• 공업화학
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• 제27권4호
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• pp.386-390
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• 2016

축전식 탈염전극의 에너지 효율을 향상시키기 위하여 탄소나노튜브를 불소화 표면처리하고 이를 도전재로 적용하였다. 탄소나노튜브는 상온에서 불소와 질소의 혼합가스로 불소화 처리되었으며, 미처리 탄소나노튜브와 불소화 탄소나노튜브를 각각 활성탄소 대비 0~0.5 wt% 첨가하여 활성탄소 기반 축전식 탈염전극을 제조하였다. 불소화 탄소나노튜브는 미처리 탄소나노튜브에 비하여 전극 슬러리 및 전극 내에서 분산성이 향상된 것을 제타 전위와 전자주사현미경을 통해 확인하였다. 불소화 탄소나노튜브를 첨가한 전극은 미처리 탄소나노튜브를 첨가한 전극보다 전체적으로 높은 탈염효율을 보였으며, 에너지 소비량 역시 감소하였다. 이는 불소화 표면처리로 인한 탄소나노튜브의 분산성 향상으로 인해 축전식 탈염 전극의 저항이 감소되었기 때문이다.

• 한국안전학회지
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• 제23권5호
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• pp.54-60
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• 2008

The objective of this study is to obtain the optimal process condition and the maximum decomposition efficiency by measuring the decomposition efficiency, electricity consumption, and voltage in accordance with the change of the process variables such as the frequency, maintaining time period, concentration, electrode material, thickness of the electrode, the number of windings of the electrode, and added materials etc. of the harmful atmospheric contamination gases such as NO, $NO_2$, and $SO_2$ etc. with the plasma which is generated by the discharging of the specially designed and manufactured $TiO_2$ catalysis reactor and SPCP reactor. The decomposition efficiency of the NO, the standard samples, is obtained with the plasma which is being generated by the discharge of the combination effect of the $TiO_2$ catalysis reactor and SPCP reactor with the variation of those process variables such as the frequency of the high voltage generator($5{\sim}50kHz$), maintaining time of the harmful gases($1{\sim}10.5sec$), initial concentration($100{\sim}1,000ppm$), the material of the electrode(W, Cu, Al), the thickness of the electrode(1, 2, 3mm), the number of the windings of the electrode(7, 9, 11turns), basic gases($N_2$, $O_2$, air), and the simulated gas($CO_2$) and the resulting substances are analyzed by utilizing FT-IR & GC.

• 신재생에너지
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• 제19권4호
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• pp.20-26
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• 2023

Emitted CO₂ is an attractive material for microbial electrochemical CO₂ reduction. Microbial electrochemical CO₂ reduction (i.e., microbial electrosynthesis, MES) using biocatalysts has advantages compared to conventional CO₂ reduction using electrocatalysts. However, MES has several challenges, including electrode performance, biocatalysts, and reactor optimization. In this study, an MES system was investigated for optimizing reactor types, counter electrode materials, and CO₂-converting microorganisms to achieve effective CO₂ upcycling. In autotrophic cultivation (supplementation of CO₂ and H₂), CO₂ consumption of Rhodobacter sphaeroides was observed to be four times higher than that with heterotrophic cultivation (supplementation of succinic acid). The bacterial growth in an MES reactor with a single-chambered shape was two times higher than that with a double chamber (H-type MES reactor). Moreover, a single-chambered MES reactor equipped with titanium mesh as the counter electrode (anode) showed markedly increased current density in the graphite felt as a working electrode (cathode) compared to that with a graphite felt counter electrode (anode). These results demonstrate that the optimized conditions of a single chamber and titanium mesh for the counter electrode have a positive effect on microbial electrochemical CO₂ reduction.

• 대한소아치과학회지
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• 제24권1호
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• pp.125-138
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• 1997

Along with recent economic prosperity, the consumption of commercially available beverages has increased dramatically. Beverages on the market are replacing tap water and constituting an increasing large proportion of the total daily fluoride intake. If such changes in the source of fluid intake are not taken into consideration, effective fluoride intake would become difficult in the fluoridated area while there would be confusion as to the basis for proper fluoride supplement prescription in the nonfluoridated area. So, dietary consultation is recommended for every pediatric patient. This study was conducted to provide the reference for dietary consultations on the subject of fluoride supplement using 72 beverages on the market. The fluoride content was measured and the fluoride intake from each age groups was calculated using fluoride ion specific electrode and HMDS-microdiffusion technique. 1. The average fluoride concentration of the 72 beverages was $0.23{\pm}0.10ppm$, from 0.0106ppm to 2.2050ppm. 2. Natural fruit juices, diluted fruit juices, carbonated beverages and mixed beverages showed average fluoride concentration of $0.15{\pm}0.66ppm$, $0.09{\pm}0.11ppm$, $0.15{\pm}0.23ppm$, $0.50{\pm}0.66ppm$, respectively. There were significant differrence between diluted friut juice drinks and mixed beverage, and between the carbonated beverages and mixed beverges(p<0.05). 3. Using available data on the daily total consumption of beverages and the relative consumption of beverages on the market according to age, daily fluoride intake for various age groups was calculated. According to the results, 2 to 3 year-old children need 0.13mgF/day, those between 4 and 6 year-old need 0.15mgF/day, and those between 7 and 10 year-old need 0.17mgF/day.

• 한국환경과학회지
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• 제20권10호
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• pp.1273-1284
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• 2011

The aim of this research was to evaluate the performance of insoluble electrode for the purpose of degradation of Rhodamine B (RhB) and oxidants generation [N,N-Dimethyl-4-nitrosoaniline (RNO, indicator of OH radical), $O_3$, $H_2O_2$, free Cl, $ClO_2$)]. Methods: Four kinds of electrodes were used for comparison: DSA (dimensional stable anode; Pt and JP202 electrode), Pb and boron doping diamond (BDD) electrode. The effect of applied current (0.5~2.5 A), electrolyte type (NaCl, KCl and $Na_2SO_4$) and electrolyte concentration (0.5~3.5 g/L) on the RNO degradation were evaluated. Experimental results showed that the order of RhB removal efficiency lie in: JP202 > Pb > BDD ${\fallingdotseq}$ > Pt. However, when concerned the electric power on maintaining current of 1 A during electrolysis reaction, the order of RhB removal efficiency was changed: JP202 > Pt ${\fallingdotseq}$ Pb > BDD. The total generated oxidants ($H_2O_2$, $O_3$, free Cl, $ClO_2$) concentration of 4 electrodes was Pt (6.04 mg/W) > JP202 (4.81 mg/W) > Pb (3.61 mg/W) > BDD (1.54 mg/W), respectively. JP202 electrode was the best electrode among 4 electrodes from the point of view of performance and energy consumption. Regardless of the type of electrode, RNO removal of NaCl and KCl (chlorine type electrolyte) were higher than that of the $Na_2SO_4$ (sulfuric type electrolyte) RNO removal. Except BDD electrode, RhB degradation and creation tendency of oxidants such as $H_2O_2$, $O_3$, free Cl and $ClO_2$, found that do not match. RNO degradation tendency were considered a simple way to decide the method which is simple it will be able to determinate the electrode where the organic matter decomposition performance is superior. As the added NaCl concentration was increases, the of hydrogen peroxide and ozone concentration increases, and this was thought to increase the quantity of OH radical.

• 한국안전학회지
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• 제14권3호
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• pp.93-100
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• 1999

Decomposition efficiency, power consumption, and applied voltage of CFC(Chlorofluorocatbon) were investigated by SPCP(surface induced discharge plasma chemical processing) reactor to obtain optimum process variables and maximum decomposition efficiencies. Decomposition efficiency of CFC-12 with various electric frequencies(5~50kHz). flow rates (100~1,000mL/min), initial concentrations(100~1,000ppm), electrode materials(W, Cu, Al). electrode thickness(1, 2, 3mm) and reference gases($N_2$, $O_2$, air) were measured and the products were analyzed with FT-IR. Experimental results showed that at the frequency of 10kHz, the highest decomposition efficiency of 92.7% for CFC-12 were observed at the power consumptions of 29.6W. respectively, and that decomposition efficiency decreased with increasing frequency above 20kHz and decomposition efficiency per unit power were 3.13%/W for CFC-12. Decomposition efficiency was increased with increasing residence times and with decreasing initial concentration of pollutants. Decomposition efficiency was increased with increasing thickness of discharge electrode and the highest decomposition efficiency was obtained for the electrode diameter of 3m. As the electrode material, decomposition efficiency was in order that tungsten(W), copper(Cu), aluminum (Al). Decomposition of CFC-12 in the reference gas of $N_2$ showed the highest efficiency among three reference gases, and then the effect of reference gas on the decomposition efficiency decreased in order of air and $O_2$. The optimum power for the maximum decomposition efficiency was 25.3W for CFC.

• 한국수소및신에너지학회논문집
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• 제26권6호
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• pp.532-540
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• 2015

Electrochemical alane ($AlH_3$) production process can be provided as a synthesis route which close a reversible cycle. In this study, growth inhibition of dendrite as key issues in this process was investigated. Main cause of dendrite growth was because Al fine powder separated in consumption process of Al electrode was moved to Pd electrode. In an effort to avoid this, use of glass block with uniform holes was the most effective to inhibit the amount of dendrite to that of $AlH_3$. Furthermore, effects of Al electrode (anode) type and electrolyte concentration were investigated and the optimal condition for inhibiting dendrite formation was proposed.

• Food Science and Biotechnology
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• 제18권6호
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• pp.1358-1364
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• 2009

Electric polarity of working electrode and counter electrode was periodically switched at the intervals of 30 sec. Electric current generated by anodic and cathodic reaction of working electrode was reached to +30 and -12 mA in low intensity pulsed electric field (LIPEF). The yeast growth, ethanol production, and malate consumption in the initial cultivation time were more activated in the LIPEF than the conventional condition (CC). Polyphenol, total phenolic contents (TPC), and total flavonols (TF) were gradually decreased in all cultivation conditions during incubation for 2 weeks but antioxidation activity was not. TF was significantly lower in 3 and 4 V of LIPEF than CC and 2 V of LIPEF; however, the polyphenol, TPC, and antioxidation activity were a little influenced by the LIPEF. After ripening of the winemaking culture for 15 days, polyphenol, TPC, and TF were a little increased but the antioxidation activity was not.

• Journal of Electrochemical Science and Technology
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• 제8권1호
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• pp.77-86
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• 2017

The valorization of domestic wastes becomes a very important research axis that can reduce the energy consumption and protect our environment. The objective of this study is to remove zinc ions from wastewater by using banana peels after their activation as sensor in the working electrode for an environmental application. Banana peels were dried, crushed and treated with sulfuric acid then mixed with polyaniline to improve their electrical conductivity. Cyclic voltammetry and chronoamperometry were used for electrochemistry tests. The obtained voltammogramms at well optimized conditions of applied potential of -1.3 V/SCE and initial zinc concentration of 0.2M during 2 hours of electrolysis, showed the reduction peak of the zinc at a potential of -1.14 V/SCE, which confirmed the activity of this electrode. The modeling of experimental data revealed that the adsorption was fitted by the Langmuir isotherm with a maximal adsorption capacity of 3.4188 mg/g. Changes in the structure of the powder after the electrosorption was noticed by SEM and EDX. Finally, the dosage of the electrolytic solution showed a diminution of the zinc concentration with yield of 99.99%.

• Korean Chemical Engineering Research
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• 제49권6호
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• pp.697-703
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• 2011

축전식 탈염(CDI)은 높은 비표면적을 갖는 전극에 전기화학적 원리로 이온을 흡착하여 제거하는 기술이다. CDI 기술은 낮은 전위에서 작동하기 때문에 에너지 소비가 작고, 전극을 재생할 때 산, 염기 혹은 염을 사용하지 않기 때문에 환경친화적인 기술이다. 본 연구에서 우리는 CDI 기술의 동향을 알아보기 위해 특허와 논문을 조사했다. 데이터베이스는 WIPS와 Scopus를 사용하여 얻었으며 전극기술, 모듈기술 및 응용기술에 따라 조사되었다. CDI의 기술 동향은 연도별, 국가별, 출원인별, 기술별로 조사되었다.