• 한국환경보건학회지
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• 제23권3호
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• pp.1-6
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• 1997

This research was conducted in the laboratory to investigate an alternative of Copper(Cu) removal from an heavymetal wastewater using the electrochemical precipitation(ECP) process. The ECP unit consisted of an electrolytic cell made of Titanium plate and Steel plate representing anode and cathode. The DC power source applied to the ECP unit had electrical potential(E) of 50$\pm$ 1V, respectively. The synthetic wastewater used in the experiments contained Cu in the 10 mg/l concentration and the electrode separation were 2, 3, 4 cm and the initial pH were 3, 6, 9, 12, and electrolytic concentration were 0.005, 0.0125, 0.025, 0.0375 mole, and the real heavymetal wastewater used in the experiments. From the experiment for removal efficiency according to pH variation, the low pH area doesn't give the coagulation effect by Ti(OH)$_4$ because process interfere with the coagulation and oxidation reaction, therefore the optimum pH was 4-7. The removal rate was 97.75% after the lapse of 30 minutes when copper concentration and electrolytic concentration were respectively 10 mg/l and 0.025 mole. The removal rate was 96.41% after the lapse of 30minutes when the real heavymetal wastewater used. The optimum consumption of power showed 27KWh/m$^3$ when copper concentration, electrolyte concentration and cell potential were respectively 10 mg/l, 0.025 mole and 50$\pm$ 1 Volt.

• 한국환경과학회지
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• 제21권11호
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• pp.1371-1377
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• 2012

The simulated dyes solution containing Basic Red 46(BR 46), Yellow 21(Y 21), and Maxilon Blue 30(MB 30) were electrochemically oxidized using carbon fiber as an anode. The electrolyses were performed in a electrolytic flow cell constructed by Vycor glass tube. The carbon fiber was positioned in the inside of Vycor glass tube and platinum wire coiled around outside of tube as a cathode. Several operating variables, such as current, time, pH and flow rate of solution were studied. Increasing current density would lead to a corresponding increase in the dye removal efficiency 99.2 % at a 200 mA. The electrolyses time could also improve and removal efficiency was about 99 % after 1.5 hours of electrolyses. The removal efficiency was increased with the increase of flow rate of solution and optimum flow rate was 5 mL/min. THe pHs of solution affect the removal efficiency. The removal efficiency was decreased with the increase of pH of solution and optimum pH was 5.05 (0.1 M $KNO_3$).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1252-1254
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• 1997

Direct methanol fuel cell based on a proton-exchange membrane electrolyte was investigated. 60% Pt-Ru/C and 60%Pt/C catalysts were employed for methanol oxidation and oxygen reduction, respectively. Morphologies of the catalysts were investigated by x-ray power diffraction, energy dispersive x-ray spectroscopy, and transmission microscopy. Electrochemical characteristics of the catalysts were tested by using cyclic voltametry technique. I-V characteristics of the fuel cell were tested by changing methanol concentration, temperature, and Nafion type as a proton-exchange membrane electrolyte. AC impedance technique was used to investigate the electrochemical performance of the fuel cell. The performance of single cell was enhance with increasing cell temperature. High operation temperature attributed to the combined effects of the reduction of ohmic resistance and polarization. High cell voltage was obtained from the concentration of 205M methanol. With Nafion 112, a current density of $230mA/cm^2$ at 0.55V was obtained from the concentration of 2.5M methanol.

• Bulletin of the Korean Chemical Society
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• 제27권2호
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• pp.281-285
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• 2006

Microbial fuel cells (MFC) stacked with bipolar plates have been constructed and their performance was tested. In this design, single fuel cell unit was connected in series by bipolar plates where an anode and a cathode were made in one graphite block. Two types of bipolar plate stacked MFCs were constructed. Both utilized the same glucose oxidation reaction catalyzed by Gram negative bacteria, Proteus vulgaris as a biocatalyst in an anodic compartment, but two different cathodic reactions were employed: One with ferricyanide reduction and the other with oxygen reduction reactions. In both cases, the total voltage was the mathematical sum of individual fuel cells and no degradation in performance was found. Electricity from these MFCs was stored in a supercapacitor to drive external loads such as a motor and electric bulb.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2002년도 추계학술대회 발표 논문집
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• pp.117-119
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• 2002

A semiconductor cleaning technology has been based upon RCA cleaning which consumes vast amounts of chemicals and ultra pure water. This technology hence gives rise to many environmental issues, and some alternatives such as electrolyzed water are being studied. In this work, intentionally contaminated Si wafers were cleaned using the electrolyzed water. The electrolyzed waters were obtained in anode and cathode with oxidation reduction potentials and pH of -1050mV and 4.8, and -750mV and 10.0, respectively. The electrolyzed water deterioration was correlated with $CO_2$ concentration changes dissolved from air. Overflowing of electrolyzed water during cleaning particles resulted in the same cleanness as could be obtained with RCA clean. The roughness of patterned wafer surfaces after EW clean maintained that of as-received wafers. RCA clean consumed about $9\ell$ chemicals, while electrolyzed water clean did only $400m\ell$ HCl or $600m\ell$ $NH_4$Cl to clean 8" wafers in this study. It was hence concluded that electrolyzed water cleaning technology would be very effective for releasing environment, safety, and health(ESH) issues in the next generation semiconductor manufacturing.ring.

• 한국전자통신학회논문지
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• 제8권9호
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• pp.1307-1312
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• 2013

본 논문에서는 알칼리성 또는 산성을 띠는 특정 용액 내에서 전기분해 원리를 이용하여 금속 표면을 산화시켜 절연피막을 형성하는 장치를 개발한다. 기존에는 주로 양극에만 펄스 형태로 전압을 인가하는 단극성(unipolar) 방식이지만 본 논문에서는 H-브리지를 이용하여 양극에 양(+)전압과 음(-)전압을 번갈아 가면서 전압을 공급하는 양극성(bipolar) 장치를 제작하였으며, 금속 시편의 특성에 맞는 다양한 전기적인 조건을 가지고 산화피막을 형성할 수 있는 장치를 개발하였다. 공급전류 가변은 PWM 변조를 이용하였으며, (+)와 (-)의 극성변화는 H-브리지를 이용하여 양극성 펄스전압을 공급할 수 있도록 하였다. 그 결과로써 단극성보다 균일한 기공을 갖는 피막이 형성되었다.

• 공업화학
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• 제3권3호
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• pp.482-490
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• 1992

세종류의 금속산화물 전극을 양극으로 사용하여 methanol 용액중에서 furfuryl alcohol을 양극산화 시켜 2,5-dimethoxy-2,5-dihydrofurfuryl alcohol을 전해합성 하였다. 각 전극들은 티타늄 재질상에 산화주석($SnO_2$)과 삼산화이안티몬($Sb_2O_3$)의 반도체 혼합물층을 전기로 내에어 만들고, 그 위에 양극산화방법으로 ${\alpha}-PbO_2$, ${\beta}-PbO_2$, $MnO_2$등의 금속산화물을 전착(electrodeposition)하여 3종의 전극을 제작하였다. 이산화납 전극이 이산화망간 전극에 비하여 양극 내식성이 우수하였으며 생성물의 수율(92%)도 백금전극을 사용했던 결과와 대등하였다.

• Bulletin of the Korean Chemical Society
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• 제21권1호
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• pp.44-48
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• 2000

Microbial fuel cells comprising the microorganism P. vulgaris, thionin as a mediator, and various mono- and disaccharides in an anodic compartment have been developed. A cathodic compartment containing a Pt electrode and Fe$(CN)_6^{3-}$ was separated from an anode by the Nafion membrane. From absorbance-time measurements, it was found that the absorbance of thionin was not altered by the addition of P. vulgaris, even in the presence of sugars. However, thionin was effectively reduced when P. vulgaris was present. These results differ substantially from the case of safranine O, a phenazine-derivative, indicating that thionin takes up electrons during the metabolic oxidation processes of carbohydrates. Maximum fuel cell efficiency was observed at 37 $^{\circ}C$, optimum temperature for the growth of P. vulgaris, and 0.5 V cell voltage was obtained, which indicates that the metabolism of the microorganism directly affects the efficiency. Thionin concentration was closely related to cell performance. When the charging-discharging characteristics were tested with glucose, galactose, sucrose, maltose, and trehalose as carbon sources, galactose was found to give the highest coulombic efficiency. Cell performance was almost fully recovered with only small degradation when glucose and sucrose were used in the repetitive operation. Current was maintained nearly twice as long for sucrose than in the case of glucose.

• 분석과학
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• 제10권4호
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• pp.264-273
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• 1997

수용액 중의 trihalomethane을 제거하기 위하여 양극 산화반응을 시키고 solid phase microextraction(SPME) fiber로 추출한 다음 GC-ECD로 분석하였다. 반응 용기 내부로 염소이온 등이 오염되는 것을 방지하기 위해 음극과 양극은 $KNO_3$-agar bridge로서 연결시켰다. 6종의 trihalomethane들은 성분에 따라 감도의 차이가 있었지만, 검량선은 수 ppb에서 수백 ppb 범위에서 좋은 직선관계를 보였다. 백금(Pt), 티탄(Ti), 지르코늄(Zr), Ti 금속상에 이리듐(Ir)을 도포시킨 고체 전극, 및 유리질 탄소에 루테늄(Ru)을 도포한 양극들을 사용하여 THM 성분을 제거하려 하였다. 제거효율이 가장 우수한 것은 Ti-Ir 양극으로서, 9V의 전압을 걸었을 때 약 1.5시간 이후에는 모든 성분들이 제거되었음을 알 수 있었다. 다양한 산화상태(mv)의 루테늄으로 유리질 탄소전극을 도포시킨 전극은 초기에는 제거효율이 우수하였으나, 시간이 경과할수록 전극 표면의 훼손으로 인해 제거효율은 약 60% 정도로 감소하였다. 특히 클로로포름은 약간 증가되는 경향을 보임으로써, 이것은 전극반응에 의하여 오히려 재생되는 것으로 생각된다.

• 청정기술
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• 제13권1호
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• pp.54-63
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• 2007

고분자 전해질 연료전지에 사용되는 개질 수소 속에는 미량의 일산화탄소가 존재할 수 있으며, 이는 연료전지의 백금 성분의 양극 전극을 비활성화로 이끌며, 그로 인하여 전기 출력이 급격히 떨어지게 된다. 본 연구는 담체의 조성을 달리한 여러 가지 $Cu/Ce_xZr_{1-x}O_2$ (x=0.0-1.0) 촉매들을 합성하고 그들 특성이 분석되었으며, 또한 일산화탄소의 산화반응과 수소 분위기에서의 일산화탄소에 대한 선택적 산화반응을 수행하였다. 이들 촉매들은 수열합성법과 침적-침전법을 조합하여 제조되었으며, XRD, XRF, SEM, TEM, BET, $N_2O$ 분해실험, 산소저장능력 측정 기법 등에 의해 그들의 물리화학적 성질들이 분석되었다. 담체의 조성과 반응물 산소의 과잉정도에 따른 영향들이 여러 반응온도에서 반응활성과 이산화탄소 선택도 등에 의해 조사되어졌다. 합성된 여러 조성을 달리한 $Cu/Ce_xZr_{1-x}O_2$ 촉매들 가운데 $Cu/Ce_{0.9}Zr_{0.1}O_2$와 $Cu/Ce_{0.7}Zr_{0.3}O_2$ 두 가지 촉매는 $170^{\circ}C$ 반응온도 부근의 PROX 반응에서 99% 이상의 CO 전환율과 50% 내외의 선택도를 나타내었다. 이와 같은 비교적 완화된 조건에서의 우수한 활성은 높은 산소저장능력을 지닌 $Ce_xZr_{1-x}O_2$ 담체를 사용함으로서 구리촉매의 산호-환원 활성이 증가한 것에 기인하며, 결국 수소분위기에서의 일산화탄소의 산화 반응에 대한 높은 활성과 선택도를 이끌었다.