슬관절 골관절염 환자에서 근육내 자극요법의 치료 효과

박영규,우종웅,안승렬,김정아,윤도경,박승회,조경환,홍명호 대한노인병학회 2001 대한노인병학회지 Vol.5 No.4

Mesoporous carbon for efficient removal of microcystin-LR in drinking water sources, Nak-Dong River, South Korea: Application to a field-scale drinking water treatment plant

Park, Jeong-Ann,Jung, Sung-Mok,Choi, Jae-Woo,Kim, Jae-Hyun,Hong, Seungkwan,Lee, Sang-Hyup Elsevier 2018 CHEMOSPHERE - Vol.193 No.-

<P><B>Abstract</B></P> <P>Microcystin-LR (MC-LR) is a growing issue as it is toxic and difficult to remove in drinking water treatment plants (DWTPs). Mesoporous carbon (MC) is evaluated as an alternative adsorbent for MC-LR removal and compared with three widely-used powdered activated carbons (PACs). MC was more favorable for MC-LR removal than PACs. MC-LR adsorption on MC was a rapid process (<I>k</I> <SUB> <I>2</I> </SUB> = 1.02 × 10<SUP>−4</SUP> g/μg/min) that completed within 15 min, while adsorption on PACs took 60 min. The maximum adsorption capacity of MC-LR was 18,008 μg/g (MC), which was higher than that of the PACs. Two mechanisms were associated with adsorption: the small hydro-dynamic diameter of MC in an aqueous solution increased the instantaneous attraction of MC-LR to its surface, and the numerous mesopores enhanced pore diffusion. The MC could remove MC-LR to meet the drinking water guidance level (1 μg/L) from an the MC-LR concentration range of 5–20 μg/L in drinking water sources, and 10 min of treatment was sufficient to meet this level (MC dose = 20 mg/L). The field-scale DWTP was operated by adding 1 or 5 mg/L MC to the mixing basin, and 49.49% and 74.50% of MC-LR was removed, respectively. Geosmin and 2-methylisoborneol were slightly reduced when 5 mg/L of MC was applied.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Mesoporous carbon is more effective to adsorb MC-LR than PACs. </LI> <LI> Numerous mesopores enhanced MC-LR adsorption by pore diffusion. </LI> <LI> Mesoporous carbon can be used as an alternative method in conventional DWTPs. </LI> <LI> Mesoporous carbon remove MC-LR in drinking water sources to levels below 1 μg/L. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Ultrasonic spray pyrolysis synthesis of reduced graphene oxide/anatase TiO₂ composite and its application in the photocatalytic degradation of methylene blue in water

Park, Jeong-Ann,Yang, Boram,Lee, Joongki,Kim, In Gyeom,Kim, Jae-Hyun,Choi, Jae-Woo,Park, Hee-Deung,Nah, In Wook,Lee, Sang-Hyup Elsevier 2018 CHEMOSPHERE - Vol.191 No.-

<P><B>Abstract</B></P> <P>Reduced graphene oxide (RGO)/anatase TiO<SUB>2</SUB> composite was prepared using a simple one-step technique—ultrasonic spray pyrolysis—in order to inhibit the aggregation of TiO<SUB>2</SUB> nanoparticles and to improve the photocatalytic performance for degradation of methylene blue (MB). Different proportions (0–5 wt%) of RGO/TiO<SUB>2</SUB> composites were characterized by scanning electronic microscopy (SEM), dispersive X-ray spectrometry (EDS), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) surface area, X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD), Raman spectroscopy, UV–vis spectroscopy, and electrochemical impedance spectroscopy (EIS) to verify mechanism. From these analysis, TiO<SUB>2</SUB> nanoparticles are distributed uniformly on the RGO sheets with crumpled shape during ultrasonic spray pyrolysis and surface area is increasing by increasing portion of RGO. Band gap of RGO<SUB>5</SUB>/TiO<SUB>2</SUB> (5 wt% of RGO) composite is 2.72 eV and band gap was reduced by increasing portion of RGO in RGO/TiO<SUB>2</SUB> composites. The RGO<SUB>5</SUB>/TiO<SUB>2</SUB> composite was superior to other lower content of RGO/TiO<SUB>2</SUB> composites with a rapid transport of charge carriers and an effective charge separation. The highest removal efficiency of MB was obtained at the RGO<SUB>5</SUB>/TiO<SUB>2</SUB> composite under UVC irradiation, which coincided with the EIS, and the optimal dose of the composite was determined to be 0.5 g/L. The RGO<SUB>5</SUB>/TiO<SUB>2</SUB> composite improve the photocatalytic degradation rate of MB over the TiO<SUB>2</SUB> due to a retardation of electron-hole recombination. The MB adsorption capacity and photocatalytic degradation efficiency were greatly affected by pH changes and increased with increasing pH due to electrostatic interactions and generation of more hydroxyl radicals. The reusability of RGO<SUB>5</SUB>/TiO<SUB>2</SUB> composite was examined during 3 cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> RGO/TiO<SUB>2</SUB> composite was successfully prepared by one-pot ultrasonic spray pyrolysis. </LI> <LI> The highest MB removal efficiency was obtained at the proportion of 5 wt% RGO. </LI> <LI> The MB adsorption capacity of RGO<SUB>5</SUB>/TiO<SUB>2</SUB> was enhanced at high solution pH. </LI> <LI> RGO/TiO<SUB>2</SUB> composite retarded electron-hole recombination verified with EIS. </LI> <LI> RGO/TiO<SUB>2</SUB> composite had reduced E<SUB>bg</SUB> and improved the photocatalytic MB degradation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Blend-electrospun graphene oxide/Poly(vinylidene fluoride) nanofibrous membranes with high flux, tetracycline removal and anti-fouling properties

Park, Jeong-Ann,Nam, Aram,Kim, Jae-Hyun,Yun, Seong-Taek,Choi, Jae-Woo,Lee, Sang-Hyup Elsevier 2018 CHEMOSPHERE - Vol.207 No.-

<P><B>Abstract</B></P> <P>Graphene oxide (GO)/poly(vinylidene fluoride) (PVDF) electrospun nanofibrous membranes (ENMs) have been fabricated to remove tetracycline (TC) from water via adsorptive-filtration. The pure water permeation flux of GO/PVDF ENMs (27,407–29,337 LMH/bar) was increased compared with that of PVDF ENMs. The flow pore diameter was steadily reduced by increasing the GO content from 0 to 1.5 wt% in the GO/PVDF ENMs. The maximum TC adsorption capacity of GO is 720.26 mg/g (Langmuir model) and GO retained its TC adsorption property after incorporation into GO/PVDF ENMs during water filtration (transmembrane pressure = 0.91 bar). The maximum experimental TC removal capacity (<I>q</I> <SUB> <I>a</I> </SUB>,<SUB> <I>exp</I> </SUB>) was 17.92 mg/g with 1.5 wt% of GO (GO<SUB>1.5</SUB>/PVDF) ENMs, which was similar to the modified dose-response model value of 18.03 mg/g. In the presence of natural organic matter, TC adsorption was enhanced, because hydrophobic organic carbon improved hydrophobic and π-π interactions. The presence of Cu(II) further improved the TC adsorption capacity of GO<SUB>1.5</SUB>/PVDF ENMs through cation bridging. However, the presence of Ca(II) hindered TC adsorption by an electron shielding effect. For examining anti-fouling activity of GO<SUB>1.5</SUB>/PVDF ENMs, the log removal values of both bacteria, <I>Escherichia coli</I> and <I>Staphylococcus aureus,</I> were maintained at over 5 during water filtration. In addition, incorporation of GO in PVDF ENMs prevents bovine serum albumin (BSA) adsorption by both increasing the hydrophilicity of the ENMs forming hydration layer on the surface and electrostatic repulsion between both negatively charged BSA and GO in GO<SUB>1.5</SUB>/PVDF ENMs (zeta potential = - 14.14 mV, deionized water at pH 6).</P> <P><B>Highlights</B></P> <P> <UL> <LI> GO retains its TC adsorption capacity after incorporation into PVDF ENMs. </LI> <LI> Flow pore diameter is reduced and water flux is increased by increasing GO content. </LI> <LI> TC adsorption is enhanced by both presence of NOM and Cu(II). </LI> <LI> LRVs of both <I>E.coli</I> and <I>S. aureus</I> were maintained over 5 via sieving and cell death. </LI> <LI> GO/PVDF ENMs prevent adsorption of BSA and enhance desorption of it. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Anti-biofouling enhancement of a polycarbonate membrane with functionalized poly(vinyl alcohol) electrospun nanofibers: Permeation flux, biofilm formation, contact, and regeneration tests

Park, Jeong-Ann,Kim, Song-Bae Elsevier 2017 Journal of membrane science Vol.540 No.-

<P><B>Abstract</B></P> <P>In this study, benzyl triethylammonium chloride (BTEAC)-functionalized poly(vinyl alcohol) (PVA) nanofibers were fabricated via electrospinning and deposited on a commercial polycarbonate (PC) membrane (f-PVA/PC membrane) in order to enhance the anti-biofouling activity of the membrane. Permeation flux, biofilm formation, contact, and regeneration tests were performed to evaluate the anti-biofouling potential of the f-PVA/PC membrane against bacteria, including <I>Klebsiella pneumoniae</I>, <I>Pseudomonas aeruginosa</I>, <I>Staphylococcus aureus,</I> and <I>Escherichia coli</I>. The permeation flux test showed that the normalized flux of the f-PVA/PC membrane was retained at 1.0 after filtration of 500mL of the bacterial solution (<I>K. pneumoniae</I>), whereas the fluxes of the PC and PVA/PC membranes decreased to 0.57 and 0.84, respectively. In the biofilm formation test, the number of biofilm cells on the f-PVA nanofibers (<I>P. aeruginosa</I> = 4.21–4.98log colony-forming unit (CFU), <I>S. aureus</I> = 3.74–4.39log CFU) was less than those on the PVA nanofibers (<I>P. aeruginosa</I> = 5.68–6.89log CFU, <I>S. aureus</I> = 4.72–5.82log CFU). The contact test demonstrated that mortality rates (contact time = 60min) on the f-PVA/PC membrane (<I>K. pneumoniae =</I> 94.08%, <I>S. aureus</I> = 99.99%, <I>E. coli</I> = 92.30%) were greater than those on the PC membrane (<I>K. pneumoniae =</I> 73.75%, <I>S. aureus</I> = 62.41%, <I>E. coli</I> = 76.80%). Fluorescence microscopy images illustrated that the population of red (dead) bacterial cells on the f-PVA/PC membranes was greater than that on the PVA/PC membrane. The regeneration test indicated that the f-PVA/PC membrane retained its anti-biofouling activity during regeneration and reuse over six cycles with mortality rates of 93.82–96.29% (<I>K. pneumoniae</I>), 74.27–85.15% (<I>S. aureus</I>), 91.68–95.19% (<I>E. coli</I>), and 94.94–96.90% (mixed-strain bacteria). The results demonstrated that the f-PVA nanofibers could enhance the anti-biofouling potential of the membrane through both anti-adhesive and anti-bacterial surface modifications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Functionalized PVA nanofibers were deposited on the PC membrane (f-PVA/PC membrane). </LI> <LI> The f-PVA nanofibers could reduce the biofilm formation on the nanofiber surfaces. </LI> <LI> The f-PVA/PC membrane had the anti-biofouling potential against bacteria. </LI> <LI> The f-PVA/PC membrane retained the permeation flux during bacterial solution application. </LI> <LI> The f-PVA/PC membrane retained its anti-biofouling activity during regeneration and reuse. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Pyrophyllite clay for bacteriophage MS2 removal in the presence of fluoride

Park, Jeong-Ann,Kim, Jae-Hyun,Lee, Chang-Gu,Kim, Song-Bae IWA Publishing 2014 Water science & technology--water supply Vol.14 No.3

<P>The aim of this study was to investigate the removal of the bacteriophage MS2 from aqueous solution using pyrophyllite. Batch experiments were conducted to examine MS2 sorption to pyrophyllite. The influence of fluoride, a groundwater contaminant, on the removal of MS2 was also observed. Column experiments were performed with pyrophyllite to examine MS2 removal in the absence and presence of fluoride. Batch results demonstrated that pyrophyllite was effective in MS2 removal. The percentage removal of MS2 increased from 5.26% to 99.99% (4.0 log removal) with increasing pyrophyllite concentrations from 0.2 to 20 g/L. At fluoride concentrations of 5 and 10 mg/L, the log removals of MS2 by pyrophyllite were 3.05 and 2.54, respectively, which were lower than that with no fluoride present. The results suggested that the removal of MS2 by pyrophyllite was influenced by fluoride ions because fluoride ions could compete with MS2 for sorption sites on the pyrophyllite surfaces. Column results showed that pyrophyllite was effective in MS2 removal under flow-through conditions, with a removal capacity of 8.17 × 10<SUP>6</SUP>pfu/g with no fluoride present and 4.70 × 10<SUP>6</SUP>pfu/g with 5 mg/L fluoride present.</P>

Oxidation of geosmin and 2-methylisoborneol by the photo-Fenton process: Kinetics, degradation intermediates, and the removal of microcystin-LR and trihalomethane from Nak-Dong River water, South Korea

Park, Jeong-Ann,Nam, Hye-Lim,Choi, Jae-Woo,Ha, Junsoo,Lee, Sang-Hyup Elsevier 2017 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.313 No.-

<P><B>Abstract</B></P> <P>Due to the increased intensity and frequency of cyanobacterial blooms, taste and odor (T&O) causing compounds, geosmin (GSM) and 2-methylisoborneol (MIB), have become a cause for great concern in drinking water treatment plants (DWTPs). Advanced oxidation processes (AOPs) have been studied for the removal of GSM and MIB. However, in this work, a photo-Fenton treatment was investigated for the first time for the degradation of GSM and MIB in both synthetic and Nak-Dong River water from DWTPs. Synthetic water-based experiments were performed to investigate the optimal operation conditions for the removal of GSM and MIB, and the effects of water quality parameters of the photo-Fenton process, including the Fe(II)/H<SUB>2</SUB>O<SUB>2</SUB> concentration, reaction time, pH, organic matter, and initial concentration of GSM and MIB. Degradation intermediates of dehydration and ring-opening were observed during the photo-Fenton process. The optimal conditions were determined to be 2mg/L Fe(II) and 20mg/L H<SUB>2</SUB>O<SUB>2</SUB> at pH 5 considering both efficiency and cost. The degradation efficiency was lower than that of DI water, mainly because of the pH (7.2–7.6). Nevertheless, the photo-Fenton process meets the guideline levels (20ng/L) in South Korea when the initial concentration in the river water is below 50ng/L. In addition, trihalomethanes (THMs) and microcystin-LR (MC-LR), derived from cyanobacterial blooms and another cause for concern, were degraded effectively using the photo-Fenton process on the river water.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The photo-Fenton process is effective method to remove taste and odor compounds. </LI> <LI> Degradation intermediates are related with dehydration and ring opening pathways. </LI> <LI> Degradation efficiency of GSM and MIB was mainly affected by pH. </LI> <LI> The photo-Fenton process also removes THMs and MC-LR in Nak-Dong River water. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Transport and removal of bacteriophages MS2 and PhiX174 in steel slag-amended soils: column experiments and transport model analyses

Park, Jeong-Ann,Kang, Jin-Kyu,Kim, Jae-Hyun,Kim, Song-Bae,Yu, Seungho,Kim, Tae-Hun Taylor Francis 2014 Environmental Technology Vol.35 No.10

Bacteriophage removal in various clay minerals and clay-amended soils

Jeong Ann Park,Jin Kyu Kang,Jae Hyun Kim,Song Bae Kim,Seungho Yu,Tae Hun Kim 대한환경공학회 2015 Environmental Engineering Research Vol.20 No.2

The aim of this study was to investigate the bacteriophage removal in various clay minerals and clay-amended soils. Batch experiments in kaolinite, montmorillonite, and bentonite showed that kaolinite was far more effective at the MS2 removal than montmorillonite and bentonite. In kaolinite, the log removal increased from 0.046 to 2.18, with an increase in the adsorbent dose from 0.3 to 50 g L-1, whereas the log removals in montmorillonite and bentonite increased from 0.007 to 0.40 and from 0.012 to 0.59, respectively. The MS2 removal in kaolinite-amended silt loam soils was examined at three different soil-to-solution (STS) ratios. Results indicated that the log removal of MS2 increased with an increase in the kaolinite content and the STS ratio. At the STS ratio of 1:10, the log removal of MS2 increased from 2.33 to 2.80 with an increase in the kaolinite content from 0% to 10% in kaolinite-amended soils. The log removals of MS2 at the STS ratios of 1:2 and 1:1 increased from 2.84 to 3.47 and from 3.46 to 4.76, respectively, with an increase in the kaolinite content from 0% to 10%. Results also indicated that the log removals of PhiX174 and Qβ in kaolinite-amended soils were similar to each other, but they were far lower than those of MS2 at all the kaolinite contents. The log removal of PhiX174 increased from 0.16 to 0.32, whereas the log removal of Qβ changed from 0.17 to 0.22 with an increase in the kaolinite content from 0% to 10%.

Microbial Removal Using Layered Double Hydroxides and Iron (Hydr)oxides Immobilized on Granular Media

Jeong Ann Park,Chang Gu Lee,Seong Jik Park,Jae Hyeon Kim,Song Bae Kim 대한환경공학회 2010 Environmental Engineering Research Vol.15 No.3

The objective of this study was to investigate microbial removal using layered double hydroxides (LDHs) and iron (hydr)oxides (IHs) immobilized onto granular media. Column experiments were performed using calcium alginate beads (CA beads), LDHs entrapped in CA beads (LDH beads), quartz sand (QS), iron hydroxide-coated sand (IHCS) and hematite-coated sand (HCS). Microbial breakthrough curves were obtained by monitoring the effluent, with the percentage of microbial removal and collector efficiency then quantified from these curves. The results showed that the LDH beads were ineffective for the removal of the negatively-charged microbes (27.7% at 1 mM solution), even though the positively-charged LDHs were contained on the beads. The above could be related to the immobilization method, where LDH powders were immobilized inside CA beads with nano-sized pores (about 10 nm); therefore, micro-sized microbes (E. coli = 1.21 ?m) could not diffuse through the pores to come into contact with the LDHs in the beads, but adhere only to the exterior surface of the beads via polymeric interaction. IHCS was the most effective in the microbial removal (86.0% at 1 mM solution), which could be attributed to the iron hydroxide coated onto the exterior surface of QS had a positive surface charge and, therefore, effectively attracted the negatively-charged microbes via electrostatic interactions. Meanwhile, HCS was far less effective (35.6% at 1 mM solution) than IHCS because the hematite coated onto the external surface of QS is a crystallized iron oxide with a negative surface charge. This study has helped to improve our knowledge on the potential application of functional granular media for microbial removal.