• Title/Summary/Keyword: Anode

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Application of Single-Compartment Bacterial Fuel Cell (SCBFC) Using Modified Electrodes with Metal Ions to Wastewater Treatment Reactor

  • PARK , DOO-HYUN;PARK, YONG-KEUN;EUI, CHOI
    • Journal of Microbiology and Biotechnology
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    • v.14 no.6
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    • pp.1120-1128
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    • 2004
  • The SCBFC was composed of bilayered cathode, the outside of which was modified with $Fe^{3+}$ (graphite-Fe(III) cathode) and the inside of which was porcelain membrane, and of an anode which was modified with $Mn^{4+}$ (graphite­Mn(lV) anode). The graphite-Fe(III), graphite-Mn(IV), and porcelain membrane were designed to have micropores. The outside of the cathode was exposed to the atmosphere and the inside was contacted with porcelain membrane. In all SCBFCS the graphite-Fe(III) was used as a cathode, and graphite-Mn(IV) and normal graphite were used as anodes, for comparison of the function between normal graphite and graphite-Mn(IV) anode. The potential difference between graphite-Mn(IV) anode and graphite-Fe(III) cathode was about 0.3 volt, which is the source for the electron driving force from anode to cathode. In chemical fuel cells composed of the graphite-Mn(IV) anode and graphite-Fe(III) cathode, a current of maximal 13 mA was produced coupled to oxidation of NADH to $NAD^{+}$ the current was not produced in SCBFC with normal graphite anode. When growing and resting cells of E. coli were applied to the SCBFC with graphite-Mn(IV) anode, the electricity production and substrate consumption were 6 to 7 times higher than in the SCBFC with normal graphite anode, and when we applied anaerobic sewage sludge to SCBFC with graphite-Mn(IV) anode, the electricity production and substrate consumption were 3 to 5 times higher than in the SCBFC with normal graphite anode. These results suggest that useful electric energy might possibly be produced from SCBFC without electron mediators, electrode-active bacteria, and extra energy consumption for the aeration of catholyte, but with wastewater as a fuel.

Recovery of Tantalum Anode from Waste Tantalum Condenser by Air Classification (공기분급에 의한 폐콘덴서로부터 탄탈륨 회수)

  • Kim Sang-Bae;Cho Sung-Baek;Cho Keon-Joon;Kim Yoon-Jong;Lee Jae-Chun;Kim Won-Baek
    • Resources Recycling
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    • v.12 no.3
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    • pp.3-12
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    • 2003
  • Physical separation containing grinding, sieving, dry magnetic separation and air classification were carried out in order to recover Ta anode from waste Ta condenser. Roll crusher wat used for the liberation of resin and metals in closed circuit system. The liberation between Ta anode and resin was easily achieved, whereat some of metals did not liberated from the Ta anode when the waste condenser was crushed below 8 mesh. When the crushed sample were divided into 8/10 mesh, 10/18 mesh and -18 mesh, metals was mainly remained in 8/10 mesh in contrast to Ta anode was in +18 mesh. It was shown that resin was more easily crushed rather than metals from the result of that resin content was 71.5% in -18 mesh. The liberation efficiency was different with the input size of the crushed sample and average efficiency was 62.3% due to the locked Ta anode particles. The results of air classification test for the crushed samples showed that optimal air flow are 39㎥/h, 32㎥/h, 20㎥/h. respectively. When the sample were separated with optimal condition, 94.45% Ta anode containing 97.47 wt.% Ta anode, 0.93 wt.% resin. 1.61 wt.% metal was recovered with 49.39 wt.% yield.

Room Temperature Fabrication of Organic Flexible Displays using Amorphous IZO Anode Film (비정질 IZO 애노드 박막을 이용한 유기물 플렉서블 디스플레이의 상온 제작)

  • Moon, Jong-Min;Bae, Jung-Hyeok;Jeong, Soon-Wook;Park, No-Jin;Kang, Jae-Wook;Kim, Han-Ki
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.7
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    • pp.687-694
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    • 2006
  • We report on the fabrication of organic-based flexible displays using an amorphous IZO anode grown at room temperature. The IZO anode films were grown by a conventional DC reactive sputtering on the polycarbonate (PC) substrate at room temperature using a synthesized IZO target in a $Ar/O_2$ ambient. Both x-ray diffraction (XRD) and high resolution electron microscope (HREM) examination results show that the IZO anode film grown at room temperature Is complete amorphous structure due to low substrate temperature. A sheet resistance of $35.6\Omega/\Box$, average transmittance above 90 % in visible range, and root mean spare roughness of $6\sim10.5\AA$ were obtained even in the IZO anode film grown on PC substrate at room temperature. It is shown that the $Ir(ppy)_3$ doped flexible organic light emitting diode (OLED) fabricated on the IZO anode exhibit comparable current-voltage-luminance characteristics as well as external quantum efficiency and power efficiency to OLED fabricated on conventional ITO/Glass substrate. These findings indicate that the IZO anode film grown on PC substrate is a promising anode materials for the fabrication of organic based flexible displays.

Performance of Single Cells with Anode Functional Layer for SOFC

  • Choi, Jin-Hyeok;Lee, Tae-Hee;Park, Tae-Sung;Yoo, Young-Sung
    • New & Renewable Energy
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    • v.5 no.1
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    • pp.11-17
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    • 2009
  • To improve the performance of the anode-supported Solid Oxide Fuel Cell (SOFC) which can be operated at an intermediate temperature, the functional layer (FL) is introduced on a anode substrate. And the scandia-stabilized zirconia (ScSZ) and samaria-doped ceria (SDC) which have higher ionic conductivity and better chemical stability than yttria-stabilized zirconia (YSZ) are used as material for the anode FL with the Ni, The fabrication process of anode-supported single cell with the anode FL was established and the power density of those was evaluated. As a result, the sample with anode FL (Ni-YSZ) has higher power density than normal cell. The single cell which was composed of the FL (Ni-YSZ) and electrolyte (YSZ) showed about $550mW/cm^2$ of the maximum power density at $650^{\circ}C$ and $1430mW/cm^2$ at $750^{\circ}C$ respectively, In case of the single cell using the ScSZ and SDC as anode FL, the performance of samples decreased rapidly and those showed unstable voltage during long-term test. In case of using methane as a fuel, the cell performance with each FL decreased comparing with $H_2$ fuel. In the region of a high current density, there are large concentration polarizations.

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A preliminary study of pilot-scale electrolytic reduction of UO2 using a graphite anode

  • Kim, Sung-Wook;Heo, Dong Hyun;Lee, Sang Kwon;Jeon, Min Ku;Park, Wooshin;Hur, Jin-Mok;Hong, Sun-Seok;Oh, Seung-Chul;Choi, Eun-Young
    • Nuclear Engineering and Technology
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    • v.49 no.7
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    • pp.1451-1456
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    • 2017
  • Finding technical issues associated with equipment scale-up is an important subject for the investigation of pyroprocessing. In this respect, electrolytic reduction of 1 kg $UO_2$, a unit process of pyroprocessing, was conducted using graphite as an anode material to figure out the scale-up issues of the C anode-based system at pilot scale. The graphite anode can transfer a current that is 6-7 times higher than that of a conventional Pt anode with the same reactor, showing the superiority of the graphite anode. $UO_2$ pellets were turned into metallic U during the reaction. However, several problems were discovered after the experiments, such as reaction instability by reduced effective anode area (induced by the existence of $Cl_2$ around anode and anode consumption), relatively low metal conversion rate, and corrosion of the reactor. These issues should be overcome for the scale-up of the electrolytic reducer using the C anode.

Electricity Generation from MFCs Using Differently Grown Anode-Attached Bacteria

  • Nam, Joo-Youn;Kim, Hyun-Woo;Lim, Kyeong-Ho;Shin, Hang-Sik
    • Environmental Engineering Research
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    • v.15 no.2
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    • pp.71-78
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    • 2010
  • To understand the effects of acclimation schemes on the formation of anode biofilms, different electrical performances are characterized in this study, with the roles of suspended and attached bacteria in single-chamber microbial fuel cells (MFCs). The results show that the generation of current in single-chamber MFCs is significantly affected by the development of a biofilm matrix on the anode surface containing abundant immobilized microorganisms. The long-term operation with suspended microorganisms was demonstrated to form a dense biofilm matrix that was able to reduce the activation loss in MFCs. Also, a Pt-coated anode was not favorable for the initial or long-term bacterial attachment due to its high hydrophobicity (contact angle = $124^{\circ}$), which promotes easy detachment of the biofilm from the anode surface. Maximum power ($655.0\;mW/m^2$) was obtained at a current density of $3,358.8\;mA/m^2$ in the MFCs with longer acclimation periods. It was found that a dense biofilm was able to enhance the charge transfer rates due to the complex development of a biofilm matrix anchoring the electrochemically active microorganisms together on the anode surface. Among the major components of the extracellular polymeric substance, carbohydrates ($85.7\;mg/m^2_{anode}$) and proteins ($81.0\;mg/m^2_{anode}$) in the dense anode biofilm accounted for 17 and 19%, respectively, which are greater than those in the sparse anode biofilm.

Effect of Cathodic Protection of Adjacent Steel Piles on the Life of Sacrificial Anode (희생양극의 수명에 미치는 인접 강파일의 음극방식 영향)

  • Moon, Kyung-Man;Lee, Kyu-Hwan;Cho, Hwang-Rae;Lee, Myung-Hoon;Kim, Yun-Hae;Kim, Jin-Gyeong
    • Journal of Ocean Engineering and Technology
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    • v.22 no.3
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    • pp.76-81
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    • 2008
  • There are two cases when the life of a sacrificial anode is shortened from the designed life: one case results from self-corrosion of the anode due to contamination by sea water in the other case, however, electrical current to protect some given steel piles overflows to protect other, adjacent non-protected steel piles. In this study, the variation of polarization potential of nine steel piles, being protected cathodically and with anode-producing current between anode and steel piles, was investigated. Parameters were varied, such as the eighth and ninth steel piles either connected electrically or not, and whether the ninth steel pile was protected by another sacrificial anode or not. The current produced by the sacrificial anode decreased when the ninth steel pile was cathodically protected by the anode of another pile. However, produced current increased when the ninth steel pile was not connected to another anode. The study concludes that the life of a sacrificial anode can be prolonged or shortened depending on whether adjacent steel piles are cathodically protected or not.

Electrochemical treatment of cefalexin with Sb-doped SnO2 anode: Anode characterization and parameter effects

  • Ayse, Kurt;Hande, Helvacıoglu;Taner, Yonar
    • Advances in nano research
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    • v.13 no.6
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    • pp.513-525
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    • 2022
  • In this study, it was aimed to evaluate direct oxidation of aqueous solution containing cefalexin antibiotic with new generation Sn/Sb/Ni: 500/8/1 anode. The fact that there is no such a study on treatment of cefalexin with these new anode made this study unique. According to the operating parameters evaluation COD graphs showed clearer results compared to TOC and CLX and thus, it was it was chosen as major parameter. Furthermore, pseudo-first degree kd values were calculated from CLX results to show more accurate and specific results. Experimental results showed that after 60 min of electrochemical oxidation, complete removal of COD and TOC was accomplished with 750 mg L-1 KCl, at pH 7, 50 mA cm-2 current density and 1 cm anode-cathode distance. Also, the stability of the Sn/Sb/Ni anode was evaluated by taking SEM and AFM images and XRD analysis before and after of electrochemical oxidation processes. According to the results, it was not occurred too much change on the anode surface even after 300 h of electrolysis. Thus, it was thought that the anode material was not corroded to a large extent. Furthermore, the removal efficiencies were very high for almost all the time and conditions. According to the results of the study, electrochemical oxidation with new generation Sn/Sb/Ni anodes for the removal of cefalexin antibiotic was found very successful and applicable due to require less reaction time complete mineralization and doesn't require pH adjustment step compared to other studies in literature. In future studies, different antibiotic types should be studied with this anode and maybe with real wastewaters to test applicability of the process in treatment of pharmaceutical wastewaters containing antibiotics, in a better way.

A Study on the Characteristics of Cathodic Protection by Al-Alloy Sacrificial Anode in Marine Environment (해양환경중에서 A1-합금희생양극에 의한 음극방식특성)

  • 이연호
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.28 no.1
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    • pp.53-60
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    • 1992
  • In this study, cathodic protection experiment was carried out by Al-alloy sacrificial anode in marine environments which have specific resistance($\rho$) if 25~7000$\Omega$.cm and investigated protection potential, current density and loss rate of Al-alloy sacrificial anode. The main results resistance($\rho$) of 400$\Omega$.cm, the cathodic protection potential appears high about-720 mV(SCE). But below specific resistance($\rho$) of 300$\Omega$.cm, the cathodic protection potential appears low about-770 mV(SCE) and simultaneously, cathode is protected sufficiently. 2) The loss rate of Al-Alloy sacrificial anode became large with decreasing specific resistance and increasing the ratio(A sub(c)/A sub(a) of bared surface area of anode and cathode. 3) The loss rate of Al-alloy sacrificial anode(w) to the mean current density of anode(i) is as follows. w=ai+b (a, b : experimental constants)

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Characteristics of Cathodic Protection with ICCP Anode in Reinforced Concrete (철근콘크리트용 ICCP 양극의 종류별 음극방식 특성)

  • Jeong, Jin-A
    • Corrosion Science and Technology
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    • v.11 no.4
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    • pp.112-119
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    • 2012
  • This paper presents the results of a study of the effectiveness of cathodic protection with insoluble ICCP anode in reinforced concrete structures. Experimental tests were carried out on reinforced concrete specimens with 3 different commercial anodes for ICCP system in order to compare the effectiveness of cathodic protection. Results have shown that the kinds of anode for ICCP is irrelevant to the effectiveness of cathodic protection, In case of ICCP, the performance of cathodic protection has no relationship to the kinds of anode especially in concrete specimens with sea water condition. It has been found slightly more effective at Ti-Rod anode in fresh water condition and Ti-Mesh anode in atmospheric condition.