• 청정기술
• /
• 제10권3호
• /
• pp.159-168
• /
• 2004

벤젠에 대한 흡착실험이 활성탄과 제올라이트 13X 흡착제에 대하여 수행되었다. 단일 흡착탑과 두 흡착제로 충진된 이중 흡착탑에서 동적흡착특성이 조사되었다. 원료의 유량은 파과시간에 큰 영향을 주지 않았다. 활성탄에 대한 벤젠의 비흡착량이 제올라이트 13X보다 큰 반면, 제올라이트 13X의 밀도가 더 크게 때문에 흡착탑 부피당 흡착량은 제올라이트 13X가 더 컸다. 이중흡착제로 충진된 흡착탑에 대한 동적실험에서 물질전달영역의 길이가 원료의 흐름방향에 따라 달라졌다. 원료 주입구에 활성탄이 충진되고 탑의 출구에 제올라이트 13X가 충진될 때 파과시간은 더 길고 파과곡선은 더 날카롭게 얻어졌다. 또한 두 흡착제의 충진비율에 따라서 파과시간과 파과곡선의 기울기가 영향을 받았다.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제10권2호
• /
• pp.128-135
• /
• 2005

Mixed-mode hydrophobic/ionic matrices exhibit a salt-tolerant property for adsorbing target protein from high-ionic strength feedstock, which allows the application of undiluted feedstock via an expanded bed process. In the present work, a new type of mixed-mode adsorbent designed for expanded bed adsorption, Fastline $PRO^{\circledR}$, was challenged for the capture of nattokinase from the high ionic fermentation broth of Bacillus subtilis. Two important factors, pH and ion concentration, were investigated with regard to the performance of nattokinase ad-sorption. Under initial fermentation broth conditions (pH 6.6 and conductivity of 10 mS/cm) the adsorption capacity of nattokinase with Fastline PRO was high, with a maximum capacity of 5,350 U/mL adsorbent. The elution behaviors were investigated using packed bed adsorption experiments, which demonstrated that the effective desorption of nattokinase could be achieved by effecting a pH of 9.5. The biomass pulse response experiments were carried out in order to evaluate the biomass/adsorbent interactions between Bacillus subtilis cells and Fastline PRO, and to demonstrate a stable expanded bed in the feedstock containing Bacillus subtilis cells. Finally, an EBA process, utilizing mixed-mode Fastline PRO adsorbent, was optimized to capture nattokinase directly from the fermentation broth. The purification factor reached 12.3, thereby demonstrating the advantages of the mixed-mode EBA in enzyme separation.

• Carbon letters
• /
• 제15권3호
• /
• pp.203-209
• /
• 2014

The adsorption of volatile organic compounds (VOCs) was carried out using an activated carbon fiber (ACF) filter in an automobile. The adsorption capacities of formaldehyde, toluene, and benzene on an ACF filter were far better than those of a polypropylene (PP) mat filter and combined (PP+activated carbon) mat filter by batch adsorption in a gas bag. In a continuous flow of air containing toluene vapor through an ACF packed bed, the breakpoint time was very long, the length of the unused bed was short, and sharp "S" -type breakthrough curve was plotted soon after breakpoint, showing a narrow mass transfer zone of toluene on the ACF. The adsorption amount of toluene on the ACF filter was proportional to the specific surface area of the ACF; however, the development of mesopores 2-5 nm in size on the ACF was very effective with regard to the adsorption of toluene. The ACF air clarifier filter is strongly recommended to remove VOCs in newly produced automobiles.

• 생명과학회지
• /
• 제23권11호
• /
• pp.1365-1370
• /
• 2013

약 염기성 이온교환 수지에 cellulase를 고정화하였고 고정화 cellulase는 흡착 특성이 Langmuir 흡착 등온선을 잘 따랐다. pH와 온도에 대한 효소 활성은 고정화 효소가 우수한 특성을 보였다. 열에 대한 효소 활성은 1차식으로 감소하였고 고정화 효소가 자유 효소에 비해 열 안정성이 우수하였다. 초기 속도법을 통해서 자유 효소와 고정화 효소의 Michaelis-Menten 속도 상수를 결정하였고 속도상수 Km은 고정화 효소가 큰 값을 나타내었다. 충진층 반응기에서 셀룰로스의 전환 공정을 재순환에 의해 측정하였다. 투입되는 셀룰로스의 유량 변화에 대한 셀룰로스의 변환을 연속 공정에서 조사하였다. 장기 운전의 성능을 평가하기 위해 7일 통한 연속공정을 실시하였고 고정화 효소는 48%의 활성을 유지하였다.

• 한국응용과학기술학회지
• /
• 제27권3호
• /
• pp.318-324
• /
• 2010

In this study, commercial pellet type sorbents for the collection of $CO_2$ from a local municipal waste incinerator were prepared and characterized in terms of adsorption efficiency by varying the operating conditions of a field process. The concentration of $CO_2$ in the flue gas ranged from 8 to 10%, which entered the test packed bed. As a result of this experiment, the sorbent procured from A-company, which is mainly composed of calcium compounds, showed the highest adsorption efficiency. The regeneration efficiency was fairly low, however. It also was found that based on adsorption breakthrough time, the relatively low flow rate of 10 LPM into the bed allowed higher collection efficiency. The higher flow rate of 40 LPM, on the other hand, tended to decrease the retention of the adsorption.

• 상하수도학회지
• /
• 제22권4호
• /
• pp.467-473
• /
• 2008

Natural organic matter (NOM) removal by physico-chemical adsorption and biological oxidation was investigated in five slow sand filters with different media depths. Non-purgeable dissolved organic carbon(NPDOC) and $UV_{254}$ absorbance were measured to evaluate the characteristics of NOM removal at different filter depths. Removal efficiency of NOM was in the range of 10-40% throughout the operation time. At start-up of the filters packed with clean sand media, NOM was probably removed by physico-chemical adsorption on the surface of sand through the overall layer of filter bed. However, when Schumutzdecke layer was built up after 30 days operation, the major portion of NPDOC was removed by biological oxidation and/or bio-sorption in lower depth above 50 mm. NOM removal rate in the upper 50 mm filter bed was $0.82hr^{-1}$. It was about 20 times of the rate($0.04hr^{-1}$) in the deeper filter bed. Small portion of NPDOC could be removed in the deeper filter bed by both bio-sorption and biodegradation. SEM analysis and VSS measurement clearly showed the growth of biofilm in the deeper filter bed below 500 mm, which possibly played an important role in the NOM removal by biological activity besides the physco-chemical adsorption mechanism

• Advances in environmental research
• /
• 제3권3호
• /
• pp.231-251
• /
• 2014

The present study examines the phosphate adsorption potential and behavior of mixture of Ground Burnt Patties (GBP), a solid waste generated from cooking fuel used in earthen stoves and Red Soil (RS), a natural substance in fixed bed column mode operation. The characterization of adsorbent was done by Proton Induced X-ray Emission (PIXE), and Proton Induced ${\gamma}$-ray Emission (PIGE) methods. The FTIR spectroscopy of spent adsorbent reveals the presence of absorbance peak at $1127cm^{-1}$ which appears due to P = O stretching, thus confirming phosphate adsorption. The effects of bed height (10, 15 and 20 cm), flow rate (2.5, 5 and 7.5 mL/min) and initial phosphate concentration (5 and 15 mg/L) on breakthrough curves were explored. Both the breakthrough and exhaustion time increased with increase in bed depth, decrease in flow rate and influent concentration. Thomas model, Yoon-Nelson model and Modified Dose Response model were used to fit the column adsorption data using nonlinear regression analysis while Bed Depth Service Time model followed linear regression analysis under different experimental condition to evaluate model parameters that are useful in scale up of the process. The values of correlation coefficient ($R^2$) and the Sum of Square Error (SSE) revealed the Modified Dose Response model as the best fitted model to the experimental data. The adsorbent mixture responded effectively to the desorption and reusability experiment. The results of this finding advocated that mixture of GBP and RS can be used as a low cost, highly efficient adsorbent for phosphate removal from aqueous solution.

• Carbon letters
• /
• 제2권1호
• /
• pp.9-14
• /
• 2001

Adsorption and desorption characteristics of methyl iodide at high temperature conditions up to $250^{\circ}C$ by TEDA-impregnated activated carbon, which is used for radioiodine retention in nuclear facility, was experimentally evaluated. In the range of temperature from $30^{\circ}C$ to $250^{\circ}C$, the adsorption capacity of base activated carbon decreased sharply with increasing temperature but that of TEDA-impregnated activated carbon showed higher value even at high temperature ranges. Especially, the desorption amount of methyl iodide on TEDA-impregnated carbon represented lower value than that on unimpregnated carbon. The breakthrough curves of methyl iodide in the fixed bed packed with base carbon and TEDA-impregnated activated carbon at high temperature were compared. TEDA-impregnated activated carbon would be applicable to adsorption process up to $150^{\circ}C$ for the removal of radioiodine in a nuclear facility.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
• /
• pp.307-312
• /
• 2001

Adsorption capacities of toxic heavy metal ions using as-received carbon(AC), single and double surface-modified activated carbon(OAC and DSMC) in wide pH ranges are extensively evaluated. Physical and chemical properties of surface-modified activated carbons are evaluated through BET analysis, surface acidity and oxides measurements. Based oil tile adsorption isotherms of Pb, Cd and Cr ions by AC, OAC and DSMC, the adsorption amount on DSMC was obviously higher than that on the other carbons. Breakthrough behaviors of ternary metal ions in a column packed with three kinds of carbon were also characterized with respect to the variations of the influent pH and concentration. The adsorption capacity of DSMC in a fixed bed stood a favorable comparison with that of as-received carbon.

• 폴리머
• /
• 제26권1호
• /
• pp.121-127
• /
• 2002

Acrylonitrile을 그라프트시킨 아미드옥심화 polypropylene 섬유이온교환체(AOPP-g-AN)의 충전 bed 높이를 변화시켜 간수 중 우라늄 이온 흡착 특성 및 흡착 공정 특성을 관찰하였다. 아미드옥심형 섬유이온교환체의 팽윤율은 그라프트율 100%, 물과 과산화수소 용매에 대하여 각각 8.54, 8.87 g/g을 나타내었다. 이온교환용량은 그라프트율이 증가함에 따라 증가하였으며, 그라프트율 100%에서 3.99 meq/g으로 최대를 나타내었다. 회분식 흡착에서 우라늄 흡착은 10분 이내에 초기 흡착 평형에 도달하며, 흡착 속도는 9.50 mg/min으로 나타났다. 최종 흡착 용량은 3.95 meq/g이었으며, pH에 따른 흡착 특성 변화는 관찰되지 않았다. 충전비에 따른 연속식 흡착시 흡착 용량은 L/D=1에서 3.92 meq/g으로 최대를 나타내었으며, L/D<2에서 편류 및 불균일 흡착에 의한 2단계 과정으로 파과가 나타남을 확인하였다. 실제 간수에 대한 우라늄 흡착 실험 결과, 흡착 용량 및 파과시간은 각각 3.63 meq/g, 26 min으로 모의용액과 비교 시 주목할만한 흡착능 저하는 관찰되지 않았다.