• Carbon letters
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• 제3권1호
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• pp.6-12
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• 2002

A study on the electrosorption of $Co^{2+}$ and $Sr^{2+}$ ions onto a porous activated carbon fiber (ACF) was performed to treat radioactive liquid wastes resulting from chemical or electrochemical decontamination and to regenerate the spent carbon electrode. The result of batch electrosorption experiments showed that applied negative potential increased adsorption kinetics and capacity in comparison with open-circuit potential (OCP) adsorption for $Co^{2+}$ and $Sr^{2+}$ ions. The adsorbed $Co^{2+}$ and $Sr^{2+}$ ions are released from the carbon fiber by applying a positive potential on the electrode, showing the reversibility of the sorption process. The possibility of application of the electrosorption technique to the separation of radionuclides was examined. The result of a selective removal experiments of a single component from a mixed solution showed that perfect separation of $Co^{2+}$ and $Sr^{2+}$ ions was possible by the electrosorption process.

• 대한환경공학회지
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• 제29권3호
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• pp.332-340
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• 2007

강우 시 도로에서의 초기 유출수는 유 무기물질, 중금속 등 유해물질이 부유물질에 흡착되어 거동되는 비율이 높으므로 부유물질을 분리할 수 있다면 상당량의 오염부하를 줄일 수가 있다. 따라서 본 연구의 목적은 도로에서 배출되는 강우유출수의 오염저감을 위해 필터를 이용한 수리동력학적 필터분리기를 이용하여 부유물질을 처리함에 있어 필터별 오염물질 처리효율을 비교 평가함으로서 도로유출수에 대한 오염물질 저감을 위한 현장에의 적용 방안을 모색함에 있다. 사용한 여재는 perlite, 활성탄, zeolite와 이들의 혼합소재를 대상으로 하여 칼럼여과실험과 필터분리기를 이용한 현장에서의 처리실험을 통해 여재별 처리정도 및 처리효율을 비교하였다. 칼럼여과실험결과 대체로 SS는 활성탄과 perlite, 활성탄, 소성한 zeolite의 혼합여재가, 중금속은 zeolite 및 활성탄이 양호하였다. HDFS에 의한 처리실험은 perlite와 활성탄 혼합여재가 도로유출수 처리에 적합할 것으로 조사되었다. 혼합여재에 대한 평균 처리 효율은 여재층이 9 cm, 수면적부하율 192-1,469 $m^3/m^2/d$의 범위에서 SS 48.1%, BOD 31.9%, COD 32.6%, TN 15.5%, TP 17.3%의 제거율을 나타내었고, 중금속인 경우 Fe 26.0%, Cu 19.4%, Cr 25.7, Zn 16.6%, Pb 15.0%로 조사되었다. 도로유출수의 처리를 위한 HDFS의 여재로서는 perlite와 활성탄을 혼합한 여재가 적절하였다.

• 한국세라믹학회지
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• 제46권1호
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• pp.1-9
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• 2009

Activated carbon modified with nickel (Ni-AC) was employed the for preparation of Ni-activated carbon/$TiO_2$ (Ni-AC/$TiO_2$) composites. The $N_2$ adsorption data showed that the composites had a decreased surface area compared with pristine AC. This indicated blocking of the micropores on the surface of the AC, which was further supported by observation via SEM. XRD results showed that the Ni-AC/$TiO_2$ composite contained a mixed anatase and rutile phase while the untreated AC/$TiO_2$ contained only a typical single and clear anatase phase. EDX results showed the presence of C, O, and Ti with Ni peaks on the composites of Ni-AC/$TiO_2$. Subsequently, the photocatalytic effects on methylene blue (MB) were investigated. The improved decomposition of MB showed the combined effects of adsorptions and photo degradation. In particular, composites treated with Ni enhanced the photo degradation behaviors of MB.

• 한국환경과학회지
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• 제23권9호
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• pp.1593-1600
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• 2014

Adsorption and desorption characteristics of the representative 10 kinds components consisting of gasoline vapor on activated carbon were investigated at the temperature range of $-30^{\circ}C{\sim}25^{\circ}C$. The breakthrough curves of each vapors obtained by the Thomas model were well described the breakthrough experimental results of this study. The breakthrough times of each vapors were correlated with the molecular weight, density, and vapor pressure. The breakthrough times had greater correlation with boiling point than molecular weight and density. The slope of the breakthrough curve was a proportional relationship with the rate constant (k) of Thomas model expression. The higher the slope of the breakthrough curve, the rate constant was larger. The biggest slope vapor had the smallest adsorption capacity ($q_e$). Adsorption and desorption characteristics of mixed vapor similar to the gasoline vapor were studied at room temperature ($25^{\circ}C$). The mixed vapor consisting of 9 components; group A (pentane, hexene, hexane), group B (benzene, toluene), group C (octane, ethylbenzene, xylene, nonane) was examined. Group A was not nearly adsorbed because of substitution by group C, and the desorption capacity of group A was smaller than group C. The adsorbed substances were confirmed to be Group C.

• 멤브레인
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• 제28권4호
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• pp.271-278
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• 2018

본 연구에서는 활성탄소섬유를 이용하여 축전식 탈염공정에 적용할 탄소전극을 제조하였다. polyvinylidene fluoride (PVDF)를 바인더로 사용했으며 적절한 용매에 활성탄소섬유를 배합한 후 상용의 그라파이트 시트에 캐스팅하여 탄소전극을 제조하였다. 이 때 활성탄소섬유의 입자 크기를 달리하였고, 용매, 고분자 바인더 그리고 활성탄소섬유를 80 : 2 : 18, 80 : 5 : 15의 배합비율로 전극을 제조하였다. 그런 다음 염 제거 효율을 흡착전압과 시간, 탈착전압과 시간, NaCl 공급액의 농도와 유속 등에 운전조건에 대하여 염 제거 효율을 측정하였다. 대표적으로 활성탄소섬유의 입자크기가 $32{\mu}m$ 이하이며 80 : 2 : 18의 배합비율에서 1.2 V, 3분의 흡착조건, -0.1 V, 1분의 탈착조건, NaCl 100 mg/L, 15 mL/min의 공급액 조건에서 53.6%의 염 제거 효율을 보였다.

• 한국대기환경학회지
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• 제23권2호
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• pp.250-260
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• 2007

It was investigated that the emission characteristics of volatile organic compounds (VOCs) from small and medium companies located on industrial complexes in Metropolitan area. The emission characteristics are intermittent sources in which VOCs emissions are highly depends on the working condition. Optimized ventilation system to improve air quality in working area for the three typical companies were installed. Adsorption characteristics of major VOCs such as MEK, IPA, and toluene emitted front the companies were investigated for design of the activated carbon vessel as a VOCs control facility in each company. Concentration of total hydrocarbon and gas amounts needed to ventilation were also used as a design parameter. Mixed adsorbent to improve adsorption characteristics of problematic solvents like IPA and the design guideline of the activated carbon vessel have been suggested.

• 환경위생공학
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• 제16권1호
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• pp.72-90
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• 2001

This study was conducted to evaluate desorption efficiencies accuracy and precision by $CS_2$ and thermal desorption method for polar and non-polar organic solvents collected on activated carbon(AC), activated carbon fiber(ACF), carbosieve SIII, materials tested were Methyl alcohol, n-Hexane, Benzene, Trichloroethylene, Methyl isobutyl ketone and methyl cellosolve acetate and six different concentration levels of samples were made. The results were as follows ; 1. Accuracy on kind adsorbent and desorption method was low. In case of $CS_2$ desorption solvent, Overall B and Overall CV on AC and ACF were 43% and 6.63%, respectively. In case of thermal desorption method, accuracy of thermal desorption method appeared higher than solvent desorption method by AC 18.0%, 3.54%, ACF 2.6%, 2.57%, Carbosieve SIII 13.7% and 1.97%, respectively. 2. In the concentration level III, accuracy of thermal desorption method on adsorbent was in order as follow ; ACF > Carbosieve SIII > AC in the methyl alcohol and Carbosieve SIII > ACF > AC in the rest of them all subject material and Concentration levels showed good precision at EPA recommend standard (${\leq}{\;}30%$) 3. DEs by type of organic solvent adsorbent and desorption method are as follows ; In the case that desorption solvent is $CS_2$, DE of Methyl alcohol is AC 47.5%, DE of all materials is ACF about 50%. In the case of thermal desorption method, DE of Methyl alcohol is AC 82.0%, ACF 97.4%, Carbosieve SIII 86.3%. DE of the later case is prominently improved more than one of former. In particular, Except that DE of EGMEA is ACF 88.5%, DE of the rest of it is more than 95% which is recommend standard MDHS 72. With the result of this study, in order to measure various organic solvent occurring from the working environment, in the case of thermal desorption method, we can get the accurate exposure assessment, reduce the cost, and use ACF as thermal desorption sorbent which available with easy.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2002년도 추계학술대회
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• pp.273-277
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• 2002

In the electrode fabrication of unit cell, we found that optimal the electrochemical characteristics were obtained with at 90 wt.% of activated carbon(BP-20), 5 wt.% of conducting agent(Ppy, Super P) and 5 wt.% of P(VdF-co-HFP)/PVP mixed binder. The electrochemical characteristics of unit cell with Ppy improver were as follows : 37.6 F/g of specific capacitance, 0.98 $\Omega$ of AC-ESR, 2.92 Wh/kg and 6.05 Wh/L of energy density, and 754 W/kg and 1,562 W/L of power density. It was confirmed that internal resistance were reduced due to the increase of electrical conductivity and filling density by the introduction of conductivity agent, and content of conducting agent was suitable in the range of 4~6 wt.%. According to the impedance measurement of the electrode with conductivity agent, we found that it was possible to charge rapidly by the fast steady-state current convergence due to low equivalent series resistance(AC-ESR), fast charge transfer rate at interface between electrode and electrolyte, and low RC time constant.

• 한국토양비료학회지
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• 제36권2호
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• pp.86-91
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• 2003

흑연이나 활성탄등의 탄소물질이 작물의 생육을 촉진하며 유용 토양미생물의 생육을 촉진하는것으로 알려져 있어 본 실험에는 제철공정에서 재활용, 정제된 흑연을 상토의 첨가제로 시용하여 벼의 생육과 수량에 미치는 영향에 대하여 실험하였다. 실험결과, 이앙기의 생육은 대조구와 비교하여 0.1% 흑연 첨가구에서 생육 촉진효과가 보였으며 이앙후 처리구별 생육의 차이는 그다지 보이지 않았다. 다만 0.1% 첨가구에서 육묘한 벼의 수량은 특별한 통계적 유의성을 보이지 않았으나 약 1%정도 증수되었다.

• 한국항해항만학회지
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• 제39권3호
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• pp.185-192
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• 2015

본 연구에서는 표면개질 활성탄을 이용하여 수용액상에서 혼합 중금속($Cr^{6+}$, $As^{3+}$)의 흡착능을 평가하였고 또한 표면개질 활성탄을 안정화제로 활용하여 해양오염퇴적물 내 As 및 Cr에 대하여 중금속 안정화 실험을 수행하였다. 실험결과, 흡착평형은 약 120분 후에 도달하였다. 또한, 중금속 등온 흡착 특성은 Freundlich 및 Langmuir 방정식을 이용하여 해석하였으며, 평형흡착 실험결과는 Langmuir 모델에 잘 부합되었고 $As^{3+}$ (28.47 mg/g)가 $Cr^{6+}$ (13.28 mg/g)보다 평형 흡착량이 많았다. $Cr^{6+}$인 경우, 용액의 pH가 6에서 10으로 증가함에 따라서 흡착량은 감소하는 것으로 나타났다. 하지만 pH 증가 변화에서 $As^{3+}$의 흡착량은 미미한 증가를 보였다. 안정화 방법은 오염퇴적물에 표면 개질한 활성탄 첨가 후 120일간 습윤 양생 하였다. 연속추출 실험결과로부터, 미처리 오염퇴적물과 비교해서 Cr 및 As의 이온교환, 탄산염, 산화물 및 유기물 존재 형태 합의 비는 각각 5.8% 및 7.6% 감소하였다.