• Title, Summary, Keyword: Adsorption capacity

Search Result 1,232, Processing Time 0.218 seconds

Research on the Adsorption Capacity for Benzene, Toluene, Acetone and N-hexane of Activated Carbon Acquired fromthe Domestic Market (국내에서 유통되는 활성탄을 이용한 벤젠, 톨루엔, 아세톤 및 노말 헥산의 등온흡착용량 평가 연구)

  • Lee, Naroo;Yi, Gwangyong;Park, Dooyong
    • Journal of Korean Society of Occupational and Environmental Hygiene
    • /
    • v.24 no.2
    • /
    • pp.193-200
    • /
    • 2014
  • Objectives: To develop domestic charcoal tubes with good adsorption capacity, breakthrough experiments were performed on four types of activated charcoal. Materials: The adsorption capacity and the adsorption rate were determined using a modified Wheeler equation after the breakthrough experiment. For four types of charcoal (J, K, S and SKC Inc. 226-01), 100 mg were used in the breakthrough experiment. The test was done on benzene, toluene, n-hexane, and acetone in a dynamic chamber. Results: K charcoal had the greatest surface area and the highest micropore volume. J charcoal had a similar surface area and micropore volume to SKC charcoal. S charcoal had the lowest surface area and micropore volume. J charcoal had the highest adsorption capacity at 101, 252 and 609 ppm of benzene. The gap in benzene adsorption capacity among the types of charcoal was the least at 609 ppm and the greatest at 101 ppm. J charcoal showed the highest adsorption capacity at 54, 106, 228 and 508 ppm of toluene. J charcoal and SKC charcoal had a similar adsorption capacity for acetone. J charcoal had the highest adsorption capacity for n-hexane. In the experiment featuring 10% breakthrough volume, 10% breakthrough occurred at 18 liters at $2065.9mg/m^3$ for J charcoal and at 20 liters at $1771.2mg/m^3$ for K charcoal. It was difficult to judge adsorption capacity by surface area and micropore volume of charcoal. J charcoal, which was similar to SKC charcoal in surface area and micropore volume, showed good adsorption capacity at common workplace concentrations. Conclusions: The adsorption capacity of J and K charcoal was superior compared with SKC charcoal. J and K charcoal can be considered appropriate for use as sampling media based on this result.

Analysis of Siloxane Adsorption Characteristics Using Response Surface Methodology

  • Park, Jin-Kyu;Lee, Gyeung-Mi;Lee, Chae-Young;Hur, Kwang-Beom;Lee, Nam-Hoon
    • Environmental Engineering Research
    • /
    • v.17 no.2
    • /
    • pp.117-122
    • /
    • 2012
  • A central composite design and response surface methodology were applied to investigate the optimum conditions for maximum adsorption capacity in activated alumina as an adsorbent. The optimized conditions were determined for adsorption capacity using variables of flow rate and temperature. It was found that flow rate and temperature greatly influenced the adsorption capacity, as determined by analysis of variance analysis of these variables. Statistical checks indicated that second order polynomial equations were adequate for representing the experimental values. The optimum conditions for adsorption capacity were $0^{\circ}C$ and 2,718 mL/min, with the estimated maximum adsorption capacity of 17.82%. The experimental adsorption capacity was 17.75% under these optimum conditions, which was in agreement with the predicted value of 17.82%.

Effect of Airborne Organic Vapor Concentration Levels on the Adsorption Capacity of Charcoal in the Cartridges of Air Purifying Respirators (공기 중 유기용제 농도수준이 방독마스크 정화통의 활성탄 흡착용량에 미치는 영향)

  • Park, Doo-Yong
    • Journal of Environmental Health Sciences
    • /
    • v.37 no.1
    • /
    • pp.50-56
    • /
    • 2011
  • The adsorption capacity of charcoal is a function of the airborne concentration of the target chemical. To evaluate the adsorption capacity of charcoal packed in the cartridges of air purifying respirators, breakthrough tests were conducted with carbon tetrachloride for three commercial cartridges (3M models #7251, #6000 and AX) at 25, 50, 100, 250 and 500 ppm. Adsorption capacities were calculated using a mass transfer balance equation derived from the curve fitting to the breakthrough curves obtained experimentally. Carbon micropore volumes were estimated by iteration to fit the Dubinin/Radushkevich (D/R) adsorption isotherm. They were 0.6566, 0.5727 and 0.3087 g/cc for #7251, #6000 and the AX cartridge, respectively. Above 100 ppm (at high challenge concentrations), #7251 and #6000 showed higher adsorption capacities. However, as the challenge concentration decreased, the adsorption capacities of #7251 and #6000 sharply dropped. On the other hand, the adsorption capacity of the AX cartridge showed little change with the decrease of the challenge concentration. Thus, the AX showed a higher adsorption capacity than #7251 and #6000 at the 5-50 ppm level. It is concluded that service-life tests of cartridges and adsorption capacity tests of charcoal should be conducted at challenge concentration levels reflecting actual working environmental conditions. Alternatively, it is recommended to use the D/R adsorption isotherm to extrapolate adsorption capacity at low concentration levels from the high concentration levels at which breakthrough tests are conducted, at a minimum of two different concentration levels.

Adsorption Characteristics of Hydrogen Sulfide on Iron Hydroxide-based Adsorbent (수산화철계 흡착제의 황화수소 흡착 특성)

  • Ryu, Seung Hyeong;Seo, Youngjoo;Park, Joonwoo;Kim, Shin Dong;Park, Seong Soon
    • Journal of Korea Society of Waste Management
    • /
    • v.34 no.5
    • /
    • pp.468-473
    • /
    • 2017
  • This study was carried out to examine the characteristics of hydrogen sulfide adsorption using an iron hydroxide-based adsorbent. The prepared adsorbent was discussed with regard to its adsorption capacity and analyzed via surface analysis methods to illustrate the physical characteristics of hydrogen sulfide adsorption. As the drying temperature increased, the adsorption capacity of the adsorbent decreased from 29.15wt% to 22.73wt%. The adsorption capacity was decreased as the space velocity increased and showed an adsorption capacity of about 3.65 at $3,157.6h^{-1}$. The effect of sulfur dioxide was to decrease the adsorption capacity from 29.15wt% to 27.94wt%. The adsorbent exhibited the amorphous type in its physical appearance based on XRD and EDS analysis.

The Relationships between the Porosity of Activated Carbon and Hydrogen Adsorption Capacity (활성탄의 기공도와 수소홀착능 사이의 관계)

  • JIN, Hangkyo
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.14 no.4
    • /
    • pp.305-312
    • /
    • 2003
  • A study is presented of the adsorption capacity of a number of different activated carbons for hydrogen at 100 bar aad 298 K. The hydrogen adsorption isotherm was measured by isothermal gravimetric analysis, using a microbalance. The effect of activated carbon's porosity on hydrogen adsorption capacity is surveyed. It is concluded that hydrogen adsorption capacity of activated carbon is lineally increased according to the increase of specific surface area and total pore volume, It seems that microporosity is more contributive than mesoporosity. Most of the adsorbed quantity is due to physical adsorption and chemisorption is negligible, In this work, 0.79 wt.% of hydrogen adsorption capacity is reached.

Adsorption of Trichloroethylene in Water by Coconut Carbon and Coconut Activated Carbon (야자껍질 탄화탄과 야자껍질 활성탄에 의한 수중 Trichloroethylene의 흡착에 관한 연구)

  • 김영규;정문호
    • Journal of Environmental Health Sciences
    • /
    • v.19 no.4
    • /
    • pp.25-32
    • /
    • 1993
  • Granular activated carbon is commonly used in fixed-bed adsorbers to remove organic chemicals. In this experiment organic chemical solutions were prepared by adding the reagent grade organic chemical to distilled water. Isotherm adsorption tests of volatile organic chemicals were conducted using bottle-point technique and column test. Organic chemicals after passing through the column were extracted with hexane and analyzed with gas chromatography (Hewlett-Packard 5890) to check the adsorption capacity and breakthrough curve. The result were as follows: 1. The BET surface area of coconut activated carbon was 658~1,010 m$^2$/g where as coconut shell carbon was 6.6 m$^2$/g. Coconut activated carbon increased the BET surface area and adsorption capacity in bottle-point isotherm. 2. The adsorption capacity of coconut activated carbon for trichloroethylene (TCE) was reduced in the presence of humic substance. 3. A decrease in particle size of activated carbon resulted in higher adsorption capacity and lower intraparticle diffusion coefficient. It is reflected not only as a decrease in Freudlich adsorption capacity value (K) but also as an increase in Freudlich exponenent value (1/n).

  • PDF

Adsorption of Non-degradable Eosin Y by Activated Carbon (활성탄에 의한 난분해성 염료인 Eosin Y의 흡착)

  • Lee, Min-Gyu;Kam, Sang-Kyu;Suh, Keun-Hak
    • Journal of Environmental Science International
    • /
    • v.21 no.5
    • /
    • pp.623-631
    • /
    • 2012
  • The adsorption behavior of Eosin Y on activated carbon (AC) in batch system was investigated. The adsorption isotherm could be well fitted by the Langmuir adsorption equation. The kinetics of adsorption followed the pseudo-second-order model. The temperature variation was used to evaluate the values of free energy (${\Delta}G^{\circ}$), enthalpy (${\Delta}H^{\circ}$) and entropy (${\Delta}S^{\circ}$). The positive value of enthalpy change ${\Delta}H^{\circ}$ for the process confirms the endothermic nature of the process and more favourable at higher temperature, the positive entropy of adsorption ${\Delta}S^{\circ}$ reflects the affinity of the AC material toward Eosin Y and the negative free energy values ${\Delta}G^{\circ}$ indicate that the adsorption process is spontaneous. With the increase of the amount of AC, removal efficiency of Eosin Y was increased, but adsorption capacity was decreased. And adsorption capacity was increased with the decrease of particle size. With the increase of the amount of AC, removal efficiency of Eosin Y was increased, but adsorption capacity was decreased. And adsorption capacity was increased with the decrease of particle size.

Adsorption Characteristics of Toluene Vapor in Fixed-bed Activated Carbon Column (고정층 활성탄 흡착반응기에서 기상 톨루엔의 흡착특성)

  • Lim Jin-Kwan;Lee Song-Woo;Kam Sang-Kyu;Lee Dong-Whan;Lee Min-Gyu
    • Journal of Environmental Science International
    • /
    • v.14 no.1
    • /
    • pp.61-69
    • /
    • 2005
  • Adsorption characteristics of toluene vapor, which is one of important source of volatile organic compounds (VOCs), by activated carbon were investigated using a fixed bed adsorption column. The operating parameters such as breakthrough curve, adsorption capacity, mass transfer zone (MTZ), and length of unused bed (LUB) were studied. The experimental results showed that the breakthrough time decreased with increasing inlet toluene concentration and gas flow rate. MTZ and LUB increased with the increase of inlet concentration, gas flow rate, and particle size of activated carbon. The adsorption capacity increased with the increase of inlet toluene concentration, while it decreased with increasing particle size. However, it was kept at constant value regardless of the increase of gas flow rate. Adsorption isotherm of toluene vapor could be represented by the Freundlich adsorption equation fairly well. From the adsorption experiments using some VOC gases such as toluene, xylene, butyl acetate. butanol and acetone, it was also found that the adsorption capacity was higher in the case of gas with higher boiling point and lower vapor pressure.

Breakthrough Characteristics for Lithium Ions Adsorption in Fixed-bed Column Packed with Activated Carbon by Modified with Nitric Acid (질산으로 개질한 활성탄을 충전한 고정층에서 리튬이온 흡착시의 파과특성)

  • Kam, Sang-Kyu;You, Hae-Na;Lee, Min-Gyu
    • Journal of Environmental Science International
    • /
    • v.23 no.6
    • /
    • pp.1143-1149
    • /
    • 2014
  • The adsorption experiments of lithium ions were conducted in the fixed bed column packed with activated carbon modified with nitric acid. Effect of inlet concentration, bed hight and flow rate on the removal of lithium ions was investigated. The experimental results showed that the removal and the adsorption capacity of lithium ions increased with increasing inlet concentration, and decreased with increasing flow rate. When the bed height increased, the removal and the adsorption capacity increased. The breakthrough curves gave a good fit to Bohart-Adams model. Adsorption capacity and breakthrough time calculated from Bohart-Adams model, these results were remarkably consistent with the experimental values. The adsorption capacity was not changed in the case of 3 times repetitive use of adsorbent.

Studies on the Adsorption Capacity of Cd and Zn by Genus Allium Powder in aqueous solution (Allium속의 Cd 및 Zn 흡착력)

  • Kim, Seong-Jo;Baek, Seung-Hwa;Mun, Gwang-Hyeon
    • The Korean Journal of Food And Nutrition
    • /
    • v.9 no.3
    • /
    • pp.307-313
    • /
    • 1996
  • The study was performed under the various conditions, such as the edible parts and particle sizes of Allium, the concentrations, the temperatures, and the pH of heavy metal solutions to investigate their adsorption capacity of heavy metals by genus Allium. The adsorption amount of Cd by Allium in the aqueous solution was apparently higher than that of Zn by them. The larger the particle size of welsh onion and shallot was, the higher the adsorption of Cd was. But the adsorption ratio was not different. As the temperature increased, the amount of heavy metal adsorption increased in general, but the adsorption of Cd by wild garlic, Zn by garlic decreased. Adsorption of Cd and Zn to Allium was not affected by the various pH. The correlation between the amount of components in edible putts of Allium and that of adsorption of heavy metals was significantly high in amino acids containing sulfhydryl radical (-SH) and vitamin B2.

  • PDF