• Membrane and Water Treatment
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• v.9 no.4
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• pp.279-284
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• 2018

Membrane biofouling is a critical operational problem that hinders the rapid commercialization of MBRs. Quorum quenching (QQ) has been investigated widely to control membrane biofouling and is accepted as a promising anti-fouling strategy. Various QQ strategies based on bacterial and enzymatic agents have been identified and applied successfully. Whereas, this study aimed to compare indigenously isolated QQ strain i.e., Enterobacter cloaca with well reported Rhodococcus sp. BH4. Both bacterial species were immobilized in polymeric beads and introduced to two different MBRs keeping the overall beads to volume ratio as 1%. Efficiencies of these strains were monitored in terms of prolonging the membrane filtration cycle of MBR, release of extra-cellular polymeric substances, membrane resistivity measurements and mineralization of signal molecules and permeate quality. Indigenous strain (Enterobacter cloaca) was added to $QQ-MBR_E$ while Rhodococcus sp. BH4 was introduced to $QQ-MBR_R$. QQ bacterial embedded beads showed enhanced filtration cycles up to 1.4 and 2.3 times for $QQ-MBR_E$ and $QQ-MBR_R$ respectively as compared to control MBR (C-MBR). Soluble EPS concentration of 52 mg/L was observed in C-MBR while significantly lower EPS concentration of 20 and 10 mg/L was witnessed in $QQ-MBR_E$ and $QQ-MBR_R$, respectively. Therefore, substantial reduction in biofouling showed the effectiveness of indigenous strain.

• Food Science and Preservation
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• v.10 no.4
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• pp.482-487
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• 2003

The filtration effects of glass membrane filters and hollow fiber membranes with different pore size to prevent the haze of a commercial foxtail millet Yakju were investigated. The most particles(haze precusors) present in the Yakju were removed by using 1.2 $\mu\textrm{m}$ glass membrane filter. In case of using 0.45$\mu\textrm{m}$ hollow fiber membrane system, the permeate flux on the Yakju filtration was calculated to 342.8 lmh. During the 3 month storage at 4$^{\circ}C$ and room temperature for each 48 hrs in turn, alittle fine haze was observed from the Yakju even if it was filtered by using 0.7 $\mu\textrm{m}$ glass membrane filter. Anything of haze was, however, observed from the Yakju filtered by using all of hollow fiber membranes. Therefore, the 0.45$\mu\textrm{m}$ hollow fiber membrane system was effective as a final filtration process of the Yakju.

• Clean Technology
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• v.9 no.3
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• pp.107-113
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• 2003

Printing process generates a vast amount of toxical waste and wastewater by the development of printing and publishing industry. The regulations for various environmental pollution material, which were indispensably used in printing industries, were getting stronger. The printing industries should develop the cleaner technologies in order to avoid the regulations. In this paper, the separation characteristics of microfiltration, ultrafiltration, reverse osmosis were surveyed to make basic data for the optimization of process as cleaner technologies for printing industries. The $2kg/cm^2$ of operation pressure were suitable to the U/F System. Because of the permeate of U/F was below 3 NTU as turbidity, which was probed to be possible using the rinsing water in printing process. U/F System,

• Clean Technology
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• v.18 no.4
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• pp.360-365
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• 2012

With rapid increase in municipal solid waste (MSW) due to the rising economy, solid waste gasification emerges as one of the promising technologies. Separation of the carbon monoxide (CO) and hydrogen ($H_2$) from syngas obtained by gasification of MSW was studied using the polyamide composite membrane. The separation characteristics of the CO and $H_2$ were studied at different gas flow rates and stage cuts. The permeability of CO and $H_2$ along with the selectivity of $H_2$ with respect to CO was obtained. Furthermore, the Arrhenius plots were obtained to estimate the activation energies of CO and $H_2$ permeabilites.

• Membrane and Water Treatment
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• v.2 no.4
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• pp.251-266
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• 2011

This work deals with the use of High Resolution Scanning Electron Microscopy (HRSEM) to verify ultrafiltration membrane selectivity at the end of the production line as well as membrane ageing. The first part of this work is focused on new membranes. It is shown that it is better to use sputtering metallization than vacuum deposition, as this latter technique entails thermal damage to the skin layer. Moreover, the impact of the metallization layer on the determination of the membrane pore size is studied and it is observed that no impact of the metallization step can be clearly defined for a metallization layer ranging from 3 to 12 nm. For example, an average pore size of 16.9 nm and a recovery rate of 6.5 % are observed for a 150 kDa cellulose acetate membrane. These results are in agreement with those given by the manufacturer: pore size ranging from 10 to 15 nm and recovery rate ranging from 5 to 10 %. The second part of this work focuses on the study of membrane ageing. A PVDF hollow fibre membrane is studied. It is shown that a 65 % decrease in the permeate flux can be linked to a decrease in the number of pores at the surface of the membrane and a decrease in the recovery rate. In conclusion, a mapping of the pores is performed for several new hollow fibre membranes used to produce drinking water, made of different materials, with different geometries and molecular weight cut-off. These results provide reference data that will help better understand the phenomena of membrane fouling and membrane ageing.

• Membrane Journal
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• v.5 no.2
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• pp.74-80
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• 1995

Asymmetric poly(vinyl alcohol) (PVA) membranes were prepared by varying the precipitation conditions of the phase inversion technique, and the influences of precipitation conditions on the water uptake of the membrane were investigate. The degree of water uptake of the membrane increased and reached a certain maximum value, as the precipitation time increased. However, it decreded after that. As the precipition temperauure became lower, the degree of water uptake increased more or less. The addition of a nonionic surfactant to the precipitaon solution was effective reducing the precipitation time by lowering the surface tension of the precipitation solution, but ig didn't change the maximum value of its own degree of water uptake. In addition, the relationship between the degree of water uptake and the separation characteristics and mechanical properies of the membrane were investigated. The selectivity factor of the membrane for pervaperation separation decreased, but the permeate flux increased, respectively, with increasing the degree of water uptake. The tensile strength and elongation of the membrane, respectively, increased to a maximum value with increasing the degree of water uptake, and then decreased abtuptly.

• Membrane Journal
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• v.6 no.1
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• pp.44-52
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• 1996

For the purpose of the optimal design of a frame and plate type of pervaporation module, model equations which can predict the effects of feed flow condition on the temperature distribution of the feed developed in the module were established and the temperature distribution with feed flow condition was investigated through the model si$$\mu$ation. With increasing the Reynolds number of feed flow in the module, the flow velocity gradient in the channel height-direction as well as the volume rate of feed which acts as energy source for the evaporation of perrneants on the permeate-side surface of a membrane increased to such an extent that both mass and heat flux in the channel height direction could increase and the temperature drop of feed due to the evaporation of the permeant could be reduced correspondingly. A decrease in channel height caused the temperature drop of feed because of decreasing feed flow in the module. It was observed that the si$$\mu$ation result on the effect of Re on the temperature distribution of feed in the module has an agreement with experiment.

• Membrane Journal
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• v.21 no.4
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• pp.351-359
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• 2011

For advanced drinking water treatment of high turbidity water, we used the hybrid process that was composed of photocatalyst packing in space of between outside of multi-channel ceramic microfiltration membrane and membrane module inside. Photocatalyst was polypropylene (PP) beads coated $TiO_2$ powder by CVD (chemical vapor deposition) process. Instead of natural organic matters (NOM) and fine inorganic particles in natural water source, standard NOM solution was prepared with humic acid and kaolin. Water-back-flushing of 10 sec was performed per every period of 10 min to minimize membrane fouling. Resistance of membrane fouling ($R_f$) increased and J decreased as concentration of humic acid changed from 2 mg/L to 10 mg/L, and finally the highest total permeate volume ($V_T$) could be obtained at 2 mg/L. Then, treatment efficiency of turbidity and $UV_{254}$ absorbance were above 96.4% and 78.9%, respectively. As results of treatment portions by membrane filtration, photocatalyst adsorption, and photo-oxidation in (MF), (MF + $TiO_2$), (MF + $TiO_2$ + UV) processes, turbidity was treated little by photocatalyst adsorption, and photo-oxidation. However, treatment portions of $UV_{254}$ absorbance by adsorption (MF + $TiO_2$) and photo-oxidation (MF + $TiO_2$ + UV) at humic acid of 4 mg/L and 6 mg/L were above 9.0, 9.5 and 8.1, 10.9%, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2079-2086
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• 2014

Shipbuilding production management is one of the most significant activities in productivity improvement. Shop-floor managers and production planners still do not have enough production information for shop-floor scheduling due to shortage of information sharing among them. In this research, main issues were derived from requirement analysis between production planning and shop-floor control to establish a software system architecture for ship production monitoring system(SPMS), which is developed with component based design(CBD). The proposed system's key functions cover from block shop assembly to quay outfitting stage to visualize production progress as well as to maximize production information sharing. The system will allow more reliable and accurate production information to permeate down to members of the workforce just in time.

• Membrane Journal
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• v.8 no.2
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• pp.86-93
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• 1998

A permeation apparatus has been devdoped which could make the on-line measurements of both flux and permeate composition. Pervaporative experiment of a single component, i.e. water was performed by using poly(vinyl alcohol) membrane crosslinked with glutaraldehyde to confirm the validity of the apparatus. In the experiment, steady-state permeation was obtained in 15 minutes and the measurement could be completed within 20 minutes. A comparison of the on-line measurement was made with the fluxes measured simultaneously by the conventional method in which the permeates were collected by liquid nitrogen. The on-line measurement by the apparatus showed an excellent agreement with the conventional measurement within a difference of $\pm$2%. From the flux data with operating time, 3 kinds of diffusion coefficients of water $D_{slope}, D_{1/2}$, and $D_t$ were determined, which were also coincident with values in a literature. It was confirmed that accurate measurements of fluxes could be obtained from the apparatus.