• Membrane Journal
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• v.9 no.4
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• pp.202-208
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• 1999

The car washing effluent containing various oils and detergent was treated by ultrafiltration membranes. Dead-end type stirred cell (Amicon 8050) with 10, 30 and lOOk dalton membranes was used to determine permeation and rejection characteristics for the car washing effluent. In case of low molecular weight cut-off membranes, the effect of membrane fouling was weak under the applied pressures. However, the permeation flux for YM100 membrane(look dalton) may be affected by oil layer formation on the membrane surface as well as oil particle plugging for a part of membrane pores due to compressible and deformable oil properties. Oil and particle rejections in the permeates were over 95%, but detergent was passed easily through the membranes. Hence, the permeates containing detergent can be recycled to the system, and may reduce water pollution. Also, the car washing effluent was treated continuously by a capillary type ultrafiltration membrane of MWCO 50k dalton. The experimental data were fitted suitably to the cake filtration model.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.950-955
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• 1998

The objective of this study was to investigate the effect of running time, operating pressure, feed concentration and circulation rate on the permeation flux and the rejection rate in cross-flow ultrafiltration of polyethylene glycol(PEG) solution of molecular weight($M_w$) 8000 and 20000. The membranes used for this study were MWCO(Molecular Weight Cut-off) of 6 K and 20 K. The experiments were performed at the operating pressures of 7, 14 and 28 psi, the circulation rates of 1000 mL/min and 2000 mL/min, and the feed concentration of 100 mg/L and 1000 mg/L. At a constant pressure, the permeation flux and the observed rejection($R_o$) appeared to be approximately constant within the range of running time, 0~480 min. The permeation flux increased with increasing the operating pressure, and it increased with decreasing the feed concentration and decreasing Mw of PEG at a given pressure. On the other hand, $R_o$ decreased slightly with increasing the operating pressure. However, $R_o$ increased with increasing the feed concentration and increasing of $M_w$ of PEG at a given pressure. The variation in circulation rates did not cause any significant influence on the permeation flux. Increasing of circulation rate caused the increase of $R_o$, and $\alpha$ was increased substantially with the decrease of $M_w$ of PEG. The dimensionless parameter. permeability ratio($\alpha$), which was used to investigate flux-pressure behavior, was increased with the increase in circulation rate and operating presure. The value of $\alpha$ was less than 1 in all cases. The estimated intrinsic rejection(R). which was obtained from mass transfer coefficient, was decreased with the increase of operating pressure. However R increased with the increase of linear velocity of feed and $M_w$ of PEG.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.417-426
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• 1997

Rice bran protein hydrolysates were prepared and some of their physicochemical properties were investigated to utilize rice bran as starting material for functional food ingredient. Rice bran proteins (RBP) were prepared from defatted rice bran by alkaline extraction and isoelectric precipitation. The enzyme for hydrolysis of RBP was selected through measuring relative activity by pH-drop method and comparing the degree of hydrolysis (DH) of hydrolysates. The enzymatic hydrolysates prepared by $Esperase^{\circledR}$ treatment were partitioned into two fractions by ultrafiltration(UF) with a 10 kDa molecular weight cut-off membrane. Each fraction was applied to a cholic acid-conjugated ${\omega}-aminohexyl$ Sepharose 4B column and the bile acid-binding components were obtained by eluting with deoxycholate. Gel permeation chromatography on a Sephadex G-50 column revealed that molecular weight of the bile acid-binding fraction of UF permeate was distributed in ranges of $2\;kDa{\sim}10\;kDa$ and $0.2\;kDa{\sim}0.6\;kDa$. Three peaks (R-1, R-2 and R-3) were obtained by prep-HPLC of bile acid-binding fraction of UF retentate and analyzed for total and free amino acid composition. The results showed that proline content of the bile-acid binding polypeptides and peptides was four times as much as that of rice bran protein and that the peak corresponding to higher average hydrophobicity had a higher free amino acid content. Average hydrophobicity slightly increased with enzymatic hydrolysis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.198-204
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• 2000

In order to utilize by-products which would normally be discarded in marine processing plants, cod teiset protein was hydrolyzed and antioxidative actiTity of the hydrolysate was investigated. AntioxidatiTe peptide was isolated using ultrafiltration membrane, ion-exchange chromatography on a SP-Sephadex C-25 column, gel filtration on a Sephadex G-15 column, high performance liquid chromatography on an ODS column, and capillary electrophoresis chromatography. Antioxidative activities of the cod teiset hydrolysate were compared with ${\alpha}-tocopherol$, one of the commercial antioxidant. The hydrolysate passed through a membrane with molecular weight cut-off (MWCO) 1 kDa was shown the strongest antioxidative activity, and the activity was higher $10{\%}$ as compared with ${\alpha}-tocopherol$. In addition, the peptide isolated by ion-exchange chromatography, gel filtration, and HPLC, respectively, was higher $53{\%}$ as compared with ${\alpha}-tocopherol$, and the amino acid sequence was Ser-Asn-Pro-Glu-Trp-Ser-Trp-Asn.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.635-641
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• 2000

In order to utilize the protein source from a fish proessing by-product, cod was hydrolyzed with various enzymes such as tuna pyloric caeca crude enzyme (TPCCE), a-chymotrypsin, trypsin, papain and pronase E. The TPCCE hydrolysate acquired the highest sensory properties on taste, odor and color. The resultant cod rfame protein hydrolysate (CFPH) which was hydrolyzed with TPCCE, was separated through a series of ultrafiltration membranes with molecular weight cut-off (MWCO) of 30, 10, 5 and 1 kDa, and four types of permeates in cluding 30 K (permeate from 30 kDa membrane), 10 K (permeate from 10 kDa membrane), 5 K (permeate from 5 kDa membrane) and 1 K (permeate from 1 kDa membrane) were obtained. The natural sauces were prepared with 30 K, 10 K, 5 K and 1 K hydrolysate, and the sauce prepared with 1 K hydrolysate was the best score in sensory evaluations. In addition the mixed sauce prepared with 1 K hydrolysate and commercial soy sauce was similar to commercial sauce in sensory properties. These results suggest that the mixed sauce would be utilized as the substitute of acid-hydrolysis sauce.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.10
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• pp.1047-1053
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• 2008

This study was to evaluate the optimum conditions for chemical coagulation to remove color from the effluent of a piggery wastewater treatment process. The DOC concentration in the effluent was about 227.3 mg/L, color was 2,430 CU, turbidity was 22.1 NTU, and UV$_{254}$-absorbance was 3.7 cm$^{-1}$. The fractions of hydrophobic, transphilic, and hydrophilic substance of the effluent was about 55.3%, 17.4%, 27.3% respectively. Also, molecular weight cut-off(MWCO) of below 0.5 K, 0.5 K to 1 K, 1 K to 10 K, 10 K to 30 K, and over 30 K were 74.2%, 7.3%, 5.5%, 7.1%, and 5.9% respectively. SCD(streaming current Detector) was used to find out the optimum pH values and coagulant dosages. The optimum dosages and pH of Al$^{3+}$ were 5.84 mM and 5.3, while those of Fe$^{3+}$ were 9.25 mM and 5.0, respectively. At optimum conditions of coagulation, color removal efficiencies for aluminium sulfate and ferric chloride were as high as 91.9 and 98.7%, respectively. Chemical coagulation showed good performance to remove color from on biologically treated piggery wastewater.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.339-347
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• 2000

An algicidal bacterium, Micrococcus sp. LG-5 against the harmful dinoflagellate, Cochlodinium polykrikoides was isolated. The optimal conditions for the highest algicidal activity of bacterial culture filtrate showed in the range of $20{\~}30^{\circ}C$, at pH 7.0 and $3.0{\%}$ of NaCl concentration. In addition, $IC_(50)(mean of 50{\%} inhibitory concentration)$ of the culture filtrate against C. polykrikoides after incubation of 5 days was $0.482{\%}$. To investigate heat and pH stability of the culture filtrate of Micrococcus sp. LG-5, the culture filtrate ($pore size, 0.1 {\mu}m$) was heated to $121^{\circ}C for 15 min$ and adjusted pH from 2.0 to 10.0. There were no significant changes in algicidal activity by heat treatment and the pH change between pH from 5.0 to 10.0. The algicidal substances produced from Micrococcus sp. LG-5 were mainly detected in the fraction of $10,000{\~}1,000$ MWCO (molecular weight cut-off). The culture filtrate of Micrococous sp. LG-5 showed antimicrobial activity against Enterococcus faecalis, Escheiichia coli, Uebsiella pneunioniae and Vibrio altinolyticus, but did not show against Pseudomonas aeminosa, P. Buorescens, Salmonella typhi, Staphylococcus aureus, V. cholerae and V parahaemolyicus. The culture filtrate of Micrococcus sp. LG-5 was examined against 16 phytoplankton species and showed the algicidal activity against Ajexandzium tuarense, Eutreptiella Drnnastin, Gymnodinium catenatum, G. mikimotoi, G. sanguineum, eyodinium impuaicum, Heterocapsa triquetra, Heterosipa akashiwo, Prorocentrum micans and Pyraminonas sp.. However no algicidal effects of Micrococcus sp. LG-5 were observed against Chlamydomonas sp., Cylindrotheoa closterium, P. mininum, P. triestimum, Pseudonieschia sp. and Sczipuiella trochoidea. On the other hand, algicidal activity on the tested marinelivefood was not detected except for Isochrysis galbana. In addition, physiological responses of cultured olive flounder (Paralichthys oliraceus) exposed to $1 and 10{\%}$ of the culture filtrate of Micrococcus sp. LG-5 were measured. There were no clear changes in AST, GGT, creatinine, urea, total cholesterol, total protein, albumine, $Mg^(+2), Ca^(+2), Na^+, K^+, and Cl^-$. These results indicate that olive flounders were not affected when they were exposed to the culture filtrate of Micrococcus sp. LG-5.