• Title/Summary/Keyword: rapid filtration

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Impact of quorum quenching bacteria on biofouling retardation in submerged membrane bioreactor (SMBR)

  • Pervez, Saimar;Khan, Sher Jamal;Waheed, Hira;Hashmi, Imran;Lee, Chung-Hak
    • 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.

Pretreatment and Rapid Detection Methods for Wastewater-Based Epidemiology (하수역학 구축을 위한 시료 전처리 기술과 신속검출기술)

  • Lee Jai-Yeop;Lee Bokjin;Jesmin Akter;Ahn Chang Hyuk;Kim Ilho
    • Journal of Korean Society on Water Environment
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    • v.39 no.1
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    • pp.102-110
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    • 2023
  • Wastewater Based Epidemiology (WBE) provides useful information not only on the use of illegal drugs in the community, but also on the presence of hygiene and health products and infectious pathogens in sewage facilities. As a consequence of the SARS-CoV-19 virus epidemic in 2019, monitoring the status of the infection is of utmost importance. SARS-CoV-19 was also detected in sewage, and the number and trend of infections in the community suggest that the application of the WBE system would be useful and appropriate. This study introduces a pre-treatment concentration method including viruses in sewage samples. A total of seven methods which were subdivided into methods for adsorption-extraction, ultra-filtration, PEG precipitation, and ultra-centrifugation, and the results for analyzing the recovery rates were included. Meanwhile, it is necessary to pay attention to rapid detection technologies which analyze infectious pathogens at the site of sewage facilities. These can include ELISA, FTIR, SERS, and biosensor based on the detection principle, and the characteristics, advantages, and disadvantages of each were summarized herein. If rapid detection technologies and accurate quantitative analyses are further developed, the use of sewage mechanics in response to pandemic viruses is expected to expand further.

Determination of Optimal Coagulation Condition for Coagulation-UF Water Treatment Process (응집-UF 정수공정을 위한 칠적응집조건의 결정)

  • Lee, Chul-Woo;An, Su-Kyong;Kang, Lim-Seok
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.8
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    • pp.799-806
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    • 2005
  • Applying coagulation process before membrane filtration showed not only reducing membrane fouling, but also improving the removal of dissolved organic materials that might otherwise not be removed by the membrane alone. Also, slow mixing didn't affect the reduction of membrane fouling, and rapid mixing using an in-line static mixer was more effective than using backmixer. In addition, only 11 percent of dissolved organic matter in raw water was the primary cause of fouling. Furthermore, tile primary foulant of UF membrane was hydrophobic substance, which can easily be removed by coagulation.

Evaluation of Rapid IgG4 Test for Diagnosis of Gnathostomiasis

  • Wang, Yue;Ma, An;Liu, Xiao-Long;Eamsobhana, Praphathip;Gan, Xiao-Xian
    • Parasites, Hosts and Diseases
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    • v.59 no.3
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    • pp.257-263
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    • 2021
  • Human gnathostomiasis is a parasitic disease caused by Gnathostoma nematode infection. A rapid, reliable, and practical immunoassay, named dot immuno-gold filtration assay (DIGFA), was developed to supporting clinical diagnosis of gnathostomiasis. The practical tool detected anti-Gnathostoma-specific IgG4 in human serum using crude extract of third-stage larvae as antigen. The result of the test was shown by anti-human IgG4 monoclonal antibody conjugated colloidal gold. The sensitivity and specificity of the test were both 100% for detection in human sera from patients with gnathostomiasis (13/13) and from healthy negative controls (50/50), respectively. Cross-reactivity with heterogonous serum samples from patients with other helminthiases ranged from 0 (trichinosis, paragonimiasis, clonorchiasis, schistosomiasis, and cysticercosis) to 25.0% (sparganosis), with an average of 6.3% (7/112). Moreover, specific IgG4 antibodies diminished at 6 months after treatment. This study showed that DIGFA for the detection of specific IgG4 in human sera could be a promising tool for the diagnosis of gnathostomiasis and useful for evaluating therapeutic effects.

Purification of Staphylococcal Enterotoxin A (Staphylococcal Enterotoxin A 의 분리 정제)

  • Lee, Jeong-Hee;Shin, Hyun-Kil;Kim, Jong-Bae;Kim, Jae-Jong;Yoon, Hao-Jung
    • Korean Journal of Food Science and Technology
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    • v.20 no.6
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    • pp.780-786
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    • 1988
  • In order to investigate the most efficient and rapid method for the purification of enterotoxin A from Staphylococcus aureus M 7/1, various methods such as ion-exchange chromatography on Amberlite, and CM-cellulose. gel filtration on Sephadex G-50, 75, 100 and Sephacryl, and fast protein liquid chromatography (FPLC) were applied and compared in terms of purity and speed. Although ion-exchange chromatography on Amberlite resin was good enough to remove other materials in culture medium from enterotoxin, and convenient, and fast method, the purity of this method was less than 70%. However. carboxymethyl ion-exchange column showed to be better purity than that of Amberlite method. The yields of these two methods were about 70% and 75%, respectively. When gel filtration methods on Sephadex G-50, 75, 100 and Sephacryl were applied, the purity was about 90%. Fast protein liquid chromatography was found to be the most efficient method in terms of purity (97%) and speed. The combined method, gel filtration after CM-cellulose column (stepwise elution) treatment can be also used as a efficient method particularly for the purification of large volume of sample.

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A Study on the Diatomaceous Earth Filtration of Settling Basin Effluent (정수장 침전지 유출수의 규조토 여과에 관한 연구)

  • Shin Dae-Yewn;Ji Sung-Nam;Moon Ok-Ran;Kim Ji-Yeong;Suh Dong-Woo;Cho Young-Kwan
    • Journal of Environmental Health Sciences
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    • v.30 no.5 s.81
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    • pp.410-416
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    • 2004
  • The objective of this investigation was to evaluate applicability of precoat filtration that can be substituted for rapid sand filter of conventional water treatment system(CWTS). Precoat filter used in this experiment are candle filter. Element disk of candle are pore size $10{\mu}m(R),\;20{\mu}m(B)$ And diatomaceous earth are cake pore size $3.5{\mu}m$(Standard Super- Cel; A), $7{\mu}m$(Hyflo Super-Cel; B) and $17{\mu}m$(Celite 545RV; C). $2kg/m^2$ diatomaceous earth is used for precoating, it coated candle in $5{\sim}6mm$ thickness. 1. Al adsorption dosages by diatomaceous earth used in experimental we Hyflo Super-Cel 0.843mg/g, Standard Super-Cel 0.782 mg/g and Celite 545RV 0.766 mg/g. 2. Filtrate of precoat filter during 60min are R-C combination 20.7($m^3/m^2$)>B-C 18.3($m^3/m^2$)>B-B 15.0($m^3/m^2$)> R-B 12.9($m^3/m^2$)> R-A 11,093($l/m^2$). 3. Water quality of precoat filter effluent are thus. $KMnO_4$ consumption are $1.10{\sim}2.20mg/l$, removal rate are $30.9{\sim}65.6\%$. They are R-A 1.10(mg/l)(removal rate $65.6\%$). R-C(2.20 mg/l)(removal rate $30.9\%$). 4. $Al^{3+}$ are not detected with all combination, removal rate $100\%$. 5. Considering water quality and flux, continued running time of R-A combination is 7 hr. Accumulated filtrate are $74.4 m^3/m^2$, average flux is $177.2 l/m^2{\cdot}min$. And filtrate per diatomaceous earth 1g are 37.2 l. 6. R-A effluent's water quality are $KMnO_4$ Consumption 1.10(mg/l), DOC 1.161 mg/1, Al 0.0 mg/1, $UV_{254}$ 0.016/cm, Turbidity 0.1(NTU). R-A combination is suitable to precoat filtration for the settling basin effluent treatment.

Abscisic Acid Binding to Extracts from Normal and Viviparous-1 Mutant Aleurone Layers of Zea mays L.

  • Bai, Dong-Gyu
    • Journal of Plant Biology
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    • v.37 no.2
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    • pp.151-158
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    • 1994
  • Aleurone layers of normal and vp1 mutant maize kernels were extracted and centrifuged at 100,000g to yield a cytosol fraction. Binding of [3H]ABA cis, trans (+)ABA to a soluble macromolecular components present in the cytosol was demonstrated by Sephadex chromatography and non-denaturing PAGE. The binding component was of high molecular weight and seems to be an aggregate of proteins. A rapid DEAE-cellulose filter method for assaying bound [3H]ABA to a soluble protein was adapted. Binding assays were performed with cytosol that had been preheated or incubated with several enzymes, indicating that heat and protease treatments disrupted the binding. This suggested that binding occurred to proteins. Some properties of the ABA binding proteins were described. The [3H]ABA binding were reduced dramatically when unlabeled ABA was added as a competitor, suggesting a specific binding of [3H]ABA. Gel filtration profiles and autoradiogram of [3H]ABA binding showed no difference in the binding components of Vp1 and vp1/vp1 mutant cytosol, indicating that Vp1 protein is not a sole ABA binding protein.

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Antibacterial Activity of Enzymatic Hydrolyzates of Lactoferrin derived from Korean Native Cattle (한우 Lactoferrin 가수분해물의 항균 활성)

  • 이수원;양희진
    • Food Science of Animal Resources
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    • v.18 no.4
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    • pp.316-321
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    • 1998
  • In this study, we carried out to isolate lactoferrin from Korean native cattle and Holstein cow by batch extraction, ion exchange chromatography, gel filtration, and affinity chromatography. The purity of the isolated lactoferrin was higher than that of lactoferrin purchased from Sigma, when determined by SDS-PAGE and HPLC analysis. Antibacterial activity of E. coli O111 by Korean native cattle lactoferrin was lower than that of Holstein lactoferrin. A minimal inhibitory concentration(MIC) of Korean native cattle lactoferrin and Holstein lactoferrin was 2.75 mg/ ml and 1.5 mg/ml respectively. The lactoferrin hydrolyzate of Korean native cattle exhibited antimicrobial activity at 0.25 mg/ml, whereas that of Holstein cow exhibited antimicrobial activity at 0.12 mg/ml. The antibacterial potency of the hydrolyzate was at least tenfold greater than that of undigeated lactoferrin with strains tested. The effect of hydrolyzate was bactericidal as indicated by rapid loss of viability of E. coli O111.

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Membrane Concentrate Thickening by Hollow-fiber Microfilter in Drinkin Water Treatment Processes

  • Lee, Byung-Ho
    • Korean Membrane Journal
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    • v.1 no.1
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    • pp.100-105
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    • 1999
  • A novel system to thicken the concentrated colloidal solution from membrane water treat-ment processes was developed. A hollow-fiber microfilter(hydrophilic polyethylene nominal pore size 0.1 ${\mu}$m total surface area 0.42 m2) was installed in an acrylic housing that has an aeration port 5 cm below the membrane and a clarifier in the bottom. The concentrate was uniformly supplied from the top of the housing. Bacuum filtration caused downward flow of concentrate and as a result thickening interface. The addition of poly-aluminum chloride (PAC) resulted in rapid increase of trans-membrane pressure (TMP) and in no improvement of the filtered water turbidity and thickening process. Two types of con-centrate and concentrate turbidity had little effect on the increase of TMP and concentrate thickening. It was observed that for the same height of membrane housing membrane surface area to housing volume (A/V) ratio had significant effect on the increase of TMP. When the housing volume was increased ten times the increasing rate of TMP was three times faster as compared to the original housing. A hydraulic model successfully simulated the formation and sedimentation of thickening interface.

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Diagnosis and Renovation of a Time-worn Rapid Sand Filter used for Drinking Water Treatment (정수장의 노후 급속 모래여과지 진단 및 개량)

  • Kim, Sang-Goo;Park, Hyun-Seog;Son, Hee-Jong;Lee, Jeong-Gyu;Ryu, Dong-Choon;Yoo, Pyung-Jong
    • Journal of Environmental Science International
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    • v.25 no.7
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    • pp.999-1005
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    • 2016
  • The H water treatment plant has been operating since 1982 and has had no renovation. It is assumed that the filters have been operated for more than 30 years and therefore are deteriorated. Many of the filters show an unequal state of air scouring during backwashing. For this study one filter, which was presumed most deteriorated among eighteen filters, was selected as a model filter for renovation. Some of the effects seen after renovation of the underdrain system were a lower average filtrated turbidity by approximately 0.02 NTU and an equal backwash state throughout the filter bed. Sand wash efficiencies by backwash before renovation of the underdrain system were 28%, 8%, and 5% at the surface, 50 cm depth, and 100 cm depth, respectively, and after renovation of the underdrain system were 94%, 26%, and 15%, respectively. The standard deviation of the effective sand size was 0.025-0.033 mm before renovation of the underdrain system and 0.002-0.011 mm after renovation of the underdrain system, meanings there was equal backwash pressure throughout the filter. Filtration time after renovation was approximately 2 times longer than before renovation.