• 분석과학
• /
• 제13권2호
• /
• pp.194-199
• /
• 2000

본 연구에서는 Ni가 처리된 PAN계 ACFs에 대하여 흡착, 표면특성 및 항균효과를 통하여 물리 화학적인 특성과 생물학적인 특성을 제시하였다. Ni가 처리된 PAN계 ACFs의 흡착에 관한 연구로부터 N1-N3에 대하여 Type I의 흡착등온곡선과 N4-N6에 대하여 Type II와 III의 흡착등온곡선을 각각 얻었다. 이들 시료에 대하여 흡착된 부피는 Ni의 몰농도의 증가와 함께 천천히 감소함을 알 수 있었다. BET식을 사용하여 계산된 $S_{BET}$값은 $692.58-895.24m^2/g$의 범위에 분포하였다. 또한 common-t값을 사용하여 ${\alpha}_s$-법으로부터 구한 단위 질량 당 미세 동공 부피는 $0.19-0.56cm^3/g$이었다. SEM 모폴로지의 결과로부터 PAN계 ACFs의 표면은 Ni를 처리함에 따라 부분적으로 피복됨을 관찰 할 수 있었다. 최종적으로 Shake flask법을 사용한 대장균(E. coli)에 대한 항균 효과를 측정한 결과, 각각의 시료들은 92.5-100%의 효과를 나타내었다. 이러한 항균 효과는 역시 Ni의 몰농도의 증가와 함께 향상됨을 알 수 있었다.

• 한국토양비료학회지
• /
• 제7권4호
• /
• pp.193-196
• /
• 1974

토양(土壤)에 흡착(吸着)되는 애트라진(Atrazine)의 양(量)은 마사츄세츠의 토양(土壤)에서는 다음과 같은 조건(條件)에 의(依)해서 결정(決定)된다. 1. 토양유기물(土壤有機物)이 여러 요인중(要因中) 가장 직접적(直接的)인 영향(影響)을 미친다. 2. 흡착작용(吸着作用)과 토양산도(土壤酸度)는 반비예적(反比例的)인 관계(關係)가 있고 토양산도(土壤酸度)는 N-KCl가용(可溶) 알루미늄의 양(量)과 깊은 관계(關係)가 있다.

• 환경위생공학
• /
• 제22권1호
• /
• pp.17-27
• /
• 2007

This study was conducted the adsorption experiment way of organic wastewater (BOD, COD, TOC, T-N, T-P) by changing the carbonization temperature and the size of adsorbent to examine the adsorption capacity of Korean traditional charcoal which has similar characteristics to activated carbon of organic pollutants. Also, it was performed the basic experiment for pH and inorganic materials. As a result of observing Korean traditional charcoal with has the greatest inorganic contents which are the important factor of chemical adsorption. As the carbonization temperature was better high temperature charcoal than law temperature charcoal to adsorption capacity of pollutant and as the particle was minute (D size : $3.35mm{\sim}2.0mm$), it was most effective. The result of adsorption experiment of organic wastewater show that the elimination ratio of pollutants by bamboo high temperature charcoal was found as BOD(82.1%), COD(91.7%), TOC(52.4%), T-N(66.6%), T-P(83.2%) and it has most excellent adsorption capacity of organic pollutants.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
• /
• pp.130.1-130.1
• /
• 2013

We made attempts to improve photocatalytic activity of $TiO_2$ nanoparticles under visible light exposure by combining two additional treatments. N-doping of $TiO_2$ by ammonia gas treatment at $600^{\circ}C$ increased absorbance of visible light. By coating thin film of polydimethylsiloxane (PDMS), and subsequent vacuum-annealing at $800^{\circ}C$, $TiO_2$, became more hydrophilic, thereby enhancing photocatalytic activity of $TiO_2$. Four types of $TiO_2$ samples were prepared, bare-$TiO_2$, hydrophilic-modified $TiO_2$ ($h-PDMS/TiO_2$), N-doped $TiO_2$ ($N/TiO_2$) and hydrophilic-modified and N-doped $TiO_2$ ($h-PDMS/N/TiO_2$). Adsorption capability was evaluated under dark condition and photocatalytic activity of $TiO_2$ was evaluated by photodegradation of MB under blue LED (400 nm< ${\lambda}$) irradiation. N-doping on $TiO_2$ was characterized using XPS and hydrophilic modification of $TiO_2$ surface was analyzed by FT-IR spectrometer. It was found that N-doping and hydrophilic modification both had positive effect on enhancing adsorption capability and photocatalytic activity of $TiO_2$ at the same time. Particularly, N-doping enhanced visible light absorption of $TiO_2$, whereas hydrophilic surface modification increased MB adsorption capacity. By combining these two strategies, photocatalytic acitivity under visible light irradiation became the sum of individual effects of N-doping and hydrophilic modification.

• Carbon letters
• /
• 제19권
• /
• pp.99-103
• /
• 2016

Porous carbons have attracted much attention for their novel application in gas storage. In this study, porous graphite nano-fiber (PGNFs)-based graphite nano fibers (GNFs) were prepared by KOH activation to act as adsorbents. The GNFs were activated with KOH by changing the GNF/KOH weight ratio from 0 through 5 at 900℃. The effects of the GNF/KOH weight ratios on the pore structures were also addressed with scanning electron microscope and N₂ adsorption/desorption measurements. We found that the activated GNFs exhibited a gradual increase of CO₂ adsorption capacity at CK-3 and then decreased to CK-5, as determined by CO₂ adsorption isotherms. CK-3 had the narrowest micropore size distribution (0.6–0.78 nm) among the treated GNFs. Therefore, KOH activation was not only a significant method for developing a suitable pore-size distribution for gas adsorption, but also increased CO₂ adsorption capacity as well. The study indicated that the sample prepared with a weight ratio of ‘3’ showed the best CO₂ adsorption capacity (70.8 mg/g) as determined by CO₂ adsorption isotherms at 298 K and 1 bar.

• 한국환경보건학회지
• /
• 제21권3호
• /
• pp.77-86
• /
• 1995

Lead(II) removal efficiency by natural kaolinite was investigated through laboratory experiments. This study was conducted in two phases-sorption and desorption. In the adsorption study, the influence of sorption kinetics and sorption isotherm and various parameters such as pH, temperature, coexisting other heavy metal ions on the lead adsorption was investigated. And desorption study was carried out in order to find the re-usability of kaolinite as an adsorbent. The results of the study are as follows. 1. Sorption kinetics was investigated under the condition of 2.5 mg/l adsorbent concentration, pH 6.5$\pm$0.05, temperature $30\pm 0.5\circ$C, initial lead(II) concentration 25 mg/l. Adsorption rate was initially rapid and the extent of adsorption arrived at adsorption equilibrium with 73% adsorption efficiency in an hour. 2. The sorption isotherm experiment was made with different initial lead(II) concentration. A linearized Freundlich equation was used to fit the acquired experimental data. As a result, Freundlich constants, the sorption intensity (1/n) was 0.47 and the measure of sorption (k) was 2.44. So, it was concluded that sorption of lead(II) by kaolinite is effective. 3. The effect of pH on lead(II) sorption by kaolinite shows that at a pH of 3, only 6% of the total lead(II) was adsorbed and at a pH 9, 97% of the lead(II) was removed. And the effect of temperature on lead(II) sorption by kaolinite shows that as the temperature increased, the amount of lead(II) sorption per unit weight of kaolinite increased. But the effect was minor (p<0.05). 4. Sorption isotherm of lead coexisting cadmium (II) or zinc (II) was lower than that of lead itself. It was caused by the result of competitive sorption to adsorption site. And there was no difference between the sorption isotherm of cadmium and zinc. 5. In desorption studies, only 5.12% desorption took place in distilled water, while 52.08% in 0.1 N hydrochloric acid. Consequently used kaolinite could be regenerated by hydrochoric acid.

• 한국산업보건학회지
• /
• 제5권2호
• /
• pp.119-127
• /
• 1995

The purpose of this study was to determine the effects of surface-treatment by zinc salts on break-through and adsorption capacity of toluene. Firstly, the coconut activated carbon treated the surface with zinc salts, were exposed by the spike sample(toluene, 69.02ppm, $260.1mg/m^3$), and then the effects of zinc salts were examined by using the gas adsorption kinetics. The results obtained were as follows : 1) BET(Brumaure Emmett Teller) surface area were $954.4m^3/g$ in coconut activated carbon treated with 0.0001 N $Zn(NO_3)_3$ $6H_2O$, and $830.3m^2/g$ in coconut activated carbon treated with 0.0001 N $ZnCl_2$. 2) Migration was decreased in coconut activated carbon treated with the thin level of zinc salts. 3) Breakthrough volume were 73.07 L in coconut activated carbon treated with 0.0001 N $Zn(NO_3)_3$ $6H_2O$, and 72.76 L in charcoal treated with 0.0001 N $ZnCl_2$. 4) ${\tau}$ values(the time required for 50% breakthrough) were 1046.1 min in coconut activated carbon treated with 0.0001 N $ZnCl_2$ and 921.2 min in coconut activated carbon treated with 0.0001 N $Zn(NO_3)_3$ $6H_2O$. 5) Maximum adsorption capacity was 53.9 mg/tube in coconut activated carbon treated with 0.0001 N $ZnCl_2$ and 47.4 mg/tube in coconut activated carbon treated with 0.0001 N $Zn(NO_3)_3$ $6H_2O$. In conclusion, the coconut activated carbon treated the surface with the thin concentration of zinc salts, decreased the breakthrough and increased the BET surface area and the adsorption capacity in case of sampling airborne toluene.

• Bulletin of the Korean Chemical Society
• /
• 제31권1호
• /
• pp.162-167
• /
• 2010

We investigated the adsorption and desorption characteristics of benzene molecules on $Si(001)-2{\times}n$ surfaces using a variable-low temperature scanning tunneling microscopy. When benzene was adsorbed on a $Si(001)-2{\times}n$ surface at a low coverage, five distinct adsorption configurations were found: tight-binding (TB), standard-butterfly (SB), twisted-bridge, diagonal-bridge, and pedestal. The TB and SB configurations were the most dominant ones and could be reversibly interconverted, diffused, and desorbed by applying an electric field between the tip and the surface. The population ratios of the TB and SB configurations were affected by the benzene coverage: at high coverage, the population ratio of SB increased over that of TB, which was favored at low coverage. The desorption yield decreased with increasing benzene coverage and/or density of vacancy defect. These results suggest that the interaction between the benzene molecules is important at a high coverage, and that the vacancy defects modify the adsorption and desorption energies of the benzene molecules on Si(001) surface.

• Carbon letters
• /
• 제2권1호
• /
• pp.15-21
• /
• 2001

In this work, activated carbon fibers (ACFs) were plated with copper metal using electroless plating method and the effects of surface properties and pore structures on chromium adsorption properties were investigated. Surface properties of ACFs have been characterized using pH and acid/base values. BET data with $N_2$ adsorption were used to obtain the structural parameters of ACFs. The electroless copper plating did significantly lead to a decrease in the surface acidity or to an increase in the surface basicity of ACFs. However, all of the samples possessed a well-developed micropore. The adsorption capacity of Cr(III) for the electroless Cu-plated ACFs was higher than that of the as-received, whereas the adsorption capacity of Cr(VI) for the former was lower than that of the latter. The adsorption rate constants ($K_1$, $K_2$, and $K_3$) were also evaluated from chromium adsorption isotherms. It was found that $K_1$ constant for Cr(III) adsorption depended largely on surface basicity. The increase of Cr(III) adsorption and the decrease of Cr(VI) adsorption were attributed to the formation of metal oxides on ACFs, resulting in increasing the surface basicity.

• 공업화학
• /
• 제26권5호
• /
• pp.581-586
• /
• 2015

입상 활성탄을 사용하여 수용액으로부터 Safranin의 흡착에 대해 조사하였다. 회분식 실험은 흡착제의 양, 초기농도와 접촉시간과 온도를 흡착변수로 사용하여 수행하였다. 흡착평형자료는 Langmuir, Freundlich 및 Dubinin-Radushkevich식을 사용하여 해석한 결과 Freundlich식이 가장 좋은 일치도를 나타냈다. 평가된 Langmuir 분리계수, $R_L=0.183{\sim}0.254$와 Freundlich 분리계수, 1/n = 0.518~0.547로부터 이 흡착공정이 적절한 처리방법이 될 수 있음을 알았다. 흡착속도실험자료를 유사1차 및 유사2차 반응속도식에 적용해 본 결과는 유사2차반응속도식에 잘 맞는 것으로 나타났다. 음수값의 Gibbs 자유에너지(${\Delta}G=-3.688{\sim}-7.220kJ/mol$)와 양수값의 엔탈피(${\Delta}H=33.126kJ/mol$)는 흡착이 자발적이고 흡열공정으로 진행된다는 것을 나타냈다.