance with a fitting parameter (${\omega}$), indicating fraction of permeate flow rate.

• Membrane Journal
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• v.8 no.2
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• pp.94-101
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• 1998

The oil separation is effectively performed from the oil containing alkaline cleaner solution by using a backflushed ultrafiltration system, where hollow fibers commercially made by polyacrylonitrile copolymer are bundled. Backflushing to reduce membrane fouling during crossflow ultrafiltration is investigated. Experimental observations allow us to understand the behavior of permeate flux according to the relative operating conditions, and determine the optimum condition of normal operation and backflushing. The maximum improvement of net permeate flux owing to backflushing was found to be about 23 % with the condition of 10 min/40 sec for the cycle of normal/backflushing operations. Note that, however, the maintenance of stable permeate flux is lost as the duration of normal operation is increased. The permeate flux depends on both the backflushing pressure and the feed flow rate. It is obvious that there is a critical velocity of feed flow, in which permeate flux is practically independent of backflushing pressure. Above this critical value, the permeate flux is proportional to an appropriate power of the backflushing pressure, $\Delta P_{back}^n$, where exponent n is enhanced with increasing feed velocity.

• Membrane Journal
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• v.8 no.1
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• pp.42-49
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• 1998

Effects of operating time, pH, temperature, concentration and addition of proteolytic enzyme on permeate flux for the ultrafiltration of gelatin and bovine serum albumin(BSA) solutions were studied. The results showed that permeate flux of gelatin solution was maintained almost constant during the operating time, and that of BSA solution was decreased to 66% of the initial value after 40 min operation. The permeate flux of gelatin solution was increased by increasing temperature. The permeate flux of BSA solution was constant in the temperature range of 30~$50{\circ}C$, but increased at $60{\circ}C.$. The permeate fluxes of gelatin and BSA solution showed minimum values near the isoelectric point of pH 5.0. The permeate fluxes of 1%(w/v) and 6% gelatin solution were $43.0l/m^2\cdot hr$ and $13.5l/m^2\cdot hr$, respectively. Those of 1% and 4% BSA solution were $33.0l/m^2\cdot hr$ and $14.0l/m^2\cdot hr$, respectively. The permeate fluxes of gelatin and BSA solutions were decreased to 68.6% and 57.6% of their initial values by increasing their concentration, respectively. The permeate fluxes of gelatin and BSA solutions were enhanced by 30% with the addition of proteolytic enzyme.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1615-1622
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• 2014

An accurate assessment of moisture content in feed ingredients is important because moisture influences the nutritional evaluation of feedstuffs. The objective of this study was to evaluate various methods for moisture content determination. In Exp. 1, the weight loss on drying (LOD) of corn, soybean meal (SBM), distillers dried grains with solubles (DDGS), whey permeate, whey powder, spray-dried porcine plasma (SDPP), fish meal, and a mixed diet of these 7 ingredients were measured by oven drying at $135^{\circ}C$ for 2 h. Additionally, the samples were dried at $105^{\circ}C$ for 3, 6, 9, 12, or 15 h. The LOD contents of the DDGS, whey permeate, and whey powder measured by drying at $135^{\circ}C$ for 2 h were greater than the values measured by drying at $105^{\circ}C$ for 3 h (p<0.05). All samples except SDPP (p = 0.70) dried at $105^{\circ}C$ for 6, 9, 12, or 15 h caused more LOD compared with the samples dried for at $105^{\circ}C$ for 3 h (p<0.05). The LOD contents of the individual ingredients were additive when dried at $105^{\circ}C$ regardless of drying time. In Exp. 2, moisture contents of corn, SBM, wheat, whey permeate, whey powder, lactose, and 2 sources of DDGS (DDGS1 and DDGS2) were measured by the Karl Fischer method, oven drying at $135^{\circ}C$ for 2 h, and oven drying at $125^{\circ}C$, $115^{\circ}C$, $105^{\circ}C$, or $95^{\circ}C$ for increasing drying time from 1 to 24 h. Drying samples at $135^{\circ}C$ for 2 h resulted in higher moisture content in whey permeate (7.5% vs 3.0%), whey powder (7.7% vs 3.8%), DDGS1 (11.4% vs 7.5%), and DDGS2 (13.1% vs 8.8%) compared with the Karl Fischer method (p<0.05). Whey permeate and whey powder were considerably darkened as the drying time increased. In conclusion, drying samples at $135^{\circ}C$ for 2 h is not appropriate for determining the moisture content in whey permeate, whey powder, or DDGS as well as the mixed diet containing these ingredients. The oven-drying method at $105^{\circ}C$ for 5 to 6 h appears to be appropriate for whey permeate and whey powder, and at $105^{\circ}C$ for 2 to 3 h for DDGS.